1587 results about "Microwave frequency" patented technology

A system is provided for locating a vehicle. The system comprises a transmission device such as a key fob for transmission and receiving of a signal. Typically the key fob has a plurality of indicators such as LED indicators arranged in a circle. The key fob is adapted to transmit a radio frequency or microwave frequency transmission signal. An antenna array is positioned on or in a vehicle. The array comprises a plurality of antennas, generally arranged in a circular pattern. The array is adapted to receive the transmission signal from the transmission device which is converted to be analyzed by a microcontroller unit (MCU). The MCU is adapted to: (i) receive digital data converted from the transmission signal, (ii) calculate an angle of arrival (AOA) or direction of arrival (DOA) based on known components and an algorithm, and (iii) transmit a selection signal back to the key fob. A signal processing unit is coupled to the plurality of antennas and the MCU. The signal processing unit is adapted to receive the signal transmission from each antenna, convert the signal to digital data, and transmit the digital data to the MCU.

Printed antenna devices are provided, which can operate at RF and microwave frequencies, for example, while simultaneously providing antenna performance characteristics such as high gain / directivity / radiation efficiency, high bandwidth, hemispherical radiation patterns, impedance, etc., that render the antennas suitable for voice communication, data communication or radar applications, for example. Further, apparatus are provided for integrally packaging such printed antenna devices with IC (integrated circuit) chips (e.g., transceiver) to construct IC packages for, e.g., wireless communications applications.

A load balancing system for dynamic balancing of load between sectors of a sectored cellular base station, comprises a plurality of repeaters with local coverage in the sectors, and a switching matrix, for associating between the repeaters and the base station, and for allowing the repeaters to be switched between different sectors. If the system uses the base station assigned frequency band for communication with the repeaters then the system can be provided with minimal interference as an add-on to a legacy base station. An add-on may also be provided using microwave frequency and dedicated antennas.

Apparatus for minimally invasively measuring concentrations of constituents contained within a biological tissue structure includes a microwave energy source arranged generate a range of microwave frequencies, a first antenna coupled to the microwave energy source and arranged to transmit at least a portion of the microwave energy into the tissue structure, a second antenna arranged to receive at least a portion of the microwave energy transmitted through the tissue structure, a signal processor arranged to determine the resonant frequency of the received microwave energy, and a data processor arranged to provide an output of the concentration of constituents within the biological tissue structure according to the determined resonant frequency.

A method and system for examining biological tissue includes the steps of radiating a tissue region with a plurality of microwave radiation pulses. The microwave pulses are swept across a range of microwave frequencies. In response to the swept frequency microwave pulses, the tissue region emits a plurality of thermoacoustic signals. At least one image of the tissue region is formed from the plurality of thermoacoustic signals. The signals can be ultrawideband signals.

A filtered button DC interconnect employing a compressible conductor such as a finely wound wire mesh imbedded within a series of dielectric and ferrite cylinders. The compressible conductor is captivated within the series of dielectric and ferrite cylinders to ensure proper contact with mating surfaces of interconnected circuits. The interconnect serves as an RF filter by providing rejection of RF and microwave frequencies between the interconnected circuits.

A method for heating heavy oil inside a production well. The method raises the subsurface temperature of heavy oil by utilizing an activator that has been injected below the surface. The activator is then excited with a generated microwave frequency such that the excited activator heats the heavy oil.

Microelectromechanical RF and microwave frequency power limiter and electrostatic protection devices for use in high-speed circuits are presented. The devices utilize an airbridge or a cantilever arm including a contact pad positioned operatively adjacent to an electrically conductive and substantially planar transmission line. When the power level in the transmission line exceeds a particular threshold, the airbridge or cantilever arm yields due to force between the contact pad and the transmission line, directing undesired power away from active devices. This characteristic can either serve as a method by which to limit the amount of power passing through the transmission line to a determined value or as a method by which to protect devices along the transmission line from damage due to large electrostatic bursts.

