An Injection-Lockable InP-DHBT Source Operating at 421 GHz with −2.4 dBm Output Power and 1.7% DC-to-RF Efficiency

In this work, an injection-lockable push-push oscillator operating at 421 GHz is presented. The circuit is based on a 0.5 um transferred substrate InP DHBT MMIC process. A peak output power of −2.4 dBm is measured at 34.6 mW DC-power consumption, resulting in 1.7% DC-to-RF conversion efficiency. The oscillator can be injection-locked through a dedicated locking port which, along with the compact core measuring 0.53 × 0.49 mm2, makes this design suitable for efficient injection-locked oscillator arrays comprising a beam steering function by phase tuning.