Design of Broadband Power Amplifier with Enhanced Concurrent Efficiency for Wireless Communication

This paper proposes a design method for a broadband power amplifier (PA) capable of concurrent dual-band operation at any two distinct frequency points within its operational bandwidth. The concurrent performances of a broadband PA versus the variation in baseband impedance are analyzed. To enhance the concurrent efficiency, the baseband impedance of the broadband PA is controlled over a wide baseband frequency range through a novel control network. A 1.75–2.25 GHz PA is designed and fabricated. Under a single-tone continuous-wave (CW) signal excitation, the fabricated PA achieves 40.9–42.0 dBm maximum output power and 63.3–77.3% drain efficiency (DE) in its operational bandwidth. When operating under a balanced concurrent mode, its measured output power exceeds 39.6 dBm and its DE surpasses 66.2% in the tone spacing range of 0–500 MHz.