Title :
High-power broad-band AlGaN/GaN HEMT MMICs on SiC substrates
Author :
Green, Bruce M. ; Tilak, Vinayak ; Lee, Sungjae ; Kim, Hyungtak ; Smart, Joseph A. ; Webb, Kevin J. ; Shealy, James R. ; Eastman, Lester F.
Author_Institution :
Semicond. Products Sector, Motorola Inc., Tempe, AZ, USA
fDate :
12/1/2001 12:00:00 AM
Abstract :
Broad-band high-power cascode AlGaN/GaN high electron-mobility transistor monolithic-microwave integrated-circuit (MMIC) amplifiers with high gain and power-added efficiency (PAE) have been fabricated on high-thermal conductivity SiC substrates. A cascode gain cell exhibiting 5 W of power at 8 GHz with a small-signal gain of 19 dB was realized. A nonuniform distributed amplifier (NDA) based on this process was designed, fabricated, and tested, yielding a saturated output power of 3-6 W over a dc-8-GHz bandwidth with an associated PAE of 13%-31%. A broad-band amplifier MMIC using cascode cells in conjunction with a lossy-match input matching network showed a useful operating range of dc-8 GHz with an output power of 5-7.5 W and a PAE of 20%-33.% over this range. The third-order intermodulation products of the amplifiers under two-tone excitation were studied and third-order-intercept values of 42 and 43 dBm (computed using two-tone carrier power) for the lossy match and NDA amplifiers were obtained
Keywords :
HEMT integrated circuits; III-V semiconductors; MMIC power amplifiers; aluminium compounds; field effect MMIC; gallium compounds; intermodulation distortion; wide band gap semiconductors; wideband amplifiers; 19 dB; 3 to 6 W; 8 GHz; AlGaN-GaN; HEMT MMIC amplifiers; HEMT MMICs; MMIC power amplifiers; SiC; cascode gain cell; high gain; high power-added efficiency; high-power broad-band MMICs; lossy-match input matching network; multioctave power amplifiers; nonlinear transistor model; nonuniform distributed amplifier; saturated output power; small-signal gain; third-order intermodulation products; Aluminum gallium nitride; Conductivity; Gallium nitride; HEMTs; High power amplifiers; MMICs; MODFETs; Power amplifiers; Power generation; Silicon carbide;
Journal_Title :
Microwave Theory and Techniques, IEEE Transactions on
