Qualification:
Ph.D
m_jayakumar@cb.amrita.edu
Phone:
+91 9442709489 | +91 422 2685000 Ext.5720

Dr. Jayakumar joined Amrita Vishwa Vidyapeetham in July 2004 after serving in satellite communication industries for eight years. His area of research includes, radio frequency systems, antennas, RF integrated circuits and wireless communication systems.

Dr. Jayakumar obtained his PhD from the University of Delhi in 1996 in the area of Microwave planar components and circuits using high temperature superconducting materials. Most of his experimental works were carried out in National Physical Laboratory, New Delhi mainly adopting indigenously developed high temperature superconducting materials. As a part of his research work he has developed a Novel Cavity Resonator operating at 24GHz based measurement system to measure the electromagnetic properties of high temperature superconducting thin films and bulk samples. This fetched him to get the IEEE student award in one of the IEEE conference (IEEE – InterMag –MMM - 1994) in Albuquerque, New Mexico, USA. He was awarded Dr. K.S. Krishnan Research Fellowship by the department of Atomic Energy (DAE) in Engineering Science during his research work. He started his professional career in teaching and research from Thapar University Patiala for a brief period.

Dr. Jayakumar served at Vikram Sarabhai Space Center, Indian Space Research Organization, Trivandrum from 1996 to 2001 as Scientist in the radio frequency systems for space vehicle projects. He has several contributions in various satellite launch missions in the specialized antenna and subsystems. Major contributions includes, Antenna systems for space vehicle to geo-satellite telemetry links, Miniaturized planar conformal antennas for ultra-thin sounding rockets, Portable ground station telemetry planar antenna, Analysis of pre and post mission link data.

Dr. Jayakumar worked as Senior Manager – Satellite Spectrum Management in Agarni Satellite Services Limited, Mumbai from 2001 to 2004. He was actively participating and dealing with International satellite spectrum management for operating a private satellite network in India to initiate direct to home television network services. He contributed in the satellite orbit-frequency coordination and transponder channel allocation and management with several satellite operators from European and American continents. He was a member of delegations to ITU Geneva, Switzerland, for several satellite coordination committee meetings and conferences.

Currently, he is actively carrying out research in the area which includes Gallium Nitride device based RF systems, Compact conformal antennas for air-borne vehicle communication links, Antenna systems for wireless systems like MIMO, Dielectric properties of specialized materials for identifying its suitability in RF systems, Substrate integrated waveguide based antennas and filters, Millimeter wave MIMO and Miniaturization of antenna and RF subsystems. He is having more than 50 research publications in Journals and conferences and a co-author in two book chapters published by Nova Publishers Inc USA. He is supervising five doctoral students and several post graduate projects.

Currently he is a Professor and Chairperson of the Department of Electronics and Communication Engineering, Amrita School of Engineering, Coimbatore campus. He is also member of various academic and administrative committees in various institutions and organizations. He is a member and Honorable Secretary of Institution of Electronics and Telecommunication Engineers (IETE) Coimbatore Center.

## Research Expertise

Radio Frequency system Design, Planar antenna systems, RFIC design, Hardware Security, Systems design for air-borne vehicles, Wireless Communication Systems.

## Ongoing Research

• MOSFET Modeling and Design of Low Noise Amplifier at millimeter wave Frequencies
• Investigations and Performance Studies on Substrate Integrated Waveguide based Slot Antennas for MIMO in Mobile Devices
• Studies on Channel Estimation of Time Varying Channel in MIMO-OFDM Systems
• Investigation of Coding Technique for Gigabit Wireless Networks in millimeter Wave Communication Systems.
• Development of Electromagnetic Absorbers using Low Profile Composites

## Funded Projects

• Hardware Trojan Detection and Consistency based Diagnosis, SAG, DRDO, Delhi, 2015 - 2017

## Teaching

• Applied Electromagnetics
• Transmission Lines and waveguides
• Antenna Systems and Design
• Microstrip Devices and Circuits
• RFIC Design

## Ongoing Funded Projects

1. Hardware Trojan Detection and Consistency based Diagnosis, SAG, DRDO, Delhi, 2015 - 2018
2. Capacity, bit error rate and performance analysis of MIMO based communication system in minimized multipath environment ISRO RESPOND, ISRO, Bangalore, 2017-2019
3. Automated structural evolution and performance optimization of RF band-pass Filters - An evolutionary Algorithmic Design Approach, ISRO-RESPOND, Bangalore, 2018-2020

## Publications

### Publication Type: Journal Article

Year of Conference Publication Type Title

2018

Journal Article

P. Sudheesh and Dr. Jayakumar M., “Non linear Tracking Using Unscented Kalman Filter”, Advances in Intelligent Systems and Computing, vol. 678, pp. 38-46, 2018.[Abstract]

Accurate localization of mobile robots to locate its position and orientation is of key importance since it enables a mobile robot to navigate properly in any given environment. Various techniques of localization used are such as GPS/GNSS, IMU sensors or by using odometric measurements. However each of these techniques suffers from various drawbacks. Dead-reckoning (DR) is a popular client to get precise localization information. DR estimates the current position based on the previous positions observed over a span of time. However DR depends on encoder and odometric information which are subject to major errors due to surface roughness, wheel slippage and tolerance rate of the machine which leads to an accumulation of errors. Many researchers have addressed this problem by adding certain external sources such as encoded magnetic compass, rate-gyros etc., However addition of these sensors has led to various new errors. In this paper, the use of unscented Kalman filter (UKF) is proposed along with the DR to get accurate localization information. UKF uses a deterministic sampling approach that captures the estimates of mean and covariance with a set of sigma points. The simulation results show that the proposed method is able to track the desired path with least error when compared to DR used alone. The localization of a mobile robot with the proposed system is also highly reliable.

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2018

Journal Article

P. Sudheesh and Dr. Jayakumar M., “Tracking of Nonlinear Variations of the Parameters of High Mobility Systems”, International Journal of Pure and Applied Mathematics, Open Access, vol. 118, no. 7, pp. 221-226, 2018.[Abstract]

Monitoring the parameters of high mobility trains are required for the safe navigation and reliable communication applications of the high speed vehicle. The localization of the train accurately is a challenging task. Hence an effective model and an efficient algorithm must be used. Some of the traditional methods of locating the position of the high speed train include the use of GPS. However, GPS cannot always give precise location as other external factors like climate and mobile environment also plays a major role. So, there is a need for localization of the train by itself. Thus, extra sensors are needed which can increase the precision of localization. Localization of high speed train not only falls into the domain of safety enhancement but also falls into the domain of designing smart trains which are energy efficient and intelligent. This information is also useful for establishing a real time wireless communication link in high mobility system. In this paper, we proposed an algorithm which involves estimating two angles, pitch angle and roll angle in addition to the velocity of the train from the noisy sensors like gyro-meter and accelerometer. This problem falls under the conventional non-linear estimation problem. Choosing the correct estimation algorithm is as important as correctly modeling the train dynamics. Existing literature made use of the extended Kalman filter (EKF) to estimate the state variables accurately for different physical models. In this paper, we propose to use the unscented Kalman filter (UKF). Theoretically, UKF is a better estimator compared to EKF because it captures higher order statistics of the system. The simulation results show that the proposed UKF based tracking algorithm is a reliable estimator by comparing the estimation error of UKF algorithm and EKF algorithm for estimating the pitch angle, roll angle and velocity of the train.

