98results about How to "Low loss" patented technology

Light outputs from many LEDs are uniformized and power consumption required for such uniformizing is suppressed, in an LED lighting circuit to be used for illuminating apparatus and the like. Currents flowing from a DD converter to an LED module are detected by a current detection resistor and compared with a reference voltage (Vref) from a reference voltage source by a comparison circuit. Corresponding to the comparison results, a control circuit controls the DD converter, and the currents flowing to the LED module are controlled to be constant currents at the same time. Furthermore, in LED load circuits configuring the LED module, control elements configuring a current mirror circuit are arranged in series, a corresponding control element is permitted to have a diode structure by having a circuit with the highest sum of the LED ON voltages as a reference, the flowing current values of the control elements of the remaining circuits are interlocked, and the LED load circuits are balanced.

A logging system and method for measuring propped fractures and down-hole subterranean formation conditions including: a radar source; an optical source; an optical modulator for modulating an optical signal from the optical source according to a signal from the radar source; a photodiode for converting the modulated optical signal output from the optical modulator to the source radar signal. A transmitter and receiver unit receives the source radar signal from the photodiode and transmits the source radar signal via at least one antenna attached to the casing and in communication with at least one photodiode into the formation and receives a reflected radar signal. A mixer mixes the reflected radar signal with the source radar signal to provide an output. This can describe fractures connected to the wellbore and differentiate between the dimensions of the two vertical wings of a propped fracture.

A semiconductor device having a super junction MOS transistor includes: a semiconductor substrate; a first semiconductor layer on the substrate; a second semiconductor layer on the first semiconductor layer; a channel forming region on a first surface portion of the second semiconductor layer; a source region on a first surface portion of the channel forming region; a source contact region on a second surface portion of the channel forming region; a gate electrode on a third surface portion of the channel forming region; a source electrode on the source region and the source contact region; a drain electrode on a backside of the substrate; and an anode electrode on a second surface portion of the second semiconductor layer. The anode electrode provides a Schottky barrier diode.

In electric machines, core losses limit, at high fundamental frequency, the permissible full-load power. The aim of the invention is to develop a design which enables a high power density at high magnetic reversal frequencies and which is easy to produce. To this end, the primary part comprises coils which, for the majority of their length, run in the direction of movement and which are surrounded in this area on three sides by soft magnetic material. In the direction of movement, at least two coils are arranged one behind the other. Coils of different phase are arranged perpendicular to the direction of movement inside different running tracks. In the secondary part, at least two oppositely magnetized hard magnets with three collector segments, which are flatly adjacent in a manner that is perpendicular to the direction of movement, form magnet poles having a high flux concentration. The primary and secondary parts can be shifted with regard to one another in a manner that is perpendicular to the direction of movement by means of a mechanism. The machine is characterized by having an easily producible modular design which has low core losses also at high frequencies. A high power density and, at the same time, a large low-loss field control area is realized in compact dimensions.

The invention relates generally to an electric device, such as an electric motor, a generator, or a regenerative motor, having a wound stator core made from advanced low-loss material. In preferred embodiments, the electric device is an axial airgap-type configuration. The invention provides an electric device having a high pole count that operates at high commutating frequencies, with high efficiency and high power density. Advanced low-loss materials exploited by the present invention include amorphous metals, nanocrystalline metals, and optimized Si—Fe alloys.

In a semiconductor device having a pair of IGBT and diode which are connected to each other in inverse-parallel in which a collector-electrode of the IGBT and a cathode-electrode of the diode are wired to each other, and an emitter-electrode of the IGBT and an anode-electrode of the diode are wired to each other, when a breakdown voltage of a junction of a p-type emitter layer and an n-type buffer layer of the IGBT is represented as BVec, and a forward voltage occurring while the diode transits from a state of blocking to a state of forward conduction is represented as VF, a relationship of VF<BVec is satisfied in a predetermined current value Id of a current flowing in the diode, and the maximal doping concentration of the n-type cathode layer of the diode is higher than that of the n-type buffer layer of the IGBT.

