A high-frequency and high-power quasi-class-E amplifier design using a finite bias feed inductor

This paper presents a design method for a compact high-efficiency quasi-class-E amplifier, using a finite bias feed inductor. It isvery difficult to achieve proper class-E operation from high-power transistors operating in the high-frequency region because of their internal parasitic components. To mitigate the effects of internal parasitic components on class-E operation, a finite DC feed inductance is introduced to resonate out the capacitive parasitic components. A quasi-class-E amplifier with a finite DC feed inductor was designed and implemented at 1.2 GHz using a high-power laterally diffused metal-oxide-semiconductor field-effect transistor (LDMOSFET). We compared simulated time domain current and voltage waveforms with ideal ones. As the test results indicated, power-added efficiency as high as 70.4% was achieved, at high output power of 39,55 dBm, without losing the circuits' simplicity, one of the most important advantages of class-E operation.