EP0293167A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
A communications jammer
Assignee: BAE Systems PLC
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Filing: 1988-05-24
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Granted: —
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Expires: 2008-05-24
Abstract
Abstract A jammer includes means (5,14) for receiving a local radio transmission and means (8,9,10,11) for determining the frequency of the local radio transmission. The jammer includes monitoring means (11,15,16) which are arranged to detect the end of the local radio transmission and only then to trigger the transmitting of a jamming signal by jamming signal transmitting means (5,14). In this manner the jammer jams local reception of the response of a non-local station to the detected local transmission. The jammer is able to jam effectively using a low power signal. The reduction in the power-consumption of the jammer makes it particularly suitable for use as a leave-behind jammer for military applications.
Inventors
- 👤 Anthony Michael New
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-04 13:05
CPC Classifications
H; H04; H04K; H04K3/00; H04K3/40; H04K3/45; H04K3/41; H04K3/42
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
170 words
A jammer comprising receiving means (5, 13) for receiving a local radio transmission, frequency determining means (8, 9, 10, 11) for determining the frequency of the local radio transmission, and jamming signal transmitting means (5, 14) for transmitting a jamming signal at a frequency controlled in accordance with the frequency determined by the frequency determining means (8, 9, 10, 11) at a time subsequent to the reception of the local radio transmission by the receiving means, characterised in that the receiving means include monitoring means (11, 15, 16) arranged to detect the end of the local radio transmission and to trigger the operation of the jamming signal transmitting means (5, 14) only after the end of the local radio transmission and in that the jamming signal transmitting means (5, 14) are arranged to transmit a low power signal for a period of time after the end of the local radio transmission so that the jammer jams local reception of a response of a non-local station to the local radio transmission.
Claim 2
Dependent Claim
170 words
A jammer comprising receiving means (5, 13) for receiving a local radio transmission, frequency determining means (8, 9, 10, 11) for determining the frequency of the local radio transmission, and jamming signal transmitting means (5, 14) for transmitting a jamming signal at a frequency controlled in accordance with the frequency determined by the frequency determining means (8, 9, 10, 11) at a time subsequent to the reception of the local radio transmission by the receiving means, characterised in that the receiving means include monitoring means (11, 15, 16) arranged to detect the end of the local radio transmission and to trigger the operation of the jamming signal transmitting means (5, 14) only after the end of the local radio transmission and in that the jamming signal transmitting means (5, 14) are arranged to transmit a low power signal for a period of time after the end of the local radio transmission so that the jammer jams local reception of a response of a non-local station to the local radio transmission.
Claim 3
Dependent Claim
49 words
A jammer according to Claim 1, in which the monitoring means (11, 15, 16) include logic circuits (11) arranged to analyse the received local radio transmission to discriminate between hostile and non-hostile transmissions and to control the frequency determining means to stop monitoring at the frequency of non-hostile transmissions.
Claim 4
Dependent Claim
27 words
A jammer according to Claim 2, in which the jamming signal transmitting means (5, 14) include means (17) for imposing an identification code on the jamming signal.
Claim 5
Dependent Claim
82 words
A jammer according to any one of the preceding Claims, in which the jammer includes a local frequency oscillator (8) common to the receiving means (5, 13) and the jamming signal transmitting means (5, 14) and a switch (12) arranged to connect the local frequency oscillator (8) to other components of the transmitting means (5, 14) when the jammer is in a transmitting mode and to other components of the receiving means (5, 13) when the jammer is in a receiving mode.
Claim 6
Dependent Claim
41 words
A jammer according to Claim 4, in which the local frequency oscillator (8) is a fast-settling frequency synthesiser arranged when the jammer is in the receiving mode to scan through a range of frequencies until a local radio transmission is detected.
Claim 7
Independent Claim
84 words
A method of operating a jammer to disrupt radio communications comprising detecting a hostile local transmission, determining the frequency of the local transmission, subsequently transmitting a jamming signal at a frequency controlled in accordance with the determined frequency, and ceasing transmission of the jamming signal until a further local transmission is detected characterised in that the jamming signal is transmitted only after the cessation of the local transmission to jam the local reception of a response of a non-local station to the local transmission.
Claim 8
Independent Claim
84 words
A method of operating a jammer to disrupt radio communications comprising detecting a hostile local transmission, determining the frequency of the local transmission, subsequently transmitting a jamming signal at a frequency controlled in accordance with the determined frequency, and ceasing transmission of the jamming signal until a further local transmission is detected characterised in that the jamming signal is transmitted only after the cessation of the local transmission to jam the local reception of a response of a non-local station to the local transmission.
Claim 9
Dependent Claim
29 words
A method according to claim 6, further comprising analysing the local transmission to discriminate between hostile and non-hostile transmissions and ceasing monitoring of any transmission determined to be non-hostile.
Claim 10
Dependent Claim
17 words
A method according to claim 6 or 7, further comprising imposing an identification on the jamming signal.
Claim 11
Dependent Claim
35 words
A method according to claim 8 when dependent on claim 7, in which the step of analysing the local transmission includes determining whether the local transmission includes a signal identifying the local transmission as non-hostile.
References Cited (Backward Citations)
No citation records indexed.
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