One bit distributed X-band phase shifter design based on RFMEMS switches

This article describes the design of a one- bit low-loss X-band phase shifter based on MEMS capacitors. The phase shifter shows a phase shift of 90deg at 7.5 GHz, 135deg at 11.4 GHz and 180deg at 15 GHz with applied bias of 33.24 V. The insertion losses are less than 0.2 dB and return losses are more than 14 dB over the desirable frequency ranges from 0 to 16 GHz. Total length of 12 MEMS bridges phase shifter is 2.83 mm. At 7.5 GHz, the phase shift per unit length is 31.8deg/mm, 47.7deg/mm at 11.4 GHz and 63.6deg/mm at 15 GHz showing very large phase shift per length.