| 摘要 |
A multi-superheterodyne receiver having a first local oscillator for generating a first local frequency signal, a first frequency converter for converting to a first intermediate frequency signal a received signal in response to the first local frequency signal, a second local oscillator for generating a second local frequency signal, a second frequency converter for converting to a second intermediate frequency signal the first intermediate frequency signal in response to the second local frequency signal, includes judging circuitry for judging if a residual spurious component is generated when harmonic waves of at least one of the local frequency signals are at certain frequencies. Control circuitry shifts the first local frequency signal by a first predetermined frequency to cause the first intermediate frequency signal to suppress the residual spurious component, and shifts the second local frequency signal by a second predetermined frequency to maintain the frequency of the second intermediate frequency signal constant, when the judging circuitry determines that a residual spurious component will be generated at a preset receiving frequency. Thus, intermodulation disturbances in the receiver are suppressed.
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