A Dual-Band Outphaisng Power Amplifier Based on Multi-Topology Fitting

This paper presents the design of a dual-band outphasing power amplifier (OPA) using a new method based on multiple topology fitting based on non-commensurate transmission lines (NCTLs) and extended transmission lines (ETLs). The proposed method enables flexible and efficient design of dual-band OPA by fitting the electrical lengths and characteristic impedance of each branch network at both bands. An OPA prototype operating at 2.6 and 3.5 GHz was fabricated using two 10W GaN HEMT transistors to verify the concept. Test results show that the realized power amplifier achieves maximum output power of 44.4 and 44.3 dBm and peak drain efficiencies of 69.5% and 69.2% at these two bands. The corresponding efficiencies of 62.4% and 63.5% are obtained at the 6-dB power back-off points, respectively.