An electronically reconfigurable patch antenna design for polarization diversity with fixed resonant frequency

Abstract

In this paper, an electronically polarization re-configurable circular patch antenna, with fixed resonantfrequency and operating at Wireless Local Area Network(WLAN) frequency band (2.4–2.48 GHz,) is presented. Thestructure of the proposed design consists of a circularpatch as a radiating element fed by a coaxial probe, coop-erated with four equal-length slits etched on the edge alongthe x-axis and y-axis. A total of four switches were usedand embedded across the slits at specific locations, thuscontrolling the length of the slits. By activating and deacti-vating the switches (ON and OFF) across the slits, the cur-rent on the patch is changed, thus modifying the electricfield and polarization of the antenna. Consequently, thepolarization excited by the proposed antenna can beswitched into three types; linear polarization, left-handcircular polarization or right-hand circular polarization.This paper proposes a simple approach that enablesswitching the polarizations and excites at the same oper-ating frequency. Simulated and measured results of theideal case (using copper strip switches) and the real case(using PIN diode switches) are compared and presented todemonstrate the performance of the antenna.