EP0089853A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Interference wave detection circuit for use in radio receiver
Assignee: NEC Corp
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Filing: 1983-03-22
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Granted: —
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Expires: 2003-03-22
Abstract
Abstract An interference wave detection circuit includes an amplifier (1) for amplifying a received carrier wave in response to a control signal; an amplitude detector (2) for amplitude-detecting the output of the amplifier; the output of said amplitude detector (2) being connected to the amplifier (1) as the control signal so as to make the output level of the amplifier (1) substantially constant; level measuring means (3) for measuring the level of the output fluctuation of the amplitude detector (2); a comparator (4) for comparing the output level of the level measuring means (3) with a predetermined level (Vc) to provide a compared output as an interference wave detection signal to the output of the interference wave detection circuit; discriminating means (6) connected to the output of the amplifier (1) for judging whether the received carrier wave is modulated or not; and gate means (7)(8) responsive to the output of the discriminating means (6) for preventing the compared output from reaching the output of the interference wave detection circuit when the discriminating means (6) judges that the received carrier wave is modulated.
Inventors
- 👤 Kouzou Kage
- 👤 Hiroshi Watanabe
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-28 16:28
CPC Classifications
H; H04; H04B; H04B1/00; H04B1/06; H04B1/10; H04B1/1027
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
186 words
An interference wave detection circuit characterised in that it includes an amplifier (1) for amplifying a received carrier wave in response to a control signal; an amplitude detector (2) for amplitude-detecting the output of the amplifier; the output of said amplitude detector (2) being connected to the amplifier (1) as the control signal so as to make the output level of the amplifier (1) substantially constant; level measuring means (3) for measuring the level of the output fluctuation of the amplitude detector (2); a comparator (4) for comparing the output level of the level measuring means (3) with a predetermined level (Vc) to provide a compared output as an interference wave detection signal to the output of the interference wave detection circuit; discriminating means (6) connected to the output of the amplifier (1) for judging whether the received carrier wave is modulated or not; and gate means (7)(8) responsive to the output of the discriminating means (6) for preventing the compared output from reaching to the output of the interference wave detection circuit when the discriminating means (6) judges that the received carrier wave is modulated.
Claim 2
Dependent Claim
186 words
An interference wave detection circuit characterised in that it includes an amplifier (1) for amplifying a received carrier wave in response to a control signal; an amplitude detector (2) for amplitude-detecting the output of the amplifier; the output of said amplitude detector (2) being connected to the amplifier (1) as the control signal so as to make the output level of the amplifier (1) substantially constant; level measuring means (3) for measuring the level of the output fluctuation of the amplitude detector (2); a comparator (4) for comparing the output level of the level measuring means (3) with a predetermined level (Vc) to provide a compared output as an interference wave detection signal to the output of the interference wave detection circuit; discriminating means (6) connected to the output of the amplifier (1) for judging whether the received carrier wave is modulated or not; and gate means (7)(8) responsive to the output of the discriminating means (6) for preventing the compared output from reaching to the output of the interference wave detection circuit when the discriminating means (6) judges that the received carrier wave is modulated.
Claim 3
Dependent Claim
181 words
An interference wave detection circuit characterised in that it includes an amplifier (1) for amplifying a received carrier wave in response to a control signal; an amplitude detector (2) for amplitude-detecting the output of the amplifier; the output of the amplitude detector (2) being connected to the amplifier (1) as the control signal so as to make the output level of the amplifier (1) substantially constant; level measuring means (3) for measuring the level of output fluctuation of said amplitude detector (2); discriminating means (6) connected to the output of the amplifier (1) for judging whether the received carrier wave is modulated or not; an analog gate (8) responsive to the output of the discriminating means (6) for preventing the output of the level measuring means (3) from passing therethrough when the discriminating means judges that the received carrier wave is modulated; a low-pass filter (14) for filtering the output of the analog gate (8); and a comparator (4) for comparing the output of the low-pass filter with a predetermined level to provide the resultant as an interference wave detection signal.
