Autonomous analog orthogonal load modulation power amplifier

A method for operating an analog orthogonal load modulation power amplifier (A-OLMPA) with a radio frequency (RF) input and an RF output, the method comprising:

• dividing an RF signal into two portions;
• directing one portion through a variable attenuator to a first port of an input quadrature coupler;
• directing another portion through a delay element to a second port of the input quadrature coupler;
• generating a power sample signal representing a power level associated with the RF signal;
• autonomously generating an attenuation control signal via an attenuation controller based on the power sample signal;
• and
• applying the autonomously generated attenuation control signal to the variable attenuator.

A load modulation amplifier comprising:

• a first power amplifier having a first input and a first output;
• a second power amplifier having a second input and a second output;
• an input quadrature coupler with a first port, a second port, a third port, and a fourth port, wherein the third port is coupled to the second input of the second amplifier and the fourth port is coupled to the first input of the first amplifier;
• an output quadrature coupler with a first port, a second port, a third port, and a fourth port, wherein the first port is coupled to the second output of the second amplifier and the second port is coupled to the first output of the first amplifier;
• a splitter having a first splitter output, a splitter input coupled to a radio frequency (RF) signal input, and a second splitter output coupled to the second port of the input quadrature coupler;
• and
• a termination impedance coupled to the fourth port of the output quadrature coupler, wherein the second amplifier is configured to be supplied by a voltage greater than the voltage supplied to the first amplifier when the termination impedance at the output of the amplifier is substantially an open impedance.