A Compact 5-bit Switched-line Digital MEMS Phase Shifter

A compact 5-bit digital MEMS phase shifter that employs 3-port RF MEMS switches is designed and fabricated. It is based on the switched-line design and totally twenty switches are used. Measurements of the 3-port switch indicate an insertion loss of 0.66dB and an isolation of 23.3dB at 10GHz. The 5-bit MEMS phase shifter are fabricated on 200 μ m high resistivity silicon substrates with total size of 7mm×4mm. PCM (Process Control Monitor) is applied to control the stability and consistency of the process. The phase shifter performed well in X band, with an average 3.6dB insertion loss and phase shift error less than 5° at 10GHz.