High efficiency current-mode class-D amplifier with integrated resonator

• Published in: 2004 IEEE MTT-S International Microwave Symposium Digest (IEEE Cat. No.04CH37535) Vol. 3; pp. 2035 - 2042 Vol.3
• Main Authors: Tsai-Pi Hung, Metzger, A.G., Zampardi, P.J., Iwamoto, M., Asbeck, P.M.
• Format: Conference Proceeding
• Language: English
• Published: Piscataway NJ IEEE 2004
• Subjects: Amplifiers; Applied sciences; Bonding; Circuit properties; Electric, optical and optoelectronic circuits; Electronic circuits; Electronics; Exact sciences and technology; Inductors; Magnetic devices; Oscillators, resonators, synthetizers; Parasitic capacitance; Power amplifiers; Power generation; Radio frequency; Radiofrequency amplifiers; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Shunt (electrical); Topology; Transistors; Zero voltage switching; Performance evaluation; High strength current; Resonator; Output power; High Q factor; Shunt; LC circuit; Zero voltage switching; Amplifier; Inductor; Implementation; Current mode; Collector; Capacitance; Parasitic resistance; Heterojunction bipolar transistors
• ISBN: 0780383311; 9780780383319
• ISSN: 0149-645X; 2576-7216
• DOI: 10.1109/MWSYM.2004.1339013

This paper shows that current mode class-D (CMCD) amplifiers with integrated parallel LC resonator can achieve high efficiency at RF frequencies. In contrast to the conventional class-D amplifier, output shunt capacitance discharge loss is eliminated in a CMCD amplifier topology by satisfying the zero voltage switching (ZVS) condition. To reduce parasitic resistance, bondwires are utilized to implement a high Q inductor in the LC resonator. An experimental CMCD amplifier with collector efficiency of 78.5% at output power of 29.5dBm (0.89W) is demonstrated using GaAs HBTs at 700 MHz.