Magnitude and phase adjustment method for high output power rf power amplifier combining

A transmitter, configured to transmit radio frequency, RF, signals, the transmitter comprising:

• an adjustment circuit configured to make first adjustments to a magnitude and phase of a received signal to produce a first amplifier input signal and to make second adjustments to the magnitude and phase of the received signal to produce a second amplifier input signal;
• first and second power amplifiers in communication with the adjustment circuit, the first and second power amplifiers configured to amplify a respective one of the first and second amplifier input signals;
• and
• a combiner in communication with the first and second power amplifiers, the combiner configured to combine outputs from each of the first and second power amplifiers to produce a first transmit signal, the combiner further configured to produce an isolation signal, the isolation signal being based at least in part on an amount by which the outputs from the first and second power amplifiers differ in magnitude and phase, the isolation signal being used to determine the first and second adjustments to the magnitude and phase of the received signal to drive the isolation signal toward zero.