| 摘要 |
PURPOSE:To reduce the influence of interference disturbance due to the unrequired radiation of a circuit, etc., by constituting an SS modulator so as to perform FSK modulation and PSK modulation by switching by means of one switch. CONSTITUTION:The switch Sw1 is connected to a contact (a) in the case where the FSK modulation is performed, an information signal from an input terminal In1 is supplied to a voltage controlled oscillator 4. Therefore, an FSK modulation signal can be obtained from the oscillator 4. While the modulation signal is N-multiplied by a multiplier 6, it is subjected to 1/N2 frequency-division by means of a frequency divider 7, and is supplied to a spread code generator 8 as a clock signal. A generated spread code is supplied to an X-OR gate 9. At the gate 9, the spread code is subjected to phase inversion, and is supplied to a multiplier 11. SS modulation by multiplication is performed by the multiplier 11. In the case where PSK modulation is performed, the switch Sw1 is connected to a contact (b). In this way, since no input signal is supplied to the oscillator 4, SS modulated waves subjected to primary modulation is applied is outputted from the multiplier 11. |
