Low-voltage and broadband V-band InP HEMT frequency doubler MMIC

A broadband single-ended V-band InP HEMT frequency doubler MMIC is demonstrated. The fabricated frequency doubler MMIC was operated at 1 V drain supply voltage. The doubler consists of a fundamental input matching circuit and a (proposed herein) fundamental signal rejection filter that also operates as an output matching circuit. The fundamental signal rejection bandwidth of the proposed filtering circuit is more than four times wider than that of a conventional open stub circuit. The doubler MMIC realizes around 0 dB conversion gain and more than 22 dB isolation between the fundamental signal and 2nd harmonic signal over the output frequencies from 54 GHz to 70 GHz. The bandwidth over which both the 3-dB bandwidth and the isolation of 20 dB are satisfied is more than 26%. The maximum conversion gain is 1.8 dB with 30.4 dB fundamental signal suppression at 60 GHz output frequency. The MMIC occupies just 0.89 mm₂ and consumes only 8mW.