Heterogeneous coupled ring oscillator arrays for reduced phase noise at lower power consumption

Phase noise in coupled-oscillator arrays of single-ended inverter-based ring-oscillators has been analysed using a time-domain delay-based model for injection locking. This paper demonstrates a heterogeneous coupled-oscillator array (multiple frequency oscillators coupled to each other) which can decrease phase noise, with an improvement in power consumption, viz. for a 15 dB reduction in phase noise, we increase power consumption by only 12 dB. An oscillator running at 2.56 GHz coupled with an oscillator array of 36 coupled oscillators running at 1.28 GHz, was measured to have a phase noise of -103 dBc/Hz at a 1 MHz offset from the center frequency of 2.56 GHz, with a total power consumption of 3.7 mW.