An efficient 4-way-combined 291 GHz signal source with 1.75 mW peak output power in 65 nm CMOS

In this paper, an efficient 291 GHz injection-locked signal source using two power-combined of 4-cell zero-phase coupled oscillator networks (CON) is demonstrated. The proposed signal source was fabricated in a 65 nm CMOS process with core area of 0.12 mm
²
. The source exhibits 7.5% tuning range centered at 291 GHz or equivalently operating frequency range of 280 - 302 GHz. It achieves a peak output power of 1.75 mW at 291 GHz with a DC-RF efficiency of 3.09%.