Full-phase control millimetre wave metasurface element enabled by air-bridged Schottky diodes

A novel design of a full-phase control metasurface element using two independent controlled diodes in a millimetre wave frequency band is presented. By individually providing a reverse bias to two air-bridged Schottky diodes placed respectively on two split dipoles in a periodic unit cell, it is possible to control the capacitance and, therefore, the reflected phase of the metasurface. Importantly, a parasitic element coupling technique is used to achieve full phase control and improve the reflection losses. Simulations of the proposed design are presented. CST Microwave Studio was used to evaluate the tuning range and the reflection characteristics of the proposed design.