Reconfigurable antenna with multiple linear and circular polarization diversity for WLAN applications

Abstract

In this paper, the principle and experimental validation of a multipolarization reconfigurable antenna is presented. The antenna is composed of four straight dipoles as radiating elements and six pairs of PIN diodes are used to adjust the antenna's polarization. By turning these PIN diodes on or off, the proposed design is able to realize linear polarization in horizontal, vertical, and two diagonal directions. In addition, dual-sense circular polarization (CP) radiations are also achieved based on the method of using two orthogonal dipoles with different lengths. An antenna prototype is designed for wireless LAN applications and fabricated for validation. Measurements demonstrate that the proposed design achieves overlapped impedance and axial-ratio bandwidths from 2.34 to 2.48 GHz and from 2.42 to 2.48 GHz, respectively. Measured broadside gains for all polarization states are from 6.2 to 6.7 dBi.