RECEIVER, RECEPTION SIGNAL DETECTING CIRCUIT, AND SYNCHRONIZING CIRCUIT

摘要

PROBLEM TO BE SOLVED: To provide a receiver accelerating processing of determining presence/absence of a communication signal, a reception signal detecting circuit used therefor and a synchronizing circuit used therefor.

SOLUTION: The receiver is provided with: a first differentiation circuit 5, for which a time constant is set to a value dividing a cycle with 2πor more, for differentiating an envelope signal of a radio signal with a pulse periodically; a second differentiation circuit 6, for which a time constant is set to a value dividing the cycle with 2πor less; an integration circuit 8 for integrating a differentiation signal for a first integration period; and a control unit 12 which judges that the radio signal is not received when an integration value of a differentiation signal of the first differentiation circuit 5 is zero, or judges that the radio signal is received when the integration value is not zero. The control unit 12 changes a timing of the first integration period with a variation corresponding to the integration value of the differentiation signal of the second differentiation circuit 6 when it is judged that the radio signal is received, and restores data using a data restoration unit 11 when the integration value is a positive value.

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