>300GHz fixed-frequency and voltage-controlled fundamental oscillators in an InP DHBT process

We report fundamental fixed-frequency and voltage-controlled oscillators operating at >300 GHz fabricated in a 256 nm InP DHBT technology. Oscillator designs are based on a differential series-tuned topology followed by a common-base buffer. Measured oscillation frequencies of fixed-frequency designs are 267.4, 286.8, 310.2, and 346.2 GHz, at P_DC = 35 mW. At optimum bias, the output power was measured to be -5.1, -6.9, -9.2, and -11.0 dBm for each design (no probe loss correction), with P_DC ≤ 115 mW. Measured phase noise was -96.6 dBc/Hz at 10 MHz offset. Varactor-tuned designs demonstrated 10.6-12.3 GHz of tuning bandwidth.