Optical variable delay devices for providing variable true time delay to multiple optical beams simultaneously. A ladder-structured variable delay device comprises multiple basic building blocks stacked on top of each other resembling a ladder. Each basic building block has two polarization beamsplitters and a polarization rotator array arranged to form a trihedron; Controlling an array element of the polarization rotator array causes a beam passing through the array element either going up to a basic building block above it or reflect back towards a block below it. The beams going higher on the “ladder”experience longer optical path delay. An index-switched optical variable delay device comprises of many birefringent crystal segments connected with one another, with a polarization rotator array sandwiched between any two adjacent crystal segments. An array element in the polarization rotator array controls the polarization state of a beam passing through the element, causing the beam experience different refractive indices or path delays in the following crystal segment. By independently control each element in each polarization rotator array, variable optical path delays of each beam can be achieved. Finally, as index-switched variable delay device and a ladder-structured variable device are cascaded to form a new device which combines the advantages of the two individual devices. This programmable optic device has the properties of high packing density, low loss, easy fabrication, and virtually infinite bandwidth. The device is inherently two dimensional and has a packing density exceeding 25 lines / cm2. The delay resolution of the device is on the order of a femtosecond (one micron in space) and the total delay exceeds 10 nanosecond. In addition, the delay is reversible so that the same delay device can be used for both antenna transmitting and receiving.

An arrangement comprising a printed wiring board (210) having a number of electrical contact areas on a surface thereof (216) and one or more indents or apertures (218) residing next to the contact areas, one or more diffractive light guides (214) respectively positioned to said one or more indents or apertures (218) so that the one or more diffractive light guides (214) at least partly reside below the surface level of the printed wiring board (210), and at least one light source (212) positioned on or next to the printed wiring board (210) for emitting light to the one or more diffractive light guides (214). Also a keypad assembly utilizing the arrangement and various uses thereof are presented.

A slot antenna includes: a first electrically conductive member having a first electrically conductive surface; a second electrically conductive member having a second electrically conductive surface opposing the first electrically conductive surface; a waveguide member between the first electrically conductive member and the second electrically conductive member, the waveguide member having an electrically conductive waveguide face of a stripe shape opposing the first electrically conductive surface, the waveguide member extending in a first direction along the first electrically conductive surface; and an artificial magnetic conductor extending on both sides of the waveguide member, between the first electrically conductive member and the second electrically conductive member. The first electrically conductive member has one or more slots. At least one of the slot or slots is a complex slot having a pair of vertical portions and a lateral portion that interconnects the pair of vertical portions. The lateral portion of the complex slot opposes the waveguide face, and intersects the first direction.

Photonic integrated circuits (PICs) are based on quantum cascade (QC) structures. In embodiment methods and corresponding devices, a QC layer in a wave confinement region of an integrated multi-layer semiconductor structure capable of producing optical gain is depleted of free charge carriers to create a low-loss optical wave confinement region in a portion of the structure. Ion implantation may be used to create energetically deep trap levels to trap free charge carriers. Other embodiments include modifying a region of a passive, depleted QC structure to produce an active region capable of optical gain. Gain or loss may also be modified by partially depleting or enhancing free charge carrier density. QC lasers and amplifiers may be integrated monolithically with each other or with passive waveguides and other passive devices in a self-aligned manner. Embodiments overcome challenges of high cost, complex fabrication, and coupling loss involved with material re-growth methods.

An array antenna comprises a first substrate comprising a first plurality of ceramic layers; a second substrate comprising a second plurality of ceramic layers; a bottom ground plane stacked on the bottom of the second ceramic substrate; a plurality of quasi-cavity-backed patch antennas mounted on a top surface the first substrate, each of the patch antennas including a radiating element and two grounded grid-like conductor walls; and a mixed feeding network coupled to each of the patch antennas. The array antenna working at mm-wave frequency band can provide high radiation efficiency and low loss from feeding network by using quasi-cavity-backed patch elements and a mixed feeding network configuration.

