A broadband GaN power amplifier with multi-resonator matching networks for 5G microcell applications

Abstract This paper presents the design and electromagnetic-circuit co-simulation of a watt-level sub-6 GHz power amplifier (PA) employing novel Multi-resonator LC-coupled wideband matching networks (MRWMN). The proposed design targets fifth-generation (5G) low and mid-frequency bands, specifically supporting the 5G-NR (New Radio) n77, n78, and n79 bands. Both the input and output matching networks are implemented using the MRWMN approach, enabling a wide 3 dB bandwidth of 3.9 GHz (0.7–4.6 GHz) with sharp out-of-band roll-off characteristics. This represents the widest bandwidth among the reported PAs designed using the CGH40010F GaN HEMT device to the best of authors knowledge. The implemented PA achieves a maximum output power of 40.6 dBm, a gain ranging from 8.3 to 10.8 dB, and a peak drain efficiency of 64.1%. Over the 0.8–4.6 GHz operating band, the input (S11) and output (S22) reflection coefficients remain better than—13 dB, indicating good impedance matching, while the forward transmission coefficient (S21) exceeds 10 dB and the reverse isolation (S12) stays below—14 dB, confirming stable and efficient amplifier performance. Furthermore, the PA is evaluated under 256-QAM (Quadrature Amplitude Modulation) excitation, achieving an adjacent channel power ratio of around −45 dBc without employing digital predistortion. Enhanced third-order intermodulation distortion performance is also observed across these bands with a total layout area of 60.7 mm × 29.1 mm, demonstrating the amplifier’s excellent linearity and suitability for wideband 5G communication systems.