RF-MEMS Tuned GaN HEMT based Cavity Oscillator for X-band

This letter presents a radio frequency micro-electromechanical systems (RF-MEMS) tuned cavity oscillator for X-band. The active part of the oscillator is implemented in GaN-HEMT MMIC technology. The RF-MEMS-switches are realized on a quartz substrate that is surface mounted on a low loss PCB. The PCB is intruded in an aluminum cavity acting as an electrically moveable wall. For a three-row RF-MEMS setup, a tuning range of 5 % around an oscillation frequency of 10 GHz is demonstrated in measurements. The phase noise is as low as -140 dBc/Hz to -129 dBc/Hz at 100 kHz from the carrier, depending on the configuration of the RF-MEMS