A radar level gauge system is disclosed, having a transmitter for transmitting measuring signals towards the surface of the filling material, a receiver for receiving echo signals from said surface and a fastening structure adapted to secure said transmitter and receiver in a measuring position on a feed-through structure located in an upper boundary of said container. Further, a sealing unit is arranged between said fastening structure and said feed-through, and adapted to provide a pressure seal between the inside and the outside of the container, and in addition, there is provided means for blocking electromagnetic energy, adapted to block net transfer of electromagnetic energy between the inside and the outside of the container through said sealing unit.

Provided is an electrostatic transducer which is driven by a boosted driving signal by boosting a modulated signal obtained by modulating a carrier wave with an acoustic signal in an audio frequency band, the transducer including: an output transformer T which connects the electrostatic transducer to a secondary side winding thereof in parallel and boosts the modulated signal; and a resistor R and a coupling capacitance C1 connected in series to a primary side winding of the output transformer T, wherein a circuit constant of a primary side circuit of the output transformer T including a serial circuit of the resistor R and the coupling capacitance C1 and a circuit constant of a secondary side circuit of the output transformer including a self-inductance L2 and a load capacitance CL of the secondary side winding of the output transformer T are set such that a resonance frequency f0 of a circuit formed by the self-inductance L2 of the secondary side winding of the output transformer T and the load capacitance CL of the electrostatic transducer is matched or approximately matched to a carrier wave frequency fc of the electrostatic transducer.

In order to provide a SAW filter having a wide passband matching to the digital TV broadcast waves so as to be low-loss, and obtaining a sharp and large attenuation in the outside of the TV broadcast waves, a constant-K filter is composed of series arm SAW resonators and parallel arm SAW resonators, and a circuit component is formed by connecting an inductor for shifting a resonant point / antiresonant point to the series arm SAW resonator in series or to the parallel arm SAW resonator in parallel. A plurality of the circuit components are connected in a cascade connection to each other in a plurality of stages via inductors for shifting the resonant point / antiresonant point.

The invention relates to a thermosetting resin composition and a prepreg and a laminate for printed circuits thereby. The thermosetting resin composition comprises at least an epoxy resin of the structural formula (I) and a cyanate resin. The thermosetting resin composition of the invention has high heat resistance, low dielectric constant and low dielectric dissipation factors, thus being used for manufacturing the resin sheets, resin composition copper foils, the prepregs, the laminate and the printed circuit boards. R is (a), and n and m are natural numbers.

The invention provides a metamaterial substrate and a preparation method thereof. A metamaterial substrate with hollow microspheres is prepared by using a microsphere foaming agent, and the density and dielectric constant of the substrate are reduced by introducing air; a material with thermoplastic polymer as a main body is used as the substrate, which has a light mass, a small dielectric constant, low loss, and wide application fields when compared with hard ceramic materials; By controlling the ratio of the microsphere foaming agent and selecting microsphere foaming agents with different expansion ratios, metamaterial substrates with different dielectric constants can be prepared, and the application is expanded.

A distributed arbitrary waveform generator (DAWG) synthesizes the target waveform using a series of narrow pulses generated by a number of pulse generators. To achieve this, it uses an input trigger signal to control all the pulse generators, each of which generates a narrow pulse (impulses) at a specific sample time, and then all the impulses are combined to generate the output waveform. The input trigger signal is distributed to each pulse generator by a trigger distribution network. Impulses generated by pulse generators can be tuned in both pulse amplitude and width, and the spacing between them can be tuned by the trigger distribution network. Therefore the waveforms generated are completely reconfigurable.

A system of reflectors is used to form beam-expanding and collimating electro-optic transducer devices, including radiation sources and / or detectors. Preferably, the reflector system is of the Cassegrainian or Ritchey-Chretien type. Radiation such as light signals can be conducted to or from the transducers by fiber-optic cables. Alignment of optical conductors or “cores” of the fiber-optic cables or the reflector system with a transducer is provided by coupling a magnetic member to the conductor or reflector system and applying a controllable magnetic field from outside of the device to provide alignment, and then fixing the components in place by the use of means such as light-curable epoxy resin.

The invention relates generally to a nanolaminate structure involving Al2O3 thin films as a main component. The nanolaminate is used between a top electrode and a bottom electode to form a capacitor. The naonolaminate layer comprises alternating layers of Al2O3 and TiO2 and an interfacial layer.

