Patent ID: 8320853

Claim:
A radio communication device comprising: a radio transmitting unit that generates a transmission signal containing a transmission carrier; a radio receiving unit including a frequency conversion circuit that performs frequency down-conversion of a received signal containing a received carrier with substantially the same frequency as the transmission carrier; a transmission/reception separating circuit including a first port connected to the radio transmitting unit, a second port connected to the radio receiving unit and a third port connected to an antenna, that outputs the transmission signal input into the first port to the third port and outputs the received signal input into the third port to the second port; and a transmission power control unit that performs control related to a transmission power of the transmission signal based on a low-frequency signal obtained by supplying a leakage component of the transmission signal leaking from the first port to the second port to the frequency conversion circuit and down-converting the leakage component, wherein the radio receiving unit further includes: an A/D conversion circuit that performs A/D conversion of the down-converted received signal, and a high-pass filter that is placed between the frequency conversion circuit and the A/D conversion circuit and removes a direct-current component contained in an output of the frequency conversion circuit, and the transmission power control unit enables the A/D conversion circuit to detect the direct-current component of the low-frequency signal by stopping removal of the direct-current component by the high-pass filter or bypassing the high-pass filter during execution of the control related to the transmission power.