Amplitude stabilized power amplifier

A method for stabilizing the amplitude of a power amplifier, said method comprising:

• splitting the power of an input signal into a predetermined number of channels;
• shifting the phase angle characteristic of the power signal of one of the channels with respect to the phase angle of the power signal of another channel;
• amplifying the power signal of each of the channels;
• combining the amplified signals of the channels to provide a power amplified output signal;
• generating a first signal representative of the power level of the power amplified output signal;
• generating a second signal representative of a predetermined power level independent of the input signal;
• and
• continuously controlling the phase shift of the power signal of said one channel to, at times, shift the phase angle of the power signal of said one channel with respect to the phase angle of the power signal of another channel with a magnitude in proportion to the difference between the first and second signals thereby limiting the efficiency of the combination of the amplified signals such that the power level of the power amplified output signal remains substantially constant.

An amplitude stabilized power amplifier comprising:

• a power splitter for dividing the power of an input signal in substantially equal proportions between a predetermined number of channels;
• a phase shifter that is responsive to the power signal of one of said channels, said phase shifter being operative to shift only the phase characteristic of the power signal of said one channel;
• a plurality of amplifiers for amplifying the power signal of each of the channels of the power splitter;
• a power combiner for combining the amplified power signals of the channels to provide a power amplified output signal;
• means to generate a first signal representative of the power level of the power amplified output signal;
• means to generate a second signal representative of a predetermined power level independent of the input signal;
• and
• means governed by the first and second signals for continuously controlling the efficiency of said power combiner by causing said phase shifter to shift only the phase angle characteristic of the power signal of said one channel with respect to the phase angle characteristic of the power signal of another channel with a magnitude in proportion to the difference between the first and second signals such that the power level of the power amplified output signal remains substantially constant.

A method for stabilizing the amplitude of a power amplifier, said method comprising:

• splitting the power of an input signal in substantially equal proportions between a predetermined number of channels;
• shifting only the phase angle characteristic of the power signal of only one of the channels;
• amplifying the signal of each of the channels at the amplifying saturation level;
• combining the amplified signals of the channels to provide a power amplified output signal;
• generating a first signal representative of the power level of the power amplified output signal;
• generating a second signal representative of a predetermined power level independent of the input;
• and
• continuously controlling the efficiency of combining the amplified signals by shifting the phase angle of the power signal of said one channel with respect to the phase angle of the power signal of another channel with a magnitude in proportion to the difference between the first and second signals such that the power level of the power amplified output signal remains substantially constant.