Abstract
Due to low distortion and high power efficiency over 80%, the hybrid class-BD power amplifier (HBD) is attractve for battery powered systems, but high cost on producing it of discrete parts decreases the utility.
This paper present a new architecture for the HBD amplifier suited to monolithic integration. This architecture enables to reduce a half of the high frequency power circuits based on the original architecture.
In new circuits, the signal is amplified by one unit of class-D power amplifier, unlike the original circuits by two units. The absolute value signal synthesized from input signal is amplified by the class-D power amplifier, and is feeded to the load resistor through full-bridged transistors to control load current directions. The power efficiency and harmonic distortions of the new circuits are the same as those of the original circuits.
This simplification facilitates to integrate the HBD amplifier, and enables us to reduce the size and costs.
An experimental HBD power amplifier powered by a single 9V supply based on new architecture has been fabricated. The maximum total stage power efficiency factor was 85% under 0.2% of total harmonic distortions.