Claim 4
Dependent Claim
181 words
An interference wave detection circuit characterised in that it includes an amplifier (1) for amplifying a received carrier wave in response to a control signal; an amplitude detector (2) for amplitude-detecting the output of the amplifier; the output of the amplitude detector (2) being connected to the amplifier (1) as the control signal so as to make the output level of the amplifier (1) substantially constant; level measuring means (3) for measuring the level of output fluctuation of said amplitude detector (2); discriminating means (6) connected to the output of the amplifier (1) for judging whether the received carrier wave is modulated or not; an analog gate (8) responsive to the output of the discriminating means (6) for preventing the output of the level measuring means (3) from passing therethrough when the discriminating means judges that the received carrier wave is modulated; a low-pass filter (14) for filtering the output of the analog gate (8); and a comparator (4) for comparing the output of the low-pass filter with a predetermined level to provide the resultant as an interference wave detection signal.
Claim 5
Dependent Claim
162 words
An interference wave detection circuit characterised in that it includes an amplifier having an automatic gain control function for amplifying a received carrier wave; an amplitude detector (2) for detecting the fluctuation of the level in the output of the amplifier; level measuring means (3) for measuring the level of' the output fluctuation of the amplitude detector (2); a comparator (4) for comparing the output level of the level measuring means (3) with a predetermined level (Vc) to provide a compared output as an interference wave detection signal to the output of the interference wave detection circuit; discriminating means (6) connected to the output of the amplifier (1) for judging whether the received carrier wave is modulated or not; and gate means (7) (8) responsive to the output of the discriminating means (6) for preventing the compared output from reaching to the output of the interference wave detection circuit when the discriminating means (6) judges that the received carrier wave is modulated.
Claim 6
Dependent Claim
162 words
An interference wave detection circuit characterised in that it includes an amplifier having an automatic gain control function for amplifying a received carrier wave; an amplitude detector (2) for detecting the fluctuation of the level in the output of the amplifier; level measuring means (3) for measuring the level of' the output fluctuation of the amplitude detector (2); a comparator (4) for comparing the output level of the level measuring means (3) with a predetermined level (Vc) to provide a compared output as an interference wave detection signal to the output of the interference wave detection circuit; discriminating means (6) connected to the output of the amplifier (1) for judging whether the received carrier wave is modulated or not; and gate means (7) (8) responsive to the output of the discriminating means (6) for preventing the compared output from reaching to the output of the interference wave detection circuit when the discriminating means (6) judges that the received carrier wave is modulated.
Claim 7
Dependent Claim
161 words
An interference wave detection circuit characterised in that it includes an amplifier (1) having an automatic gain control function for amplifying a received carrier wave; an amplitude detector (2) for detecting the fluctuation of the level in the output of the amplifier; level measuring means ( 3 ) for measuring the level of the output fluctuation of the amplitude detector (2); discriminating means (6) connected to the output of the amplifier (1) for judging whether the received carrier wave is modulated or not; an analog gate (8) responsive to the output of the discriminating means (6) for preventing the output of the level measuring means (3) from passing therethrough when the discriminating means (6) judges that the received carrier wave is modulated; a low-pass filter (14) for filtering the output of the analog gate (8); and a comparator (4) for comparing the output of the low-pass filter with a predetermined level to provide the resultant as an interference wave detection signal.
Claim 8
Dependent Claim
161 words
An interference wave detection circuit characterised in that it includes an amplifier (1) having an automatic gain control function for amplifying a received carrier wave; an amplitude detector (2) for detecting the fluctuation of the level in the output of the amplifier; level measuring means ( 3 ) for measuring the level of the output fluctuation of the amplitude detector (2); discriminating means (6) connected to the output of the amplifier (1) for judging whether the received carrier wave is modulated or not; an analog gate (8) responsive to the output of the discriminating means (6) for preventing the output of the level measuring means (3) from passing therethrough when the discriminating means (6) judges that the received carrier wave is modulated; a low-pass filter (14) for filtering the output of the analog gate (8); and a comparator (4) for comparing the output of the low-pass filter with a predetermined level to provide the resultant as an interference wave detection signal.
