Hybrid millimeter-wave push-push oscillators using silicon-germanium HBTs

Push-push design has proven to be an efficient way to extend the usable frequency range of active devices for oscillator applications. In this paper, the basic principles of push-push oscillator design are explained and various possibilities to realize this concept are shown. Several examples of hybrid millimeter-wave push-push oscillators using SiGe HBTs as active devices are discussed. Details on large-signal modeling of the SiGe HBTs using both a vertical bipolar integrated-circuit model, as well as a customized large-signal model are given. Measured key performance data of microstrip resonator oscillators at 57 and 58 GHz are output power levels of +1 dBm and single-sideband phase-noise figures (1-MHz offset from carrier) of -106 and -108 dBm/Hz, respectively. For the dielectric-resonator oscillators, a maximum output power of -8 dBm and an optimum phase noise of -112 dBc/Hz (14-dBm output power), as well as a mechanical tuning range of 500 MHz were measured.