摘要:
The present invention is a magnetic sensor used with one or more frequency band pass filters and a logic circuit that produces a ("critical") signal that is used for enabling and disabling an external electronic circuit, e.g. a computer circuit. The magnetic sensor produces a signal when excited by an externally applied alternating current (ac) magnetic field. The external ac magnetic field can comprise one or more frequencies, each of which induces an electrical signal at the respective frequency in the sensor. Depending on the linearity of the sensor, one or more harmonic frequencies of the signal frequencies can also be induced in the sensor. One or more bandpass filters is connected to the magnetic sensor and each of the bandpass filters is tuned to filter the signal to select filtered signals, from the output of the sensor. A logic circuit is activated by one or more of the filtered signals or a combination of one or more of the signal frequencies. When the logic circuit is activated, a critical signal is applied to an electronic circuit to enable or disable the external electronic circuit.
摘要:
A combination of a radio frequency identification transponder (RFID Tag) and to a magnetic electronic article surveillance (EAS) device is disclosed. The present invention relates generally to radio frequency identification (RFID) systems, and more specifically to RFID transponders for use in RFID systems and the method for their assembly.
摘要:
A combination of a radio frequency identification transponder (RFID Tag) and to a magnetic electronic article surveillance (EAS) device is disclosed. The present invention relates generally to radio frequency identification (RFID) systems, and more specifically to RFID transponders for use in RFID systems and the method for their assembly.
摘要:
Methods and apparatus applying RFID technology to identify electronic components, devices, and systems to provide functions such as, for example, security of the assets, inventory tracking of the assets, identification of the assets, and short distance communication between the assets are disclosed. RFID transponders are integrated into electronic components, devices and systems at the component level (i.e., circuit chip, circuit board, etc.), the asset level (i.e., box, computer, etc.), or system level (i.e., network system, computer system, etc.).
摘要:
A radio frequency identification transponder (RFID tag) includes an RFID antenna and one or more elements of nonlinear magnetic material tuned to resonate at substantially the same frequency as the resonant frequency of the tag antenna. This co-resonance amplifies signals that impinge upon the antenna, yielding both a higher level signal from the antenna to the tag electronics and wider operational bandwidth for the tag. With the addition of the nonlinear magnetic material, the tag may also be employed as a magnetic surveillance tag, with the attendant non-screening capabilities. With a plurality of nonlinear magnetic elements tuned to different resonant frequencies, the tag may provide more "non-screenable" information, that is, two bits, or four binary states, for example, when two such elements are employed.
摘要:
A system and method for detecting parallel marketing of an item, include forming at least one of a coating and a code on the item, interrogating the at least one of the coating and said code, and determining from the interrogating whether the item has been transferred from an authorized merchant to an unauthorized merchant.
摘要:
A method and system for preventing counterfeiting of an item, include an interrogatable tag attached to the item. The item includes visible indicia for comparison with secret, non-duplicable information stored in the tag designating authenticity.
摘要:
The invention relates to a special type of magnetic tag that serves both as an identifier of the article to which it is attached and as an antitheft device. Identification comes about through the use of an array of individual magnetic elements that are closely spaced, preferably along and perpendicular to an amorphous wire or strip. The wire or strip forms an integral part of the identification array and can be used as an anti-theft device to trigger an alarm when activated by an external field from a magnetic gate. The array may be personalized (coded) by leaving out elements of the array or by driving selected elements to saturation while others remain demagnetized. The elements can also be in the form of a double array to constitute `l`s and `0`s to form a code. Reading of the elements (code) is accomplished with a special reading head consisting of one or more small magnetic circuits coupled to one or more pickup loops utilizing, in some cases, the Matteucci effect.
摘要:
An inexpensive multibit magnetic tag is described which uses an array of amorphous wires in conjunction with a magnetic bias field. The tag is interrogated by the use of a ramped field or an ac field or a combination of the two. The magnetic bias is supplied either by coating each wire with a hard magnetic material which is magnetized or by using magnetized hard magnetic wires or foil strips in proximity to the amorphous wires. Each wire switches at a different value of the external interrogation field due to the difference in the magnetic bias field acting on each wire.
摘要:
A transponder is disclosed comprising a resonant RLC circuit with one or more components that can be connected or disconnected non-destructively using switches that respond to an externally applied magnetic field. The switching in or out of the components causes a change in the resonant frequency of the original RLC circuit that is detected by the base station sweeping a carrier signal through a range of frequencies to detect a returned signal that changes when the carrier signal frequency matches the resonant frequency of the resonant circuit/tag. The resonant frequency changes when one or more of the circuit components is connected or disconnected. Each switch transfers at a unique magnetic field intensity so that electrical contact is achieved at a predetermined value of an externally applied magnetic field. The detected changes are used to create a code that is used to pass information from the resonant circuit/tag to the base station.