A 14-GHz LC-VCO with SiGe Anti-Parallel Core Configuration and a High-Quality Inductor

In this paper, A 14-GHz LC Voltage-Controlled Oscillator (VCO) is introduced employing a Silicon-Germanium (SiGe) Heterojunction Bipolar Transistor (HBT) anti-parallel core. The design introduces a high quality factor inductor alongside a 3-bit binary-weighted capacitor bank, which utilizes SiGe anti-parallel switches. This setup integrates a secondary LC-VCO in an anti-parallel arrangement with the primary core, further enhanced by a inverse-active SiGe HBT current mirror applied to both cores. The developed VCO achieves a Frequency Tuning Range (FTR) of 11.6%, covering frequencies from 13.26 to 14.9 GHz, and records a low phase noise (PN) of -116.2 dBc/Hz at a 1 MHz offset from 14 GHz, demonstrating 5.6 dB enhancement compared to the single-core VCO, with low 1/f<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> corner frequency of 150 kHz.