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2018

Journal Article

M. N. Devi, Jacob, I. S., Ranjani, R. S., and Dr. Jayakumar M., “Detection of Malicious Circuitry Using Transition Probability Based Node Reduction Technique”, Telkomnika (Telecommunication Computing Electronics and Control) Open Access, vol. 16, no. 2, pp. 573-579, 2018.[Abstract]

In recent years, serious concerns have been raised against the tampering of integrated circuits due to outsourcing of circuits for fabrication. It has led to the addition of malicious circuitry known as Hardware Trojan. In this paper, a transition probability based node reduction technique for faster and efficient Hardware Trojan (HT) detection has been attempted. In the proposed method, the fact that the least controllable and observable nodes or the nodes with least transition probability are more vulnerable as Trojan sites is taken into consideration. The nodes that have lesser activity than the threshold are the candidate nodes. At each candidate node, segmentation is done for further leakage power analysis to detect the presence of Trojans. Experimental results observed on ISCAS’85 and ISCAS’89 benchmark circuits illustrate that the proposed work can achieve remarkable node reduction upto 78.81% and time reduction upto 58.7%. It was also observed that the circuit activity can be increased by varying the input probability. Hence, for further reduction in the Trojan activation time, the weighted input probability was obtained.

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2018

Journal Article

N. Mohankumar, Dr. Jayakumar M., and M. Devi, N., “CRC-Based Hardware Trojan Detection for Improved Hardware Security”, Lecture Notes in Electrical Engineering, vol. 471, pp. 381-389, 2018.[Abstract]

Several methodologies aim at tackling the issue of Hardware Trojans through the help of a “Golden Reference”, which is not always available; thereby arises the need for an efficient method without a Golden Reference. This work involves the detection of Hardware Trojan in a circuit using an improved voting algorithm employing CRC. Two modifications to a conventional voting algorithm are proposed in this chapter along with CRC to improve the detection efficiency. This logic-based detection procedure avoids the requirements of complex pre-processing procedures like segmentation, fingerprinting, thermal imaging, etc., The following proposed modifications (i) incapacitates the bias toward 1s and incorporating CRC for comparison of bit streams and (ii) equal weight of 1 is given as initial weight to all CUTs, which gives better results in voting algorithm. Detection accuracy is found to be around 95.27% based on the detailed analysis with infected and non-infected ISCAS’85 and ISCAS’89 circuits.

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2017

Journal Article

Dr. Ramanathan R. and Dr. Jayakumar M., “A Support Vector Regression Approach to Detection in Large-MIMO Systems”, Telecommunication Systems, vol. 64, no. 4, pp. 709 - 717, 2017.[Abstract]

We propose a support vector regression approach for symbol detection in large-MIMO systems employing spatial multiplexing. We explore the applicability of machine learning algorithms, in particular support vector machines, to address one of the recent research problem in communications.The machine learning capability is exploited to achieve fast detection in large dimension systems. The performance of the proposed method is compared with lattice reduction aided detection which is currently the popular choice and the improvement in terms of bit error rate is demonstrated. The sparse formulation of the problem matrix reduces the computational complexity and enables faster detection. The proposed detection algorithm is tailored to address both uncorrelated and correlated channel conditions as well.

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2016

Journal Article

K. B Thilagam, Kartha, M. M., and Dr. Jayakumar M., “Performance Analysis of Cylindrical Dielectric Resonator Antenna with various slot configurations on Substrate Integrated Waveguide”, I J C T A, vol. 9, no. 15, pp. 7581-7588, 2016.[Abstract]

A Dielectric Resonator loaded Substrate integrated waveguide cavity backed slot antenna (SIDRA) is proposed for two slot polarizations and orientation. A SIW-fed cylindrical DRA using rectangular slot is used for obtaining bandwidth of about 5% at 6.15 GHz. For enhancing bandwidth, a plus shaped slot with bandwidth of about 8.80% and gain of 3.7 dB is proposed. The proposed antenna represents S11<-10 dB for C-band with good bandwidth and gain characteristics. Study of cylindrical dielectric resonator antenna (CDRA) at C-Band (4-8 GHz) is discussed and presented for Satellite Application. The parametric study of various slot position is discussed.

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2016

Journal Article

M. M. Kartha, B. Thilagam, K., and Dr. Jayakumar M., “Performance analysis of dielectric resonator antenna on substrate integrated waveguide cavity with dumbbell slot for wideband applications”, International Journal of Control Theory and Applications, vol. 9, pp. 7471-7478, 2016.[Abstract]

The Dielectric Resonator Antenna (DRA) is one of the efficient radiator which is used to achieve broadband and cost effective communication in wireless technology. The Substrate Integrated Waveguide (SIW) technology is the most assuring structure for implementation of circuits and components for millimeter wave and microwave applications. A design approach to improve the impedance bandwidth of cavity backed dumbbell slot antenna using Substrate Integrated Waveguide for X band (8-12 GHz) application is presented in this paper. The proposed design improves impedance bandwidth by the use of Cylindrical Dielectric Resonator Antenna and metal strip along with offset feeding technique. The performance characteristics of the proposed antenna design is evaluated and studied. More »»

2016

Journal Article

, Sudheesh, P., and Dr. Jayakumar M., “Indoor robot localisation using Kalman filter”, Indian Journal of Science and Technology, vol. 9, 2016.[Abstract]

Objective of this paper is to reduce the error in the estimation of the position of the robot. The localization of robot is a critical aspect in making them completely autonomous. Hence accuracy in estimating the position of the robot is of paramount importance. In order to make decisions without direct manual instructions the robot has to be aware of its position in the environment along with the situation at hand. For this effect the robots are built with sensors specifically designed to suit the need of the environment to gain feedback from the surrounding thereby obtaining data about its placement and the conditions around it. It is here that the problem of accuracy arises as there are uncertainties in both the feedback system as well as controlling system of the robot. To make a logical decision, the errors have to be minimized by optimally combining the data received from all the sources. The estimation theory provides us with a solution in the form of Kalman filter algorithm. It is an adaptive filter that combines uncertain data to obtain valid values of output required. It is seen that as SNR increases MSE in the position of the robot decreases thus accuracy increases. In this paper we concentrate on the issue of robot localization in closed space whose dimensions are previously known. We model the localization process as a linear phenomenon, as Kalman filter algorithm can only be used for linear systems. Using MATLAB Simulink we simulate our model to verify the concepts and validate the use of this filter in accurately determining the position of robot.

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2016

Journal Article

S. Vikranth, Sudheesh, P., and Dr. Jayakumar M., “Nonlinear tracking of target submarine using extended Kalman filter (EKF)”, Communications in Computer and Information Science, vol. 625, pp. 258-268, 2016.[Abstract]

This paper presents the effective method for submarine tracking using EKF. EKF is a Bayesian recursive filter based on the linearization of nonlinearities in the state and the measurement system. Here the sonar system is used to determine the position and velocity of the target submarine which is moving with respect to non moving submarine, and sonar is the most effective methods in finding the completely immersed submarine in deep waters. When the target submarines position and velocity is located from the reflected sonar, an extended Kalman filter is used as smoothening filters that describes the position and velocity of the ship with the noisy measurements given by sonar that is reflected back. By using the algorithm of extended Kalman filter we derived to estimate the position and velocity. Here the target motion is defined in Cartesian coordinates, while the measurements are specified in spherical coordinates with respect to sonar location. When the target submarine is located, the alert signal is sent to the own ship. This can be excessively used in military applications for tracking the state of the target submarine. Prediction of the state of the submarine is possible, with Gaussian noise to the input data. The simulation results show that proposed method is able to track the state estimate of the target, this was validated by plotting SNR vs MSE of state estimates. Here in this algorithm regressive iteration method is used to converge to the actual values from the data received. © Springer Nature Singapore Pte Ltd. 2016.

