Patent ID: 7696835

Claim:
A communication system comprising: a transmitting device, configured to transmit data, including first and second transmission lines, disposed in parallel at a predetermined gap, configured to propagate a microwave signal, and a differential signal outputter configured to generate differential signals having opposite phases from the microwave signal corresponding to the data, and to output one of the differential signals to the first transmission line and the other differential signal to the second transmission line; and a receiving device, configured to receive the data, including third and fourth transmission lines, disposed in parallel at the predetermined gap, configured to propagate the microwave signal, and a converter configured to convert the differential signals having opposite phases generated at the third and fourth transmission lines by line-to-line couplings into the microwave signal corresponding to the data, and to output the converted microwave signal, wherein the differential signals are generated at the third and fourth transmission lines by the line-to-line couplings when the third and fourth transmission lines are brought closer to the first and second transmission lines that are propagating the differential signals so that the third and fourth transmission lines face the first and second transmission lines, respectively; and a comparator configured to compare the level of the signal supplied from the converter with a predetermined level, and to perform wave-shaping on the supplied signal.