Gm Global Technolgoy Operations, Inc.

Delphi Technologies, Inc.

Other

Adolph L Micheli

Joseph V Mantese

Norman William Schubring

Dennis F Dungan

Antonio B Catalan

Aboud H Hamdi

David B Hicks

Jayant K Bhagat

Ruth Carol Laugal

Larry D McMillan

Jolanta Bozena Celinska

Gregory William Auner

Andrew Mark Mance

Dominic Anthony Messuri

Shih-Chia Chang

Steven A Musick

William Thomas Phillips, Jr

Clyde Maynord Callewaert

Michael W Putty

Carlos P De Araujo

Ratna Naik

Wey-Chaung Kuo

Mohammad A Habib

Shyam P Maheswari

Edward Patrick Manning

Dennis Forest Dungan

Andrew W Schubring

Clyde M Callewaert

Said A Mansour

Joseph Vito Mantese

A pyroelectric sensor for determines a charge output of a ferroelectric scene element of the sensor by measuring the hysteresis loop output of the scene element several times during a particular time frame for the same temperature. An external AC signal is applied to the ferroelectric scene element to cause the hysteresis loop output from the element to switch polarization. Charge integration circuitry is employed to measure the charge from the scene element. The ferroelectric of the scene element is made of strontium bismuth tantalate, or derivative thereof, disposed directly between top and bottom electrodes. The polarization of the reference element which is compared to and subtracted from the polarization of the scene element for each cycle. The polarization difference measured for each cycle over a set time period are summed by an integrating amplifier to produce a signal output voltage.

Pyroelectric sensor

Systems and methods for determining a temperature of a ferroelectric sensor are provided. The ferroelectric sensor has operational characteristics defined by a polarization versus voltage hysteresis loop. In one exemplary embodiment, the method includes applying a symmetrical periodic voltage waveform to the ferroelectric sensor so as to induce the ferroelectric sensor to traverse the polarization versus voltage hysteresis loop. The method further includes monitoring voltages across the ferroelectric sensor and polarization states of the ferroelectric sensor over a first time interval to determine a first zero field polarization state and a first coercive field voltage. The method further includes determining a first temperature value indicative of the temperature of the ferroelectric sensor based on the first coercive field voltage.

Systems and methods for determining a temperature of a ferroelectric sensor

A circuit device that make use of graded ferroelectric structures and techniques by which such structures can be excited by external and internal stimuli to render the device useful for a variety of circuit applications. The device comprises at least two ferroelectric films, each of the films having a graded dipole moment in a thickness direction normal to the surfaces thereof. The graded dipole moment of each film is effective to produce a change in the dipole charge density, and hence an apparent net charge, on the first and second surfaces of each film when an alternating electric field is applied to the film and additional energy is imparted to the film. By providing an electrical connection between the films, changes in the dipole charge density of the films generated by application of the alternating electric field yield a device charge separation output that differs from the individual changes in the dipole charge density of the films.

Circuit device comprising multiple polarization-graded ferroelectric elements and method of using

A pyroelectric sensor having an active regulation for maximizing pyroelectric sensor sensitivity is disclosed. The pyroelectric sensor comprises a ferroelectric transducer, and a regulator. The ferroelectric transducer may either be a homogenous ferroelectric transducer, a compositionally graded ferroelectric transducer, or an externally graded ferroelectric transducer. The regulator may either be an excitation regulator or a temperature regulator. A method for regulating the excitation or the temperature of a pyroelectric sensor for maximizing sensitivity of the pyroelectric sensor is also disclosed.

Active regulator for maximizing pyroelectric sensitivity

The subject invention includes a composite material comprising a ferroelectric material and a ferromagnetic material having a loss factor (tan &dgr;) for the composite material which includes a dielectric loss factor of the ferroelectric material and a magnetic loss factor of the ferromagnetic material. The composite material achieves the loss factor of from 0 to about 1.0 for a predetermined frequency range greater than 1 MHz. The ferroelectric material has a dielectric loss factor of from 0 to about 0.5 and the ferromagnetic material has a magnetic loss factor of from 0 to about 0.5 for the predetermined frequency range. The ferroelectric material is present in an amount from 10 to 90 parts by volume based on 100 parts by volume of the composite material and the ferromagnetic material is present in an amount from 10 to 90 parts by volume based upon 100 parts by volume of the composite material such that the amount of the ferroelectric material and the ferromagnetic material equals 100 parts by volume.

