Analysis on simple feed microstrip patch array antenna design for circular polarization diversity and beam switching with DOA estimation.

Abstract

The terminal node antenna of a wireless communication device should possess the ability to perform many roles since modern communication necessitates the adoption of advanced approaches to address the rapidly evolving needs of end users. Circular polarization diversity, beam switching, and direction-of-arrival estimation (DOA) are advanced antenna applications that can enhance power efficiency and enable lossless transmission, therefore addressing the demands of the present time. In addition, it is necessary for the devices, especially the antennas, to have lower dimensions, even when considering long-distance communication, which typically requires a large-scale array antenna. Integrating microstrip patch antennas, which have a low profile and are lightweight, into transmitting or receiving devices can resolve the problem. This thesis study focuses on the design and simulation of a microstrip patch array antenna. The purpose is to analyze its applicability in the areas of circular polarization, beam-switching, and DOA estimation. A microstrip patch array antenna is constructed using both-sided microwave integrated circuit (MIC) technology to achieve circular polarization while keeping the feed network simple. A four-element microstrip patch array antenna is constructed, simulated, and validated to determine the feasibility of creating a large extensible array with 256 elements. The antenna utilizes a simple single feed to achieve circular polarization. By making a simple adjustment to the feed line, the formation of a Magic-T junction enables beam switching. Additionally, a simple modification in the design allows for direction of arrival (DOA) estimation. The simulation results demonstrate that the antennas have the capacity to transmit across long distances with circular polarization, achieving a gain of more than 26.15 dBic. Additionally, the antennas can alter their beam direction by up to ±17◦. Additionally, they have the capability to determine position by isolating the sum signal and the difference signal by different ports. Keywords: Array antenna, Beam switching, Both-sided MIC, Circular polarization, DOA estimation, Left-hand circular polarization (LHCP), Magic-T, Microstrip patch, Right-hand circular polarization (RHCP).