A semi-insulating bulk single crystal of silicon carbide is disclosed that has a resistivity of at least 5000 OMEGA-cm at room temperature and a concentration of trapping elements that create states at least 700 meV from the valence or conduction band that is below the amounts that will affect the resistivity of the crystal, preferably below detectable levels. A method of forming the crystal is also disclosed, along with some resulting devices that take advantage of the microwave frequency capabilities of devices formed using substrates according to the invention.

An autonomous battery-free microwave frequency communication device which includes a capacitance, at least one antenna, a microwave energy harvesting system, a microwave frequency transceiver, and a control system. The energy harvesting system is configured to harvest and store microwave energy received via the antenna onto the capacitance. The transceiver is empowered by energy stored on the capacitance, and is configured to autonomously generate a microwave frequency carrier and to autonomously transmit information using the microwave frequency carrier according to a predetermined communications protocol via the antenna. The control system is empowered by energy stored on the capacitance, and is configured to provide information for transmission. Energy may be harvested from various communication forms, such as wireless network protocols or cellular communications. The frequency band from which energy is harvested may differ from the frequency band used for communications. The energy storage enables autonomous communications with external devices according to common or standard wireless communication protocols.

Printed antenna devices are provided, which can operate at RF and microwave frequencies, for example, while simultaneously providing antenna performance characteristics such as high gain / directivity / radiation efficiency, high bandwidth, hemispherical radiation patterns, impedance, etc., that render the antennas suitable for voice communication, data communication or radar applications, for example. Further, apparatus are provided for integrally packaging such printed antenna devices with IC (integrated circuit) chips (e.g., transceiver) to construct IC packages for, e.g., wireless communications applications.

The invention described herein generally pertains to utilization of high power density microwave energy to reduce organic compounds to carbon and their constituents, primarily in a gaseous state. The process includes, but is not limited to, scrap tires, plastics, asphalt roofing shingles, computer waste, medical waste, municipal solid waste, construction waste, shale oil, and PCB / PAH / HCB-laden materials. The process includes the steps of feeding organic material into a microwave applicator and exposing the material to microwave energy fed from at least two linear polarized sources in non-parallel alignment to each other, and collecting the material. The at least two sources of microwave energy are from a bifurcated waveguide assembly, whose outputs are perpendicular to each other and fed through waveguide of proper impedance, such that the microwave sources are physically and electrically 90° out of phase to each other. The microwave frequency is between 894 and 1000 MHz, preferably approximately 915 MHz.

A method and system for examining biological tissue includes the steps of radiating a tissue region with a plurality of microwave radiation pulses. The microwave pulses are swept across a range of microwave frequencies. In response to the swept frequency microwave pulses, the tissue region emits a plurality of thermoacoustic signals. At least one image of the tissue region is formed from the plurality of thermoacoustic signals. The signals can be ultrawideband signals.

The invention relates to a wireless-receiving system for detecting microelectronic mechanical microwave frequency and a preparation method thereof. The wireless-receiving system for detecting the microelectronic mechanical microwave frequency has quite simple structure, large measurement magnitude range, no direct-current power consumption and easy integration. In the system for detecting the microelectronic mechanical microwave frequency, gallium arsenide is used as a substrate, wherein a microwave antenna (A), a one-three power splitter (B), a coplanar waveguide transmission line (C), a two-in-one power combiner (D), an MEMS cantilever capacitive microwave power sensor (E) and an MEMS thermoelectric microwave power sensor (F) are designed on the substrate; and then a phase difference between a signal 3 and a signal 2 after the signal 3 passes through the coplanar waveguide transmission line with the length of lambda / 2 can be determined according to a law of cosines. Because the phase difference corresponds to the frequency of the signal, the frequency of the signal can be measured.

Apparatus and method for plasma deposition of thin film photovoltaic materials at microwave frequencies. The apparatus avoids unintended deposition on windows or other microwave transmission elements that couple microwave energy to deposition species. The apparatus includes a microwave applicator with conduits passing therethrough that carry deposition species. The applicator transfers microwave energy to the deposition species to activate or energize them to a reactive state conducive to formation of a thin film material. The conduits physically isolate deposition species that would react or otherwise combine to form a thin film material at the point of microwave power transfer. The deposition species are separately energized and swept away from the point of power transfer to prevent thin film deposition. Suitable deposition species include precursors that contain silicon, germanium, fluorine, and / or hydrogen. The invention allows for the ultrafast formation of silicon-containing amorphous semiconductors that exhibit high mobility, low porosity, little or no Staebler-Wronski degradation, and low defect concentration.

