DESIGN AND ANALYSIS OF APERTURE COUPLED ANTENNA WITH DEFECTIVE GROUND

Abstract

Aperture Coupled Micro-Strip Antenna Design and Analysis A linearly-polarized aperture coupled patch antenna design is characterized and optimized using Agilent ADS antenna simulation software [1]. This thesis focuses on the aperture coupled patch antenna due to the lack of fabrication and tuning documentation for the design of this antenna and its usefulness in arrays and orthogonally polarized communications. The goal of this thesis is to explore dimension effects on aperture coupled antenna performance, to develop a design and tuning procedure, and to describe performance effects through electromagnetic principles. Antenna parameters examined in this study include the dimensions and locations of the substrates, feed line, ground plane coupling slot, and patch. The operating frequency, input VSWR, percent bandwidth, polarization ratio, and broadside gain are determined for each antenna configuration. The substrate material is changed from RT Duroid (material in nominal ADS design [1]) to FR4 due to lower cost and availability. The operating frequency is changed from 2.3GHz (specified in nominal HFSS design) to 2.4GHz for wireless communication applications. Required dimensional adjustments when changing substrate materials and operating frequencies for this antenna are non-trivial and the new design procedure is used to tune the antenna. The antenna is fabricated using 59mil thick double and single sided FR4 boards joined together with double sided 45mil thick acrylic tape. The antenna is characterized in an anechoic chamber and experimental results are compared to theoretical predictions.