5-mW and 5% efficiency 216-GHz InP-based heterostructure barrier varactor tripler

We report on record performance in terms of efficiency and output power for an InP-based heterostructure barrier varactor (HBV) tripler. Owing to a step-like InGaAs/InAlAs/AlAs barrier scheme, the device exhibits excellent voltage handling with low leakage current (10 A/cm
²
) up to at least 5 V. A 4×12 μm
²
finger-shaped device in a dual configuration yielded a delivered output power of 5 mW (5.4% conversion efficiency) at 216 GHz.