New implementation of injection locked technique and its application to low phase noise quadrature oscillators
A new implementation of the injection locked technique is proposed. The incident signal is directly injected into the common-source connection node of the sub-harmonic oscillator instead of the gate of the tail current source, and a narrowband noise filtering network is inserted into the same node to suppress the tail current source noise. A novel quadrature oscillator with the proposed injection locked technique is presented. The simulations show that the phase noise of the quadrature oscillator is about 7dB better than that of the stand-alone sub-harmonic oscillator. The quadrature oscillator has been implemented in 0.25um CMOS process and the measured results show that the proposed quadrature oscillator could achieve a phase noise of ?130dBc/Hz at 1MHz offset from 1.13GHz carrier while only drawing an 8.0mA current from the 2.5V power supply.
phase noise quadrature oscillator cmos rf