Efficiency Improvement for Diode-Clamped Linear Amplifier Using Unequally Divided Voltage Power Supply

A high-efficiency diode-clamped linear amplifier (DCLA) has been proposed to realize low electromagnetic interference caused by switching operations. In this article, a new concept of the DCLA, namely the higher efficiency unequally divided voltage power supply DCLA (DCLA-UeDV), is proposed-it uses the same circuit topology but changes the supply voltage ratio of the series-connected supply. It is well-known that the main loss component of a DCLA is caused by the semiconductor device under linear operation depending on the supply voltage and current flowing. In a conventional DCLA, an equally divided voltage is used to supply power. In this study, a lower supply voltage is applied for a higher current device, and a higher supply voltage is applied to the lower current device in the proposed DCLA-UeDV-the optimized voltage ratio being theoretically derived. Applying the optimized voltage ratio to a four-stage DCLA-UeDV, the power loss theoretically decreased by 10.7%, resulting in an efficiency improvement of 1.7 percentage points. The validity of the proposed method was verified by simulations of a four-stage and an eight-stage DCLA-UeDV and experiments based on the four-stage device.