Title :
A 68% efficiency, C-band 100W GaN power amplifier for space applications
Author :
Yamasaki, T. ; Kittaka, Y. ; Minamide, H. ; Yamauchi, K. ; Miwa, S. ; Goto, S. ; Nakayama, M. ; Kohno, M. ; Yoshida, N.
Author_Institution :
High Freq. & Opt. Device Works, Mitsubishi Electr. Corp., Itami, Japan
Abstract :
This paper describes a high efficiency (68%), high output power (100 W), high reliability GaN HEMT amplifier for C-band space applications. The high efficiency is achieved by 2nd-harmonic frequency (2fo) tuning circuits in the input and output matching circuits. The input circuit uses open-ended stubs located nearby FET gate terminals for setting the 2fo reflection-phase at the optimum phase. In the output circuit, the optimum 2fo reflection phase is realized using three transmission-line transformers while matching loss is kept low at fundamental frequency. In addition, a 3000 hour´s RF overdrive life test reveals that an estimated mean time to failure (MTTF) is 1×107 hours at 150°C channel temperature, proving that the amplifier has sufficient reliability for space applications. To the best of our knowledge, the efficiency of 68% is the highest of 100-W class C-band amplifiers ever reported, and is also comparable to that of commercially available traveling wave tube amplifiers.
Keywords :
gallium compounds; high electron mobility transistors; microwave power amplifiers; satellite communication; semiconductor device reliability; space vehicle electronics; transformers; wide band gap semiconductors; 2nd-harmonic frequency tuning circuits; C-band GaN power amplifier; FET gate terminals; GaN; RF overdrive life test; channel temperature; efficiency 68 percent; fundamental frequency; high reliability GaN HEMT amplifier; input matching circuits; matching loss; mean time to failure; open-ended stubs; optimum 2fo reflection phase; output matching circuits; power 100 W; satellite communication; temperature 150 degC; time 3000 hour; transmission-line transformers; traveling wave tube amplifiers; Circuit optimization; FETs; Frequency; Gallium nitride; HEMTs; High power amplifiers; Impedance matching; Power amplifiers; Power generation; Reflection; GaN HEMT; High efficiency; High power amplifiers; High reliability; Satellite communication;
Conference_Titel :
Microwave Symposium Digest (MTT), 2010 IEEE MTT-S International
Conference_Location :
Anaheim, CA
Print_ISBN :
978-1-4244-6056-4
Electronic_ISBN :
0149-645X
DOI :
10.1109/MWSYM.2010.5517228