A collision warning system (10) discriminates between objects which pose a threat of collision from those which do not by measuring the relative sightline rate of the object, this being a measure of the rate of change of angular position of the object if the sightline rate is above a threshold value, there is little risk of collision. To measure the sightline rate, a radar source (20) emits microwave frequency radiation which is received by two detectors (22 and 24) after reflection from a target. Signals from the detectors are processed by processing means (26). The processing means determines if the sightline rate of an object is below a certain threshold. If it is, and the relative velocities of the object and the system are such that a collision is likely, a warning buzzer (28) sounds.

The invention relates glass ceramic articles suitable for use as electronic device housing or enclosures which comprise a glass-ceramic material. Particularly, a glass-ceramic article housing / enclosure comprising a glass-ceramic material exhibiting both radio and microwave frequency transparency, as defined by a loss tangent of less than 0.5 and at a frequency range of between 15 MHz to 3.0 GHz, a fracture toughness of greater than 1.5 MPam 1 / 2 , an equibiaxial flexural strength (ROR strength) of greater than 100 MPa, a Knoop hardness of at least 400 kg / mm2, a thermal conductivity of less than 4 W / m DEG C and a porosity of less than 0.1 %.

A method of obtaining a material property of a pavement material from a microwave field generally includes generating a microwave frequency electromagnetic field of a first mode about the pavement material. The frequency response of the pavement material in the electromagnetic field can be measured, such as by a network analyzer. The measurement of the frequency response permits correlating the frequency response to a material property of the pavement material sample, such as the density. A method of correcting for the roughness of a pavement material divides the pavement into a shallow layer and a deep layer. Two planar microwave circuits measure the permittivity of the shallow and deep layer. The permittivities are correlated to correct for roughness. An apparatus for obtaining the density of a pavement sample includes a microwave circuit and a network analyzer. The network analyzer measures the frequency response to determine the density of the pavement material.

The invention discloses an online microwave frequency detector and a detecting method thereof based on a cantilever beam and a direct-type power sensor. The detector is prepared on a GaAs substrate and comprises coplanar waveguide (CPW) transmission lines, four micro-electromechanical system (MEMS) cantilever beam structures of the completely same structure, a power combiner and three MEMS direct-type microwave power sensors of the completely same structure. The micro-electronic mechanical online microwave frequency detector provided by the invention not only has the advantages of being novel in structure and smaller in size, but also can realize online detection on a microwave signal frequency, and can be compatible with a GaAs single wafer microwave integrated circuit.

An RMS-to-DC converter implements the difference-of-squares function by utilizing two identical squaring cells operating in opposition to generate two signals. An error amplifier nulls the difference between the signals. When used in a measurement mode, one of the squaring cells receives the signal to be measured, and the output of the error amplifier, which provides a measure of the RMS value of the input signal, is connected to the input of the second squaring cell, thereby closing the feedback loop around the second squaring cell. When used in a control mode, a set-point signal is applied to the second squaring cell, and the output of the error amplifier is used to control a variable-gain device such as a power amplifier which provides the input to the first squaring cell, thereby closing the feedback loop around the first squaring cell. Accurate square law approximation at microwave frequencies can be achieved by implementing the squaring cells as series-connected three-transistor multi-tanh transconductance cells. By using carefully balanced squaring cells and a well-balanced error amplifier, approximation errors are cancelled and accurate RMS measurement is realized at high frequencies. A feedforward bootstrapping feature uses an op amp to balance the voltages at the common nodes of the transconductance squaring cells and also provides a balanced differential input drive to one of the squaring cells. A base current compensation circuit for providing accurate base compensation current to both of the squaring cells prevents errors due to DC offset voltages.

