Low power and low phase noise complementary voltage controlled oscillator optimised by a meta-heuristic algorithm

This paper presents a differential complementary metal oxide semiconductor inductor-capacitor voltage controlled oscillator (LC-VCO). The VCO is adopted from the gate-to-source capacitor feedback Colpitts VCO which has the advantage of large value of negative conductance. Due to the large negative conductance, the VCO has a more reliable startup oscillation at the lower currents. The main characteristics of the VCO such as negative conductance, oscillation frequency and phase noise are discussed and analysed. The value of parameters in this circuit have been determined using Non-dominated Sorting Genetic Algorithm (NSGA-II) to have the optimum performance. The designed VCO oscillates at 2.76 GHz under a supply voltage of 1.4 V. Power dissipation of the proposed VCO is 873 mu W which is significantly lower than that of some other VCOs. The post-layout simulation results of the proposed VCO are presented and compared with the performance of some other VCOs. An optimised differential complementary metal oxide semiconductor LC-VCO is proposed in this paper. Due to the large negative conductance, the VCO has a more reliable startup oscillation at the lower currents.image