A Highly-Efficient 120 GHz and 240 GHz Signal Source in a SiGe-Technology

This work presents a highly-efficient signal source for radar applications at 120 GHz and 240 GHz in a 130-nm SiGe-technology. A low DC-Power consumption of only 78 mW - respectively 264 mW is needed to provide as much as 7.1 dBm (7 dBm) output power at RF-frequencies. The resulting DC-to-RF efficiency is 6.58 (1.88) %. For the signal generation, a Colpitts VCO followed by a bootstrapped gilbert doubler and two power amplifier stages are used at a supply voltage of 3.3 V. The used technology offers new HBTs with an f t of around 470 GHz and f max of 700 GHz. For the use in radar applications, the VCO frequency can be swept with a bandwidth of 16.3 GHz, while the center frequency can be adjusted using laser-fuses.