Compensation method for unbalance of the multichannel class E power amplifier using the closed loop frequency control

Class E power amplifiers are widely used in communication fields, particularly for repeaters, due to their high efficiency. In the field of communications, they transmit tens of watts of power at frequencies greater than several tens of MHz. To use a Class E power amplifier for applications requiring high frequency and high output, multiple PAs must be operated in parallel. When operating in parallel, individual channels may experience imbalance caused by errors or parasitic components in passive elements such as inductors and capacitors, which can lead to reduced lifespan. This paper presents a method for detecting channel imbalances and resolving them through frequency compensation, thereby eliminating the imbalance in paralleled-driven power amplifiers and extending their lifespan. The proposed circuit was verified by implementing an eight-channel multi-power amplifier with a capacity of 2kW.