Novel Frequency- and Pattern-Reconfigurable Rhombic Patch Antenna With Switchable Polarization

This letter presents the design of a novel patch antenna with frequency and pattern reconfiguration with polarization switching. The proposed antenna consists of a rhombus-shaped radiator with three excitation lines oriented at different angles. All the excitation lines are connected to a common feedline. The reconfiguration is achieved by changing the bias states of three pairs of p-i-n diodes. The dynamic nature of the antenna offers two operating bands, viz., 5.2/5.8 GHz, and provides linear/circular/±45° slant polarization. Furthermore, the pattern can be tilted 30° in right- and left-hand directions. The proposed antenna exhibits cross-polarization discrimination greater than 20 dB in all the operating modes. The prototype antenna is fabricated, and the simulation results are verified using measurements.