Sanjeev Kulshrestha

Pole discontinuity removal using artificial neural networks for microstrip antenna design

This article presents the use of artificial neural networks for the evaluation of integrals with finite number of pole singularities while formulating the integral equation for the electric surface current density. A feed-forward single-layer back-propagated artificial neural network (ANN) model has been trained to approximate the discontinuous integrand function. Generation of a soft continuous function obtained from the ANN model and closed-loop expressions for the evaluation of the integrals are presented. The proposed technique is applied to compute the input impedance of microstrip antenna and results have been compared with IE3D. Integration has been performed using n-point Gaussian quadrature rule for evaluating the reaction matrix.

Square Coaxial Beam Forming Network for Multilayer Microstrip Antenna

This paper presents the design of square coaxial beam former and its transition from square coaxial line to microstrip line. Impedance matching has been achieved by creating a groove discontinuity in inner conductor. A cone has been provided for smooth impedance transformation for required broad banding. The measured performance of the beam former has been obtained by feeding it to feed layer of the electromagnetically coupled multilayer patch antenna. Equal and unequal power divider has been designed with proper impedance transformer by changing dimensions of the inner conductor keeping same outer conductor dimensions. Smooth linear taper has been provided at impedance transformer junction. High power calculations are also presented for SCL to handle several kW of power.