CA1073076A - Beat frequency interference rejection circuitry - Google Patents
Beat frequency interference rejection circuitryInfo
- Publication number
- CA1073076A CA1073076A CA278,050A CA278050A CA1073076A CA 1073076 A CA1073076 A CA 1073076A CA 278050 A CA278050 A CA 278050A CA 1073076 A CA1073076 A CA 1073076A
- Authority
- CA
- Canada
- Prior art keywords
- frequency
- signal
- beat
- swept
- transmitter
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
- 230000035559 beat frequency Effects 0.000 title claims abstract description 18
- 230000002452 interceptive effect Effects 0.000 claims abstract description 20
- 238000001514 detection method Methods 0.000 claims description 10
- 230000005672 electromagnetic field Effects 0.000 claims description 9
- 238000010009 beating Methods 0.000 claims description 4
- 230000001702 transmitter Effects 0.000 claims description 3
- 230000002401 inhibitory effect Effects 0.000 claims description 2
- 239000000306 component Substances 0.000 description 11
- 238000001228 spectrum Methods 0.000 description 6
- 238000000034 method Methods 0.000 description 2
- 150000001768 cations Chemical class 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
Classifications
-
- G—PHYSICS
- G08—SIGNALLING
- G08B—SIGNALLING OR CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS
- G08B13/00—Burglar, theft or intruder alarms
- G08B13/22—Electrical actuation
- G08B13/24—Electrical actuation by interference with electromagnetic field distribution
- G08B13/2402—Electronic Article Surveillance [EAS], i.e. systems using tags for detecting removal of a tagged item from a secure area, e.g. tags for detecting shoplifting
- G08B13/2465—Aspects related to the EAS system, e.g. system components other than tags
- G08B13/2468—Antenna in system and the related signal processing
- G08B13/2471—Antenna signal processing by receiver or emitter
Landscapes
- Engineering & Computer Science (AREA)
- Signal Processing (AREA)
- Physics & Mathematics (AREA)
- Automation & Control Theory (AREA)
- Computer Security & Cryptography (AREA)
- Electromagnetism (AREA)
- General Physics & Mathematics (AREA)
- Burglar Alarm Systems (AREA)
- Radar Systems Or Details Thereof (AREA)
- Noise Elimination (AREA)
- Emergency Alarm Devices (AREA)
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US05/777,524 US4117466A (en) | 1977-03-14 | 1977-03-14 | Beat frequency interference rejection circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1073076A true CA1073076A (en) | 1980-03-04 |
Family
ID=25110489
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA278,050A Expired CA1073076A (en) | 1977-03-14 | 1977-05-10 | Beat frequency interference rejection circuitry |
Country Status (13)
| Country | Link |
|---|---|
| US (1) | US4117466A (enExample) |
| JP (2) | JPS53113492A (enExample) |
| AU (1) | AU511099B2 (enExample) |
| CA (1) | CA1073076A (enExample) |
| DE (1) | DE2725169C2 (enExample) |
| DK (1) | DK147169C (enExample) |
| ES (1) | ES459235A1 (enExample) |
| FR (1) | FR2384306A1 (enExample) |
| GB (1) | GB1580412A (enExample) |
| IT (1) | IT1082816B (enExample) |
| MX (1) | MX143644A (enExample) |
| SE (1) | SE427882B (enExample) |
| ZA (1) | ZA772858B (enExample) |
Families Citing this family (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4484182A (en) * | 1981-07-01 | 1984-11-20 | Shorrock Developments Limited | Intruder detection apparatus for functioning free of disturbance while in close proximity to high-power pulse-moldulated radars |
| US4429302A (en) | 1981-10-08 | 1984-01-31 | I. D. Engineering, Inc. | Electronic security system with noise rejection |
