US 4,048,570 AGranted

Multiple-band digital frequency synthesizer receiver

AssigneesSanyo Electric Co., Ltd., Tottori Sanyo Electric Co., Ltd.

InventorYasuaki Sumi

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Abstract

A multiple-band superheterodyne receiver, comprising a high frequency amplifier for receiving a high frequency signal, a local oscillator for providing an oscillation frequency signal the frequency of which is different by a given frequency difference from the received high frequency signal, a mixer for mixing these two frequency signals for providing an intermediate frequency signal, a band selecting switch, and means for setting the data concerning the frequency of a high frequency signal to be received, said local oscillator comprising a voltage controlled oscillator for providing an oscillation frequency signal the frequency of which is variable as a function of a given control voltage, a frequency divider for frequency dividing the output from the voltage controlled oscillator, a read only memory for storing the data concerning a plurality of frequency differences, each corresponding to one of said plurality of receiving frequency bands and responsive to the band selecting signal for selectively withdrawing the data concerning the corresponding frequency difference of the selected band, means responsive to the read only memory and the high frequency setting means for varying the rate of frequency division of the frequency divider to a value determined by the frequency difference and the set high frequency, and a phase detector responsive to a reference oscillator and the frequency divider for providing a control voltage associated with the frequency of the output from the frequency divider to the said voltage controlled oscillator, whereby the intermediate frequency of the said receiver is adaptably changed in response to the band selecting switch, with the result that the difference in the intermediate frequency is compensated which is caused depending on the receiving band, the broadcasting standard, and the like.

A multiple-band superheterodyne receiver, comprising means for receiving a plurality of receiving frequency bands each containing high frequency signals of different frequencies, local oscillating means for providing an oscillation frequency signal the frequency of which is different by a given frequency difference from a said received high frequency signal, mixing means responsive to a said received high frequency signal in a given receiving frequency band and said local oscillation frequency signal for providing an intermediate frequency signal, means for selecting one of said plurality of receiving frequency bands for reception, and means for setting information concerning the frequency of a high frequency signal to be received in a selected receiving frequency band, said local oscillating means comprising

voltage controlled oscillating means for providing an oscillation frequency signal the oscillation frequency of which is variable as a function of a given control voltage,
means for storing information concerning a plurality of frequency differences, each corresponding to one of said plurality of receiving frequency bands and responsive to the operation of said band selecting means for selectively withdrawing the information concerning the frequency differences of the corresponding selected receiving frequency band,
first means responsive to said withdrawn information concerning said frequency difference and said information concerning the frequency of a high frequency signal to be received for producing an output at a first frequency which is a function of the sum or difference of said two pieces of information, and
means responsive to the output from said first means for providing a control voltage to said voltage controlled oscillating means, whereby said local oscillating means provides a local oscillation frequency signal the frequency of which is function of the output of said first means which in turn is a function of said two pieces of information.

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Abstract

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