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A microstrip - like interconnection with an aperture in the ground plane below the line is investigated. The resultant geometry leads to a sharp variation in the 50% delay time, 90% rise time and ± 5% settling time. Using second - order approximation, the transient analysis of such an interconnection is presented in this paper. The interconnect parameters are extracted using variational technique...
A theory to design a tunable ultraviolet filter using a 1-D metallodielectric photonic crystal composed of alternate layers of MgF2 and Co is proposed. It is possible to get different ranges of ultraviolet spectrum transmitted through the structure by varying the angle of incidence light. Due to high refractive index contrast in the present structure, regions of transmission separated by well-defined...
Artificial intelligence techniques viz. artificial neural networks (ANN) and genetic algorithms (GA) etc. are well-known in the field of soft computing to solve computationally intensive problems. Researches at Jadavpur University by the authors focussed on applying these techniques to overcoming the limitations of microstrip components and antennas in terms of several useful parameters like band...
In this paper, we have presented a comprehensive review of research on microstrip antennas conducted at the Institute of radio Physics and Electronics, University of Calcutta with an emphasis to those done in recent years.
It is well known that during long mission at low Earth orbit (LEO) as well as geosynchronous Earth orbit (GEO), electromagnetic radiation such as proton, gamma rays, alpha particles etc. creates severe damages to space electronics equipment as well as structural materials of spacecraft. In this context, present study investigates the rationale to developing space materials which could be useful as...
Neural network (NN) based CAD models have been developed for analysis and design of fin-lines. In the analysis phase, the network takes the dimensional parameters of the finline structure as its input and gives the characteristic impedance (Z0) and normalized guided wavelength (b/lambdacf) as its output. Another network, trained for design, takes Z0 along with other dimensions as input and produces...
Impedance matching for microwave amplifiers have been investigated extensively using different methods such as stub matching for broadband applications. In the present communication broadband impedance matching technique has been developed by combining the amplifier module with series microstrip transmission lines with optimum characteristic impedance (Zc) and electrical length. Resistive loading...
This paper describes the design and development of S-band GaAs MMIC chipset consisting of a digital phase shifter, a digital attenuator, and a SPDT switch. The MMICs have been designed using a mature 0.5mum InGaAs pHEMT technology. To offer an attractive solution for phased array systems, the chipset has been integrated in a small form factor hermetically sealed metal package with plug and play features...
Variable energy cyclotron centre (VECC) is presently developing an isotope separator on-line (ISOL) postaccelerator type of radioactive ion beam (RIB) facility. A 33.7 MHz, 1.7 meter long heavy-ion radio frequency quadrupole (RFQ) linear accelerator has recently been commissioned. The design of loop coupler for RF power feeding and also of a tuner for fine frequency tuning of this RFQ cavity are presented.
The challenges facing modern engineering education, in general, and microwave education, in particular, are many and warrant new educational approaches to be tried. This work is concerned with the challenge relating to the perceived absence of dasiahuman facepsila in education. The desirability of integrating historical content into engineering teaching in this context is considered. A recent survey...
EMI is everywhere, inside and outside of all electrical equipment. Man-made EM1 is on the increase daily, due to the increased use of electrical and electronic equipment. The successful detection and elimination of EMI require a systematic search for EM1 sources as well as knowledge of interference susceptibilities of the equipment. Familiarity with the environment in which the equipment will work...
The alternating-direction implicit (ADI) finite-difference time-domain (FDTD) method allows larger time steps than the traditional explicit method by bypassing the Courant limit, thus leading to shorter simulation times. In this paper, the use of the ADI-FDTD method in D-H formulation, to compute low-frequency induced fields due to contact electrodes in the human body is reported. Since the frequency...
An inverse iterative algorithm for microwave imaging based on moment method solution is presented here. This algorithm is based on Levenberg - Merquardt regularization technique with multiple illuminations of the target. It produces better reconstructed image of numerical model under noisy condition in comparison to that developed by our previous algorithms.
A balanced amplifier based rectangular microstrip patch antenna is proposed that exhibit circularly polarized radiation. The inherent benefits of good isolation between input and out put ports as well improved matching capabilities of balanced amplifiers provide overall system gain of 5.21 dB. This system will be immune to the spectral impurity, since microstrip patch antenna basically being high...
The Ca5-xMgxNb4TiO17 (x = 0-3) ceramics were prepared by conventional solid state ceramic route. The microstructure of the ceramic was studied using scanning electron spectroscopy. The microwave dielectric properties (Quxf, epsivr and tauf) were measured using a vector network analyser. Ca5Nb4TiO17 ceramics have a relative permittivity(epsivr) of 45, quality factor (Quxf) of 17600 GHz (at 4.13 GHz),...
A novel formulation of emission from a line source covered by an electromagnetic crystal embedded in a magnetized ferrite slab with a perfectly conductive reflection-plate is described. The method employs the spectral domain approach. The spectral response of electromagnetic crystal embedded in a magnetized ferrite slab is calculated using the lattice sums, the T-matrix of a circular cylinder in magnetized...
In this paper, we propose a theoretical model to estimate the resonance frequency and the magnetic polarizability of the square split ring resonators (S-SRR) having varying gap width within the rings. The model also predicts the quantitative change in polarizability depending on the geometrical orientation of the S-SRR. The computed results are verified with results obtained using an electromagnetic...
The phase pure dielectric ceramic with composition 0.95MgTiO3-0.05CaTiO3 (MCT) were prepared using solid state ceramic route and the effect of 60-ZnO30-B2O310-SiO2 (ZBS) on the sinterability, microstructure and dielectric properties were studied. The structural characterization using X-ray diffraction (XRD), microstructure analysis, was carried out using SEM microstructure EDAX and the microwave dielectric...
This paper proposes a new composite right/left handed transmission line metamaterial with a series parallel LC circuit & a shunt series LC tank circuit. A shorted interdigital capacitor (IDC) provide the shunt series LC tank circuit, while the right handed parasitic series inductance & shunt series capacitance are generated by the metallic connections in the direction of propagation. A transmission...
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