X-band two-stage high-efficiency switched-mode power amplifiers

• Published in: IEEE transactions on microwave theory and techniques Vol. 53; no. 9; pp. 2899 - 2907
• Main Authors: Pajic, S., Narisi Wang, Watson, P.M., Quach, T.K., Popovic, Z.
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01-09-2005; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Amplifiers; Applied sciences; Circuit properties; Class E; Design optimization; Design. Technologies. Operation analysis. Testing; Double heterojunction bipolar transistors; Electric, optical and optoelectronic circuits; Electronic circuits; Electronics; Exact sciences and technology; Gain; Heterojunction bipolar transistors; High power amplifiers; Integrated circuits; load-pull; MESFETs; Microwave amplifiers; Microwave circuits, microwave integrated circuits, microwave transmission lines, submillimeter wave circuits; Microwave devices; Microwaves; Noise levels; Optimization; Power amplifiers; Power generation; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Space technology; two stage; X-band; Performance evaluation; Microwave power amplifiers; Multistage method; Output power; Class E; X band; Microwave; Centimetric wave; two stage; Output stage; Optimization; Mode switching; Wide band; Simulation; Space technology; Class AB; power amplifiers; Heterojunction bipolar transistors; Power amplifier; Monolithic integrated circuit; Metal semiconductor field effect transistor; load-pull; Gain
• ISSN: 0018-9480; 1557-9670
• DOI: 10.1109/TMTT.2005.854239

This paper presents efficiency optimization of X-band two-stage microwave power amplifiers (PAs) in which the output stage is designed to operate in class-E mode. A hybrid PA which uses the same MESFET devices in both stages achieves 16 dB of saturated gain with an output power of 20 dBm and total power added efficiency (PAE) of 52% at 10 GHz. A broadband monolithic two-stage double heterojunction bipolar transistor PA, fabricated by Northrop Grumman Space Technology, with a class-AB first stage and class-E second stage achieves 24.6 dBm of output power with 24.6-dB gain and total PAE of 52% at 8 GHz. The design is performed starting from class-E theory and using load-pull measurements and/or nonlinear simulations.