Parallel operation system of transmission amplifier

A parallel operation system of transmission amplifiers, comprising:

• first and second transmission amplifier units which receive a common input signal and output respective amplified signals;
• and
• a coupling unit which combines outputs of the first and second transmission amplifier units, to provide as its output;
• the first and second transmission amplifier units each including:
• a main amplifier;
• a digital pre-distorter disposed on the input side of the main amplifier, for creating distortion anticipated values of the main amplifier to add them to the input signals;
• a quadrature modulator which quadrature modulates the output of the digital pre-distorter;
• and
• an up-converter having a local oscillator, for converting the output frequencies of the quadrature modulator;
• wherein
• the output of the up-converter included in one of the first and second transmission amplifier units is fed commonly to the main amplifiers included in the first and second transmission amplifier units.

A parallel operation system of transmission amplifiers, comprising:

• first and second systems each having a digital pre-distorter which receives digital signals, having a D/A converter which converts the output of the digital pre-distorter into an analog signal, and having a main amplifier to amplify the outputs of the D/A converter;
• a coupling unit which combines the outputs of the main amplifiers of the first and second systems;
• and
• a feedback system including an A/D converter which converts the output of the coupling unit into a digital signal, wherein
• the output of the A/D converter included in the feedback system is fed back to the digital pre-distorters of the first and second systems, and wherein
• the digital pre-distorters of the first and second systems create distortion anticipated values of the main amplifiers as a function of the fed back output level of the coupling unit and add them to the inputted digital signals, for output.

A parallel operation system of transmission amplifiers, comprising:

• first and second systems each having a pre-distorter which receives analog signals, having an up-converter which multiplies the output of the pre-distorter up to a predetermined frequency, and having a main amplifier which amplifies the output of the up-converter;
• a coupling unit which combines the outputs of the main amplifiers of the first and second systems;
• and
• a feedback system including a down-converter which reduces the output of the coupling unit into a predetermined frequency, wherein
• a common reference signal is fed to both the up-converter and the down-converter, and wherein
• the output of the down-convener included in the feedback system is fed back to the pie-distorters of the first and second systems, and wherein
• the pre-distorters of the first and second systems create distortion anticipated values of the main amplifiers as a function of the fed back output level of the coupling unit and add them to the inputted analog signals, for output.