Abstract: This paper presents the design and performance of a broadband millimeter-wave frequency doubler MMIC using active 0.15 μm GaAs PHEMT and operating at output frequencies from 20 to 44 GHz. This chip is composed of a single ended-into differential-out active Balun, balanced FETs in push-push configuration, and a distributed amplifier. The MMIC doubler exhibits more than 4 dB conversion gain with 12 dBm of output power, and the fundamental frequency suppression is typically??20 dBc up to 44 GHz. The MMIC works at VDD = 3.5 V, VSS =-3.5 V, Id = 200 mA and the chip size is 1.5×1.8 mm2.

Key words: frequency doubler,  active Balun,  distributed amplifier