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

Abstract

AbstractThis paper presents a design method for a compact high‐efficiency quasi‐class‐E amplifier, using a finite bias feed inductor. It is very 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. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 1114–1118, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI.10.1002/mop.22368