RF-input load modulated balanced amplifier

This work presents a load modulated balanced amplifier (LMBA) that directly amplifies a modulated RF input. The architecture is based on the recently proposed LMBA technique, in which a control signal applied at the output hybrid of a balanced amplifier is used to modulate the apparent load impedance of the two main devices. Here, we eliminate the need for an externally-generated control signal. Instead, the control signal is directly and simply synthesized from a modulated RF input, allowing the architecture to function directly as an RF-input / RF-output power amplifier. The technique is demonstrated at 700–850 MHz with a peak efficiency of 63.2% at peak CW output power of 41.7 dBm, and 47.1% at 6 dB back-off.

[1]  Steve C. Cripps,et al.  An Efficient Broadband Reconfigurable Power Amplifier Using Active Load Modulation , 2016, IEEE Microwave and Wireless Components Letters.

[2]  H. Chireix.  High Power Outphasing Modulation , 1935, Proceedings of the Institute of Radio Engineers.

[3]  Bumman Kim,et al.  Highly Efficient RF Transmitter Over Broad Average Power Range Using Multilevel Envelope-Tracking Power Amplifier , 2015, IEEE Transactions on Circuits and Systems I: Regular Papers.

[4]  W.H. Doherty,et al.  A New High Efficiency Power Amplifier for Modulated Waves , 1936, Proceedings of the Institute of Radio Engineers.

[5]  Taylor W. Barton,et al.  Multi-Way Lossless Outphasing System Based on an All-Transmission-Line Combiner , 2016, IEEE Transactions on Microwave Theory and Techniques.

[6]  Taylor W. Barton,et al.  An RF-input chireix outphasing power amplifier , 2016, 2016 IEEE Topical Conference on Power Amplifiers for Wireless and Radio Applications (PAWR).