Somnath Chatterjee - Academia.edu (original) (raw)

Papers by Somnath Chatterjee

Innovative Systems Design and Engineering, 2012

A two/three terminal active device integrated with a microstrip circular patch antenna is known a... more A two/three terminal active device integrated with a microstrip circular patch antenna is known as an Active Microstrip Circular Patch Antenna. In case of active antenna maximum possible radiated power can be realized when i) the generated power is maximized and ii) the radiator is matched to the intrinsic impedance of free space. To provide the best radiation performance a new relation based on nonlinear interaction between the device and circuit has been developed in this paper. Theoretical result verified with the experimental proofs. Keywords: Active Microstrip Circular Patch Antenna, Gunn Diode, Radiation Pattern.

General Assembly and Scientific Symposium, 2011

(1) How do the poles behave in soft-self and hard-self oscillators executing a process of transit... more (1) How do the poles behave in soft-self and hard-self oscillators executing a process of transition from the initial state to the final state and distortion is a desired contamination, on the complex frequency plane? (2) Do the poles ultimately reside on the imaginary axis of the complex frequency plane? (3) If the poles do not reside on the imaginary axis, what is the frequency of oscillation? (4) In such a non-steady non-linear environment where both the frequency and amplitude of oscillation are changing, then how to apply Barkhausen criteria to study oscillation growth? (5) Can we invoke the Energy Balance principle in such situations? These are some of the questions that this paper deals with.

Advanced Computational Techniques in Electromagnetics, 2013

An Active Slot-Ring Antenna (ASRA) has been studied through experiments and analysis in order to ... more An Active Slot-Ring Antenna (ASRA) has been studied through experiments and analysis in order to find the optimum location of the active device so that the best performance in antenna characteristics is realized in terms of power radiated and power received. Analyses have been carried out in terms of equivalent {ABCD} matrix parameters. Radiation pattern and locking characteristics of the ASRA have been measure and presented in support of the analytical methods.

International Journal of Microwave and Wireless Technologies, 2014

An optoelectronic oscillator (OEO) under the influence of a weak interference has been investigat... more An optoelectronic oscillator (OEO) under the influence of a weak interference has been investigated. The system equation of the OEO under the influence of interference has been derived. A novel technique for calculating the lock range of the oscillator using the harmonic balance method in presence of interference has been demonstrated. Theoretical analysis coupled with experimental results has been presented.

ENERGY, 2012

Abstract: This paper introduces one of the most interesting energy operators, Teager Energy Opera... more Abstract: This paper introduces one of the most interesting energy operators, Teager Energy Operator in a new application in the context of signal processing. Modfied energy separation algorithm is proposed in this paper for the distortionless demodulation of the FM signals. ...

Optik - International Journal for Light and Electron Optics, 2016

Abstract In the present paper a theoretical analysis of pole movement in dual loop optoelectronic... more Abstract In the present paper a theoretical analysis of pole movement in dual loop optoelectronic oscillator (DLOEO) has been carried out. A new circuit arrangement for DLOEO is proposed, where the band pass filter (BPF) has been replaced by an oscillator using injection locking technique. It has been seen from the theoretical and simulation results that the performance of the proposed system is similar to that of the conventional DLOEO. Moreover the proposed system eliminates the requirement of RF filter in the feedback loop of the Optoelectronic Oscillator (OEO).

An antenna where the diode is placed within the patch is capable of producing high power output w... more An antenna where the diode is placed within the patch is capable of producing high power output with spectral purity, yet suffers certain difficulties: (a) Whenever a device is integrated within the patch it affects the field equations as well as the resonant frequency. (b)When desired frequency of oscillation is high, patch dimension become comparable to the active device and is difficult to design in practice. (c) Diode has a finite dimension, which limits the placement of it in the exact location on the patch. To overcome these limitations an excellent way of integrating a two terminal device (Gunn diode) within the patch through a microstrip transformer is proposed in this paper. To obtain perfect matching between antenna and the device so that maximum power output, stable oscillation, uniform radiation pattern, and pure spectrum can be achieved, the transformer sections are designed properly.

Multiple Cyclic passage approach has been used to develop Barkhausen criteria in Laser Induced Mi... more Multiple Cyclic passage approach has been used to develop Barkhausen criteria in Laser Induced Microwave Oscillator (LIMO) and having been applied to study the transient and steady state behaviour of LIMO for first time. A novel structure of LIMO has been introduced for further improving its spectral purity. Equation for Microwave oscillation Envelope in case of single loop Optoelectronic Oscillator is determined from Barkhausen criteria. A detailed study is performed on the stability of oscillator.

The possibility of simultaneous oscillation in waveguide mounted Gunn oscillator has been investi... more The possibility of simultaneous oscillation in waveguide mounted Gunn oscillator has been investigated in detail theoretically and practically. The Gunn oscillator, like any other oscillator, is basically a regenerative system incorporating a limiter type non-linear element, and as such the strongest signal is captured and the weaker ones are rejected. Naturally single mode oscillation is expected but here multi-frequency oscillation is reported. No theoretical justification is available in the literature. The present paper provides an answer to this end.

The behaviour of a quadrature oscillator when subjected to a synchronizing signal has been analys... more The behaviour of a quadrature oscillator when subjected to a synchronizing signal has been analysed and experimentally studied in depth. It has led to the development of a single shot tracking FM discriminator with excellent interference rejection capability. It can also be used as a phase locked demodulator exploiting tracking capability.

