Design, Development and Fabrication of Patch Compensated Wideband Vivaldi Antenna and Its Analysis in Radome Chamber

Abstract

Design, development and fabrication of micro-stripline based Vivaldi Antenna for frequency range of 5.5-8.5 GHz has been presented. The Vivaldi antenna is a planner antenna, fabricated at micro-strip by having an exponentially tapered slot profile on it. A parametric study is done to clearly understand the antenna design and parametric variation effects on the radiation pattern. After that an optimized computer aided design has been developed and simulated where the results obtained are for the desired radiation parameters in terms of the VSWR, directionality, beam-width and bandwidth. The optimized design has been fabricated and tested. Wherever results are not found in agreement to simulation; problem has been comprehensively investigated and analysed. This is found associated with discontinuity at feed line, fabrication tolerance constraints and parasitic capacitance at edges or bent of micro-stripline which introduce the parasitic reactance in antenna design. A generalized theoretical procedure has been developed which explores that the associated problems can be compensated by incorporating inductive patch on feed line. The developed theory is applied in fabrication and effectively compensated the associated problems where test results are found in good agreement with simulation results. Further the Vivaldi antenna is studied in Radome enclosure for the operating frequency of 5 GHz. A computer aided design is developed in order to study the effect of Radome boundary on the radiation pattern and the performance characteristics of the Vivaldi Antenna. The design computes the VSWR, directionality, beamwidth and side lobes patterns that are being affected by using the Radome boundary. The overall design is simulated on COMSOL Multiphysics software.