A 7.4dBm EIRP, 20.2% DC-EIRP Efficiency 148 GHz Coupled Loop Oscillator with Multi-feed Antenna in 22nm FD-SOI

This paper presents a 148 GHz coupled loop oscillator with multi-feed (MF) octagonal slot antenna. The MF antenna combines the output power from four single ended fundamental oscillators (f_o) and back radiates the combined fundamental power through a silicon lens. The output power from each oscillator is ac coupled to the following stage using a phase compensation capacitor, whose value is selected to increase the oscillation frequency of the coupling loop network. The oscillator is fabricated in 22nm FD-SOI process and has a peak EIRP of 7.4 dBm and a corresponding DC-EIRP efficiency of 20.2%. To the best of the authors' knowledge, this offers over an order of magnitude improvement in DC-EIRP efficiency among 100-200 GHz VCOs reported to date.