Harmonic controlled three-way doherty amplifier with improved efficiency and linearity

In this paper the operation behavior of three-way Doherty amplifier loaded with harmonic control circuit is analyzed, including the efficiency and linearity. Amplifier is designed in configuration with two quarter-wave impedance transformers in the output combining circuit with LDMOSFETs in carrier and peaking amplifies in periphery relations 1:2.5:2.5. The signals for linearization: the fundamental signals' second harmonics-IM2 and fourth-order nonlinear signals-IM4 are extracted at the output of peaking cells suppressing the third-and fifth order intermodulation products of Doherty amplifier.

[1]  L.C.N. de Vreede,et al.  A High-Efficiency 100-W GaN Three-Way Doherty Amplifier for Base-Station Applications , 2008, IEEE Transactions on Microwave Theory and Techniques.

[2]  S.P. Stapleton,et al.  Linearity optimization of a high power Doherty amplifier based on post-distortion compensation , 2005, IEEE Microwave and Wireless Components Letters.

[3]  Bumman Kim,et al.  Linear power amplifier based on 3-way Doherty amplifier with predistorter , 2004, 2004 IEEE MTT-S International Microwave Symposium Digest (IEEE Cat. No.04CH37535).

[4]  Bumman Kim,et al.  Optimum operation of asymmetrical-cells-based linear Doherty power Amplifiers-uneven power drive and power matching , 2005, IEEE Transactions on Microwave Theory and Techniques.

[5]  Jangheon Kim,et al.  Analysis of a Fully Matched Saturated Doherty Amplifier With Excellent Efficiency , 2008, IEEE Transactions on Microwave Theory and Techniques.

[6]  T. Ogawa,et al.  High efficiency feed-forward amplifier using RF predistortion linearizer and the modified Doherty amplifier , 2004, 2004 IEEE MTT-S International Microwave Symposium Digest (IEEE Cat. No.04CH37535).

[7]  S.P. Stapleton,et al.  A highly efficient Doherty feedforward linear power amplifier for W-CDMA base-station applications , 2005, IEEE Transactions on Microwave Theory and Techniques.

[8]  Y. Suzuki,et al.  Highly efficient feed-forward amplifier using a Class-F Doherty amplifier , 2003, IEEE MTT-S International Microwave Symposium Digest, 2003.

[9]  Gottfried Magerl,et al.  High efficiency harmonic control amplifier , 1996, 1996 IEEE MTT-S International Microwave Symposium Digest.