US4761828A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Radio receiver
Assignee: Telefunken Electronic GmbH
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Filing: 1985-12-09
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Granted: 1988-08-02
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Expires: 2005-12-09
Abstract
Abstract In a radio receiver in which the received signal is converted by mixing into an intermediate frequency signal and/or a baseband signal, the degree of distortion of received disturbance signals in the receiver is temporarily changed and a recognition circuit is used which recognizes from the change in the signal gaining demodulation, caused by the change in the degree of distortion, whether the receiver is receiving spurious interference signals falling into the useful channel, and which, in the event of such a disturbance signal reception, initiates a suppression or reduction of the spurious interference signals.
Inventors
- 👤 Heinz Rinderle
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 22:00
CPC Classifications
H; H04; H04B; H04B1/00; H04B1/06; H04B1/10; H04B1/1027; H03; H03G; H03G3/00; H03G3/20; H03G3/30; H03G3/34; H03G3/345
Claims Analysis
Total Claims: 26
Claim 1
Independent Claim
155 words
A radio receiver comprising: an input stage for receiving a radio signal composed of a desired signal in a first selected frequency range and an undesired disturbance signal; a mixer connected to said input stage for converting the received radio signal into a lower frequency signal in a second selected frequency range lower than the first selected range; signal distortion means connected in said receiver for imparting to the disturbance signal a distortion which temporarily changes in degree; a recognition circuit connected to monitor the distorted disturbance signal, based on the change in the received signal due to the change in degree of distortion, for producing a recognition signal if the received signal contains a disturbance signal lying in the first selected frequency range; and signal modifying means connected to said recognition circuit and responsive to the recognition signal for initiating suppression or reduction of a disturbance signal lying in the first selected frequency range.
Claim 2
Dependent Claim
155 words
A radio receiver comprising: an input stage for receiving a radio signal composed of a desired signal in a first selected frequency range and an undesired disturbance signal; a mixer connected to said input stage for converting the received radio signal into a lower frequency signal in a second selected frequency range lower than the first selected range; signal distortion means connected in said receiver for imparting to the disturbance signal a distortion which temporarily changes in degree; a recognition circuit connected to monitor the distorted disturbance signal, based on the change in the received signal due to the change in degree of distortion, for producing a recognition signal if the received signal contains a disturbance signal lying in the first selected frequency range; and signal modifying means connected to said recognition circuit and responsive to the recognition signal for initiating suppression or reduction of a disturbance signal lying in the first selected frequency range.
Claim 3
Dependent Claim
38 words
A radio receiver according to claim 1 further comprising means connected to said mixer for deriving a receiver output signal from the converted signal, and wherein said signal modifying means are operative for suppressing the receiver output signal.
Claim 4
Dependent Claim
30 words
A radio receiver according to claim 1 further comprising station finding means connected for varying the tuning frequency of said input stage in response to occurrence of the recognition signal.
Claim 5
Dependent Claim
17 words
A radio receiver according to claim 1 wherein the recognition signal acts to attenuate the received signal.
Claim 6
Dependent Claim
32 words
A radio receiver according to claim 1 wherein said input stage comprises means for effecting a preselection of the received signal and responsive to the recognition signal for increasing the preselection effected.
Claim 7
Dependent Claim
30 words
A radio receiver according to claim 1 wherein said input stage comprises a preamplifier and the change in degree of distortion takes place in one of said mixer and preamplifier.
Claim 8
Dependent Claim
45 words
A radio receiver according to claim 1 wherein said input stage comprises a preamplifier and a band-pass filter, and further comprising means connected for rectifying a signal derived from the output of one of said preamplifier, band-pass filter and mixer to produce a second signal.
Claim 9
Dependent Claim
18 words
A radio receiver according to claim 1 wherein said signal distortion means comprise at least one PIN diode.
Claim 10
Dependent Claim
25 words
A radio receiver according to claim 8 wherein said input stage comprises operating current supply means connected to supply control current to said PIN diode.
Claim 11
Dependent Claim
20 words
A radio receiver according to claim 1 wherein said distortion means operate to effect signal attenuation in said input stage.
Claim 12
Dependent Claim
20 words
A radio receiver according to claim 1 wherein the recognition circuit comprises a sample and hold circuit and a comparator.
Claim 13
Dependent Claim
34 words
A radio receiver according to claim 1, wherein the change in the degree of distortion takes place in the signal path between the input of the input stage and the output of the mixer.
Claim 14
Dependent Claim
23 words
A radio receiver according to claim 6, wherein the change in the degree of distortion is effected by correspondingly low negative signal feedback.
Claim 15
Dependent Claim
23 words
A radio receiver according to claim 6, wherein the change in the degree of distortion is effected by a corresponding operating point setting.
Claim 16
Dependent Claim
21 words
A radio receiver according to claim 6, wherein said signal means are connected to said one of the preamplifier and mixer.
Claim 17
Dependent Claim
22 words
A radio receiver according to claim 6, wherein said one of the mixer and preamplifier are designed to produce the desired distortion.
Claim 18
Dependent Claim
36 words
A radio receiver according to claim 7 further comprising a coupling circuit which couples the recognition signal and the second signal to produce an output signal which is fed to the input stage of the receiver.
Claim 19
Dependent Claim
17 words
A radio receiver according to claim 17, wherein the coupling circuit comprises an adder and a multiplier.
Claim 20
Dependent Claim
14 words
A radio receiver according to claim 1, wherein said input stage is frequency tunable.
Claim 21
Dependent Claim
21 words
A radio receiver according to claim 1 comprising a mute circuit to suppress the output signal in the event of disturbance.
Claim 22
Dependent Claim
18 words
A radio receiver according to claim 1 comprising a pulse generator for temporarily changing the degree of distortion.
Claim 23
Dependent Claim
20 words
A radio receiver according to claim 1, wherein the recognition circuit comprises two sample and hold circuits and a comparator.
Claim 24
Dependent Claim
52 words
A radio receiver according to claim 22 further comprising a signal rectifier providing a signal which is fed directly to one input of the comparator and to its other input via one sample and hold circuit, and the output signal of the comparator is fed to the other sample and hold circuit.
Claim 25
Dependent Claim
18 words
A radio receiver according to claim 20, wherein the comparator is in the form of a differential amplifier.
Claim 26
Dependent Claim
17 words
A radio receiver according to claim 4 comprising a transformer network to effect the temporary signal attenuation.
References Cited (Backward Citations)
US3622887A
Cited
DE2550176A1
Cited
US4126828A
Cited
US4172239A
Cited
DE2943375A1
Cited
US4245353A
Cited
US4355414A
Cited
DE3005537A1
Cited
DE3210454A1
Cited
US4580288A
Cited
US4479254A
Cited
JPS59168728A
Cited
US4653116A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-08-02 | 1992-02-01 | 1992-08-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-08-02 | 1996-02-01 | 1996-08-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-08-02 | 2000-02-01 | 2000-08-02 | $7700.00 | Window Closed / Lapsed |