Novel multi-band matching scheme for highly efficient power amplifier

This paper proposes a novel multi-band matching scheme employing a multisection transformer in multi-band power amplifiers (PAs) that are applicable to spectrum aggregation technology. One section of the transformer, which comprises two reactive blocks, is designed to achieve matching in one of the required operation bands. Tank circuits installed in that section are used to prevent deviation in the matching caused by the section in other bands. A 1W-class triple-band PA following the proposed scheme achieves a maximum power added efficiency of greater than 54% with a high output power of greater than 30 dBm in three different frequencies, i.e., 1.47 GHz, 1.94 GHz, and 2.65 GHz.