Comparison of Direct Contact Feeding methods for a Rectangular Microstrip Patch Antenna

Abstract

Microstrip patch antennas have a variety of feeding technique applicable to them. It can be categorized in accordance to the main power transfer mechanism from the feed line to the patch. Contactingfeeds investigated in this work are coaxial probe feed and transmission line feed. This work is an effort to design, model, simulate, fabricate and measure allfour different types of microstrip antenna's non-contacting feed techniques on a similar sized, rectangular patch. Simulation is done using the circuit model (CM) derived from the Transmission Line Model (TLM), and is compared with another simulation set of feeding methods produced using the Method of Moments (MoM). Both methods are simulated on Microwave Office. This design intends to focus on studying the differences in measured and simulated parameters of the patch and its respective feeds, simulate it using MoM, and finally, the fabrication process. Radiation measurements are also presented. Designs for each feeding technique achieved the best return loss (KL) at the desired frequency range, which is 2.4 GHz. The fabricated hardware produced good RL, bandwidth (BW), and comparable radiation performance compared against simulation using MoM. All antennas produced maximum E-and H-plane co- and cross-polarisation difference in the magnitude of -18 dB and half-power beam widths (HPBW) in the magnitude of 90°.