The invention relates to glass articles suitable for use as electronic device housing / enclosure or protective cover which comprise a glass material. Particularly, a housing / enclosure / cover comprising an ion-exchanged glass exhibits the following attributes: (1) radio, and microwave frequency transparency, as defined by a loss tangent of less than 0.03 and at a frequency range of between 15 MHz to 3.0 GHz; (2) infrared transparency; (3) a fracture toughness of greater than 0.6 MPa*m<1 / 2>; (4) a 4-point bend strength of greater than 350 MPa; (5) a Vickers hardness of at least 450 kgf / mm<2> and a Vickers median / radial crack initiation threshold of at least 5 kgf; (6) a Young's Modulus ranging between about 50 to 100 GPa; (7) a thermal conductivity of less than 2.0 W / m DEG C; and (9) at least one of the following attributes: (i) a compressive surface layer having a depth of layer (DOL) greater and a compressive stress greater than 400 MPa, or, (ii) a central tension of more than 20 MPa.

Low Q associated with passive components of monolithic integrated circuits (ICs) when operated at microwave frequencies can be avoided or mitigated using high resistivity (e.g., ≧100 Ohm-cm) semiconductor substrates (60) and lower resistance inductors (44′, 45′) for the IC (46). This eliminates significant in-substrate electromagnetic coupling losses from planar inductors (44, 45) and interconnections (50-1′, 52-1′, 94, 94′, 94″) overlying the substrate (60). The active transistor(s) (41′) are formed in the substrate (60) proximate the front face (63). Planar capacitors (42′, 43′) are also formed over the front face (63) of the substrate (60). Various terminals (42-1′, 42-2′, 43-1, 43-2′,50′, 51′, 52′, 42-1′, 42-2′, etc.) of the transistor(s) (41′), capacitor(s) (42′, 43′) and inductor(s) (44′, 45′) are coupled to a ground plane (69) on the rear face (62) of the substrate (60) using through-substrate-vias (98, 98′) to minimize parasitic resistance. Parasitic resistance associated with the planar inductors (44′, 45′) and heavy current carrying conductors (52-1′) is minimized by placing them on the outer surface of the IC where they can be made substantially thicker and of lower resistance. The result is a monolithic microwave IC (46, 58) previously unobtainable.

An RF interconnect is incorporated in RF module packages for direct attachment onto a multi-layer PWB using compressible center conductor (fuzz button) interconnects. The module has circuitry operating at microwave frequencies. The module package includes a metal housing including a metal bottom wall structure. The module includes a plurality of RF interconnects, which provide RF interconnection between the package and the PWB. Each interconnect includes a feedthrough center pin protruding through an opening formed in the metal bottom wall, with isolation provided by a dielectric feedthrough insulator. The center pin is surrounded with a ring of shield pins attached to the external surface of the bottom wall of the module housing. The pins are insertable in holes formed in the PWB, and make contact with fuzz button interconnects disposed in the holes. Circuitry connects the fuzz button interconnects to appropriate levels of the PWB for grounding and RF signal conduction.

A passive microwave thermography apparatus uses passive microwave antennas designed for operation, for example, at WARC protected frequencies of 1.400 to 1.427 GHz and 2.690 to 2.70 GHz (for core body gradient temperature measurement) and 10.68 to 10.700 GHz or higher microwave frequency (for surface body gradient temperature measurement) and a related directional antenna or antenna array to measure microwave radiation emanating from an animal, especially, a human body. The antennae may be radially directed toward a point within or on the surface of a human body for comparison with known temperature distribution data for that point and a given ambient temperature. Each frequency band may provide a plurality of adjacent noise measuring channels for measuring microwave noise naturally emitted by the human body. The apparatus measures short-term changes in, for example, core and body surface temperatures to establish a basal metabolic rate. Changes in core body temperature may be stimulated by the administration of food or certain organic and drug-related substances or stress to induce a change in basal metabolic rate over time. These changes correlate directly with a human subject's metabolism rate at rest and under certain dietary constraints and can be used to determine courses of treatment for obesity, metabolic disease, and other disorders. The apparatus can also be used to remotely monitor patients and subjects without physical contact.

