A low noise, inductor-less, integer-N RF synthesizer using phase-locked loop with reference injection (PLL-RI)

In this paper, a Reference Injected Phase-Locked Loop (PLL-RI) with delay-line ring-type oscillator is employed to implement a low-noise, fast locking integer-N frequency synthesizer. This inductor-less PLL-RI is fabricated in a 1.2V, 130nm RF CMOS process with a 0.5-1.7GHz tracking range in a 0.02 mm² core area. Simulation and measurement results show phase noise reduction and improved settling behavior of a PLL-RI synthesizer compared to a conventional synthesizer. Integrated RMS phase jitter from 10KHz to 30MHz is 0.84ps with a power consumption of 2.6mW at a 1GHz frequency.