A 300 GHz Push-Push Coupling VCO Employing T-embedded Network in CMOS Technology

This letter proposes a 300 GHz high output power and high efficiency push-push coupling voltage-controlled oscillator using T-embedded network. To achieve high output power, eight single-ended T-embedding oscillators are coupled together. The second harmonic of oscillators is extracted by push-push topology and the output power is combined. The procedure of realizing optimal second harmonic output power is introduced and the approach to synthesizing components' parameter of embedded network is presented. Measurement result shows that the proposed coupling oscillator can be tuned from 297 to 305 GHz and delivers 2.8 dBm output power with peak efficiency of 2.85%. The measured phase noise at 10 MHz offset frequency is about -96 dBc/Hz for center frequency.