A 300-GHz Fundamental-Mode Differential Colpitts Voltage-Controlled Oscillator Based on InP HBT Technology

In this work, a 300-GHz fundamental-mode differential Colpitts voltage-controlled oscillator (VCO) has been developed based on a 250-nm InP HBT technology. All inductive components are realized with inverted transmission lines while varactors are implemented by HBTs with base and emitter tied together. The VCO exhibits a frequency tuning range of 294.6 GHz to 301.7 GHz with a maximum output power of -1.9 dBm. The total DC power consumption is 59.8 mW. The circuit size including pads is 460
$\mu \mathrm{m}\times 675\ \mu \mathrm{m}$
. Imaging was successfully demonstrated with the developed VCO used as the signal source.