Coupling coefficient reconfigurable quadrature coupler based on mechanical switches

Abstract

The conventional reconfigurable quadrature coupler configuration usually requires an external supply voltage which reduces its robustness. A new quadrature coupler with reconfigurable coupling coefficient is implemented using a mechanical control approach to simultaneously satisfy high performance and reliability requirements. Two mechanical switches are firstly implemented on a circular patch to realize two states with different coupling coefficient. To further increase the flexibility in reconfigurability, two more mechanical switches are employed. For demonstration purposes, two patch quadrature couplers were designed, simulated, and measured. The coupling coefficient of coupler I can be switched between 9 dB and 3 dB from 4.9 GHz to 5.3 GHz. Coupler II gave a reconfigurable coupling coefficient, which can be switched between 4 dB, 6 dB, and 11 dB at 3.5 GHz.