One to 40 GHz ultra‐wideband RF MEMS direct‐contact switch based on GaAs MMIC technique

This study presents a 1–40 GHz ultra‐wideband radio frequency (RF) micro‐electro‐mechanical systems (MEMS) direct‐contact switch based on a GaAs microwave monolithic integrated circuit (MMIC) process. The proposed switch utilises an inline cantilever membrane and a pull‐in electrode to achieve ‘off’ and ‘on’ states. It has been manufactured by micro‐machining, which is completely compatible with the GaAs MMIC process. An equivalent distributed parameter circuit model of the switch is established to analyse the microwave performances. The measured S ‐parameters show that the isolation ( S 21 ) in the ‘off’ state is better than 22.5 dB from 1 to 40 GHz. In the ‘on’ state, the input reflection coefficient ( S 11 ) is less than −20.9 dB and the forward transmission coefficient ( S 21 ) is better than −0.25 dB over the complete band. In addition, the measured pull‐in voltage is ∼17.5 V. The measured maximum power handling capacity is 36.5 dBm. A lifetime of 2.4 × 10 7 switching cycles is also verified by this design. The whole structure is designed with the purpose of expanding its working bandwidth and achieving higher microwave performances over current state of art.