Novel high gain polarization switchable rectangular slot antenna for L-band applications

A novel high gain polarization switchable rectangular slot antenna is proposed in this paper. Antenna consists of a rectangular slot can be switched in three polarization states; left hand circular polarization (LHCP), linear polarization (LP), and right hand circular polarization (RHCP) by controlling the bias voltage of PIN diodes. The proposed antenna is fabricated on a RT/duroid 5880 substrate with a dielectric constant (εr) of 2.2 and thickness (h) of 0.787mm. Slots are etched on one side of the substrate, while the microstrip feed network is printed on the other side. A metal reflector is placed in a plane parallel to the slot surface to make radiation pattern unidirectional and hence increase the overall gain of the antenna. Measured results are well matched with the simulated ones. Measured 3dB axial ratio bandwidths for LHCP and RHCP are 125 MHz and 120 MHz, respectively. Measured gain of the antenna is around 7 dB at 1.2 GHz in all three states. Proposed antenna can be used for wireless applications such as security cameras and systems.