A High‐Efficiency Concurrent‐Capability Tri‐Band Power Amplifier Based on T‐ and L‐Section Dual‐Band Transformers

This paper presents a simple three‐frequency matching structure formed by cascading T‐ and L‐Section dual‐band transformers (DBT). The main principle is that the T‐ and L‐Section DBT achieves tri‐band operate by jointly matching at three target frequencies, and based on this matching network, an optimal impedance matching design for a tri‐band concurrent power amplifier (PA) was carried out to achieve better performance. To verify the feasibility of the inference, a tri‐band concurrent output PA operating at 2.1/3.35/4.65 GHz was designed and fabricated. The measurement results show that the maximum drain efficiency (DE) of the PA is 66%/64.3%/52.2%, respectively, and the corresponding maximum output power is 40.5/40.4/41.3 dBm at this time. For this PA, this paper completed a digital predistortion (DPD) test using a 10‐MHz bandwidth and a peak‐to‐average power ratio (PAPR) of 7 dB for long‐term evolution (LTE) signals. The adjacent channel power ratio (ACPR) is −47.2/−45.8/−46.3 dBc, respectively.