| 摘要 |
PROBLEM TO BE SOLVED: To provide an FSK demodulator capable of generating a detection signal hard to wrongly determine when a phase difference &thetas; is less than ±180°, but also when it is equal to or more than ±180°.SOLUTION: An FSK demodulator comprises: a logic circuit 70 to which an in-phase component and an orthogonal component of an FSK modulated modulation wave are input and which generates a detection signal on the basis of both of the components; and a determination circuit 80 which generates a data signal representing data in the modulation wave by comparing the detection signal with a determination threshold of a signal level. The logic circuit 70 modifies a calculating formula for generating the detection signal on the basis of first and second phase differences so that the detection signal for the first phase difference between a modulation wave at a first time and a modulation wave at a second time different from the first time, becomes a unique value, and a difference between a second phase difference between the modulation wave at the second time and a modulation wave at a third time different from the first and second times, and the first phase difference does not exceed 180°. |