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2016

Journal Article

Dr. Ramanathan R. and Dr. Jayakumar M., “A Low Complex Sparse Formulation of Semidefinite Relaxation Detector for Large-MIMO Systems Employing BPSK Constellations”, Wireless Personal Communications, vol. 90, pp. 1317–1329, 2016.[Abstract]

Semidefinite relaxation detector is a promising approach to large-MIMO detection but for its computational complexity. The major computational cost is incurred in solving the semidefinite program (SDP). In this paper, we propose a sparse semidefinite relaxation (S-SDR) detector by reformulating the SDP problem thereby reducing the computational complexity. We formulate the system model using a sparse approach and further introduce a regularization term inducing sparsity into the semidefinite programming model. We provide a sparse formulation requiring approximately 50 % of the computations compared to the conventional semidefinite programming approach. We apply the proposed semidefinite relaxation detector in large-MIMO channels upto 100×100 systems and compare its BER performance and complexity. We observe that the BER performance is similar to the conventional semidefinite relaxation with the proposed S-SDR detector requiring relatively fewer computations.

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2016

Journal Article

A. Ravindran, Balamurugan, K., and Dr. Jayakumar M., “Design of Cascaded Common Source Low Noise Amplifier for S-Band using Transconductance Feedback”, Indian Journal of Science and Technology, vol. 9, 2016.[Abstract]

2015

Journal Article

L. Kumar Goel, Sasi K Kottayil, Dr. Kirthiga S., and Dr. Jayakumar M., “SMART GRID TECHNOLOGIES Performance Studies and Review of Millimeter Wave MIMO Beamforming at 60 GHz”, Procedia Technology, vol. 21, pp. 658 - 666, 2015.[Abstract]

Millimeter wave systems offer high date rate due to huge bandwidth but suffers from poor link budget. This is due to the blockage of the millimeter wave signal by the obstacles of size comparable to that of the wavelength of the signal. Various analysis in improving the signal strength is reported. One of them suggests use of directional antenna which guarantees signal delivery if line of sight communication between the transmitter and receiver exists. The other alternative scheme is Multi Input Multi Output (MIMO) beamforming that uses the channel statistics to steer the beam thereby improving the multiplexing gain and beamforming gain. In this paper, extensive research work carried out by us in MMW MIMO at 60GHz covering aspects related to MIMO fixed-beam, adaptive beam and multibeam beamformers addressing line-of-sight and non-line-of-sight channel for MMW 60GHz system is reviewed. More »»

2015

Journal Article

S. Kirthiga and Dr. Jayakumar M., “Performance Studies and Review of Millimeter Wave MIMO Beamforming at 60 GHz”, Procedia Technology, vol. 21, pp. 658–666, 2015.[Abstract]

Millimeter wave systems offer high date rate due to huge bandwidth but suffers from poor link budget. This is due to the blockage of the millimeter wave signal by the obstacles of size comparable to that of the wavelength of the signal. Various analysis in improving the signal strength is reported. One of them suggests use of directional antenna which guarantees signal delivery if line of sight communication between the transmitter and receiver exists. The other alternative scheme is Multi Input Multi Output (MIMO) beamforming that uses the channel statistics to steer the beam thereby improving the multiplexing gain and beamforming gain. In this paper, extensive research work carried out by us in MMW MIMO at 60 GHz covering aspects related to MIMO fixed-beam, adaptive beam and multibeam beamformers addressing line-of-sight and non-line-of-sight channel for MMW 60 GHz system is reviewed.

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2015

Journal Article

Dr. Ramanathan R. and Dr. Jayakumar M., “A novel cuckoo search approach to detection in spatially correlated MIMO channels”, International Journal of Mathematical Modelling and Numerical Optimisation, vol. 6, no. 2, pp. 101-113, 2015.[Abstract]

In this paper, we propose a cuckoo search approach to detect the transmitted symbols in spatially correlated multiple input multiple output (MIMO) channels. Detection is considered to be a challenging task in correlated channels due to the fact that the channel matrix tends to be ill conditioned or sometimes rank deficient. Currently, lattice reduction aided detection is understood to be the best approach for detection in spatially correlated channels. We propose cuckoo search as an effective approach to solve this problem. We provide the performance comparison of the proposed detector with various other detectors including lattice reduction aided detector. Through the results, we demonstrate the efficiency of cuckoo search detector over other detectors in uncorrelated and correlated channels as well. We corroborate that cuckoo search detector is a better choice over other existing detectors especially in spatially correlated MIMO channels.

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2015

Journal Article

Dr. Ramanathan R. and Dr. Jayakumar M., “A Performance Study of Semidefinite Relaxation Detector in Spatially Correlated and Rank Deficient Large MIMO Systems”, Wireless Personal Communications, vol. 83, pp. 2883-2897, 2015.[Abstract]

Large MIMO detection has gained significant attention in the recent past with computational complexity as the research focus. However, they assume the channel to be i.i.d and uncorrelated, which is not a valid assumption in practice due to the fixed physical space constraints in large MIMO. Nevertheless, there is a little work carried out in these lines. In this paper, we consider the problem of detection in large spatial multiplexing MIMO systems and we investigate the semidefinite relaxation (SDR) approach to solve this problem. We investigate the applicability of SDR approach in large MIMO setting and study its performance in spatially correlated and rank deficient channel conditions. Through the simulation results, we demonstrate the superior performance of semidefinite relaxation detector over other existing methods in uncorrelated and correlated large MIMO systems especially in low SNR regime. The performance of SDR detector is noteworthy with large number of antennas despite the system being rank deficient and the average running time also scales up well for large systems. Â© 2015, Springer Science+Business Media New York.

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2015

Journal Article

H. Damodaran, Sudheesh, P., and Dr. Jayakumar M., “Extended kalman filter for channel estimation combined with decision feedback equalizer for very high mobility system”, International Journal of Applied Engineering Research, vol. 10, pp. 33914-33918, 2015.[Abstract]

Training sequence based channel estimation in combination with Decision Feedback Equalizer (DFE) is used for OFDM based communication receivers. Channel estimation is performed based on Extended Kalman Filter (EKF) algorithm where a two-step predictor corrector mechanism is carried out. In very high mobility environment for LTE downlink usual channel estimation algorithms are incapable due to its nonlinear nature. So an EKF is used for the estimation of complex-valued channel impulse response from the received signal in the non linear environment where the velocity is very large. EKF jointly estimates both time varying channel parameters as well as time correlation coefficients.. Furthermore a DFE is also modeled for eliminate the Inter Symbol Interference (ISI) and for better performance. Performance is evaluated by plotting Mean Square Error (MSE) as well as Bit Error rate (BER). © Research India Publications.

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2015

Journal Article

Karthigha Balamurugan, Dr. Nirmala Devi M., and Dr. Jayakumar M., “Performance analysis of 60 GHZ low noise amplifiers using multi-gate mosfets”, Journal of Theoretical and Applied Information Technology, vol. 77, pp. 373-381, 2015.[Abstract]

Short-channel devices are preferred for realizing millimetre circuits, but these are affected by the short- channel effects (SCE). Multi-Gate (MG) MOSFET is found to be an alternative to overcome this drawback. In this paper, study and analysis of DC and AC parameters of MG MOSFETs have been attempted and small signal gain (y21) of multi-gate structure is analytically derived. Design of low noise amplifier (LNA) at 60 GHz using the channel charging resistance model has been done.Small signal gain and noise figure using the channel charging resistance model has been derived and analysed. The proposed LNA circuit uses various multi-gate MOSFET structures and the results are compared with conventional MOSFET based design. The designed LNA using a Quadruple Gate structure exhibited the noise figure improvement of 24.4% and 42.79% when operated at 1 V and 1.5 V respectively. Also the corresponding gain increases by 2.38 times and 4.9 times compared with conventional single gate MOSFET design. © 2005 - 2015 JATIT &amp; LLS. All rights reserved.

