| 摘要 |
PURPOSE:To eliminate spurious radiation due to the discontinuity of a phase at the switching of FSK modulation and FM modulation by synthesizing outputs of an FSK modulation section and an FM modulation section so as to attain the incorporation of the titled modulator. CONSTITUTION:An FM modulation signal 3d is zero at a control circuit 3 in FSK modulation and an output of an FM modulation section 2 has a no modulation carrier only. On the other hand, a control data 3c is a mark/space so as to hange the frequency dividing ratio of a variable frequency divider 8. Thus, an output of the FSK modulation section 1 is modulated and an FSK modulation wave is obtained in the output of a mixer 5. An FM modulation signal 3d is transmitted from the control circuit 3 and FM-modulated by the FM modulation section 2. On the other hand, since the control data 3c fixes the frequency dividing ratio of the frequency divider 8 to an intermediate level between the mark and space, the output of the FSK modulation section 1 has the no modulation carrier only. In this case, an FM modulation wave is obtained in the output of the mixer 5. |