______________________________________________________________________________ ABSTRACTS The modi... more ______________________________________________________________________________ ABSTRACTS The modified Optical Phase Lock Loop, as suggested in this paper, considerably improve the performance of the microwave signal generation technique over the earlier technique with the help of commercially available DFB lasers with linewidth of about 4.0 MHz. This modified OPLL seems a realistic approach for generating reference signal for future advanced communication systems with active phased array antennas. This opto-electronic technique provides the advantage of low weight, small size, flexible, immunity to EMI and above low cost because the proposed technique significantly reduces the requirement of narrow linewidth lasers. Moreover, it has been observed that bulk and surface acoustic waves in the power and frequency ranges of a few mW and KHz respectively are capable of modifying both the cavity length and refractive index of the material of semiconductor lasers.

Notwithstanding the efforts of earlier workers some fundamental aspects of an introductory course... more Notwithstanding the efforts of earlier workers some fundamental aspects of an introductory course on numerical methods have been overlooked. This paper dwells on this aspect. It is sometimes felt that the step size is root cause for such misconceptions. But it is hardly felt that clubbing of the for-ward Euler algorithm with the backward Euler algorithm for convenience can lead to serious misconceptions and of course it depends on the nature of the problems. With this in mind we consider few such problems that falls under the category of Ordinary Differential Equation (ODE), a differential equation containing one or more derivatives of the dependent variable. However nothing is discussed on the error due to nesting of forward Euler method in backward Euler method. It is shown in this paper that there is a maximum value of step size up to which the numerical algorithms are stable. This tutorial paper attempt to illustrate these issues by taking some practical example that has exact a...

Advanced Computational Techniques in Electromagnetics, 2013

A Gunn mounted active microstrip patch antenna (AMPA) and active microstrip slot antenna (ASRA) h... more A Gunn mounted active microstrip patch antenna (AMPA) and active microstrip slot antenna (ASRA) has been investigated for the reception of FM microwave signal. Current well/valley phenomenon has been successfully utilized to demodulate the modulation information. Reception poperty of the both antennas are studied in multi-channel environment. Because of its simple circuit configuration and similarity in transmitter and receiver architecture, active patch antenna as demonstrated is well suited for commercial and military application as a two-way microwave communication system. A comparative study on the role of AMPA and ASRA as a receiver shows that ASRA do better performances than AMPA. In case of ASRA the modulating signal are demodulated without any distortion. ASRA also has large locking range (29 MHz) compare to AMPA (5 MHz). So the ASRA has broad band tuning capabilities than AMPA. With ASRA configuration demodulation bandwidth in excess of 14 MHz is realizable which can successfully accommodate a large number of voice or data channels.

International Journal of Microwave and Wireless Technologies, 2013

The microstrip active patch antenna behaves like a resonant circuit/cavity with multiple resonant... more The microstrip active patch antenna behaves like a resonant circuit/cavity with multiple resonant frequencies; furthermore, depending on the non-linearity of the device, it generates significant amount of second harmonic radiation. The location of the device on the patch that maximizes the fundamental radiated power output is found to be not the position corresponding to the minimum second harmonic content in radiated power. An optimum location of the diode on the patch has been suggested. The paper also discusses the modification of the behavior of the active antenna, which is first an oscillator; and then a radiator, under injection-locked condition. The results are presented with respect to a Gunn-mounted rectangular patch.

Progress In Electromagnetics Research Letters, 2012

Gunn mounted active microstrip slot-ring antenna (ASRA) has been investigated for the reception o... more Gunn mounted active microstrip slot-ring antenna (ASRA) has been investigated for the reception of FM microwave signal. Current well/valley phenomenon has been successfully utilized to demodulate the modulation information. The monolithic behaviour of an active slot-ring antenna as a lock-in amplifier, FM (Frequency Modulation) to AM (Amplitude Modulation) converter and square law detector has been demonstrated in this paper. Theoretical analysis coupled with experimental results has been presented. The proposed receiving scheme is unique in the sense that it does not require IF electronics for the purpose of demodulation. It also works well in a multi-channel environment due to the excellent noise-squelching property of an Injection Locked Gunn Oscillator.

General Assembly and …, 2011

It has been pointed out that Barkhausen criterion cannot be used as a general oscillation conditi... more It has been pointed out that Barkhausen criterion cannot be used as a general oscillation condition, to evaluate (1) growth of oscillation, (2) steady state amplitude of oscillation in terms of circuit and active device parameters and (3) to as certain amplitude and frequency stability of oscillation, (4) to audit the nature of oscillation whether it is soft-self or hard-self excited. Here it has been shown that all these limitations can be over come through clubbing of quasi-state and quasi-linearization techniques and modified Barkhausen criterion can also be applied to four terminal as well as two terminal oscillators.

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For solving the nonlinear differential equation of the pendulum, here we adopt a method that tran... more For solving the nonlinear differential equation of the pendulum, here we adopt a method that transforms the nonlinear differential equation into an equivalent linear one and then evaluate the period oscillation. We also apply the energy conservation principle to find the dependence of the time period on the amplitude of oscillation. Also harmonic balance method is applied to find an expression for the period of oscillation. Theoretical curves, simulation results and experimental results are given in support of the findings. Nonlinear method 1 proves that the pendulum oscillation is periodic but it has also very small amount of third harmonic. FFT analysis has been carried out of the data as obtained from the simulation results and it is found that system is almost free from harmonic distortion.

Innovative Systems Design and Engineering, 2012

General Assembly and Scientific Symposium, 2011

Advanced Computational Techniques in Electromagnetics, 2013

International Journal of Microwave and Wireless Technologies, 2014

ENERGY, 2012

Optik - International Journal for Light and Electron Optics, 2016

Advanced Computational Techniques in Electromagnetics, 2013

International Journal of Microwave and Wireless Technologies, 2013

Progress In Electromagnetics Research Letters, 2012

General Assembly and …, 2011

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