A switchless wireless communication device (100; 200), comprising: a first amplifier (31; 126) for amplifying a transmission signal; a transmission circuit for processing the transmission signal amplified by the first amplifier; an antenna for transmitting the transmission signal processed by the transmission circuit; a reception circuit for processing a reception signal received by the antenna; a second amplifier for amplifying the reception signal processed by the reception circuit; and a control unit for alternately activating and deactivating the first amplifier and the second amplifier, such that when the first amplifier is activated the second amplifier is deactivated and when the second amplifier is activated the first amplifier is deactivated, wherein, provided that an impedance as seen from the antenna toward the transmission circuit when the first amplifier is activated by the control unit is denoted by ZonT and an impedance as seen from the antenna toward the transmission circuit when the first amplifier is deactivated by the control unit is denoted by ZoffT, wherein, provided that an impedance as seen from the antenna toward the reception circuit when the second amplifier is activated by the control unit is denoted by ZonR and an impedance as seen from the antenna toward the reception circuit when the second amplifier is deactivated by the control unit is denoted by ZoffR, characterized in that ZonT is different from ZonR and ZoffT is different from ZoffR, and the transmission circuit comprises: a first impedance matching circuit (32, 40; 131) for shifting ZonT and ZoffT such that ZonT matches an impedance of the antenna and an absolute value of a voltage reflection coefficient Γ corresponding to ZoffT increases with respect to an absolute value of a voltage reflection coefficient corresponding to ZonT; a first phase adjustment circuit (33; 132) for further shifting ZoffT to a high impedance state, and the reception circuit comprises: a second impedance matching circuit (35, 41; 134) for shifting ZonR and ZoffR such that ZonR matches an impedance of the antenna and an absolute value of a voltage reflection coefficient r corresponding to ZoffR increases with respect to an absolute value of a voltage reflection coefficient corresponding to ZonR; and a second phase adjustment circuit for further shifting ZoffR (34; 133) to a high impedance state. a first amplifier (31; 126) for amplifying a transmission signal; a transmission circuit for processing the transmission signal amplified by the first amplifier; an antenna for transmitting the transmission signal processed by the transmission circuit; a reception circuit for processing a reception signal received by the antenna; a second amplifier for amplifying the reception signal processed by the reception circuit; and a control unit for alternately activating and deactivating the first amplifier and the second amplifier, such that when the first amplifier is activated the second amplifier is deactivated and when the second amplifier is activated the first amplifier is deactivated, a first impedance matching circuit (32, 40; 131) for shifting ZonT and ZoffT such that ZonT matches an impedance of the antenna and an absolute value of a voltage reflection coefficient Γ corresponding to ZoffT increases with respect to an absolute value of a voltage reflection coefficient corresponding to ZonT; a first phase adjustment circuit (33; 132) for further shifting ZoffT to a high impedance state, and the reception circuit comprises: a second impedance matching circuit (35, 41; 134) for shifting ZonR and ZoffR such that ZonR matches an impedance of the antenna and an absolute value of a voltage reflection coefficient r corresponding to ZoffR increases with respect to an absolute value of a voltage reflection coefficient corresponding to ZonR; and a second phase adjustment circuit for further shifting ZoffR (34; 133) to a high impedance state. a second impedance matching circuit (35, 41; 134) for shifting ZonR and ZoffR such that ZonR matches an impedance of the antenna and an absolute value of a voltage reflection coefficient r corresponding to ZoffR increases with respect to an absolute value of a voltage reflection coefficient corresponding to ZonR; and a second phase adjustment circuit for further shifting ZoffR (34; 133) to a high impedance state.