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2014

Journal Article

Dr. Kirthiga S. and Dr. Jayakumar M., “Performance of Dualbeam MIMO for Millimeter Wave Indoor Communication Systems”, Wireless Personal Communications, vol. 77, no. 1, pp. 289–307, 2014.[Abstract]

Millimeter wave (MMW) communication provides high data rates for the personal area networks with the availability of 57–64 GHz unlicensed spectrum, in indoor environment. Multipath fading being pre-dominant in indoor, multi input multi output (MIMO) technology is considered to be the ideal choice compared with the existing systems. As spatial diversity in both transmit and receive enhances the diversity gain, the performance of the system is further enhanced by introducing transmit beamforming based antenna beam diversity. In classical {\$}{\$}2{\backslash}times 2{\$}{\$} 2 × 2 MIMO, a diversity gain of 4 is achieved, whereas in this work, space time block code matrix of code rate 1/2 and dualbeam {\$}{\$}2{\backslash}times 2{\$}{\$} 2 × 2 MIMO with diversity gain 8 is considered. Dualbeam is generated by antenna array with four elements per array with out of phase feed configuration. The weight vector of the beamforming network is out of phase as to reduce the interference between the beams. The dualbeam transmitter is designed with unknown channel state information. Training symbols are transmitted to train and track the channel statistics at the receiver. The proposed work is carried out for MMW indoor system. The indoor channel is modeled using Triple Saleh–Valenzuela (TSV) model that takes into account both time of arrival and the angle of arrival information of the rays. Channel estimation is done for classical MIMO and the above proposed model in both Rayleigh and TSV channel. The orthogonal beams facilitate linear processing in the receiver. Hence maximum ratio combiner with maximum likelihood decoder is used in the receiver to decode the transmitted data. Classical MIMO and dualbeam MIMO are evaluated with respect to bit error rate and channel models. An improved diversity order is achieved with dualbeam MIMO compared to classical MIMO, with a power gain of 1.6 dB. The dualbeam MIMO using TSV is found to perform better compared to dualbeam MIMO using Rayleigh in the low Energy per bit to Noise level $$(\hbox {E}_{\mathrm{b}}/\hbox {N}_{0})$$ with a power gain of 2 dB. More »»

2012

Journal Article

S. Sari, Balamurugan, K., and Dr. Jayakumar M., “Dependence of Substrate Resistance of RF MOSFET on the Performance of LNA at 60 GHz”, International Journal of Computer Science Issues(IJCSI), vol. 9, pp. 277-283, 2012.[Abstract]

Operations in the 60 GHz band have many potential advantages compared to other unlicensed frequency bands including the availability of large bandwidth (7 GHz) and high-transmission power levels. In order to utilize this plentiful resource, it is necessary to study the MOSFET devices at 60 GHz for developing high efficiency low noise amplifier and oscillators. The modeling is mainly based on substrate resistance to improve
the operating frequency. π-type substrate resistance model of RF MOSFETs are used as composite model for MOSFET. In composite model, core transistor is modeled using BSIM4 and substrate network is added to it. The functionality of this composite model is verified by comparing with that of conventional MOSFET. To study the impact of substrate network, a 60 GHz LNA is constructed. Conventional LNA is designed
first and later MOSFET in that LNA are replaced with composite model and comparing performances in both the cases. Within the range of designs, the impact of π-type substrate resistance network on noise figure, maximum available gain, maximum stable gain, high frequency noise and stability characteristics of the LNA are significant and reported.

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2012

Journal Article

Dr. Kirthiga S. and Dr. Jayakumar M., “Performance and Capacity analysis of MIMO system at 5 GHz and 60GHz in Indoor Environment.”, WSEAS Transactions on Communications, vol. 11, 2012.

2012

Journal Article

Dr. Kirthiga S. and Dr. Jayakumar M., “Performance and capacity analysis of MIMO system at 5 GHz and 60GHz in indoor environment”, WSEAS Transactions on Communications, vol. 11, pp. 415-426, 2012.[Abstract]

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2011

Journal Article

K. R. Ravichandran, Padhi, P. Pratim, Ashmita, G., Sangamitra, N., Sreyas, V., Aghil, K. R., and Dr. Jayakumar M., “LMS Channel Estimation and Time Domain Equalization for SC-FDMA Systems”, 2011.[Abstract]

SC-FDMA (Single Carrier Frequency Division Multiple Access) has been accepted as an uplink standard in 3GPP Release 8, December 2008. As per the release the frequency domain equalization (FDE) is used to mitigate the distortion effects due to the channel. This type of equalization is complex and requires high power consumption at the receiver. In this paper we propose LMS channel estimation followed by Time Domain Equalization which offers better performance when compared to the standard FDE.

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2011

Journal Article

B. M. Nithin Krishna, Sutharshun, V., Sudheesh, P., and Dr. Jayakumar M., “Energy based Detection Scheme for Orthogonal Frequency Division Multiplexing”, 2011.[Abstract]

Orthogonal Frequency Division Multiplexing (OFDM) has been accepted as the modulation scheme of choice for the next generation high-speed wireless communication systems due to the advantages that it offers like high spectral efficiency, resistance to multipath fading and resistance to frequency selective fading. Moreover, it lends itself to simple channel equalization. Conventional single carrier systems do not provide such advantages and hence, OFDM would almost ubiquitously be used for high speed wireless data transmission. However, the main drawback of such systems over single carrier systems is that in the presence of noise, there is an increased computational complexity at the receiver end to decode the data. In this paper, a low complexity detection algorithm is proposed for OFDM systems. Maximum likelihood detection is taken as the baseline detection algorithm and the proposed algorithm is compared with ML detection algorithm. Comparison results are plotted and conclusions are drawn.

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2011

Journal Article

R. Adhira, Dr. Jayakumar M., and Karthigha, B., “Modeling a MOSFET for Monolithic Millimeterwave Integrated Circuit Design”, International Journal of Computer Science Engineering and Technology, vol. 1, no. 5, pp. 238-243, 2011.[Abstract]

The millimetre-wave spectrum at 30-300 GHz is of increasing interest to service providers and systems designers because of the wide bandwidths available for carrying communications at this frequency range. These wide bandwidths are valuable in supporting applications such as high speed data transmission and video distribution. This project mainly focuses on modeling a MOSFET for millimeter-wave integrated circuits(MMIC). There are many emerging millimeter-wave applications which demand for low unit cost manufacturing solutions. With the advent of millimeter-wave semiconductor technology a MOSFET is modeled to work efficiently at high frequency. The transistor modeling is done by developing a compact model with BSIM3v3 and external parasitics to model substrate and gate resistance. High frequency MOSFET compact model built using BSIM3v3 as intrinsic core and having parasitic elements supporting HF are designed as extrinsic subcircuit. To demonstrate the effectiveness of the proposed composite MOSFET model, the proposed methodology is then used in designing a low power millimeter-wave CMOS low noise amplifier. S-parameter analysis is to be verified for non linear large signal transistor model analysis of millimeter-wave signals. A hybrid millimeterwave modeling is done using ansoft designer by designing the appropriate extrinsic region.

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2011

Journal Article

S. Manojna, Kirthiga, S., and Dr. Jayakumar M., “Spatial multiplexing for millimeter waves using TSV model”, International Journal of Computer Science and Engineering Technology, vol. 1, pp. 244–248, 2011.[Abstract]

Millimeter waves have the potential of providing multi-gigabit per second wireless networks. Multi Input Multi Output (MIMO) is emerging to be a key technology for enabling wireless technology whose features will improve by increasing the spectral efficiency of the systems at lower cost per bit. Spatial Multiplexing MIMO is found to suffice this requirement which has the principal use of increasing the spectral efficiency. The performance of Spatial Multiplexed system for the Triple Saleh Valenzuela (TSV) Channel model is simulated by assuming a simple indoor LOS environment model. The TSV model takes in to account both the Time of arrival of the rays and Angle of Arrival information of the antenna. Assuming a perfect channel for Estimation, the Bit Error performance of the system is investigated for Zero Forcing, Minimum Mean Square and Maximum Likelihood receivers for 2x2 and 4x4 and 8x8 Spatial Multiplexed systems for BPSK modulation schemes.

