Apparatus and method for load modulating an amplifier

An apparatus for load modulating a power amplifier that is configured to output a multiband radio frequency signal comprising at least a first frequency band and a second frequency band, the apparatus comprising:

• a multiplexer coupled to receive a multiband radio frequency signal from the output of the power amplifier, and configured to separate the multiband radio frequency signal into at least first and second frequency band signals;
• a first load modulator circuit provided in a first branch, the first load modulator circuit coupled to receive the first frequency band signal, and configured to load modulate the first frequency band signal;
• and
• a second load modulator circuit provided in a second branch, the second load modulator circuit coupled to receive the second frequency band signal, and configured to load modulate the second frequency band signal,
• wherein a load modulation characteristic comprises a threshold value corresponding to a point at which load modulation is disabled or enabled, and wherein the threshold value is individually set in each load modulation circuit.