1098 results about "Wave transmission" patented technology

A millimeter-wave transmitter-receiver uses an NRD guide as a fundamental configuration and includes a millimeter-wave signal oscillator, a pulse modulator, a circulator, an antenna and a mixer. In the millimeter-wave transmitter-receiver, a line length of a third dielectric guide is set so that δ=±π in which δ is a phase difference at a center frequency between a portion of a transmission millimeter-wave signal, which is reflected via a third dielectric guide on the leading end portion of the third dielectric guide and returned to leak to a third connecting portion of the circulator, and another portion of the millimeter-wave signal, which leaks from a first connecting portion to the third connecting portion of the circulator. It is possible to reduce the change in the mixer output and enhance the millimeter-wave transmission/reception performance.

An improved E-field generator including a slow-wave transmission line structure is provided herein. In some cases, the improved E-field generator may include an inductively-loaded slow-wave transmission line structure driven by a power source at one end of the structure and terminated by a load at the other end of the structure. In other cases, the improved E-field generator may include a capacitively-loaded slow-wave transmission line structure. In either case, the improved E-field generator provides a frequency-independent, significantly increased electric field at a distance spaced from the generator without altering the dimensions of the generator and/or the input power supplied to the generator. The increase in generated field intensity is achieved by decreasing the phase velocity of the electromagnetic wave propagating along the parallel elements of the generator.

An ultrasonic probe deployment device in which an ultrasound-transmitting liquid forms the portion of the ultrasonic wave path in contact with the surface being inspected (i.e., the inspection surface). A seal constrains flow of the liquid, for example preventing the liquid from surging out and flooding the inspection surface. The seal is not rigid and conforms to variations in the shape and unevenness of the inspection surface, thus forming a seal (although possibly a leaky seal) around the liquid. The probe preferably is held in place to produce optimum ultrasonic focus on the area of interest. Use of encoders can facilitate the production of C-scan area maps of the material being inspected.

A transmitting apparatus in a TDD wireless communication system is provided. In the transmitting apparatus, a circulator transmits a signal received from a power amplifier to an antenna feed line and transmits a signal received from the antenna feed line to a quarter-wave transmission line. The quarter-wave transmission line is installed in a reception path, for reception isolation in a transmission mode. An RF switch shorts the load of the quarter-wave transmission line to the ground or connects the load of the quarter-wave transmission line to an LNA according to a control signal. The LNA low-noise-amplifies a signal received from the RF switch.

Embodiments disclosed herein may generate and transmit power waves that, as result of their physical waveform characteristics (e.g., frequency, amplitude, phase, gain, direction), converge at a predetermined location in a transmission field to generate a pocket of energy.

An example method disclosed herein includes: receiving, by a transmitter, from a tagging device, a first device tag containing first data indicating a first location of a first receiver. The method also includes: determining, by the transmitter, one or more characteristics of one or more first power waves to be transmitted to the first receiver based upon the first data indicating the first location as contained in the first device tag. The method additionally includes: transmitting, by the transmitter, the one or more first power waves having the one or more characteristics to the first location indicated by the first device tag.

A transmission power control device is provided that includes: a transmission loss calculator that calculates a transmission loss in the electric wave transmission path between a mobile station and each base station; and a transmission power control information determiner that determines which transmission power control information is to be used in a transmission power control operation at the mobile station, based on transmission power control information transmitted from each base station to the mobile station and the transmission loss in the transmission path between the mobile station and each base station calculated by the transmission loss calculator. This transmission power control device may further include an autonomous controller that increases transmission power from a current value in accordance with predetermined characteristics, regardless of transmission power control information from another communication device, when reception signal quality has become lower than a predetermined quality level. With this structure, after synchronization with a signal from the base station is established at the mobile station, the transmission power is controlled to increase from the initial value in accordance with the predetermined characteristics, regardless of the transmission power control information transmitted from the base station.

A vehicle including a ground speed sensor arranged to detect the speed of travel of the vehicle on the ground and including a wave transmitter arranged to transmit waves toward the ground, a wave receiver arranged to received waves reflected from the ground and a processor coupled to the transmitter and receiver to determine the speed of travel based on the transmitted waves and received waves. The waves are transmitted in pulses or modulated such that the processor is able to determine the distance between a wave-transmission and reception point and the ground (by time of flight for ultrasonic and electromagnetic waves or phase difference-for electromagnetic waves) and the velocity of the vehicle (using Doppler analysis).

A capacitive micromachined ultrasonic transducer having an ultrasonic wave transmission/reception surface formed by arranging a plurality of transducer cells each of which includes a membrane having a first electrode and a supporting film for supporting the first electrode, and also includes a second electrode arranged being opposite to the first electrode and being spaced apart from the first electrode at a prescribed interval, wherein: the transducer cells are arranged on the basis of resonant frequencies of the transducer cells.

