Design of Broadband Continuous Class-F−1 Power Amplifier Using Filtering Matching Network

To broaden the bandwidth of the power amplifier (PA) and achieve high efficiency, this paper presents a design method of a broadband continuous Class- F
^-1
(CCF
^-1
) PA exploiting low-pass filtering matching network. After analyzing the fundamental and harmonic impedances of the CCF
^-1
mode and converting them from the intrinsic current generator plane to the package plane, the optimal load impedances can be obtained, which were also verified by using load-pull simulations. Then, a low-pass filtering matching network was designed to achieve desired impedance transformation. A 2-4 GHz broadband CCF
^-1
PA was designed and fabricated to verify the proposed method. Experimental results show that the PA achieves 59%-74% efficiency and higher than 39.3 dBm output power over the frequency band of interest, with the gain fluctuation of less than 3 dB.