A portable radio-frequency repeater includes a housing and a transceiver. The transceiver is disposed at least partially within the housing and configured to alternatively operate in a transmitting mode and a sleep mode. The transceiver includes an antenna and a control unit. The control unit is in electrical communication with the antenna. When the transceiver operates in the transmitting mode, the control unit is configured to receive an RFID signal from the antenna, convert the RFID signal into a converted RFID signal, and transmit the converted RFD signal to the antenna. When the transceiver operates in the sleep mode, the control unit is configured to detect an interrogation signal from the antenna and not to transmit any converted RFID signal to the antenna.