Frequency and Polarization Reconfigurable Microstrip Antenna with Switching Feed Configuration

Circular microstrip reconfigurable antenna for frequency and polarization with feed configuration is presented in this paper. The wideband cascaded branch line coupler (BLC) with switching feed configuration is used to achieve horizontal linear polarization (H-LP), vertical linear polarization (V-LP), right hand circular polarization (RHCP) and left hand circular polarization (LHCP) in the antenna. The proposed cascaded BLC feed network is used to control tunable over a wideband from 1.25 to 2.95 GHz. The circular patch antenna has the tunable impedance bandwidth from 2.09 to 2.96 GHz. It is achieved by varying the varactor diode capacitance values between 4.15 pF (0V) to 0.94 pF (6V). The impedance bandwidth of BLC feed network is matching with the impedance bandwidth of patch antenna simultaneously to achieve all the performance. Measured results show good agreement.