Transmission circuit comprising multistage amplifier, and communication device

A transmission circuit comprising an amplifying circuit including a plurality of power amplifiers, wherein

• the plurality of power amplifiers includes at least a first power amplifier and a second power amplifier, the transmission circuit comprising:
• a digital block for generating an amplitude signal and a phase signal, and outputting a first offset value and a second offset value for compensating for offset characteristics of the first and second power amplifiers;
• a DAC block for converting the amplitude signal into an analogue signal and outputting the analogue signal to the first path and to the second path, and converting the first and second offset values to analogue signals and outputting the analogue signals to the first and second paths, respectively;
• a first adder for adding the first offset value to the amplitude signal outputted to the first path, and outputting a resultant amplitude signal;
• a second adder for adding the second offset value to the amplitude signal outputted to the second path, and outputting a resultant amplitude signal;
• a phase modulator for phase-modulating the phase signal, thereby outputting a phase-modulated signal;
• a power adjusting section for amplifying or attenuating the phase-modulated signal outputted from the phase modulator;
• the first power amplifier for amplifying the phase-modulated signal outputted from the power adjusting section;
• the second power amplifier for amplifying an output signal of the first power amplifier;
• a first regulator for supplying, to the first power amplifier, a voltage which is controlled in accordance with the amplitude signal outputted from the first adder;
• a second regulator for supplying, to the second power amplifier, a voltage which is controlled in accordance with the amplitude signal outputted from the second adder;
• and
• a temperature measuring section for measuring a temperature of the amplifying circuit as temperature information, wherein
• the digital block separately controls the first offset value and the second offset value in accordance with the temperature information measured by the temperature measuring section.