Design Process for a Dual Pattern Reconfigurable Antenna based on flip-chip Aluminum Gallium Arsenide (AlGaAs) PIN diodes

A dual-pattern reconfigurable antenna comprising a torus-shaped metasurface controlled by flip-chip Aluminum Gallium Arsenide (AlGaAs) PIN diodes and a bicone antenna feed is investigated. A broadband bicone antenna operating between 14 and 34 GHz is initially optimized to enhance its realized gain and achieve 4.1 dBi at 29 GHz and 4.4 dBi at 30 GHz. The designed bicone is subsequently used as a feed for the torus-shaped metasurface. A torus-shaped metasurface capable of switching between reflection and transmission is investigated in two stages. Its geometry is optimized as a metallic reflector to reduce computational time. The dimensions of the reflector are optimized to improve the gains and lower the side lobe levels (SLL). The simulation of the reflector confirms that the torus reflector with the bicone feed achieves a realized gain of 16.3 dBi at 29 GHz and 17 dBi at 30 GHz. The proposed metasurface achieves transmission and reflection switching between 27.5 and 30.5 GHz by controlling the PIN diode state. Based on the results, the proposed system can operate in two distinct modes: omnidirectional and directional. The expected omnidirectional performance of the final system corresponds to that of the standalone bicone antenna, reduced by the metasurface insertion loss. In the directional mode, the realized gain and radiation pattern are determined by the combined response of the bicone antenna and torus-shaped metasurface reflector.