This work presents multi-level supply modulation of a load modulated balanced amplifier (LMBA). The RF-input LMBA employs dynamic active matching for efficient operation over an octave bandwidth. Supply modulation is a natural candidate to further enhance the back-off efficiency of this broadband amplifier due to its independence on RF carrier frequency. In the ET-LMBA prototype demonstrated here, an efficient hybrid multi-level converter (power DAC) produces supply levels from 10 to 30 V to modulate the drain of the balanced amplifier. Digital predistortion is used to linearize the ET-LMBA behavior at discrete steps and over frequency. This system is demonstrated at 2.1, 2.7 and 3.5 GHz with a 20-MHz, 10-dB PAPR signal showing composite efficiency improvement between 9 and 12 percentage points when supply modulation is employed, while maintaining linearity.
Cappello, T., Pednekar, P.H., Florian, C., Popovic, Z., Barton, T.W. (2018). Supply Modulation of a Broadband Load Modulated Balanced Amplifier. Institute of Electrical and Electronics Engineers Inc. [10.1109/MWSYM.2018.8439462].
Supply Modulation of a Broadband Load Modulated Balanced Amplifier
Florian, Corrado
;
2018
Abstract
This work presents multi-level supply modulation of a load modulated balanced amplifier (LMBA). The RF-input LMBA employs dynamic active matching for efficient operation over an octave bandwidth. Supply modulation is a natural candidate to further enhance the back-off efficiency of this broadband amplifier due to its independence on RF carrier frequency. In the ET-LMBA prototype demonstrated here, an efficient hybrid multi-level converter (power DAC) produces supply levels from 10 to 30 V to modulate the drain of the balanced amplifier. Digital predistortion is used to linearize the ET-LMBA behavior at discrete steps and over frequency. This system is demonstrated at 2.1, 2.7 and 3.5 GHz with a 20-MHz, 10-dB PAPR signal showing composite efficiency improvement between 9 and 12 percentage points when supply modulation is employed, while maintaining linearity.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
