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:
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:
A magnetic field sensor incorporates a plurality of magnetic stripes spaced apart on the surface of a substrate such that the stray magnetic fields at the ends of the magnetic stripes are magnetostatically coupled and the magnetic stripes are magnetized respectively in alternating directions, nonmagnetic conductive material positioned in the spaces between the magnetic stripes and electrodes for passing current crosswise through the plurality of magnetic stripes to detect a change in resistance by the giant magnetoresistive effect (MGR). The invention overcomes the problem of detecting low magnetic fields since the magnetic fields required to saturate magnetic stripes depends on the magnetostatic coupling which in turn can be controlled by the geometry and position of the magnetic stripes in the sensor.
摘要:
Superconducting transition metal oxide films are provided which exhibit very high onsets of superconductivity and superconductivity at temperatures in excess of 40.degree. K. These films are produced by vapor deposition processes using pure metal sources for the metals in the superconducting compositions, where the metals include multi-valent nonmagnetic transition metals, rare earth elements and/or rare earth-like elements and alkaline earth elements. The substrate is exposed to oxygen during vapor deposition, and, after formation of the film, there is at least one annealing step in an oxygen ambient and slow cooling over several hours to room temperature. The substrates chosen are not critical as long as they are not adversely reactive with the superconducting oxide film. Transition metals include Cu, Ni, Ti and V, while the rare earth-like elements include Y, Sc and La. The alkaline earth elements include Ca, Ba and Sr.
摘要:
A transponder has a resonant RLC circuit with one or more electromagnetic energy storage components that vary in response to an externally applied modulating energy field. In addition to the externally modulating energy field, a base station transmits a carrier signal with a frequency essentially the same as the quiescent resonant frequency of the RLC circuit. As the component(s) vary, the resonant frequency of the RLC circuit changes, modulating the carrier signal with the external modulating energy field. Effects of the modulation are detected by the base station. Information (e.g., the presence of a tag) is obtained by receiving and demodulating the modulated signal at the base station. One or more or the circuit elements (e.g, different preferred embodiments of one or more capacitors, inductors, and resistors) can be varied (e.g. mechanically) to modulate the carrier signal. This allows the resonant circuit to modulate the carrier signal with multiple modulation frequencies to encode multiple bits of information on the carrier.
摘要:
A magnetoresistive sensor includes a substrate and a layer of ferromagnetic material formed over the substrate. A plurality of nonmagnetic regions is formed within the layer of ferromagnetic material. Magnetic flux paths form around each one of the plurality of nonmagnetic regions when the layers of ferromagnetic material is not in a magnetic field. The flux paths are contained completely with the layer of ferromagnetic material and do not penetrate into the plurality of nonmagnetic regions. The sensor also provides for detecting a change in resistance through the layer of ferromagnetic material as a function of a magnetic field applied to the layer of ferromagnetic material.
摘要:
A magnetic field sensor is described incorporating a plurality of magnetic stripes spaced apart on the surface of a substrate such that the stray magnetic fields at the ends of the magnetic stripes are magnetostatically coupled and the magnetic stripes are magnetized respectively in alternating directions, nonmagnetic conductive material positioned in the spaces between the magnetic stripes and electrodes for passing current crosswise through the plurality of magnetic stripes to detect a change in resistance by the giant magnetoresistive effect (MGR). The invention overcomes the problem of detecting low magnetic fields since the magnetic fields required to saturate magnetic stripes depends on the magnetostatic coupling which in turn can be controlled by the geometry and position of the magnetic stripes in the sensor.
摘要:
In a Field Effect Transistor (FET) with a semiconductor channel the use of a high Tc oxide superconductor material in the gate electrode provides both control of parasitic resistance and capacitance and a proper work function when operated at a temperature below the Tc. The 1-2-3 compound oxide superconductors with the general formula Y1Ba2Cu3O7-y where y is approximately 0.1 have the ability in use in FET's to provide convenient work functions, low resistance and capacitance, and to withstand temperatures encountered in processing as the FET is being manufactured.
摘要:
A transponder has a resonant RLC circuit with one or more electromagnetic energy storage components that vary in response to an externally applied modulating energy field. In addition to the externally modulating energy field, a base station transmits a carrier signal with a frequency essentially the same as the quiescent resonant frequency of the RLC circuit. As the component(s) vary, the resonant frequency of the RLC circuit changes, modulating the carrier signal with the external modulating energy field. Effects of the modulation are detected by the base station. Information (e.g., the presence of a tag) is obtained by receiving and demodulating the modulated signal at the base station. One or more of the circuit elements (e.g. different preferred embodiments of one or more capacitors, inductors, and resistors) can be varied (e.g. mechanically) to modulate the carrier signal. This allows the resonant circuit to modulate the carrier signal with multiple modulation frequencies to encode multiple bits of information on the carrier.
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.