A device comprising: a radio frequency (RF) coupler comprising input, output, and coupled ports; an antenna capable of receiving RF signals having a first characteristic and transmitting RF signals having a second characteristic, the antenna connected to the RF coupler to provide received RF signals to the input port of the RF coupler and transmit RF signals received at the input port via coupling to signals received at the coupled port; and signal transformation circuitry having an input connected to the output port of the RF coupler to receive RF signals provided by the antenna to the input port and an output connected to the coupled port, the signal transformation circuitry configured to transform first RF signals having the first characteristic received from the output port to second RF signals having the second characteristic and to provide them to the coupled port.