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2011

Journal Article

Aa Raj, Karthigha, Bb, and Dr. Jayakumar M., “Designing and modeling of CMOS low noise amplifier using a composite MOSFET model working at millimeter-wave band”, Information Technology and Mobile Communication in the series Communications in Computer and Information Science, vol. 147 CCIS, pp. 297-300, 2011.[Abstract]

In this paper, MOSFET modeling for millimeter wave integrated circuits is discussed. High frequency MOSFET is built using BSIM3v3 as intrinsic core and the parasitics due to HF are designed as extrinsic subcircuit. The proposed methodology is then used in designing a low power, mm-wave CMOS low noise amplifier. The operation of the circuit is simulated using a circuit simulator. The wideband characteristics are verified by implementing the LNA circuit with and without composite model. © 2011 Springer-Verlag.

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2010

Journal Article

P. Rajeswari and Dr. Jayakumar M., “Radiation Properties of Microstrip Patch Antenna on GaAs substrate for Intra-Chip Wireless Communications”, International Journal of Electronic Networks, Devices and Fields (IJNDF, vol. 2, no. 1, pp. 1-10, 2010.

2010

Journal Article

B. Balakrishnan, Geethu, T. K., Govindankutty, N., Pradeep, P., Karnani, V., Dr. Kirthiga S., and Dr. Jayakumar M., “Discrete state space channel modeling and channel estimation using Kalman filter for OFDMA systems”, Proceedings of the 12th international conference on Networking, VLSI and signal processing, pp. 283–287, 2010.[Abstract]

In this paper, a communication system using Orthogonal Frequency Division Multiple Access (OFDMA) is implemented. An iterative Kalman filtering algorithm for estimation of the time-variant Rayleigh fast fading channel is proposed. The Rayleigh channel is approximated to be a Jakes process which is modelled using an autoregressive model. An autoregressive (AR) channel model is used to provide the state space estimates necessary for Kalman filter based channel estimation. More »»

1997

Journal Article

G. P. Srivastava, Jacob, M. V., Dr. Jayakumar M., Bhatnagar, P. K., and Kataria, N. D., “Analysis of superconducting microstrip resonator at various microwave power levels”, Journal of applied physics, vol. 81, pp. 6272–6276, 1997.[Abstract]

The real and imaginary parts of the surface impedance of YBCO superconductors have been studied at different microwave power levels. Using the relations for the critical current density and the grain boundary resistance, a relation for calculating the power dependence of the surface resistance has been obtained. Also, a relation to find the resonant frequency of a superconducting microstrip resonator at various input power levels has been derived. Measurements have been carried out on various microstrip resonators to study the variation of surface resistance and resonant frequency at different rf power levels. The experimental results are in good agreement with theoretical results.

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1997

Journal Article

N. D. Kataria, Dr. Jayakumar M., and Srivastava, G. P., “Microwave Surface Impedence of High Temperature Superconductors and Device Applications”, Studies of High Temperature Superconductors, pp. 45–100, 1997.

1994

Journal Article

Dr. Jayakumar M., Kataria, N. D., and Srivastava, G. P., “10 GHz cylindrical cavity resonator for characterization of surface resistance of High T c superconducting bulk and thin films”, IEEE Transactions on Magnetics, vol. 30, pp. 4605–4607, 1994.[Abstract]

An accurate and simple measurement system incorporating a 10 GHz TE011 cylindrical cavity resonator has been established which is capable of determining the microwave surface resistance of superconducting film and bulk materials of dimension independent of cavity diameter. The advantage of this technique over the conventional end plate substitution method are discussed. The performance of the cavity as a function of temperature and surface resistance measurements on YBCO thin films of 1.0 cm×0.5 cm dimension as well as 0.5 cm diameter bulk samples are presented. The lowest surface resistance measured using this system is 2.5 mohms at 77 K for a thin YBCO film deposited on LaAl2O3 substrate

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### Publication Type: Conference Proceedings

Year of Conference Publication Type Title

2017

Conference Proceedings

V. Arvind, Sowmiya, R., Vignesh, P., Kavin, S., and Dr. Jayakumar M., “Yagi Slot Antenna Based on Substrate Integrated Waveguide Cavity for Wider Bandwidth Applications”, Proceedings of 2016 International Conference on Advanced Communication Control and Computing Technologies, ICACCCT. pp. 303 - 307, 2017.[Abstract]

Substrate Integrated Waveguide (SIW)[2] is more applicable for implementation of millimeter integrated systems. It consists of top and bottom dielectric metal layers perforated with metallic holes called vias. It uses cut off frequency as TE10, which is same as rectangular waveguide. The difference between both is that substrate integrated waveguide uses two parallel arrays of conductive via holes instead of metallic walls. The non-planar transmission lines such as wired cables and coaxial cables were initially used for transmission but later metallic waveguides like rectangular waveguide which showed better result when compared to traditional cables were used. Planar structures like substrate integrated waveguide were used as an alternative option to replace non-planar nature and bulky system. Substrate Integrated Waveguide is a planar form of waveguide satisfies several requirements for space applications. Substrate Integrated Waveguide with slot antenna is the simple configuration highly suitable for satellite application.

Authors

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2017

Conference Proceedings

G. Sudhakaran, Kandipati, B., G Surya, B., V Shree, K., Sivaprasad, M., and Dr. Jayakumar M., “Evolutionary Algorithm Based Structural Optimization for Patch Antenna Design and its Performance Analysis”, International Conference on Advances in Computing, Communications and Informatics, ICACCI 2017. pp. 2189-2192, 2017.[Abstract]

Modern communication technology demands high performance miniaturized planar antennas. Designing planar antennas such as microstrip patch are well studied and have tremendous scope in the development based on the required objectives. Several optimization techniques were reported for the design of patch antennas but limited to dimensional parameters only. In this work we have adapted evolutionary algorithm based optimization which optimizes the dimension as well as the structure of the patch. This shows unconventional structures with better electrical performances. Here we assume a unit square patch of λ/8 for the construction of the radiating structure of the antenna element using the algorithm. The antenna is designed to operate at 2.45GHz. The major outcome of this work is that the evolutionary algorithm outcome is interfaced with the RF Simulation to make it fully automatic iterative system. The performances were compared to the conventional patch and it was found that the algorithm based patch antenna gave better results.

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2016

Conference Proceedings

S. Narayanan B, R, K., and Dr. Jayakumar M., “Microwave Absorber Characterization of Fly Ash Based Planar Composites”, International Conference on Material Science and Technology (ICMTECH 2016). New Delhi, 2016.

2010

Conference Proceedings

P. Kumar and Dr. Jayakumar M., “Evaluation and analysis of bit error rate due to propagation mechanisms of millimetre waves in a QAM system”, Proceedings of the 12th international conference on Networking, VLSI and signal processing. World Scientific and Engineering Academy and Society (WSEAS), pp. 177-181, 2010.[Abstract]

The waves falling in the 40GHz to the 100GHz band in the electromagnetic spectrum are referred to as millimetre waves. Due to the large bandwidth availability, these high data-rate signals find a wide range of applications in modern communication technology such as broadband multimedia wireless systems and 4G cellular communications. Achieving a reduced Bit Error Rate (BER) of around 10-7 for high quality audio and video streaming, is a challenging task in this band of frequencies. In this paper, we have reviewed and studied the mathematical models for various propagation mechanisms that lead to an increase in the Bit Error Rate. We have then presented a formulation for the calculation of Bit Error Rate of a system employing Quadrature Amplitude Modulation.

