| 摘要 |
PURPOSE:To improve the S/N by setting the operation frequency of the switching regulator to the 4-fold value of the frequency of the reference signal and thus eliminating or reducing the mixture of the operation frequency of the switching regulator into the transmission signal by holding a high efficiency. CONSTITUTION:The L+R component and the L-R component to be the subchannel are led out with multiplication from stereo modulator 2 which supplies the left (L) and right (R) signals plus the pilot signal and then supplied to the transmission antenna through output terminal 8 after the frequency modulation via frequency modulator 4 and the amplification through power amplifier 6. The operation power is supplied to the stereo of such constitution plus frequency modulators 2 and 4, and at the same time the operation power is supplied to amplifier 6 via switching regulator 12. And the operation frequency of regulator 12 is set to the 4-fold value of the frequency of pilot signal Sp to be defined as the frequency outside the signal band, thus improving the S/N. |
