A Multidirectional Pattern-Reconfigurable Patch Antenna With CSRR on the Ground

A pattern-reconfigurable patch antenna with nine beam directions based on the complementary split-ring resonator (CSRR) loaded ground is proposed. The antenna consists of a coaxial feed rectangular patch on the top layer and a ground plane loaded with four CSRRs on the bottom layer. Two p-i-n diodes are installed on the stub of every CSRR. By changing the states of the p-i-n diodes, the main radiation direction can be switched both in the E-plane and H-plane. The operation principle of the beam switching by loading CSRRs on the ground is discussed. The prototype is fabricated with p-i-n diodes and bias circuit. The measured common impedance bandwidth of |S 11 | less than -10 dB is from 2.42 to 2.48 GHz. The 3-dB beamwidth covers the elevation angles from 0 to more than 60 and full azimuth angles. The antenna has a compact size of 0.82 0 0.78 0 , which has the potential to be used in the array design.