Self-injection locked compact coupled planar resoator based cost-effective ultra low phase noise VCOs For wireless systems

A novel self-injection locked compact coupled planar resonator (CCPR) based VCO (voltage controlled oscillator) is developed in response to expensive high Q (quality factor) ceramic and SAW resonators based signal source for wireless communications. One of the problems related to the conventional ceramic/SAW based resonators is fabrication in integrated circuit (IC) form due to 3-D structure. The typical measured phase noise for carrier frequencies 622 MHz, 2488 MHz, and 4200 MHz at 10 kHz offset are better than -135 dBc/Hz, -126 dBc/Hz, and -116 dBc/Hz respectively; and to our knowledge, this is the best phase noise performance for this class of VCOs using printed resonator in 0.35x0.35x0.16 inch circuit board size so far reported. The reported topology is not limited to this frequency, can be extended for other higher frequency by incorporating mode-injection stubs across the CCPR for desired operating frequency, thereby, user-definable.