The invention discloses a measurement system of a relative altitude and a relative attitude of an air vehicle and a measurement method thereof. Four ultrasonic ranging modules are installed at different positions of the air vehicle, ultrasonic wave emitting and receiving of the ultrasonic ranging modules are controlled through an MPU, ultrasonic wave transmission time is calculated, pressure parameters, temperature parameters and humidity parameters of atmosphere are collected so that the transmission speed of the ultrasonic waves can be compensated, meanwhile by means of a range error compensation module, range errors of an ultrasonic ranging sensor are compensated, relative height data of the air vehicle and the ground are measured, a relative height calculation model and a relative attitude calculation model are built, and the precise relative height between the centers of wings of the air vehicle and a landing runway plane and attitude angle information of an ultrasonic installation plane relative to the runway plane are calculated. The measurement system and the measurement method improve precision and stability of measurement of the relative height and the relative attitude during landing of the air vehicle.

The invention discloses a distributed fault location method for an overhead line-cable hybrid circuit. The method comprises the following steps: S1, arranging fault traveling wave detection devices at the joint of the hybrid circuit and a bus and the joints of different circuits in the hybrid circuit, judging a failed circuit according to the polarity of a first fault travelling wave head detected by each fault traveling wave detection device, wherein when fault current travelling wave heads detected by two adjacent fault travelling wave detecting devices are of opposite polarities, a circuit between the two adjacent fault travelling wave detection device is the failed circuit; and S2, judging the source of a second travelling wave head according to the arriving time of the fault travelling wave heads detected by the fault travelling wave detection devices at the two ends of the failed circuit, and selecting a proper fault location method for positioning. According to the distributed fault location method, online calculation of the travelling wave transmission speed of a power transmission line is realized, and the source of a second fault travelling wave of a detection point is judged according to the analysis of a travelling wave sequence; and the method has a good application prospect.

An ultrasonic transducer is provided with a distance measuring ultrasonic sensor for detecting a distance between the ultrasonic transducer and a surface of an inspection object and an inclination of the ultrasonic transducer with respect to the surface of the inspection object, to control the distance and the inclination of the ultrasonic transducer with respect to the inspection object based on information detected by the distance measuring ultrasonic sensor, and at least part of ultrasonic wave transmission/reception by the distance measuring ultrasonic sensor is performed during execution of aperture synthesis processing during which transmission/reception by the ultrasonic transducer is not performed.

The invention discloses a method for preparing a wave-transmission SiO2 aerogel heat-insulation composite material by using normal-pressure drying equipment. According to the method, tetraethoxysilane used as a precursor and absolute ethanol used as a solvent are subjected to acid-alkaline two-step reaction under the action of a catalyst so as to obtain SiO2 sol; and the SiO2 sol is mixed with quartz fiber, and the wave-transmission SiO2 aerogel heat-insulation composite material is prepared by the steps of performing gelling on the mixture of the SiO2 sol and the quartz fiber, aging, performing solvent replacement and surface modification, and performing gradient heating under normal pressure. The method for preparing the wave-transmission SiO2 aerogel heat-insulation composite material by using the normal-pressure drying equipment is easy to operate; equipment is simple; compared with a supercritical drying method, the method for preparing the wave-transmission SiO2 aerogel heat-insulation composite material by using the normal-pressure drying equipment has the advantage that the cost is reduced greatly; by the method, the composite material can be produced on a large scale conveniently; and a product has good wave transmission performance, heat insulation performance and the like, and has extremely obvious application value in military industry of long-endurance and high-mach aviation aerospacecrafts and the like.

The invention relates to a cement base composite wave-adsorption material and relative preparation, belonging to the cross technique field between materials science and microwave technique. The invention is characterized in that the invention uses organic and inorganic hollow wave-transmission balls with low dielectric constant to fill a cement base to improve the resistance match of the base, and coat an uniform conductive coat on the surface of the wave-transmission balls, and stuffs wave absorber or the like to improve the adsorption of base on electromagnetic wave. The inventive wave-adsorption material is in single-layer or dual-layer structure, while the match layer and adsorption layer of dual-layer structure are respectively stuffed with wave-transmission balls or wave absorber in different ratios to gradually change the resistance, and the two layers are combined tightly to improve the wave adsorption. The invention has the advantages of that the improved resistance match and gradual structure can absorb electromagnetic wave in wide frequency range, the light wave-transmission balls can reduce the specific weight of material, and the wave-transmission balls are packed by cement slurry to improve the stability and durability of material.

