Publication: CMOS 65nm cross-coupled negative-gm voltage controlled oscillator for 5G new radio application
Loading...
Date
2024-07
Authors
Puat, Eng Yap
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
The voltage-controlled oscillator (VCO) is a fundamental component in modern communication applications, including wired and wireless connections,
system synchronization, and clock generation. The VCO generates an output frequency in response to an input voltage. The importance of designing a VCO that
exhibits desired performance characteristics and high capability has increased throughout the years. The VCO under consideration prioritizes reduced phase noise, low power consumption, and 5G NR frequency band operation. The VCO was implemented using 65 nm CMOS technology. The architecture of the VCO comprises an LC tank, an NMOS cross-coupled capacitor, and a NMOS array serving as the tail current source. The LC tank circuit is configured with two capacitor varactors to adjust the frequencies. The obtained frequencies range from 3.7 GHz to 3.9 GHz, with corresponding tuning voltage of 2.2V to 2.5V. Using a cross-coupled NMOS configuration generates a negative resistance that effectively counteracts the parallel resistance of the LC circuit. The NMOS exhibits a high transconductance, effectively minimizing power consumption at the initiation of oscillation. The utilization of a NMOS array in the circuit results in a reduction in flicker and phase noise, particularly when the power consumption remains below 3 mW. The VCO under consideration achieves a figure of merit (FOM) of −172 dBc/Hz and exhibits phase noise of −105 dBc/Hz at a frequency offset of 1 MHz, operating at 3.8 GHz. The power consumption of the VCO is measured to be 2.78 mW when operated at a supply voltage of 1.2 V.