EM Design of Beam Steering Antenna using Active Frequency Selective Surfaces at 24 GHz

A beam steering antenna using active frequency selective surfaces (AFSS) has been proposed in this paper. The antenna is designed to operate in the K-band. A U-shaped microstrip patch antenna has been placed below an AFSS layer. The beam is being steered by ON and OFF state of the PIN diodes that are embedded onto the unit cells of frequency selective surface structure that is used as superstrate of antenna. The proposed antenna can achieve a maximum beam tilt of 32º and a maximum gain of 7.28 dB by changing the state of the PIN diodes. The proposed design can find its application in radar altimeter employed for space applications due to its light weight.