Design of a broadband high efficiency GaN power amplifier for GNSS applications

Abstract

This paper presents the design, implementation and experimental results of a broadband high efficiency GaN-HEMT power amplifier. The source-pull and load-pull simulations were employed to determine the optimum input and output impedance of a GaN transistor over 0.9-1.5 GHz in terms of maximum power added efficiency (PAE). A low-pass network based on a closed-form solution was applied for impedance matching and then it was transferred to a band-pass network. Norton Transformation was used to scale up impedances without sacrificing bandwidth or matching. For large signals, the amplifier can achieve a power gain of 9.5-13.5 dB across 0.9-1.5 GHz while the output power is 10-22W. The corresponding power added efficiency (PAE) is 60%-86%. This power amplifier is suitable for satellite communications systems and GNSS applications.