Patent EP0343538A2 successfully refreshed from Google Patents.
EP0343538A2
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EP
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Diversity receiver
Assignee: Sanyo Electric Co Ltd
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Filing: 1989-05-19
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Granted: —
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Expires: 2009-05-19
Abstract
Abstract A diversity receiver includes first (1) and second (2) antennae for receiving an RF signal, and an antenna switching circuit (3) for selecting one of the first and second antennae. A first detection circuit (15) having a high sensitivity, and a second detection circuit (16) having a low sensitivity are provided, each detecting a noise signal contained within the received RF signal in different sensitivity. A field strength detection circuit (17) is provided for detecting a field strength of the received RF signal, and a selection circuit is provided for selecting either one of the first and second detection circuits according to the output signal of the field strength detection circuit, and for providing a switching signal to the antenna switching circuit (3). Thus, when the field strength is relatively strong, the first detection circuit with high sensitivity is used for the noise detection, and when the field strength is relatively weak, the second detection circuit with low sensitivity is used for the noise detection.
Inventors
- 👤 Hirohisa Suzuki
- 👤 Akira Kabashima
- 👤 Mikio Yamagishi
- 👤 Ryuichi Ogawa
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-03 21:43
CPC Classifications
H; H04; H04B; H04B7/00; H04B7/02; H04B7/04; H04B7/08; H04B7/0802; H04B7/0805
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
163 words
A diversity receiver comprising: first and second antennae for receiving an RF signal; an antenna switching circuit for selecting one of said first and second antennae; first detection circuit, having a high sensitivity, for detecting a noise signal contained within the received RF signal; second detection circuit, having a low sensitivity, for detecting a noise signal contained within the received RF signal; a field strength detection circuit for detecting a field strength of the received RF signal; and a selection circuit for selecting either one of the first and second detection circuits according to the output signal of said field strength detection circuit, and for providing a switching signal to said antenna switching circuit for switching the selection of said antenna; whereby when the field strength is relatively strong, said first detection circuit with high sensitivity is used for the noise detection, and when the field strength is relatively weak, said second detection circuit with low sensitivity is used for the noise detection.
Claim 2
Dependent Claim
163 words
A diversity receiver comprising: first and second antennae for receiving an RF signal; an antenna switching circuit for selecting one of said first and second antennae; first detection circuit, having a high sensitivity, for detecting a noise signal contained within the received RF signal; second detection circuit, having a low sensitivity, for detecting a noise signal contained within the received RF signal; a field strength detection circuit for detecting a field strength of the received RF signal; and a selection circuit for selecting either one of the first and second detection circuits according to the output signal of said field strength detection circuit, and for providing a switching signal to said antenna switching circuit for switching the selection of said antenna; whereby when the field strength is relatively strong, said first detection circuit with high sensitivity is used for the noise detection, and when the field strength is relatively weak, said second detection circuit with low sensitivity is used for the noise detection.
Claim 3
Dependent Claim
33 words
A diversity receiver according to Claim 1, wherein said selection circuit selects an output of said first detection circuit when the field strength of the received signal is greater than a predetermined level.
Claim 4
Dependent Claim
88 words
A diversity receiver according to Claim 1, wherein said first detection circuit comprises a first counter for counting pulses corresponding to said noise signals and for producing a first output signal when the value of said first counter exceeds a first predetermined value, and wherein said second detection circuit comprises a second counter for counting pulses corresponding to said noise signals and for producing a second output signal when the value of said second counter exceeds a second predetermined value which is greater than said first predetermined value.
Claim 5
Dependent Claim
69 words
A diversity receiver according to Claim 3 wherein said first and second counters are comprised of a common counter in such a manner that a first output signal is output when the value of the common counter reaches a first predetermined value, and a second output signal is output when the value of the common counter reaches a second predetermined value which is greater than said first predetermined value.
Claim 6
Dependent Claim
37 words
A diversity receiver according to Claim 1 wherein said first detection circuit comprises a third counter for counting a number of noise pulses and for producing a noise signal upon counting a predetermined number of noise pulses.
Claim 7
Dependent Claim
32 words
A diversity receiver according to Claim 1 wherein said second detection circuit comprises an integrator for integrating a noise signal, and a comparator for comparing the integrated signal with a predetermined level.
Claim 8
Dependent Claim
36 words
A diversity receiver according to Claim 1 further comprising a signal blocking circuit inserted between said selection circuit and said antenna switching circuit for blocking the transmission of said switching signal to said antenna switching circuit.
Claim 9
Dependent Claim
96 words
A diversity receiver according to Claim 7, wherein said signal blocking circuit comprises an inhibit circuit inserted between said selection circuit and said antenna switching circuit, a fourth counter for counting the number of noise signals produced in a predetermined period of time, and a pulse generator for generating, when the value of said fourth counter exceeds a second predetermined value, an inhibit pulse having a predetermined pulse width to said inhibit circuit, whereby said inhibit circuit stops the transmission of said switching signal to said antenna switching circuit during the presence of said inhibit pulse.
Claim 10
Dependent Claim
84 words
A diversity receiver according to Claim 7, wherein said signal blocking circuit comprises an inhibit circuit inserted between said selection circuit and said antenna switching circuit and a second field strength detection circuit for detecting a field strength of the received RF signal and for producing an inhibit signal during when the field strength is lower than a predetermined field strength, whereby said inhibit circuit stops the transmission of said switching signal to said antenna switching circuit during the presence of said inhibit signal.
References Cited (Backward Citations)
No citation records indexed.
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