A Polarization Reconfigurable Antenna for Dual-Band Operation

A polarization reconfigurable microstrip patch antenna is presented for wireless local area network (WLAN) dual-band operation (2.4 GHz and 5.8 GHz). The microstrip patch is aperture coupled to a microstrip line located along the diagonal line of the patch. The dual-band operation is realized by adjusting the frequency ratio of the TM10 and TM30 modes using four shorting posts. PIN diodes are employed to control the connection between the centre of each edge of the patch and the ground. By switching the PIN diodes, the proposed antenna can radiate either horizontal, vertical, or 45 degrees linear polarization in the two frequency bands. The antenna are fabricated and measured. Good agreement is observed between the measured and the simulated results on reflection coefficients.