A V-Band (61-72 GHz) GaN HEMT High-Power Amplifier

This article discusses the analysis and design of a power amplifier (PA) operating from 61 to 72 GHz, which is manufactured using Fraunhofer IAF's <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$0.1 \mu \mathrm{m}$</tex> gate-length GaN-on-SiC HEMT technology. The PA features a four-stage topology, with the final stage including a four-way power combiner. This power combiner not only combines the output power of four transistors in the final stage but also performs the necessary impedance transformation to maximize the output power of each transistor. As a result, the PA delivers a saturated output power <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$(P_{\text{sat }})$</tex> of <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$35.1 \text{dBm}$</tex> with a power-added efficiency of 18.5% at 63 GHz under continuous-wave (CW) excitation. Additionally, the PA maintains a <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$P_{\text{sat }}$</tex> of over <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$33 \text{dBm}$</tex> associated with a PAE exceeding 13% across the entire frequency range from 61 to 72 GHz.