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2009

Conference Proceedings

A. .W, Dr. Kirthiga S., and Dr. Jayakumar M., “Linear Precoding based blind channel estimation in OFDM systems for fading environments”, National Conference in Recent trends in VLSI, Information Processing and Communications. 2009.

2009

Conference Proceedings

, ,, Dr. Kirthiga S., and Dr. Jayakumar M., “Pilot symbol assisted channel estimation and modulation scheme estimation in adaptive modulation system for OFDM systems”, National Conference in Recent Trends in Communication and Signal Processing. 2009.

2009

Conference Proceedings

A. .W, Dr. Kirthiga S., and Dr. Jayakumar M., “Blind channel estimation of OFDM systems in fading environments using Singular Value Decomposition”, National Conference in Recent Trends in Communication and Signal Processing. 2009.

2009

Conference Proceedings

Dr. Jayakumar M., Anooja, B., Deepika, K., ,, Shanmughpriya, K. C., K., S., and Vijay, V., “Coplanar Dual Concentric Anualar Ring Microstrip Antena for Wireless Sensors”, National Conference on Communication and Networks. Trissur, 2009.

2009

Conference Proceedings

A. S. Selvin, K. Ravi, B., Darwino, G. S., Harishankar, R., Jitha, R., and Dr. Jayakumar M., “Design and Studies on Non-planar Conformal Patch Antennas for Airborne Vehicles”, Technical Report of ECE, Electron, Special Issue, Proceedings of National Conference on Recent Trends in Communications and Signal Processing. Coimbatore, pp. 57 – 62, 2009.[Abstract]

Antennas deployed in airborne vehicle communication require a distinctive design approach from the rest of the applications. In this paper, planar microstrip antennas are conformed to non-planar structures suitable for deployment in airborne vehicles of various sizes. The design procedure for these non-planar curved microstrip patch antennas, derived from the basic rectangular microstrip patch antenna design, is explained briefly. Antenna parameters such as radiation pattern, return loss, VSWR, gain, directivity and radiation efficiency are analyzed for various degrees of curvature over the patch.

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2009

Conference Proceedings

S. Kirthiga, Sheriff, I. A., Krishnan, S., Chopra, A., Kumar, K. K., and Dr. Jayakumar M., “Blind Channel Estimation of OFDM systems in fading environments using SVD”, National Conference on Micro electronics and Communication. Chennai, 2009.

2009

Conference Proceedings

Dr. Jayakumar M., S. Selvin, A., Bharathi, R., Darwino, G. S., Harishankar, R., Jitha, R., and Jolly, R., “Design and Studies of Dielectric and Air Substrate Based H-Shaped Shorted Microstrip Patch Antenna”, National workshop on Design and Analysis of Radar Systems, DARS 2009. ISRO, Bangalore, 2009.

2008

Conference Proceedings

Dr. Jayakumar M., Ch, A., R, P., Sama, S. Deepthi, and Ashok, S. K., “Design and Analysis of Dual Beam Angle Microstrip Antenna Array for Geographically Separated WiMAX Links”, National Conference on Broad Band Technologies (BROADBAND-08). Mar Baselios College of Engineering and Technology, Thiruvananthapuram , 2008.

2008

Conference Proceedings

Dr. Jayakumar M., Dr. Ramanathan R., and B, S. Narayanan, “Air Substrate Based Shorted Rectangular Patch for Air Borne Vehicles”, International Conference on Aerospace Science and Technology (INCAST -2008). National Aerospace Laboratories, Bangalore, p. 139, 2008.

2007

Conference Proceedings

S. Ahalya, George, A., and Dr. Jayakumar M., “Design and analysis of a planar microstrip array antenna for direct to home satellite television receivers”, Second International Conference on Wireless Communications and Sensor Networks. IIIT Allahabad, 2007.

1998

Conference Proceedings

K. R. Venkataramani and Dr. Jayakumar M., “Antenna system for Launch vehicle applications: Design limitations and constraints”, National Conference on Microwave Technology and Applications. New Delhi, 1998.

1998

Conference Proceedings

Dr. Jayakumar M. and Venkataramani, K. R., “Comparative Study on Radiation pattern of quadra-loop and microstrip patch Airborne antenna systems at S-band region”, Symposium on Antenna Technology and Applied Electromagnetics. Canada, 1998.

1996

Conference Proceedings

G. P. Srivastava, Jacob, M. V., Dr. Jayakumar M., Bhatnagar, P. K., and Kataria, N. D., “Nonlinear Surface Impedance of YBCO Superconductors at High Microwave Power Levels”, Asia- Pacific Microwave Conference. New Delhi, 1996.

1995

Conference Proceedings

N. D. Kataria, Dr. Jayakumar M., Ojha, V. N., Gupta, A. K., and Srivastava, G. P., “Half Wavelength Superconducting Microstrip Resonators on Different Substrates”, National Symposium on Recent Advances in Microwaves and Lightwaves. 1995.

1995

Conference Proceedings

R. Saxena, Kataria, N. D., Dr. Jayakumar M., Ojha, V. N., and Srivastava, G. P., “Miniaturized Split Ring Resonator Filter For Cellular Communication System”, National Symposium on Recent Advances in Microwaves and Lightwaves . 1995.

1995

Conference Proceedings

G. P. Srivastava, Jacob, M. V., Dr. Jayakumar M., and Bhatnagar, P. K., “Non Linear Surface Resistance of HTS Materials”, National Symposium on Recent Advances in Microwaves and Lightwaves . 1995.

1994

Conference Proceedings

N. D. Kataria and Dr. Jayakumar M., “Accurate measurements of microwave surface resistance of superconductors by endplate substitution technique”, Solid State Physics Symposium. Jaipur, 1994.

1994

Conference Proceedings

Dr. Jayakumar M., Chandra, R., Gupta, A. K., and Kataria, N. D., “Microwave Characterization of substrate dependence of surface resistance for high Tc superconducting thin films”, 6th MMM-Intermag Conference. Albuquerque, USA, 1994.

1993

Conference Proceedings

G. P. Srivastava, Dr. Jayakumar M., and Kataria, N. D., “Uncertainty in the measurements of Surface resistance of High Tc Superconductors by cavity method”, Asia Pacific Microwave Conference. Taiwan, 1993.

1993

Conference Proceedings

N. D. Kataria, Dr. Jayakumar M., and Srivastava, G. P., “Mattis-Bardeen Analysis on Surface resistance of YBCO Polycrystalline samples”, International Symposium on Recent Advances in Microwaves . New Delhi, 1993.

### Publication Type: Conference Paper

Year of Conference Publication Type Title

2016

Conference Paper

V. Arvind, Sowmiya, R., Vignesh, P., Kavin, S., and Dr. Jayakumar M., “Yagi slot antenna based on substrate integrated waveguide cavity for wider bandwidth applications”, in Advanced Communication Control and Computing Technologies (ICACCCT), 2016 International Conference on, 2016.

2016

Conference Paper

M. M.G., Sudheesh, P., and Dr. Jayakumar M., “Channel Estimation for a high mobility MIMO system using Particle filter”, in International Conference on Recent Trends in Information Technology 2016 (ICRTIT 2016), 2016.[Abstract]

Channel estimation is an important part in a coherent detection of MIMO system. This paper proposes tracking of fast time varying channel coefficients for a MIMO system using particle filter algorithm. As the system is highly mobile, MIMO channel is fast time-varying, non-linear and non-Gaussian, particle filter is the best candidate to track the swiftly varying channel co-efficient. Even though there exist Kalman filter, the BLUE (Best Linear Unbiased Estimator), it is not suitable for nonlinear and non-Gaussian problems. Moreover Kalman filter variants namely EKF (Extended Kalman Filter) and UKF (Unscented Kalman Filter) are limited to Gaussian noise.

