| 摘要 |
PURPOSE:To make the receiver small and inexpensive and to obtain an excellent spurious characteristic by controlling a frequency interval selected by one hopping so as not to be decreased more than the frequency step of a controller so as to correct the interval. CONSTITUTION:A mixer 4 mixes an input signal with a signal from a frequency synthesizer 12 whose hopping pattern is controlled by a hopping controller 13 and an output of the mixer 4 is subject to the frequency conversion of an IF signal. The frequency interval switched by one hopping in the hopping pattern of the frequency hopping signal is controlled so as to be larger than the channel interval of the signal synthesizer 12. Thus, the signal inputted to an IF filter 5 is given as a frequency slightly deviated from a channel interval of the frequency synthesizer 12, a spurious wave is eliminated by the IF filter 5, amplified by an IF amplifier 6 and the result is inputted to a mixer 9. An offset controller 14 corrects the frequency deviation of the IF signal to allow the mixer 9 to output the IF signal without any deviation finally to an IF filter 10. |
