Research And Design Of CMOS Standing-Wave/Rotary Travelling-Wave Voltage-Controlled Oscillator

In modern VLSI systems, the clock signal, whose quality affects the performance of the whole system, is considered to be more and more important. With the circuits’ frequency increasing, high quality-clock network is facing greater and greater challenges, wich is lower power consumption and lower clock uncertainty, including skew and jitter of clock signal.Using techniques of standing wave(SWO) and rotary-travelling-wave oscillator(RTWO), the skew and jitter in global clock networks can decrease dramatically.In this paper, a λ/2-SWO which is short circuited on both sides, based on CMOS technology, is designed. With the combination of theoretical analysis and ADS software simulation, the operation principles of different parts of the oscillator are analyzed, especially the negative resistance cross-coupled pair. At last, simulation results and performance analysis are given in the time domain and frequency domain.Based on the research of λ/2-SWO, a multiphase, lower power consumption and high-frequency rotary travelling wave voltage controlled oscillator(RTW-VCO) based on micro-strip transmission line is designed. The RTW-VCO includes a differential transmission line loop mode, four basic SWOs, and high-frequency buffer using shunt peaking technology. In SWO unit, λ/4 differential transmission line is used to instead the PMOS loads in traditional cross-coupled inverters. And its resonator model was modeled and optimized by electromagnetic simulation software HFSS, so as to get the Q value as high as possible, which can improve the oscillation frequency, reduce power consumption, and optimize chip layout area. As for the differential transmission line loop, we can get the relationship between width w, space s and quality factor Q of the resonator model by the analysis and simulation in HFSS. To achieve full utilization of energy and further reduce power consumption, feed-forward technology is applied to connect the SWO units and transmission lines loop, which solves the uncertainty of rotary wave, rotated counterclockwise in this paper, and ensures the circuit started-up.Another, creating the physical model of λ/4 differential transmission line improve the performance of tuning range and phase noise.Based on 0.18-μm CMOS process, the size of chip layout is 980μm×1150μm. The post-simulation tells that the frequency of 14.4 GHz with 4.65% tuning range, the power dissipation of 24 mW and the phase noise of-95.04dBc/Hz at 1MHz offset from a single 1.2-V supply.For the creating model, the tuning range is 14.5 GHz with 6.14% and the phase noise is-96.84dBc/Hz at 1MHz.