Radio frequency tuner front end and tuner
First Claim
1. A radio frequency tuner front end, comprising:
- an input for receiving an input signal in an input band containing a plurality of channels;
filtering paths arranged to receive said input signal and having fixed frequency responses for dividing said input band into a plurality of sub-bands, each of which contains a plurality of said channels;
a signal path between said input and said filtering paths having a bandwidth sufficiently wide to pass said input band and a substantially constant voltage standing wave ratio over said bandwidth; and
a selecting arrangement for enabling any one of said filtering paths at a time to supply a filtered signal to a first mixer, wherein a first of said filtering paths for a lowest of said sub-bands has a low pass filtering response, a second of said filtering paths for a highest of said sub-bands has a high pass filtering response, and at least one other of said filtering paths has a bandpass filtering response.
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Accused Products
Abstract
A front end for a radio frequency tuner, for example for connection to a cable distribution network, including an input connected to a signal path comprising an LNA connected via an AGC stage to a signal splitter. The input path has a bandwidth sufficiently wide to pass all of the channels in an input signal and has a substantially constant voltage standing wave ratio over the bandwidth. The splitter supplies identical signals to several filtering paths, each of which comprises a fixed filter. The paths are selectable one at a time and the filters divide the input frequency band into a plurality of contiguous or slightly overlapping sub-bands. The output of the front end is supplied to, for example, a double conversion arrangement comprising an upconverter and a downconverter with first and second IF filters.
21 Citations
24 Claims
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1. A radio frequency tuner front end, comprising:
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an input for receiving an input signal in an input band containing a plurality of channels; filtering paths arranged to receive said input signal and having fixed frequency responses for dividing said input band into a plurality of sub-bands, each of which contains a plurality of said channels; a signal path between said input and said filtering paths having a bandwidth sufficiently wide to pass said input band and a substantially constant voltage standing wave ratio over said bandwidth; and a selecting arrangement for enabling any one of said filtering paths at a time to supply a filtered signal to a first mixer, wherein a first of said filtering paths for a lowest of said sub-bands has a low pass filtering response, a second of said filtering paths for a highest of said sub-bands has a high pass filtering response, and at least one other of said filtering paths has a bandpass filtering response. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
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16. A tuner comprising:
a radio frequency tuner front end including; an input for receiving an input signal in an input band containing a plurality of channels; filtering paths arranged to receive said input signal and having fixed frequency responses for dividing said input band into a plurality of sub-bands, each of which contains a plurality of said channels; a signal path between said input and said filtering paths having a bandwidth sufficiently wide to pass said input band and a substantially constant voltage standing wave ratio over said bandwidth; and a selecting arrangement for enabling any one of said filtering paths at a time to supply a filtered signal to a first mixer, wherein in which a first of said filtering paths for a lowest of said sub-bands has a low pass filtering response, a second of said filtering paths for a highest of said sub-bands has a high pass filtering response, and at least one other of said filtering paths has a bandpass filtering response; and
a first frequency changer.- View Dependent Claims (17, 18, 19, 20, 21, 22, 23, 24)
Specification