Experimental Characterization of a Dual-Input OLMBA for Back-Off Efficiency Improvement

This paper describes the characterization campaign carried out on an Orthogonal Load Modulated Balanced Amplifier with separate RF inputs aimed at optimizing back-off efficiency over a broad frequency range. The steps used to narrow down the set of available parameters, using single-input characterization, and identify the optimal conditions for dual-input drive, are described in detail. The hardware shows a 6-dB back-off efficiency in excess of 35% on most of the 1.6-3.0 GHz bandwidth, with a corresponding maximum output power of at least 45 dBm. This shows that the use of the OLMBA for back-off enhancement has great potential.