A fully synthesized injection locked ring oscillator based on a pulse injection locking technique

This paper proposes a novel, all synthesized, Injection Locked Ring Oscillator (ILRO). It employs a digitally tunable oscillator and a pulse injection locking technique. The frequency tuning range of the free running oscillator is from 210 MHz to 1.8 GHz with a 1.1 volt power supply. The tuning range from 1.0 to 1.8 GHz can be achieved with 215 tuning steps with a maximum step size of 11.2 MHz, that is well within the worst case 75 MHz (3rd sub-harmonic) and 32 MHz (9th sub-harmonic) locking range of the oscillator. The design occupies 127.5 um by 31.5 um of chip area and is implemented in TSMC's 65-nm CMOS technology. For 3rd harmonic injection locking, the ILRO's RMS jitter is 192.7 fs (1 KHz to 40 MHz) with a phase noise of -130.9 dBc/Hz at 1 MHz offset from the 1.62 GHz carrier while consuming 7.15 mW of power.