A high‐power Cartesian feedback transmitter including a compact inverted Doherty amplifier

A high-power Cartesian feedback transmitter including a compact inverted Doherty amplifier is presented. The system efficiency was further improved using a bias line adjustment method for the compact inverted Doherty amplifier. After the bias line adjustment from a λ/4 line for the Doherty amplifier, a power-added efficiency (PAE) of 6.9% points was improved from 41.3 to 48.2% at an output power level of 45 dBm. The whole Cartesian feedback transmitter system exhibited an efficiency of 40% and an adjacent channel leakage ratio of-51 dBc at an output power of 45 dBm for 859 MHz band π/4-DQPSK applications. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 944–946, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23265

[1]  Cheon-seok Park,et al.  Design of a High-Efficiency and High-Power Inverted Doherty Amplifier , 2007, IEEE Transactions on Microwave Theory and Techniques.

[2]  Bumjae Shin,et al.  A fully matched N-way Doherty amplifier with optimized linearity , 2003 .

[3]  F. Raab,et al.  Power amplifiers and transmitters for RF and microwave , 2002 .

[4]  C.A.T. Salama,et al.  CMOS wireless phase-shifted transmitter , 2004, IEEE Journal of Solid-State Circuits.

[5]  R. Kaunisto,et al.  A 2.14-GHz Chireix outphasing transmitter , 2005, IEEE Transactions on Microwave Theory and Techniques.

[6]  F. Raab,et al.  L-band transmitter using Kahn EER technique , 1998 .

[7]  P. Asbeck,et al.  High-Efficiency Envelope-Tracking W-CDMA Base-Station Amplifier Using GaN HFETs , 2006, IEEE Transactions on Microwave Theory and Techniques.