A 330-GHz Wide Tuning Range VCO Based on Common-Base Cross-Coupled Topology in SiGe BiCMOS Technology

A wide tuning range push–push voltage-controlled oscillator (VCO) based on a 130-nm SiGe BiCMOS process operating around 330 GHz is described in this letter. The proposed VCO utilizes a cross-coupled topology to output the second harmonic from the common-mode point through a matching network. To achieve a wide tuning range and high output power at high frequencies, a common-base (CB) configuration for the cross-coupled core is used instead of the traditional common-emitter (CE) configuration. A pair of transistors is employed as varactors to extend the tuning range, reduce
$K_{\mathrm {VCO}}$
, and minimize the power loss. The fabricated VCO exhibited a frequency range of 318.6–340.4 GHz (21.8-GHz tuning range, 6.62%) and a peak output power of −7.9 dBm with 31.4-mW dc power dissipation. By introducing a CB configuration into silicon-based VCO design above 300 GHz, the advantages of the wide tuning range and stable output power can be fully utilized.