Towards a Si/GaAs Based Flat-Panel Quasi-Optical Metasurface Antenna with Switchable Beam Characteristics

This paper presents a III/V compound silicon (Si) and gallium arsenide (GaAs) metasurface antenna to achieve beam-forming at 94 GHz. The metasurface antenna consists of a flat-panel system architecture and works in a holographic manner. The guided mode launched into the Si layer is converted to a planar wave-front using a quasi-optical pillbox feeding architecture, significantly simplifying the design process of the metasurface antenna. It is demonstrated that the developed metasurface can switch its radiation pattern in the azimuth plane by selectively activating between multiple input ports while beam forming in the elevation plane can be achieved by actively tuning the metamaterial elements forming the metasurface aperture. The simulated reflection coefficient patterns suggest an impedance matching better than -15dB at all input ports is achieved at 94 GHz. The radiation patterns of the antenna clearly demonstrate the 3D beam scanning capability of the presented metasurface antenna $(\theta =0^{\circ }/15^{\circ },\varphi =0^{\circ }/\pm 90^{\circ })$ at millimeter-wave frequencies.