| 摘要 |
PURPOSE:To prevent unnecessary radiation by inserting a low-pass filter LPF, whose cut-off frequency is lower than 1/2n-fold bit rate of the base band signal, to an AGC circuit. CONSTITUTION:An M-phase phase modulator 13 having a band-pass filter 14, a frequency converter 16, and a power amplifier 17 are cascaded to provide the AGC circuit which feeds back the distribution signal from the power amplifier 17 to the input circuit of the frequency converter 16. The AGC circuit is provided with an LPF 21 whose cut-off frequency is lower than 1/2n-fold bit rate of the base band signal. Thus, the AGC circuit does not follow up the amplitude variance of a band limited M-phase modulation signal, and the output signal of a transmission equipment has the band limited.
|
