| 摘要 |
<P>PROBLEM TO BE SOLVED: To output detection voltage that unaffects a data error rate without using an expensive crystal resonator to stabilize the oscillation frequency of an oscillator. <P>SOLUTION: A receiver is provided with a mixer 4 performs frequency conversion of a GMSK (Gaussian minim shift keying)-modulated high frequency signal into an intermediate frequency signal, an intermediate frequency bandpass filter 8 for transmitting the intermediate frequency signal, a quadrature detection circuit 10 for detecting the intermediate frequency signal transmitting the intermediate frequency bandpass filter 8, a voltage controlled oscillator 5 for supplying a local oscillation signal to the mixer 4, a PLL circuit 6 for controlling the oscillation frequency of the voltage controlled oscillator 5, and a reference oscillator 7 for supplying a reference signal to the PLL circuit 6, generates AFC voltage from detection voltage outputted from the quadrature detection circuit 10 and controls the oscillation frequency of a reference oscillator 7 with the AFC voltage. <P>COPYRIGHT: (C)2004,JPO |
