Load Modulation Balanced Power Amplifier Design Method Based on X-Parameter Model

Abstract

The present invention discloses a design method for a load modulation balanced power amplifier based on an X-parameter model. This method first extracts the X-parameter model of a single transistor, then selects the target impedance value through load pulling as the target for optimizing the impedance matching circuit, thereby obtaining a balanced power amplifier and a signal control power amplifier, combining them to form a classic balanced power amplifier pair, and then extracting the X-parameter model of it. According to the microstrip characteristics, a phase modulation network is inserted, and finally, the assembly of each circuit module and system-level debugging are completed. A heat dissipation device is also introduced to achieve a power amplifier that operates stably within the frequency band. The method of this application overcomes the shortcoming that the single-transistor X-parameter model only contains the amplitude and phase information of the load reflection coefficient and does not meet the structure of the load modulation balanced power amplifier. In cooperation with the load pulling method, the design of the impedance matching circuit can be completed quickly and accurately, enabling the power amplifier to maintain a stable output, achieve a high output power back-off efficiency, and a high output power back-off range.

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