A New $X$-Band Low Phase-Noise Multiple-Device Oscillator Based on the Extended-Resonance Technique

A novel multiple-device oscillator based on the extended-resonance technique is proposed. This oscillator achieves low phase noise through optimizing the circuit's group delay. Based on this technique, an X-band four-device SiGe HBT oscillator has been designed, fabricated, and tested. The measured phase noise is - 119 dBc at 100-kHz offset frequency. To the authors' best knowledge, this oscillator shows the lowest phase-noise performance among other reported X-band microwave planar hybrid free-running oscillators.