Tuner
First Claim
1. A tuner for selecting for reception any one of a plurality of channels in a broadband radio frequency input signal, said tuner comprising a plurality of stages including:
- a first filtering arrangement which, in use, passes said selected channel and adjacent ones of said channels while attenuating non-adjacent ones of said channels;
a second filtering arrangement, disposed downstream of said first filtering arrangements and having an input, for passing said selected channel and for substantially rejecting non-selected ones of said channels at said input of said second filtering arrangement; and
a controller for controlling at least one of a gain and a power consumption of at least one of said stages as a function of a first signal level upstream of said first filtering arrangement, a second signal level between said first and second filtering arrangements and a third signal level downstream of said second filtering arrangement.
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Accused Products
Abstract
A tuner is provided for selecting for reception any one of a plurality of channels in a broadband radio frequency signal supplied to its input. The tuner comprises a plurality of stages, at least some of whose gains and power consumptions can be adjusted by a controller in accordance with prevailing reception conditions. A frequency changer and variable gain amplifier provide a first filtering arrangement to reject non-adjacent channels and a tuneable filter rejects substantially all but the selected channel. Signal levels before the first filtering arrangement, between the first filtering arrangement and a second filtering arrangement formed by the tuneable filter, and after the second arrangement are supplied to the controller, which adapts the gain structure and/or individual stage power consumptions according to the prevailing reception conditions so as to provide an adequate performance for demodulation while reducing power consumption when extreme reception conditions are not encountered.
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Citations
19 Claims
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1. A tuner for selecting for reception any one of a plurality of channels in a broadband radio frequency input signal, said tuner comprising a plurality of stages including:
- a first filtering arrangement which, in use, passes said selected channel and adjacent ones of said channels while attenuating non-adjacent ones of said channels;
a second filtering arrangement, disposed downstream of said first filtering arrangements and having an input, for passing said selected channel and for substantially rejecting non-selected ones of said channels at said input of said second filtering arrangement; and
a controller for controlling at least one of a gain and a power consumption of at least one of said stages as a function of a first signal level upstream of said first filtering arrangement, a second signal level between said first and second filtering arrangements and a third signal level downstream of said second filtering arrangement. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19)
- a first filtering arrangement which, in use, passes said selected channel and adjacent ones of said channels while attenuating non-adjacent ones of said channels;
Specification