| 摘要 |
<p>A multiple conversion superheterodyne receiver system includes a first frequency synthesizer capable of generating any one of a number of predetermined first local oscillator frequencies for mixing with an incoming signal to produce a first intermediate frequency. A second frequency synthesizer selectively generates any one of two local oscillator frequencies corresponding to either high side or low side injection to be mixed with first intermediate frequency producing an appropriate second intermediate frequency. A frequency selecting circuit is operatively coupled to the first and second frequency synthesizer for selecting an appropriate one of the first local oscillator frequencies to tune the receiver to a desired channel and for selecting an appropriate one of the second local oscillator frequencies for avoiding receiver self-quieting spurious responses.</p> |