The invention provides an accident influence range analysis method and system based on dynamic traffic information. The method comprises the following steps: (101) whether a road segment is jammed is judged, the road segment is jammed if the current traffic capacity of the road segment is smaller than real-time traffic flow of the road segment, and a step (102) is executed; (102) a jam starting wave transmission speed is calculated, the transmission time of a jam wave in any road segment I is calculated, and an accident influence range, accident influence duration and a jam transmission path are estimated on the basis of the obtained jam starting wave transmission speed and the obtained transmission time of the jam wave in any road segment. According to the accident influence range analysis method and system based on the dynamic traffic information, dynamic traffic data are combined with road network data to realize urban road traffic accident influence range prediction, and therefore targeted prediction can be conducted on a specific accident. A coil, floating car and other data serve as predicted data and are input, the data are high in accuracy, and therefore the accuracy of a prediction result is guaranteed in terms of predicted data bases.

An ultrasonic flaw detection method for detecting a flaw which inspects a raceway surface 4a of an outer ring 4 as a surface to be inspected. After the surface to be inspected has finished undergoing finish grinding, a flaw is ultrasonically detected while liquid hydrocarbon 2 including kerosene is taken as an ultrasonic wave transmission medium.

A ultrasonic cleaning method is provided that performs ultrasonic cleaning without breaking a small and low-strength article-to-be-cleaned. It is a ultrasonic cleaning method that performs ultrasonic cleaning of an article-to-be-cleaned by a combination of a ultrasonic wave transmission medium and particles having a larger specific gravity than the ultrasonic wave transmission medium. The article-to-be-cleaned is cleaned by allowing at least a part of the article-to-be-cleaned to be in contact with a cleaning layer formed with the ultrasonic wave transmission medium and the particles where the mixing ratio of the particles to the ultrasonic wave transmission medium is 10 to 60 vol %, and imparting a ultrasonic wave to the cleaning layer. The particles mutually restrict their movements in a particle group thereby preventing the kinetic energy from becoming excessively large, and exhibit a frictional force and an impinging force suitable for removing the contaminant adhering to the surface without breaking the low-strength article-to-be-cleaned.

The invention discloses a frequency selective absorbing body for intermediate frequency broadband wave transmission and high frequency and low frequency wave absorbing. The body includes a periodically selected frequency selective wave absorbing unit, wherein the frequency selective wave absorbing unit includes a first metal layer, a first dielectric layer, an air layer, a second metal layer, a second dielectric layer, a third metal layer, a third dielectric layer and a fourth metal layer which are sequentially disposed, the first metal layer includes four sets of cross-toe structures surrounding a square, a set of cross-toe structures are on one side of the square, the adjacent sets of cross-toe structures are connected by a lumped resistor, each set of cross-toe structures includes three cross-toe units, and two adjacent toe units in each set of cross-toe structures are connected by metal lines. The body is advantaged in that the structure is simple, processing is easy, cost is low, and wider transmission frequency band width and smaller transmission insertion loss can be obtained.

The invention discloses a metamaterial antenna housing, including a polarization rotation metamaterial layer, a honeycomb structure layer and a frequency selection surface layer. The polarization rotation metamaterial layer includes a first dielectric substrate and a first metal structure layer; the frequency selection surface layer includes two second dielectric substrates, a second metal structure layer, a third metal structure layer and a fourth metal structure layer; and the first dielectric substrate and the second metal structure layer are attached to surfaces of two sides of the honeycomb structure layer respectively. Therefore, through arrangement of the polarization rotation metamaterial layer, the honeycomb structure layer and the frequency selection surface layer, the metamaterial antenna housing provided by the embodiment of the invention can realize efficient wave transmission of electromagnetic waves in a radome working band on the frequency selection surface, the metamaterial layer can be utilized to rotate the polarization direction of reflected electromagnetic waves out of the working band, mismatch of polarization modes of the reflected electromagnetic waves and energy detection electromagnetic waves is caused, thereby achieving the purpose of invisibility to an energy detection radar system, and thus the metamaterial antenna housing has important application prospects.

An ultrasonic endoscope comprises an insertion portion comprising a distal hard portion which has: an endoscopic observation unit; and an ultrasonic observation unit having ultrasonic transducers arranged circumferentially on an outer circumferential section of the distal hard portion, wherein the ultrasonic observation unit comprises an ultrasonic-wave transmission/reception unit having an tunnel-shaped path which has an inner circumferential surface formed as a backing layer; a distal block is arranged on a distal side in an axial direction of the distal hard portion with respect to a location where the ultrasonic-wave transmission/reception unit is arranged, and distal ends of respective members constituting the endoscopic observation unit are fixed to the distal block; and part of the members which constitute the endoscopic observation unit are fitted so as to be partially protruded from an inside diameter of the tunnel-shaped path toward an outer circumferential side thereof.