Low-Power and Low-Phase Noise 94-GHz and 107.2-GHz Differential Fundamental Oscillators in 70-nm GaAs pHEMT Technology

This paper presents a family of four W-band (<tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$75-110 \text{GHz}$</tex>) differential fundamental oscillators (<tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$94 / 102.7 / 104.4 / 107.2 \text{GHz}$</tex>) implemented in state-of-the-art <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$70-\text{nm}$</tex> GaAs pHEMT (PP07) technology, featuring a peak <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$f_{\mathrm{T}} / f_{\text {max }}$</tex> of <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$160/360 ~ \text{GHz}$</tex>. The differential oscillator core utilizes cross-coupled pair with an inherently grounded source which is optimized for mm-wave performance. The <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$94 - \text{GHz}$</tex> oscillator delivers a phase noise and a differential output power of <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$-115.2 \text{dBc} / \text{Hz}$</tex> (at <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$10-\text{MHz}$</tex> offset) and -3 dBm, respectively, while consuming 74.5 mW. The <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$107.2-\text{GHz}$</tex> oscillator, with a reduced mesa for enhanced performance, achieves a phase noise of <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$-113.3 \text{dBc} / \text{Hz}$</tex> (at <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$10-\text{MHz}$</tex> offset) and a differential output power of -8.8 dBm while consuming only 29 mW, including the output buffers. To the best of the authors' knowledge, these mm-wave oscillators achieve the highest oscillation frequencies with low phase noise and low DC power consumption among previously published GaAs pHEMT single-ended and differential fundamental oscillators.