A <i>Q</i>-Band Ultralow-Jitter Subharmonically Injection-Locked Frequency Quadrupler WithFTL and Switched-Capacitor Array

In this letter, a <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Q</i>-band ultralow jitter subharmonically injection-locked frequency quadrupler (SILFQ) with frequency-tracking loop (FTL) and 2-bit switched-capacitor array (SCA) is proposed using 90-nm CMOS process. To comprehensively enhance the overall performance of local oscillator (LO) generation, the proposed SILFQ not only employs FTL to adaptively control the locking mechanism over variations but also integrates an unprecedented combination of SCA and frequency multiplier to effectively broaden the overall locking range. The proposed SILFQ with SCA demonstrates a measured locking range of 6.4 GHz. With FTL, the measured phase noise at 1-MHz offset and root-mean-square (rms) jitter integrated from 1 kHz to 40 MHz are −128.8 dBc/Hz and 10.1 fs, respectively. The jitter degradation between injection and output signal is merely within 4 fs. The dc power consumption is 37.4 mW, with a differential output power of −2 dBm and a compact chip size of 0.7 mm<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup>. Featuring several excellent figure of merits (FoMs), this design is well-suited for advanced millimeter-wave (mm-wave) applications due to its superior circuit performance.