Abstract: A BPSK encoder is provided with a first circuit which processes a carrier signal and a binary signal to be encoded, and produces an output binary signal having synchronous phase shifts representing a change in the value of the signal to be encoded. Also, the first circuit is provided with a sampling signal from a second circuit. The second circuit includes a delay circuit to deliver a shifted carrier signal that is smaller than the half-period of the carrier signal, and a logic gate for the logic combination of the carrier signal and the shifted carrier signal. The logic gate also delivers a binary sampling signal having at least two leading or trailing edges at each period of the carrier signal.