To-Po WangZuo-Min TsaiKuo-Jung SunHUEI WANG2018-09-102018-09-102007-01https://www.scopus.com/inward/record.uri?eid=2-s2.0-33846564486&doi=10.1109%2fTMTT.2006.886912&partnerID=40&md5=b1cc2ff34a2c42649215cbe663c0f646A low phase-noise X-band push-push oscillator using proposed feedback topology is presented in this paper. The oscillator core was implemented in a 0.18-μm CMOS process. By using a power splitter and a delay path in the feedback loop connecting the output and current source of the oscillator, a part of the oscillator output power injects to the oscillator itself. With the proper phase delay in the feedback loop and high transconductance of the current source, a low phase-noise oscillator is achieved. The amplitude stability and phase stability are analyzed, the phenomena of the phase-noise reductions are derived, and the device-size selections of the oscillator are investigated. The time-variant function, impulse sensitivity function, is also adopted to analyze the phase-noise reductions of the second-harmonic self-injected push-push oscillator. These theories are verified by the experiments. This self-injected push-push oscillator achieves low phase noise of -120.1 dBc/Hz at 1-MHz offset from the 9.6-GHz carrier. The power consumption is 13.8 mW from a 1.0-V supply voltage. The flgure-of-merit of the oscillator is -188.3 dBc/Hz. It is also the first attempt to analyze the second-harmonic self-injected push-push oscillator. © 2006 IEEE.Current source; Delay line; Flgure-of-merit; High-Q resonator; Self-injectionjournal article10.1109/tmtt.2006.8869122-s2.0-33846564486