Techniques minimize the phase noise in crystal oscillator circuits

This paper reports a methodology of combining differential-phase-shift-injection-locking (DPSIL) with mode-coupled-delay-feedback (MCDF) techniques to shave the size, cost, and phase noise from Crystal oscillator circuits. An example of 100 MHz, 125 MHz and 155 MHz ovenized crystal oscillator (OCXO) is demonstrated for the validation of the novel approach, which holds good for both fundamental and higher order overtone mode high frequency crystal oscillator circuits.