An assembly includes a device for receiving at least one input to produce an output. An antenna arrangement supports the device to transfer the input to the device and further to transfer the output from the device such that the antenna arrangement supports a selected one of the input and the output as a high frequency current. The antenna includes a peripheral configuration which confines high frequency current to at least one dominant path to oscillate in the dominant path and the other one of the input and the output is a lower frequency signal present at least generally throughout the antenna arrangement. At least one port is positioned sufficiently away from the dominant path to isolate the lower frequency signal from surface current in the dominant path. The assembly is usable in modulation, emitting, mixing and detection modes and may include a resonant or non-resonant configuration.