Highly Efficient Concurrent Power Amplifier With Controllable Modes

This paper presents a controllable mode design method for a concurrent dual-mode power amplifier (PA). The principle of the controllable mode combination is proposed by investigating the characteristics of different highly efficient PA modes, which is analyzed from frequency response of the low-pass matching circuit. Then a dual-mode PA with Class- F^-1 and Class-J mode is taken for example to verify this mode combination concept. A GaN device PA with 10-W output is designed at two frequency ranges of 1.9 ~ 2.0 GHz and 2.3 ~ 2.6 GHz. Measurement results show an output power of 40.2 ~ 42.9 dBm and drain efficiency of 75.6 ~ 80.3% and 76.6 ~ 68.8% in two frequency bands. It also provides a broadband operation with drain efficiency of 60 ~ 80.3% over 1.7 ~ 2.8 GHz. To evaluate its modulated signal performance with concurrent multiband and broadband applications, dual-band signals (20 MHz + 20 MHz) with 140- and 300-MHz frequency spacing and 100-MHz long-term evolution advanced (LTE-A) signals at two modes are both employed. With digital pre-distortion algorithm, adjacent channel leakage ratio lower than -47.5, -48.6 and -46.1 dBc are achieved, indicating its excellent performance in mobile communication systems.