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2016

Conference Paper

N. R. Nair, Sudheesh, P., and Dr. Jayakumar M., “2-D airborne vehicle tracking using Kalman filter”, in Proceedings of IEEE International Conference on Circuit, Power and Computing Technologies, ICCPCT 2016, 2016.[Abstract]

This paper focuses on linear Kalman Filter and its application in 2-D tracking of airborne vehicles. Kalman filter is a powerful computation device which uses recursive computation to attain solution of discrete linear filtering. Being an adaptive filter, Kalman filter analysis the relation between its estimated value and measured value, through a feedback loop and tries to attain the result after minimising the noises in the measured value. A system based on control systems, its estimation required can be of the past, presentor the future. In this paper, application of Kalman filter for tracking has been validated with tracking of an air-borne vehicle with constant velocity and constant deceleration. The model was validated with the SNR v/s NMSE graph. Kalman Filter is provided with the (x, y) coordinates and the velocity in each coordinate based on which the next set of coordinates are estimated by the Kalman Filter. Based on the accuracy of the modelling, Kalman Filter might require several estimations to adapt and give more precise estimations. The code has been written with iterations within estimations. Further, the identification of state equations and their relation to this application has been studied. © 2016 IEEE.

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2016

Conference Paper

V. Seshadri, Sudheesh, P., Dr. Jeyakumar G., and Dr. Jayakumar M., “Tracking the variation of tidal stature using Kalman filter”, in Proceedings of IEEE International Conference on Circuit, Power and Computing Technologies, ICCPCT 2016, 2016.[Abstract]

The intent of this paper is to track the height of a tidal wave, using the Kalman filter. By using the Kalman filter algorithm, mathematical expressions are derived to determine the height of a tidal wave. By placing buoy sensors at specific locations in the sea, the real tidal wave height is measured. The buoy sensor is placed at a particular distance from the shore. The sensors continuously record data at that particular position at different time intervals and then transmit the data to the receiver on the shoreline. By continuously evaluating this data, the height of the next wave is being estimated. Since a buoy cannot be placed at every point of the wave, this method provides an easy estimation of replicating the process. These sensors are used to simulate the proposed method of tracking the height of a tidal wave and hence giving a warning in advance in case of a wave height which is more than normal. This warning helps people living in coastal areas to vacate the place in advance, therefore avoiding fatality. This tracking of the tidal wave height is useful particularly in the case of a tsunami. By adding Gaussian white noise to the input data from the buoy sensors, a prediction of the next wave height is possible. © 2016 IEEE.

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2015

Conference Paper

A. Madathil, Nair, A., Satish, C., Nair, N. R., Priyadarsini, P. V. Nivedha, and Dr. Jayakumar M., “Design and performance analysis of Substrate Integrated Waveguide based cavity backed slot antenna for MIMO configuration”, in 2015 International Conference on Advances in Computing, Communications and Informatics, ICACCI 2015, 2015, pp. 680-683.[Abstract]

Substrate Integrated Waveguide (SIW) technology is a potential candidate for implementation of microwave circuits. SIW is used for transmission of electromagnetic waves. It facilitates the realization of non-planar (waveguide based) circuits into planar form for easy synthesis with other planar circuits. In this paper, an SIW cavity backed slot antenna for 2×2 MIMO applications is proposed. This structure offers a compact, low profile, light weight and high gain antenna which is suitable for satellite communication and mobile applications. Our experiments at 2.2 GHz show a return loss below -25 dB for this antenna and a gain greater than 8 dB. © 2015 IEEE.

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2015

Conference Paper

T. S. Cousik, K. Banu, A., H. Pillai, H., and Dr. Jayakumar M., “Dependence of radius of cylindrical ground plane on the performance of coplanar based microstrip patch”, in 2015 International Conference on Advances in Computing, Communications and Informatics, ICACCI 2015, 2015, pp. 675-679.[Abstract]

There is a growing need to use conformal antennas in airborne vehicles as well as wireless applications. This paper presents a planar and five conformal coplanar patch antenna designs for airborne and mobile applications. The planar antenna consists of a rectangular patch fed by a coplanar waveguide feed and is designed to resonate at 2.2 GHz. This planar antenna is then conformed around cylinders of various radiuses and is optimized to operate at 2.2GHz. An investigation of the relationship between the antenna's gain and the radius of the cylinder is performed. While the planar antenna demonstrates a gain of 5.2 dB while conformal antennas show gains from 5.2-6.4 dB as radiuses of the cylinders vary. It is observed that the decrease in the radius of cylinder increases the gain for the antenna. Thus conformal coplanar antennas show good promise for deployment in the aforementioned applications. © 2015 IEEE.

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2014

Conference Paper

M. Archanaa, Balamurugan, K., and Dr. Jayakumar M., “Design of MOS-based all-pass filter using thermal noise models”, in 2014 International Conference on Embedded Systems (ICES), , 2014.[Abstract]

Scaling of MOSFET increases the device performance in terms of speed, current drive, operating frequency and many other parameters; but on the other end, noise aggravates due to shrinking of device dimensions. Although several noise sources are present in recent submicron device, the equivalent thermal noise is considered as a prominent one. This paper deals with analysis and computation of various available thermal noise models and also focuses on the design and implementation of MOS-based all-pass filter using the appropriate thermal noise model. Thus the drawbacks of the currently available MOSFET models which do not include the equivalent noise model, have been considerably overcome. Simulation results of MOS based all pass filter with and without the inclusion of equivalent thermal noise model have been discussed and hence the accuracy of the design is improved.

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2014

Conference Paper

S. Sarathkrishna, Balamurugan, K., Dr. Nirmala Devi M., and Dr. Jayakumar M., “Design and analysis of GaN HEMT based LNA with CPW matching”, in 2014 Eleventh International Conference on Wireless and Optical Communications Networks (WOCN), , 2014.[Abstract]

GaN based devices are in great demand due to its rugged characteristics at extreme conditions. In this paper, design of GaN monolithic microwave integrated circuit (MMIC) low noise amplifier (LNA) with coplanar waveguide matching is presented to understand the key aspects of high gain, low noise figure and high linearity. The LNA can be used in base station technologies as frequency of interest is from 0.6-3 GHz. It delivers gain of 23 dB and noise figure 0.3 dB and OIP3 upto 51 dBm. The linear performance presented here enables reconfigurable designs of LNA over multiple octaves of bandwidth.

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2014

Conference Paper

B. Vinod, Karthigha Balamurugan, and Dr. Jayakumar M., “Design of CMOS based reconfigurable LNA at millimeter wave frequency using active load”, in 2014 IEEE International Conference on Advanced Communication, Control and Computing Technologies, ICACCCT 2014, 2014, pp. 713-718.[Abstract]

Due to increased commercial and scientific applications in millimeter wave (mm wave) band, the development of mm wave transceivers is considered as prominent phase in RFIC design cycle. This paper proposes the design of reconfigurable low noise amplifier (LNA) working at 60 GHz using active load transistor. A single stage source degenerated LNA has been designed to achieve a gain of 8.38 dB and noise figure (NF) of 2.92 dB. The frequency of operation is tuned from 57 to 64 GHz i.e. at millimeter wave. Variation in gain and noise figure are achieved through the design of active load using NMOS transistor. This active load works as reconfiguration network which is subjected to proper bias voltage that yields the highest gain of 8.41 dB and the lower possible gain of 6.9 dB. Similarly the results of NF reaching 2.92 dB as minimum value and on the other end reaching 3.3 dB are observed and presented. That is, reconfigurable performance parameters are gain and NF whose variability is observed to be 17.66 % and 13% respectively. Proper bias voltage is extracted using DC characteristics of load transistor and their results are presented. Design parameter of LNA at millimeter wave frequencies, consideration of noise sources and its equivalent noise voltages, device modeling considering the parasitic effect and choice of LNA configuration have also been discussed. © 2014 IEEE.