Claim 9
Dependent Claim
40 words
An interference wave detection circuit, as claimed in claim 1, characterised in that the level measuring means (3) responds slowly when its input level is low, while the level measuring means (3) responds quickly when its input level is high.
Claim 10
Dependent Claim
50 words
An interference wave detection circuit, as claimed in claim 5, characterised in that thelevel measuring means (3) comprises a serial-connected combination of; non-linear circuit means for passing high-level components out of the input thereof; rectifier circuit means for rectifying the input thereof; smoothing circuit means for smoothing the input thereof.
Claim 11
Dependent Claim
74 words
An interference wave detection circuit, as claimed in Claim 5, wherein said level measuring means comprises a serial-connected combination of; rectifier circuit means for rectifying the input thereof; smoothing circuit means for smoothing the input thereof; and low-pass filter means for filtering the input thereof, said filter means including a primary circuit which comprises a resistor and a capacitor and a resistive circuit which includes a diode connected to both sides of said resistor.
Claim 12
Dependent Claim
50 words
An interference wave detection circuit, as claimed in Claim 2, characterized in that said low-pass filter means comprises a non-linear type low-pass filter which responds slowly when the output level of said amplitude detector means is low and quickly when the output level of said amplitude detector means is high.
Claim 13
Dependent Claim
41 words
An interference wave detection circuit, as claimed in Claim 8, wherein said low-pass filter means comprises a primary circuit which comprises a resistor and a capacitor and a resistive circuit which includes a diode connected to both sides of said resistor.
Claim 14
Dependent Claim
48 words
An interference wave detection circuit, as claimed in Claim 2, wherein said level measuring means comprises a serial-connected combination of; non-linear circuit means for passing high-level components out of the input thereof; rectifier means for rectifying the input thereof; and smoothing circuit means for smoothing the input thereof.
Claim 15
Dependent Claim
56 words
ll. An interference wave detection circuit, as claimed in Claim l,wherein said received carrier wave is angle- modulated carrier wave and wherein said discriminating means comprises means for angle-demodulating said received carrier wave to provide a demodulated output, and means for detecting said demodulated output to provide the resultant as the output of said discriminating means.
Claim 16
Dependent Claim
38 words
An interference wave detection circuit, as claimed in Claim 3, characterized in that said level measuring means responses slowly when its input level is low, while said level measuring means responses quickly when its input level is high.
Claim 17
Dependent Claim
50 words
An interference wave detection circuit, as claimed in Claim 4, characterized in that said low-pass filter means comprises a non-linear type low-pass filter which responds slowly when the output level of said amplitude detector means is low and quickly when the output level of said amplitude detector means is high.
Claim 18
Dependent Claim
48 words
An interference wave detection circuit, as claimed in Claim 4, wherein said level measuring means comprises a serial-connected combination of; non-linear circuit means for passing high-level components out of the input thereof; rectifier means for rectifying the input thereof; and smoothing circuit means for smoothing the input thereof.
Claim 19
Dependent Claim
55 words
An interference wave detection circuit, as claimed in Claim 2,wherein said received carrier wave is angle- modulated carrier wave and wherein said discriminating means comprises means for angle-demodulating said received carrier wave to provide a demodulated output, and means for detecting said demodulated output to provide the resultant as the output of said discriminating means.
Claim 20
Dependent Claim
55 words
An interference wave detection circuit, as claimed in Claim 3,wherein said received carrier wave is angle- modulated carrier wave and wherein said discriminating means comprises means for angle-demodulating said received carrier wave to provide a demodulated output, and means for detecting said demodulated output to provide the resultant as the output of said discriminating means.
Claim 21
Dependent Claim
55 words
An interference wave detection circuit, as claimed in Claim 4,wherein said received carrier wave is angle- modulated carrier wave and wherein said discriminating means comprises means for angle-demodulating said received carrier wave to provide a demodulated output, and means for detecting said demodulated output to provide the resultant as the output of said discriminating means.
References Cited (Backward Citations)
No citation records indexed.
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