Simplified Modeling, Simulation and Performance Analysis Using Circuit Model for a Corporate Feed Microstrip Patch Array

Abstract

This work is an effort in investigating and modeling an accurate circuit model derived from the transmission line method (CM/TLM) by simulating a rectangular microstrip patch array using two different simulation techniques, the transmission line method (TLM) and method of moments (MoM). Each array contains two element units of rectangular patches. This basic rectangular patch is very accurately modeled in a previous work. The array, which is a combination of several unit of this basic structure, is designed to resonate at 3G/UMTS frequency of 2 GHz. A standard software platform is chosen to simulate both techniques and Microwave Officetrade software is utilized. Both simulation sets (using CM/TLM and MoM) are compared and to determine their level of variation in terms of bandwidth, resonant frequency (fres) and S11. MoM-simulated structure is then fabricated and measured to determine the degree of distinction between hardware and the two simulation sets. Fabrication is done on an FR-4 board with a relative permittivity (epsivr) of 4.7. Antennas designed and simulated for each feeding technique achieved the best return losses at the desired frequency, which is 2 GHz, with S11 values lower than -10 dB. At the same time, both produced relatively sufficient bandwidth for its kind which is about 3.2% CM presented in this work has been found out to have less than 5% difference compared to its MoM counterpart in terms of S11 and resonant frequency (ffres), and slightly higher variation of 6.4% in terms of bandwidth