Effectiveness of Taguchi and ANOVA in design of differential ring oscillator

In this work, a new circuit of delay cell is proposed to design a wide tuning range differential ring oscillator (DRO). Statistical techniques of Taguchi design of experiments and analysis of variance (ANOVA) are used to optimize the performance parameters of the proposed circuit. Three levels and 3 factors of width (w1, w3 and w4) for various MOSFETs of delay cell, are considered as major performance controlling factors. Taguchi method identifies the significant level of a factor which affects the specific performance parameter. ANOVA analysis is used to find the critical factor for a specified response. This method is also used to find the optimum values of width w1, w3 and w4 for the overall optimum performance of the proposed circuit. Pre and post layout simulations are carried out in GPDK45 nm CMOS technology to justify the statistical results with the simulated ones. Proposed circuit offers wide tuning range of 88.04% (from 1.67 to 13.96 GHz), phase noise of - 91.38 dBc/Hz (at 10 MHz offset), power consumption of 6.93 mW (at Fosc = 11.34 GHz) and total chip area of 610 mu m(2). The proposed DRO find its suitability in high speed communication devices, medical equipment's and navigation systems.