A 27-39 GHz Fractional-N PLL For 5G mm-Wave Communication With Improved Extended Range Multi-Modulus Divider

This paper presents a 27-39 GHz fractional-N PLL (FN-PLL) with its phase noise analysis, optimization and design for the future fifth generation (5G) millimeter wave wireless transceiver. To achieve fast start-up and to solve the timing competition in the system, a multi-modulus divider (MMD) with asynchronous logic, which consists of transparent reloadable registers (TRRs) and a self-selectable multiplexer, is proposed. To mitigate noise folding caused by charge pump (CP) mismatch, a time-domain model of the quantization noise is analyzed. Based on the conclusion of the analysis, a current is added to offset the zero-crossing point of the CP current. The proposed FN-PLL was fabricated in a 65-nm CMOS process with a total power of 53 mW. An integrated jitter of 117 fs in integer-N mode and 144 fs in fractional-N mode is achieved, respectively. The FN-PLL exhibits a phase noise of - 98.5 dBc/Hz at 1-MHz offset in the fractional-N mode, corresponding to a FoMT of -235.2 dB.