B.G. Karas1, A.V. Smolin2

1,2 JSC RIE “PROTEK” (Voronezh, Russia)

Problem statement. A quadrature scheme based push-pull output stages are widely used at modern UHF and microwave power amplifiers. Output stage transistors parameters spread, matching inaccuracy and input/output impedances instability are cause of transistors’ operating modes qualitative difference. A specified effect resulting in output stage quadrature arms misbalance when amplifier operates with full capacity and consequently results to amplifier efficiency factor decreasing.

Purpose. A design of quadrature scheme based push-pull output stage with quadrature arms self balancing circuit.

Results. An UHF and microwave amplifiers output stages operation modes automatic control circuits design principles are analyzed. A quadrature scheme based push-pull output stage with quadrature arms self balancing circuit design is appropriated. Proved that proposed circuit design realizing permits to power amplifier efficiency factor, linearity and broadbandness substantial improvement. Proposed circuit design effectiveness is verified by breadboard prototype testing results.

Practical significance. Proposed circuit scheme can be applied to design and development of compact, energy-efficient UHF and microwave transmitters with power supply flat-rating.

Karas B.G., Smolin A.V. High-frequency power amplifier output stage automatic control circuit. Radiotekhnika. 2021. V. 85. № 6.  P. 94−100. DOI: https://doi.org/10.18127/j00338486-202106-15 (In Russian)

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