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US 4,132,952 AGranted
Multi-band tuner with fixed broadband input filters
AssigneeSony Corporation
InventorsMasayuki Hongu, Tsutomu Niimura, Hiromi Kawakami
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AssigneeSony Corporation
InventorsMasayuki Hongu, Tsutomu Niimura, Hiromi Kawakami
Estimating the term…
A tuner for receiving signals broadcast on two spaced bands, each divided into several channels, has two fixed bandpass filters, one to pass all of the channels in the lower frequency band and the other to pass all of the channels in the higher frequency band. The tuner includes a mixer to which signals of either band are supplied by selective operation of a double-throw switch. A tunable local oscillator supplies a heterodyning signal to the mixer to convert any selected channel of the received signal to an intermediate frequency (i.f.) band chosen to avoid image interference from undesired channels, whether the local oscillator frequency is above or below the selected channel. To ease the constraints on the choice of the i.f. band, different i.f. filters tuned to first and second i.f. bands may be used for the higher and lower received bands. A second double-throw switch ganged with the first switch can then be used to direct the heterodyned signals to the proper i.f. filter.
A tuner for receiving a selected channel of a group of channels divided into a lower band comprising a plurality of lower band channels and a higher band comprising a plurality of higher band channels, said tuner comprising:
Dependencies are inferred from the claim text.