Patent ID: 8509320

Claim:
A communication circuit comprising a transmission unit and a reception unit, the transmission unit being configured to transmit an information bit string to the reception unit, wherein the transmission unit includes: a bit string generation circuit that sequentially outputs a start bit and then outputs the information bit string; a first modulation circuit that modulates a first carrier wave by the start bit output from the bit string generation circuit to generate a first high frequency signal; a second modulation circuit that modulates a second carrier wave by the information bit string output from the bit string generation circuit to generate a second high frequency signal, wherein the first carrier wave has a frequency different from that of the second carrier wave; and a transmission circuit that transmits the first high frequency signal and the second high frequency signal from a transmitting antenna, and wherein the reception unit includes: a reception circuit that receives a signal transmitted from the transmission unit by a receiving antenna; a first detector circuit that is connected to the reception circuit and detects a signal of the first carrier wave to demodulate the start bit; a second detector circuit that is connected to the reception circuit and detects a signal of the second carrier wave to demodulate the information bit string; and a detection circuit that is synchronized by the start bit and reads out the information bit string demodulated by the second detector circuit.