A 4.5-W, 18.5–24.5-GHz GaN Power Amplifier Employing Chebyshev Matching Technique

Abstract

This article presents a gallium nitride (GaN) wideband millimeter-wave power amplifier (PA) incorporating the Chebyshev matching technique. The theoretical design method of the wideband <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$N$ </tex-math></inline-formula> -order Chebyshev matching network is proposed. Considering the insertion loss and circuit complexity, the second-order Chebyshev network is designed, which is implemented by transmission lines (TLs) and capacitors. Based on the designed matching network, a <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$K$ </tex-math></inline-formula> -band PA is designed. Fabricated in a 250-nm GaN process, our PA scores the highest in-band gain of 23.8 dB at 23.6 GHz, 28% fractional bandwidth across 18.5–24.5 GHz, 32% peak power added efficiency (PAE), and 4.5-W saturated output power. The power density is 0.96 W/mm2 and the chip area is <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$2.4\times1.95$ </tex-math></inline-formula> mm2.