A compact fully differential Doherty power amplifier

In this paper, a compact triple-transistor fully differential Doherty power amplifier (DPA) is investigated. Three active devices are combined in a very judicious way to amplify the differential signal in a way like what a typical Doherty amplifier does. Particularly, two out-of-phase carrier PAs are applied to operate in the low-power region for high efficiency. On the other hand, only one peaking PA is used in the high-power region, which shares its output evenly with the two carriers. The reduction of transistor number from four for a classic differential DPA to three greatly cuts down the realization cost and compacts the overall circuit. Theoretical analysis is given for deep understanding of the operation principle. To demonstrate the proposed technique, a prototype is implemented based on Cree's CGH40010 GaN HEMTs. Experimental result shows that 73% and 63% drain efficiencies are achieved at peak power and 6-dB back-off point, respectively.

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

[2]  Quan Xue,et al.  Optimized Load Modulation Network for Doherty Power Amplifier Performance Enhancement , 2012, IEEE Transactions on Microwave Theory and Techniques.

[3]  J.B. Hacker,et al.  Ultra-Wideband Ultra-Low-DC-Power High Gain Differential-Input Low Noise Amplifier MMIC Using InAs/AlSb HEMT , 2007, 2007 IEEE Compound Semiconductor Integrated Circuits Symposium.

[4]  Quan Xue,et al.  A novel differential bandpass filter based on double‐sided parallel‐strip line dual‐mode resonator , 2008 .

[5]  R. Castello,et al.  A CMOS low-distortion fully differential power amplifier with double nested Miller compensation , 1993 .

[6]  Daniel Segovia-Vargas,et al.  Broadband Differential Low-Noise Amplifier for Active Differential Arrays , 2011, IEEE Transactions on Microwave Theory and Techniques.

[7]  Jangheon Kim,et al.  The Doherty power amplifier , 2006, IEEE Microwave Magazine.

[8]  Quan Xue,et al.  Balanced Bandpass Filters Using Center-Loaded Half-Wavelength Resonators , 2010, IEEE Transactions on Microwave Theory and Techniques.

[9]  Xiu Yin Zhang,et al.  A Novel Differential-Fed Patch Antenna , 2006, IEEE Antennas and Wireless Propagation Letters.

[10]  Bumman Kim,et al.  A highly linear and efficient differential CMOS power amplifier with harmonic control , 2006, IEEE J. Solid State Circuits.

[11]  Liping Han,et al.  Design of Compact Differential Dual-Frequency Antenna With Stacked Patches , 2010, IEEE Transactions on Antennas and Propagation.

[12]  Yue Ping Zhang.  Design and Experiment on Differentially-Driven Microstrip Antennas , 2007, IEEE Transactions on Antennas and Propagation.

[13]  Heng Zhang,et al.  A Noise Reduction and Linearity Improvement Technique for a Differential Cascode LNA , 2008, IEEE Journal of Solid-State Circuits.