Radio communication terminal and gain control circuit for the same

A radio communication terminal comprising a radio transmission section, wherein

• the radio transmission section comprising:
• a transmission power amplifier which amplifies a transmission signal to a predetermined level;
• an adjacent channel leak power ratio monitor which finds a ratio of a distortion element corresponding to adjacent channel leak power to a main element from an output signal of the transmission power amplifier, and outputs the found ratio as an ACPR monitor value;
• a power supply control section which variably controls power supply to the transmission power amplifier with use of the ACPR monitor value supplied the adjacent channel leak power ratio monitor;
• a transmission signal level variable section which varies a level of the transmission signal by controlling a gain of a transmission signal path on the basis of a transmission level monitor value supplied from the adjacent channel leak power ratio monitor;
• and
• wherein the adjacent channel leak power ratio monitor comprises:
• a squaring circuit which squares an output signal of the transmission power amplifier;
• a first band path filter which extracts a distortion element corresponding to the adjacent channel leak power from an output signal of the squaring circuit;
• a second band path filter which extracts an element corresponding to a main part of the output signal of the squaring circuit;
• and a subtracter which performs a subtraction process between an output of the first band path filter and an output of the second band path filter.