| NL8202951A (nl) * | 1982-07-21 | 1984-02-16 | Nedap Nv | Absorptiedetectiestelsel. |
| US4595915A (en) * | 1984-02-06 | 1986-06-17 | Mrs. Lawrence Israel | Electronic surveillance system employing the doppler effect |
| US4565996A (en) * | 1984-02-06 | 1986-01-21 | Mrs. Lawrence Israel | Range limited coherent frequency doppler surveillance system |
| US4728938A (en) * | 1986-01-10 | 1988-03-01 | Checkpoint Systems, Inc. | Security tag deactivation system |
| NL8600738A (nl) * | 1986-03-24 | 1987-10-16 | Nedap Nv | Onderdrukking van valse alarmen als gevolg van aanraken. |
| US4779077A (en) * | 1987-04-13 | 1988-10-18 | Lichtblau G J | Continuously armed high reliability pulse train processor |
| US5508684A (en) * | 1995-03-02 | 1996-04-16 | Becker; Richard S. | Article tag |
| GB9702242D0 (en) * | 1997-02-04 | 1997-03-26 | Plessey Semiconductors Ltd | Alarm sensor and antenna arrangement |
| US9590761B2 (en) * | 2011-09-23 | 2017-03-07 | Commscope Technologies Llc | Detective passive RF components using radio frequency identification tags |
Family Cites Families (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3696379A (en) * | 1970-12-02 | 1972-10-03 | Knogo Corp | Apparatus for article theft detection |
| US3863244A (en) * | 1972-06-14 | 1975-01-28 | Lichtblau G J | Electronic security system having improved noise discrimination |
| US3810147A (en) * | 1971-12-30 | 1974-05-07 | G Lichtblau | Electronic security system |
| US3818472A (en) * | 1972-05-26 | 1974-06-18 | K Mauk | R.f. system for detecting unauthorized travel of articles through a selected zone |
| US3967161A (en) * | 1972-06-14 | 1976-06-29 | Lichtblau G J | A multi-frequency resonant tag circuit for use with an electronic security system having improved noise discrimination |
| NL161904C (nl) * | 1973-04-13 | Knogo Corp | Diefstal-detectiestelsel. | |
| US3961322A (en) * | 1974-07-02 | 1976-06-01 | Lichtblau G J | Real time signal discrimination circuitry |
-
1977
- 1977-03-14 US US05/777,524 patent/US4117466A/en not_active Expired - Lifetime
- 1977-04-29 SE SE7704988A patent/SE427882B/xx not_active IP Right Cessation
- 1977-04-29 DK DK189477A patent/DK147169C/da not_active IP Right Cessation
- 1977-05-10 CA CA278,050A patent/CA1073076A/en not_active Expired
- 1977-05-11 IT IT68071/77A patent/IT1082816B/it active
- 1977-05-12 GB GB20066/77A patent/GB1580412A/en not_active Expired
- 1977-05-13 ZA ZA00772858A patent/ZA772858B/xx unknown
- 1977-05-20 AU AU25352/77A patent/AU511099B2/en not_active Expired
- 1977-05-23 JP JP5891677A patent/JPS53113492A/ja active Pending
- 1977-05-26 FR FR7716143A patent/FR2384306A1/fr active Granted
- 1977-05-27 ES ES459235A patent/ES459235A1/es not_active Expired
- 1977-06-03 DE DE2725169A patent/DE2725169C2/de not_active Expired
- 1977-09-29 MX MX170738A patent/MX143644A/es unknown
-
1983
- 1983-12-27 JP JP1983199111U patent/JPS5937910Y2/ja not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| FR2384306B1 (enExample) | 1983-05-13 |
| FR2384306A1 (fr) | 1978-10-13 |
| JPS53113492A (en) | 1978-10-03 |
| US4117466A (en) | 1978-09-26 |
| DE2725169C2 (de) | 1985-08-22 |
| AU511099B2 (en) | 1980-07-31 |
| IT1082816B (it) | 1985-05-21 |
| JPS59118085U (ja) | 1984-08-09 |
| DE2725169A1 (de) | 1978-09-21 |
| AU2535277A (en) | 1978-11-23 |
| DK189477A (da) | 1978-09-15 |
| DK147169B (da) | 1984-04-30 |
| SE7704988L (sv) | 1978-09-15 |
| GB1580412A (en) | 1980-12-03 |
| DK147169C (da) | 1984-10-15 |
| ES459235A1 (es) | 1978-08-01 |
| ZA772858B (en) | 1978-04-26 |
| SE427882B (sv) | 1983-05-09 |
| MX143644A (es) | 1981-06-17 |
| JPS5937910Y2 (ja) | 1984-10-20 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |