Article ID: 20.20230435
In this letter, a second harmonic suppressed millimeter-wave (mm-wave) gallium nitride (GaN) monolithic microwave integrated circuit (MMIC) power amplifier (PA) using the self-resonate characteristic of the capacitor is proposed. Based on a simple modified band-pass output matching network, a novel second harmonic suppression method by utilizing the self-resonate characteristic of the on-chip capacitor is proposed, which can realize the harmonic suppression without any additional tuning structures. For verification, a 24-to-28-GHz GaN MMIC PA was designed using a 150-nm GaN on silicon carbide high electron mobility transistor process. The fabricated PA achieved a saturated power range of 32.5-34 dBm, with a corresponding power-added efficiency (PAE) of 37.5%-44.5%. The amplifier achieved good linearity when excited by a 400-MHz orthogonal frequency division multiplexing signal after applying digital predistortion.
