High-Efficiency Millimeter-Wave Single-Ended and Differential Fundamental Oscillators in CMOS

Abstract

This paper reports an approach to designing compact high efficiency millimeter-wave fundamental oscillators operating above the fmax/2 of the active device. The approach takes full consideration of the nonlinearity of the active device and the finite quality factor of the passive devices to provide an accurate and optimal oscillator design in terms of the output power and efficiency. The 213-GHz single-ended and differential fundamental oscillators in 65-nm CMOS technology are presented to demonstrate the effectiveness of the proposed method. Using a compact capacitive transformer design, the single-ended oscillator achieves 0.79-mW output power per transistor (16 µm) at 1.0-V supply and a peak dc-to-RF efficiency of 8.02% (VDD=0.80 V) within a core area of 0.0101 mm 2 , and the measured phase noise is −93.4 dBc/Hz at 1-MHz offset. The differential oscillator exhibits approximately the same performance. A 213-GHz fundamental voltage-controlled oscillator (VCO) with bulk tuning method is also developed in this work. The measured peak efficiency of the VCO is 6.02% with a tuning rang of 2.3% at 0.6-V supply.

Optoelectronic oscillator for 5G wireless networks and beyond

“…The prototype chip implemented in a 65 nm CMOS process covers a 219-238 GHz frequency band with the output power of 3.4 dBm, while the minimum measured phase noise is −105.8 dBc Hz −1 at 10 MHz offset frequency. Furthermore, Wang et al reported an approach to design compact high-efficiency THz fundamental oscillators and it can be operated above half of the maximum frequency of the active device [63]. A 213 GHz signal-ended and differential fundamental oscillator was fabricated by 65 nm CMOS technology.…”