LC resonant circuits based matching networks for continuous mode MMIC power amplifiers

This paper presents a practical design methodology to construct output matching networks for broadband continuous mode monolithic microwave integrated circuit (MMIC) power amplifiers (PAs). Unlike conventional harmonic manipulation approaches, combinationsof parallel and series LC resonant circuits are utilized to build the matching networks as it can generate frequency-dependent components and locate the varying impedance of continuous mode. With a proper design, the impedance variation in frequency domain can be mapped to the frequency response of the matching network at the fundamental frequency and the second harmonic simultaneously. Matching network design procedures are demonstrated and results show that the frequency response of the network has verygood approximation with the desired continuous mode conditions. A prototype PA is implemented on 0.25-µm Gallium Nitride (GaN) MMIC process, and tested with both continuous-wave and modulated signals. Measurement results show 50.82%maximum drain efficiency and 8.5 dB gain can be achieved across the operation bandwidth of 5.4 to 6.4 GHz.