| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide an FM modulator which has high linearity of the potential- frequency displacing characteristic and also has a small distortion factor. SOLUTION: An FM modulator includes of an operational amplifier 12, a time constant circuit consisting of a capacitor 17 which is connected between the inverted input terminal of the amplifier 12 and the ground and a 1st resistor 16 which is connected between the output terminal and the inverted input terminal of the amplifier 12, and an astable multivibrator 2 containing a feedback 2nd resistor 15 which connected between the output terminal and the non- inverted input terminal of the amplifier 12. Furthermore, the bias voltage generation means 4 and 5 are added to apply the bias voltage to the non-inverted input terminal of the amplifier 12. Then the modulated signals are superimposed on the bias voltage of fixed level generated by the means 4 and 5.</p> |
