A 2.4/3.5 GHz Dual-Band Power Amplifier with Filter-Based Bias Network and SRFT Matching

Abstract

This paper presents a dual-band power amplifier (PA) design approach that decouples the bias network and matching network designs despite widely-spaced operating bands. A broadband bias network is designed by applying filter techniques to present a high impedance at the fundamental through third harmonics of the two bands. Because this network does not load the device, the simplified real frequency technique can then be applied to design the dual-band matching network with reactive harmonic terminations. The demonstrator PA operates at 2.4 and 3.5 GHz with peak output power and drain efficiency of 41.5 dBm / 66% and 40.7 dBm / 58% respectively. The PA is characterized with a 10 MHz LTE signal, performing without digital predistortion with -38.5 dB ACLR at 33.1 dBm average output power at 2.4 GHz and -33.2 dB ACLR at 33.8 dBm average power at 3.5 GHz.