A 38-GHz Millimeter-Wave Double-Stacked HBT Class-F−1 High-Gain Power Amplifier in 130-nm SiGe-BiCMOS

Investigations into integrated millimeter-wave (mmW) Class-F
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power amplifier (PA) in stacked configuration have not been reported previously. This article presents a novel two-stage double-stacked heterojunction bipolar transistor (HBT) Class-F
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PA in the 130-nm SiGe-BiCMOS technology. The proposed amplifier operates at the mmW center frequency of 38 GHz. The driving stage of the amplifier is loaded with a Class-F harmonic network and the double-stacked power stage incorporates Class-F
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loading. An interstage matching network is designed to deliver maximum power transfer from the driving stage to the power stage. The proposed new HBT amplifier yields a saturated output power of 21.2 dBm along with an overall gain of 22.1 dB and a peak power-added efficiency (PAE) of 30.1%. A figure-of-merit (FoM) of 69.68 was achieved for this amplifier which is the highest so far when compared with various recently reported integrated mmW Class-F
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/F PAs.