High-Efficiency 7 GHz Doherty GaN MMIC Power Amplifiers for Microwave Backhaul Radio Links

The potentialities of GaN monolithic technology for the growing microwave backhaul power amplifier market are discussed in this paper. To support this discussion, two GaN monolithic Doherty power amplifiers for 7 GHz backhaul applications are presented. They exhibit 5 W output power, with almost 10 dB gain and high efficiency at 7 dB output power back-off. In particular, one module has been optimized for maximum efficiency at center frequency (47% at 7 dB output power back-off), while the other for high efficiency on a larger bandwidth (15% fractional bandwidth).

[1]  S. Little.  Is microwave backhaul up to the 4G task? , 2009, IEEE Microwave Magazine.

[2]  Franco Giannini,et al.  An X-Band GaAs MMIC Doherty Power Amplifier , 2010, 2010 Workshop on Integrated Nonlinear Microwave and Millimeter-Wave Circuits.

[3]  V. Camarchia,et al.  7 GHz MMIC GaN Doherty Power Amplifier With 47% Efficiency at 7 dB Output Back-Off , 2013, IEEE Microwave and Wireless Components Letters.

[4]  Inder J. Bahl.  1.6 W K‐band MMIC power amplifier developed using low loss matching technique for point‐to‐point radio applications , 2007 .

[5]  M.R. Lyons,et al.  Design of low-cost 4W & 6W MMIC high power amplifiers for Ka-band modules , 2004, 2004 IEEE MTT-S International Microwave Symposium Digest (IEEE Cat. No.04CH37535).

[6]  Craig Steinbeiser,et al.  Digital Pre-distortion for improving efficiency, linearity and average output power of microwave Point-to-Point power amplifiers used in cellular backhaul telecommunication systems , 2012, 2012 IEEE/MTT-S International Microwave Symposium Digest.

[7]  Franco Giannini,et al.  The Doherty power amplifier , 2009 .

[8]  F. Giannini,et al.  Increasing Doherty Amplifier Average Efficiency Exploiting Device Knee Voltage Behavior , 2011, IEEE Transactions on Microwave Theory and Techniques.

[9]  V. Camarchia,et al.  Real-time FPGA-based baseband predistortion of W-CDMA 3GPP high-efficiency power amplifiers: Comparing GaN HEMT and Si LDMOS predistorted PA performances , 2009, 2009 European Microwave Conference (EuMC).

[10]  C. F. Campbell,et al.  A K-Band 5W Doherty Amplifier MMIC Utilizing 0.15µm GaN on SiC HEMT Technology , 2012, 2012 IEEE Compound Semiconductor Integrated Circuit Symposium (CSICS).

[11]  D. Kuylenstierna,et al.  A Wideband and Compact GaN MMIC Doherty Amplifier for Microwave Link Applications , 2013, IEEE Transactions on Microwave Theory and Techniques.

[12]  F.M. Ghannouchi,et al.  Behavioral modeling and predistortion , 2009, IEEE Microwave Magazine.