A Linearized 2–3.5 GHz Highly Efficient Harmonic-Tuned Power Amplifier Exploiting Stepped-Impedance Filtering Matching Network

This letter presents the analysis, implementation and experimental results of a broadband highly efficient power amplifier (PA) using harmonic-tuned method for long-term evolution (LTE)-advanced application. Load-pull simulation has been employed to obtain the optimal load impedances, especially the second harmonic impedances, for high efficiency and output power over wide bandwidth. A stepped-impedance low-pass matching network was then designed to achieve the desired impedance transformation. Experimental results show that the PA achieves 64%-76% efficiency and higher than 40 dBm output power over the frequency band from 2 to 3.5 GHz. When driven by a 100 MHz LTE-advanced signal at an average output power of 33.5 dBm, the average efficiency of 33.8%, 34.9%, and 37.8% was measured at 2.15, 2.55, and 3.45 GHz, respectively. The corresponding adjacent channel leakage ratio can be linearized to about -48 dBc by using digital pre-distortion technique.

[1]  Lei Zhang,et al.  Efficiency enhanced class-F Doherty power amplifier at 3.5GHz for LTE-Advanced application , 2013, 2013 Asia-Pacific Microwave Conference Proceedings (APMC).

[2]  D. Peroulis,et al.  Design of Broadband Highly Efficient Harmonic-Tuned Power Amplifier Using In-Band Continuous Class- ${\hbox{F}}^{-1}/{\hbox{F}}$ Mode Transferring , 2012, IEEE Transactions on Microwave Theory and Techniques.

[3]  Lei Guan,et al.  A Simplified Broadband Design Methodology for Linearized High-Efficiency Continuous Class-F Power Amplifiers , 2012, IEEE Transactions on Microwave Theory and Techniques.

[4]  Kenle Chen.  Design of Broadband Highly Efficient Harmonic-Tuned Power Amplifier Using In-Band Continuous Class (-1 ) / F Mode Transferring , 2016 .

[5]  J. Lees,et al.  A Methodology for Realizing High Efficiency Class-J in a Linear and Broadband PA , 2009, IEEE Transactions on Microwave Theory and Techniques.

[6]  Ling Tian,et al.  A wideband digital pre-distortion platform with 100 MHz instantaneous bandwidth for LTE-advanced applications , 2012, 2012 Workshop on Integrated Nonlinear Microwave and Millimetre-wave Circuits.

[7]  Christian Fager,et al.  Design of a Highly Efficient 2–4-GHz Octave Bandwidth GaN-HEMT Power Amplifier , 2010, IEEE Transactions on Microwave Theory and Techniques.

[8]  Songbai He,et al.  Design of Broadband Linear and Efficient Power Amplifier for Long-Term Evolution Applications , 2013, IEEE Microwave and Wireless Components Letters.