A frequency-variable high frequency filter comprises: a substrate; a ground conductor having an opening provided on one principal surface of the substrate; a center conductor provided in the opening to make up a coplanar line resonator with the substrate and the ground conductor; an input line and an output line provided on the other principal surface of the substrate and electromagnetically coupled with the center conductor; and a variable reactance element. The center conductor is divided into two conductor section at the position of the null point of the voltage displacement of a standing wave created in the coplanar line resonator so that the two conductor sections are separated in the longitudinal direction of the center conductor. The variable reactance element is inserted in the center conductor to connect the two conductor sections of the center conductor.

A control method for a PWM cyclo-converter is provided in which a voltage can be accurately generated even when a voltage command is small.In the PWM cyclo-converter, the turning on and off operations of two-way semiconductor switch are repeated at intervals of short time. As switching patterns, within the intervals of short time, a first terminal of output side terminals outputs in order a maximum potential phase P, an intermediate potential phase M and the maximum potential phase N, a second terminal of the output side terminals outputs in order the maximum potential phase P, the intermediate potential phase M, a minimum potential phase N, the intermediate potential phase M and the maximum potential phase P, and a third terminal of the output side terminals outputs in order the intermediate potential phase M, the minimum potential phase N and the intermediate potential phase M.

The invention belongs to the technical field of building materials and in particular relates to a sintered water permeable brick prepared by taking a ceramic waste material as a main material and a preparation method thereof. The sintered water permeable brick is prepared from the following raw materials in parts by weight: 40 to 60 parts of the ceramic waste material, 25 to 55 parts of ceramic polishing dreg and 5 to 15 parts of kaolin. The preparation method of the sintered water permeable brick comprises the following steps: (1) adding water and mixing the ceramic waste material, the ceramic polishing dreg and the kaolin to obtain a mixture; (2) transferring the mixture treated by the step (1) into a brick pressing machine, and pressing and molding to form a water permeable brick blank; (3) drying the water permeable brick blank obtained by the step (2) to control the moisture content of the water permeable brick blank to be lower than 3 percent; (4) transferring the water permeable brick blank treated by the step (3) into a kiln and sintering; cooling to room temperature along the kiln to obtain the sintered water permeable brick. The water permeable brick is simple in composition and low in cost; the preparation method is simple and the problems that the comprehensive utilization efficiency of the ceramic waste material is low and the environment is polluted are solved.

The invention belongs to the technical field of spatial filtering, and particularly relates to a three-way bandwidth frequency band frequency selecting surface structure and an antenna cover. The antenna cover can serve as the antenna cover of a multi-frequency antenna of communication systems, such as radar and a satellite. The three-way bandwidth frequency band frequency selecting surface structure comprises a layer medium substrate, and two layers of same frequency selecting surfaces which are positioned on the upper side and the lower side of the layer medium substrate, wherein each frequency selecting surface consists of patch units which are arranged periodically; each patch unit comprises a square patch of which the four sides are cut into notches; the notches are rectangular openings, are positioned on the axes of the square, are in two-to-two correspondence and are not communicated with one another; a rectangular wave-shaped metal line extends from each rectangular opening; each metal line is connected with the metal lines of adjacent patch units on the periphery; the metal lines are positioned on the two symmetry axes of the square. The antenna cover is mounted out of an antenna or an antenna array; an electromagnetic valve incident plane of the antenna cover is formed by the three-way bandwidth frequency band frequency selecting surface structure.

A high power, TEM mode directional microwave coupler having low loss and expanded bandwidth uses novel thick suspended substrate conductors to provide multi-octave bandwidth performance in a practical package. Each of two center conductors is formed using metal layer deposited onto three surfaces of a thick dielectric substrate. The conductors, which can be edge-coupled or offset-coupled, form a novel structure in which the non-metallized side of the substrate is oriented toward the facing outside vertical walls. This effectively reduces the effect of the package wall on the coupling structure, permitting a smaller, constant-width dimension, which in turn raises the waveguide cut-off frequency. The result is a directional coupler with an extended high frequency performance, with reduced physical size and low loss.