Ferroelectric and ferromagnetic material having improved impedance matching

An EMI filter ( ) that makes use of a ferroelectric-ferromagnetic composite, member, or slab ( ) in connection with capacitive and inductive elements. The geometrical structure of the filter ( ) is such that the mutually orthogonal electric fields and magnetic fields generated by the capacitive and inductive elements penetrate the volume of the composite ( ). In some designs, capacitive plates ( ) are split to avoid setting up eddy currents in the plates ( ) which oppose the penetration of magnetic flux through the composite ( ). Various structural designs can be provided to define the capacitive elements and the inductive elements in different configurations relative to the composite to satisfy the desirable requirements. One particular low-pass design includes providing a slab ( ) of the composite with plates ( ) on opposite sides of the slab ( ) that define capacitors, and a conductive strip ( ) wrapped around the slab ( ) and electrically connected to the hot capacitive plates ( ) that define the inductor. This basic configuration can be extended to a cylinder ( ) made of the composite, where a ground plane ( ) is provided on one surface ( ) of the cylinder ( ), and the hot capacitor plates ( ) are provided on the other surface ( ) of the cylinder ( ), where a conductive strip ( ) on the other surface ( ) defines the coil. A multi-layer filter ( ) can be provided that includes layered substrates ( ) where metallized vias ( ) extending through the substrates ( ) define a coil, and ground planes ( ) and capacitive plates ( ) on alternating substrates ( ) define the capacitive elements.

EMI/RFI filter including a ferroelectric/ferromagnetic composite

A ferroelectric/pyroelectric sensor that employs a technique for determining a charge output of a pyroelectric element of the sensor by measuring the hysteresis loop output of the element several times during a particular time frame for the same temperature. An external AC signal is applied to the pyroelectric element to cause the hysteresis loop output from the element to switch polarization. Charge integration circuitry, such as a combination capacitor and operational amplifier, is employed to measure the charge from the element. A mechanical shutter is not used, and thus the charge integration output from the element is directly proportional to the incident radiation thereof.

Ferroelectric thermometry and pyrometry by active operation

A ferroelectric/pyroelectric sensor that employs a technique for determining a charge output of a pyroelectric element of the sensor by measuring the hysteresis loop output of the element several times during a particular time frame for the same temperature. An external AC signal is applied to the pyroelectric element to cause the hysteresis loop output from the element to switch polarization. The frequency of the external AC signal is greater than the frequency of a chopper selectively applying a reference temperature and a scene temperature alternately to the pyroelectric element. Each time the chopper provides the reference temperature or the scene temperature to the element, the alternating external source covers multiple cycles so that the hysteresis loop output is switched multiple times for increased signal averaging. Because the shape and size of the loop is different for the reference temperature and the scene temperature, a comparison between the measured charge for both time periods can be provided to give a signal having an increased signal-to-noise ratio.

Pyroelectric sensor sensitivity enhanced by active hysteresis excitation

A material which possesses both capacitive and inductive properties for suppressing electromagnetic interference is provided, wherein the material is a composite of a ferroelectric material and a ferromagnetic material. The ferroelectric-ferromagnetic composite material is formulated and processed so as to retain the distinct electrical properties of the individual constituents according to the relative quantities of the constituents present in the ferroelectric-ferromagnetic composite material. As a unitary composite element, the ferroelectric-ferromagnetic composite is readily formable to provide a compact electrical filter whose filtering capability is highly suitable for suppressing electromagnetic interference from sources internal and external to an automotive environment. The sintered composite has a very low porosity; interconnectivity between the ferroelectric and ferromagnetic phases; and has no chemical reaction between the ferroelectric and ferromagnetic phases to produce a third phase.

Filter with ferroelectric-ferromagnetic composite materials

Barium-strontium titanate ferroelectric materials and AFe.sub.2 O.sub.4 -type ferrite ferromagnetic materials may be consolidated into a ferroelectric-ferromagnetic composite having useful electromagnetic interference attenuation properties over a wide range of electromagnetic frequencies by fluxing the barium-strontium titanate with a combination of (1) a lithium compound and barium oxide or (2) copper oxide and barium oxide and thereafter mixing the fluxed ferroelectric with the ferromagnetic and sintering the combination at reduced temperature in the range of 1060.degree. C. to 1150.degree. C.

Method of making ferroelectric-ferromagnetic composite materials

Ferroelectric-ferromagnetic composite materials

Filter elements having ferroelectric-ferromagnetic composite materials

A film having a unique asymmetrical hysteresis, a method of making, and a method of using such a film in and/or as a device. An example describes a distinctive ferroelectric device as an infrared detector that operates at generally ambient conditions.

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Mt. Clemens, MI, United States of America

Adolph L Micheli