A Low-Power Differential Ring VCO Using An Active Inductor For Wireless Applications

In this paper, the design of a Voltage-Controlled Oscillator (VCO), which is considered one of the essential blocks in modern wireless communication systems, is the focus. The general structure of the proposed VCO consists of a four-stage differential dual-delay-path cell interconnected in a ring topology. The output signal frequency is controlled by altering the value of the control voltage. The circuit has profited from Lin-Payne active inductor and pre-discharged path at the output of each delay circuit to achieve an efficient power consumption, wide tuning range, and higher frequency. This work is designed and simulated in TSMC $0.18 \ {\mu} \mathrm{m}$ technology with a 1.8 V supply voltage (V
DD
). The design could achieve the frequency tuning range from 2.27 to 3.6 GHz with the control voltage varied from 2 to 0.8 V. By consuming average power of only 1.4 mW, -90.74 dBc/Hz at 1MHz phase noise achieved, which could gain a figure of merit (FoM) equals to -158.6 dBc/Hz.