The invention belongs to the technical field of spatial filtering and discloses a light-controlled polarization reconfigurable frequency selective surface unit structure and a radar communication radome. The light-controlled polarization reconfigurable frequency selective surface unit structure comprises an intermediate three-layer dielectric substrate, two layers of patches with different structures on the upper and lower sides of the dielectric substrate, two light-controlled microwave switches on a lower layer patch, and a metal pillar which is connected to the upper and lower layer patchesand passes through the dielectric substrate, wherein an I-shaped slit is formed at the right side of a metal layer according to an upper layer patch structure, two mutual perpendicular T-shaped slitsare formed in the metal layer, two light-controlled microwave switches are loaded to the two T-shaped slits, and the ON and OFF of the light-controlled microwave switches are controlled by introducing laser with fibers. According to the invention, on one hand, the effect of spatial filtering can be achieved, and on the other hand, the 0-degree and 90-degree polarization reconfigurable functions of the antenna can be achieved.

The invention relates to an epoxy resin and a preparation method thereof. The epoxy resin has the following structural formula (I). The preparation method can adopt a one-step method, namely directlycondensing the mixture of hydroxystyrene / styrene copolymer and epihalohydrin in the presence of alkali to obtain the epoxy resin, and also can adopt a two-step method, namely firstly etherifying the hydroxystyrene / styrene copolymer and epihalohydrin in the presence of catalysts and then closing loop in the presence of alkali liquor. The epoxy resin of the invention has high heat resistance, low dielectric constant and low dielectric dissipation factors, thus being used for manufacturing the resin sheets, resin composition copper foils, the prepregs, the laminate and the printed circuit boards.R is shown in (II), and n and m are natural numbers.

There is provided a signal dividing device (10) for use in a co-axial network used for distributing signals within the home, the signal dividing device (10) comprising an impedance transformer (12), a first (14) and a second (16) two-way signal splitter, each two-way signal splitter having an input, and first and second outputs. The output (22) of the impedance transformer is connected to the input of the first and the second signal splitter, the other port (20) of the impedance transformer being connected to earth. Resistive elements (32, 34) are connected between the outputs of the first and second signal splitters respectively. A diplex filter (40) may be connected at the input (18) of the impedance transformer (12).

The invention provides a line loss optimization method for a parallel alternating-current and direct-current system. The method comprises the following steps: (1) calculating the loss rate xii of transmitting power of a direct-current transmission line; (2) calculating the loss rate etai of a direct-current system; (3) establishing a minimum direct-current loss value optimization model fmincon(x); and (4) establishing a minimum total rate loss value optimization model fmincon(y) of the parallel alternating-current and direct-current system. The line loss optimization method is applied to a parallel alternating-current and direct-current cross-regional transmission system; a minimum alternating-current and direct-current total rate loss value optimizing model is established between an alternating-current power transmission system and a direct-current power transmission system; the optimal power distribution of the alternating-current system and the direct-current system can be accurately calculated; and the minimum power total loss and total loss rate of the cross-regional transmission system are achieved.

The invention discloses a lifting type wireless control turnover throwing machine which comprises a local / long-range control mainframe, a trackless or track lifting type turnover throwing machine body and a programmable logic controller (PLC) module and an industrial wireless communication module, wherein the PLC module and the industrial wireless communication module are arranged on the lifting type turnover throwing machine body in a matching way; the PLC module is used for acquiring the actuating signal of the lifting type turnover throwing machine body in real time and transmitting the acquired actuating signal into the local / long-range control mainframe; the PLC module is also used for acquiring the command of the local / long-range control mainframe and controlling the lifting type turnover throwing machine body according to the command to execute the corresponding action; and the industrial wireless communication module is used for realizing the signal transmission between the PLC module and the local / long-range control mainframe. The lifting type wireless control turnover throwing machine overcomes the defects of high mechanical loss, poor rigidity, high labor intensity of workers, low working efficiency and the like in the prior art, thus realizing the advantages of low mechanical loss, good rigidity, low labor intensity of the workers and high working efficiency.