A method of obtaining a material property of a pavement material from a microwave field generally includes generating a microwave frequency electromagnetic field of a first mode about the pavement material. The frequency response of the pavement material in the electromagnetic field can be measured, such as by a network analyzer. The measurement of the frequency response permits correlating the frequency response to a material property of the pavement material sample, such as the density. A method of correcting for the roughness of a pavement material divides the pavement into a shallow layer and a deep layer. Two planar microwave circuits measure the permittivity of the shallow and deep layer. The permittivities are correlated to correct for roughness. An apparatus for obtaining the density of a pavement sample includes a microwave circuit and a network analyzer. The network analyzer measures the frequency response to determine the density of the pavement material.

A method for fabricating a Thin Film Bulk Acoustic Wave Resonator (FBAR). The method comprises the steps of: (A) forming a sacrificial layer comprising one of a metal and a polymer over a selected portion of a substrate; (B) forming a protective layer on the sacrificial layer and on selected portions of the substrate; (C) forming a bottom electrode layer on a selected portion of the protective layer; (D) forming a piezoelectric layer on a selected portion of the bottom electrode layer and on a selected portion of the protective layer; (E) forming a top electrode on a selected portion of the piezoelectric layer; and (F) removing the sacrificial layer to form an air gap. The use of a metal or a polymer material to form sacrificial layers has several advantages over the use of zinc-oxide (ZnO) to form such layers. In accordance with a further aspect of the invention, an FBAR is provided which includes a glass substrate. The use of glass to form substrates offers several advantages over the use of other materials to form substrates. By example, most types of glass are less expensive than semiconductor materials, and exhibit low permittivity characteristics, and low parasitic capacitances. In addition, most glass materials are substantially loss free when being used in microwave frequency applications.

An electrosurgical instrument for delivering radiofrequency (RF) electromagnetic (EM) energy and microwave frequency EM energy from a coaxial feed cable through an instrument tip into tissue. The instrument tip comprises a dielectric body separating first and second conductive elements, which act as active and return electrodes to convey the RF EM radiation by conduction, and as an antenna to radiate the microwave EM radiation. The instrument also has a fluid feed incorporated into its tip, e.g. in an additional dielectric element mounted on the underside of the tip, for delivering fluid. The delivered fluid may be a gas plasma to assist treatment or a liquid to plump up a tissue region before treatment. The instrument may fit in an endoscope.

The invention discloses a microwave sensor based on an NV color center diamond. A diamond internally containing a Nitrogen-Vacancy color center is adopted as a sensitive element, electronic energy level stimulation is achieved through lasers, an additionally-arranged static magnetic field is scanned, and the microwave frequency and the microwave intensity are measured through fluorescence intensity detection. Dependency of electronic rabi-flopping of the NV color center in the diamond on the external microwave magnetic field is brought into play, high theoretical accuracy and good stability are achieved, the microwave sensor has the advantages of being small in size, low in cost, high in accuracy, large in temperature range, simple in operation condition and the like and rotates on the basis of solid atoms, and the microwave sensor can serve in all the fields with the requirements for the low-cost high-accuracy microwave frequency and intensity detection in the future.

An RMS-to-DC converter implements the difference-of-squares function by utilizing two identical squaring cells operating in opposition to generate two signals. An error amplifier nulls the difference between the signals. When used in a measurement mode, one of the squaring cells receives the signal to be measured, and the output of the error amplifier, which provides a measure of the RMS value of the input signal, is connected to the input of the second squaring cell, thereby closing the feedback loop around the second squaring cell. When used in a control mode, a set-point signal is applied to the second squaring cell, and the output of the error amplifier is used to control a variable-gain device such as a power amplifier which provides the input to the first squaring cell, thereby closing the feedback loop around the first squaring cell. Accurate square law approximation at microwave frequencies can be achieved by implementing the squaring cells as series-connected three-transistor multi-tanh transconductance cells. By using carefully balanced squaring cells and a well-balanced error amplifier, approximation errors are cancelled and accurate RMS measurement is realized at high frequencies. A feedforward bootstrapping feature uses an op amp to balance the voltages at the common nodes of the transconductance squaring cells and also provides a balanced differential input drive to one of the squaring cells. A base current compensation circuit for providing accurate base compensation current to both of the squaring cells prevents errors due to DC offset voltages.