Active complementary coupled resonator for low phase noise X-band oscillator

This work presents a novel active complementary coupled resonator (CCR) for X-band low phase noise oscillator which operates at 10 GHz band. The active resonator is based on a complementary coupled resonator proposed recently using substrate integrated waveguide (SIW) technology. The proposed active CCR demonstrates a measured unloaded Q of 21172 at the highest. Utilizing the proposed active CCR, an X-band oscillator using hetero-junction field effect transistors (HJ FETs) is realized and measured. The best measured phase noise of the X-band oscillator at 1MHz offset is -127dBc/Hz, which results in a figure-of-merit (FOM) of -195.15 dBc/Hz. In addition, the proposed oscillator occupies only one square inch of area on a printed circuit board (PCB).