Slot-antenna with switchable polarization

Abstract

Antennas in modern wireless communication systems are required to operate with different polarizations in order to adapt the system to various transmission environments. A novel PIN-diode switched planar slot-loop antenna is introduced which allows switching between linear and circular polarization with a single antenna element. A further advantage of this solution is its uniplanar structure which makes it easy to implement PIN-diodes. The antenna is designed for the 2.45 GHz range and achieves excellent performance with both types of polarization at the same frequency. Simulation and experimental results are shown for a uniplanar antenna with polarization switched between RHCP and LHCP and between circular and linear polarization. The EM simulation of the structure is done with ENSEMBLE from Ansoft. The non-ideal characteristics of the diodes are taken into account in the simulation.