The invention provides a mobile communication apparatus including a plurality of transmitter-receivers of different transmission/reception systems wherein a drop of the sensitivity of one system is minimized. The mobile communication apparatus includes a first transmitter-receiver including a transmission antennae and operable for outputting, upon transmission, a gain decrease instruction, a second transmitter-receiver including a plurality of antennae and operable for selecting one of the plurality of antennae which has a high antenna gain so as to be used for reception, and a gain adjustment section for decreasing an antenna gain of one of the plurality of antennae of the second transmitter-receiver which has a high degree of coupling to the transmission antenna of the first transmitter-receiver in accordance with the gain decrease instruction. |