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2011

Conference Paper

S. D. Manojna, Kirthiga, S., and Dr. Jayakumar M., “Study of 2×2 spatial multiplexed system in 60 GHz indoor environment”, in International Conference on Process Automation, Control and Computing, PACC 2011, Coimbatore, 2011.[Abstract]

The Millimeter Waves are allocated with 60GHz frequency range as an unlicensed band worldwide. Millimeter waves become very useful for short-range communications because of its high data rate, its large-available bandwidth of 7GHz and the Oxygen absorption present at that band. The 60GHz indoor channel contains much of multipath components and needs the use of statistical parameters in modeling the channel. At 60 GHz, the free space loss is higher and thus requires the use of antennas with more pattern directivity along with having small antenna dimensions. Considering these factors, in this paper, Triple Saleh Valenzuela (TSV) model is chosen as a suitable model for millimeter waves. The performance of Spatial Multiplexed system for TSV channel model is simulated by assuming a simple indoor Line of Sight (LOS) environment model. Assuming perfect channel estimation, the Bit Error Rate (BER) performance of the 2×2 system is investigated for Zero Forcing (ZF), Minimum Mean Square Error (MMSE), and Maximum Likelihood (ML) receivers. © 2011 IEEE.

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2011

Conference Paper

T. Abeesh and Dr. Jayakumar M., “Design and studies on dielectric resonator on-chip antennas for millimeter wave wireless applications”, in 2011 - International Conference on Signal Processing, Communication, Computing and Networking Technologies, ICSCCN-2011, Thuckalay, 2011, pp. 322-325.[Abstract]

Dielectric resonator antenna systems are more realistic antenna system for VLSI Chips due to its simplicity in the integration with other system and monolithic fabrication. The dielectric contains the antennas near field and therefore prevents it from interfering with other nearby antennas or circuits, making it suitable for miniature and compact equipments. DRAs have attracted the antenna designers in microwave and millimeter wave band due to its features like high radiation efficiency, light weight, small size, and low profile, low temperature coefficient of frequency, zero conductor losses and suitable scale in microwave band. DRs of low loss dielectric material, having dielectric constant as 10 &lt; εr &lt; 100 are ideally suitable for antenna applications. These antennas can also be easily integrated into portable communication devices. Dielectric resonator with coplanar wave guide provide better antenna parameters. When a dielectric resonator is not entirely enclosed by a conducting boundary, it can radiate, and so it becomes an antenna, named Dielectric resonator antenna (DRA).As compared to microstrip antenna, DRAs have much wider impedance bandwidth and they don't support surface waves. Various DRA modes can be excited using different excitation techniques, for example the conducting probe, microstrip line, co-planar waveguide. In this paper we studied the cylindrical Dielectric resonator antenna configuration along with co-planar waveguide on a semiconductor substrate for millimeter wave wireless application (60GHz). © 2011 IEEE.

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2010

Conference Paper

P. Kumar and Dr. Jayakumar M., “Comparison of Bit Error Rate for propagation mechanisms of millimeter waves in a practical communication systems employing PSK and FSK”, in PIERS 2010 Cambridge - Progress in Electromagnetics Research Symposium, Proceedings, Cambridge, USA, 2010, pp. 292-295.[Abstract]

Millimeter waves have opened a new door to next generation communication systems. These high-frequency signals are advantageous due to the high bandwidths, and hence, the high data rates they present. However, their main drawback is the presence of attenuation factors that adversely affect the quality of the received signal. We have described the various propagation mechanisms that lead to the attenuation of radio waves in the frequency range of 40 GHz for different modulation techniques such as m-PSK and m-FSK. The comparison shows that, as the number of signals needed to represent the digital information increases, the Bit Error Rate (BER) of the PSK system increases, while the BER of an FSK system decreases. We have concluded that BPSK, QPSK or 8FSK are the most advantageous modulation schemes in a practical communication system, under worst case climatic conditions.

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2010

Conference Paper

Dr. Kirthiga S. and Dr. Jayakumar M., “AutoRegressive channel modeling and estimation using Kalman filter for downlink LTE systems”, in Proceedings of the 1st Amrita ACM-W Celebration on Women in Computing in India, 2010.[Abstract]

In this paper, the channel for the downlink of Long-Term Evolution (LTE) that uses Orthogonal Frequency Division Multiple Access (OFDMA) is modelled and estimated. The Rayleigh channel is approximated to be a Jakes process which is modelled using an autoregressive (AR) model. An iterative Kalman filtering algorithm for estimation of the time-variant Rayleigh fast fading channel is proposed. An AR channel model is used to provide the state space estimates necessary for Kalman filter based channel estimation. The Kalman algorithm, using state space concepts, computes the channel matrix which can then be used to estimate the baseband signal transmitted. Since this algorithm uses both pilot sequences and the underlying channel model to estimate the channel, they are more bandwidth efficient compared to only data-based algorithms. The channel quality index obtained in this estimation technique can be used in the dynamic allocation of subcarriers to multi-user. The performance is compared with blind channel estimation technique, subspace based Singular Value Decomposition (SVD). From the simulation results, it is verified that significant signal-to-noise ratio (SNR) gain and bit-error rate (BER) is achieved using Kalman filter compared to SVD. More »»

2001

Conference Paper

Dr. Jayakumar M. and Venkataramani, K. R., “Analysis of airborne radiation pattern and simulation of RF link for launch vehicle”, in National Symposium on Mathematical tools for Antenna Theory and Design, BIT, Ranchi, 2001.

1995

Conference Paper

N. D. Kataria, Dr. Jayakumar M., and Ojha, V. N., “Characterisation of $łambda$/2 microstrip YBCO resonators”, in Proceedings of the DAE solid state physics symposium. V. 38C, 1995.

### Publication Type: Book Chapter

Year of Conference Publication Type Title

1997

Book Chapter

M. Misra, Kataria, N. D., Dr. Jayakumar M., and Gupta, A. K., “Analysis of microwave surface resistance of YBCO thin films by structural dependent two fluid model”, in Advances in superconductivity: new materials, critical currents and devices, Condensed Matter Physics, Superconductivity And Superfluidity (G6411) , 1997, pp. 230-234.[Abstract]

An analysis of microwave surface resistance of high Tc thin film based on modified two fluid model is presented. It incorporates the structural anomalies due to grains and grain boundaries in the material. The experimental surface resistance values of the films, having different structural morphology are fitting well with this theory.

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1993

Book Chapter

N. D. Kataria, Dr. Jayakumar M., and Srivastava, G. P., “Microwave surface impedance of High Temperature superconductors and device Applications”, in Studies in High Temperature Superconductors, Ed by A.V.Narlikar, USA: NOVA Science Publications, 1993.

1993

Book Chapter

N. D. Kataria, Hinken, J. H., and Dr. Jayakumar M., “Microwave High temperature Superconductivity”, in Recent Advances in Microwaves, ed. By G.P.Srivastava, Narosa Publishing Co. Ltd, 1993, pp. 1-45.

Scopus Orcid ID: 0000-0003-0206-3796 | Scopus ID: 15831531100 | Vidwan Profile: Link

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