Coupled feed phased array antenna integrated with MEMS phase shifter

The structure design of a MEMS (Micro-electromechanical System) phase shifter used in phase array antennas was studied and its integration method with a coupled feed phased array antenna was given. The length of the transmission line according to the phase shift principle and the beam scanning principle was calculated. Then, the cantilever MEMS switch was designed and the optimization method of the switch was summarized. Finally, the integration method of the MEMS phase shifter with the coupled feed antenna array was presented. The results show that the insertion loss and the isolation of the optimized switch are less than 0.2 dB and more than -15 dB within 25 GHz, respectively. The phase shifter has a good impedance matching in 15 GHz-20 GHz, and its phase shift characteristics vary linearly. The shift phase is 45° with a maximum phase error of ±5°. The 2×2 MEMS coupled antenna array integration with this phase shifter can complete a beam steering angle of ±30° at 17.3 GHz. The highest gain of the array is 9.3 dB. This phase shifter meets low-cost monolithic integrated demand of the phased array antennas.