1010results about "Dielectric property measurements" patented technology

A dual-band antenna matching system and a method for dual-band impedance matching are provided. The method comprises: accepting a frequency-dependent impedance from an antenna; and, selectively supplying a conjugate impedance match for the antenna at either a first and a second communication band, or a third and a fourth communication band. More specifically, the method comprises: tuning a first tuning circuit to a first frequency; and, simultaneously tuning a second tuning circuit to a second frequency. In response, a conjugate match is supplied to the antenna in the first communication band in response to the first frequency. Simultaneously, the antenna is matched in the second communication band in response to the second frequency. When the first tuning circuit is tuned to a third frequency, and the second tuning circuit is tuned to a fourth frequency, then conjugate matches are supplied for the third and fourth communication bands, responsive to the third and fourth frequencies, respectively.

A system and method is provided for full-duplex antenna impedance matching. The method comprises: effectively resonating a first antenna at a frequency selectable first channel in a first frequency band; generating a first antenna impedance at the first channel frequency; effectively resonating a second antenna at a frequency selectable second channel in the first frequency band; generating a second antenna impedance at the second channel frequency; supplying a first conjugate impedance match at the first channel frequency; and, supplying a second conjugate impedance match at the second channel frequency. For example, the first antenna may be used for transmission, while the second antenna is used for received communications. The antennas effectively resonant in response to: supplying frequency selectable conjugate impedance matches to the antennas; generating frequency selectable antenna impedances; and/or selecting the frequency of antenna resonance.

A sensor product for electric field sensing. The sensor includes a substrate, at least one electrically conductive area on the surface of the substrate, an output, and at least one conductor between the at least one electrically conductive area and the output. Also a sensor product web.

The sample measuring face of a dielectric resonator (20) is placed near a standard sample having a known dielectric constant at a fixed interval D. While appropriately varying the dielectric constant and thickness of the standard sample under the above condition, the variation of the resonance frequency of the dielectric resonator (20) is measured for each varied dielectric constant and thickness to draw a calibration curve of the varied resonance frequency depending on the dielectric constant and thickness. Under the same condition where calibration curve is drawn, the variation of the resonance frequency of the dielectric resonator (20) for a sample having a known thickness is measured. The dielectric constant of the sample is found from the measurement value and the calibration curve. The dielectric constant of not only a sheetlike sample but also a three-dimensional molded article or a liquid sample can be measured easily.

The invention discloses a cable operation state diagnosis system. The system realizes cable operation state diagnosis by measuring and analyzing cable broadband impedance spectrum data, and specifically includes three major functions: (1) cable overall operation state evaluation; (2) cable local Locating and diagnosing latent defects; (3) Rapidly locating permanent cable faults. The main components of the system are as follows: firstly, the cable initial characteristic parameter management module realizes the calculation of the initial characteristic parameters of the cable by inputting the cable geometric dimension data and the cable insulating material dielectric function data; then the cable broadband impedance spectrum measurement module automatically selects the appropriate frequency according to the cable length range, measure the broadband impedance spectrum of the head end of the cable under test; finally, the cable broadband impedance spectrum positioning analysis module analyzes and processes the initial characteristic parameters of the cable and the measured impedance spectrum data, so as to realize the evaluation of the overall aging state of the cable, the diagnosis of local latent defects of the cable and Cable permanent fault fast location function. The invention fills the gap of using the cable broadband impedance spectrum data to diagnose the running state of the cable at present, and has the characteristics of convenient use, high accuracy and no damage to the cable.

The invention provides a transformer oil-paper insulation frequency domain dielectric loss integral reduction method under different temperature. An oil-paper insulation moisture and aging test product is prepared, and the characteristic quantity-frequency domain dielectric loss integral of the dielectric loss cumulative value of a certain frequency domain section of the oil-paper insulation test product under five different temperature is measured by using an insulation diagnostic instrument IDAX-300; the maximum value of the dielectric loss integral area of the oil-paper insulation moisture and aging test product at the 0.1-10Hz frequency band is acquired, and the maximum value of the dielectric loss integral area acts as a characteristic parameter; and fitting of the measurement temperature and the maximum value of the frequency domain dielectric loss integral area is performed through the least square method so that an expression of the frequency domain dielectric loss integral and aging and wetting under different temperature is acquired. Conversion of the frequency domain dielectric loss integral characteristic quantity under different temperature can be effectively performed so that accurate analysis of the test result of the transformer oil-paper insulation system frequency domain dielectric loss integral under different environmental temperature can be realized, and the influence of the measurement temperature on the transformer insulation state assessment through the frequency domain dielectric loss integral characteristic quantity can be eliminated.

A preferred method for identifying a type of abnormality in an insulation system of a power transformer comprises measuring dielectric losses in a section of the insulation system, calculating theoretical dielectric losses for the section based on the material properties, geometry, and temperature of the section, and generating a graphical representation of a percent difference between the measured and calculated dielectric losses. The preferred method also comprises comparing a shape of the graphical representation with a shape of one or more graphical representations of a percent difference between measured and theoretical dielectric losses in one or more other sections of insulation each known to have a specific type of abnormality.

According to one embodiment of the present invention, a touch detection apparatus for a touch panel, including a plurality of sensor pads and signal wires connected to the plurality of sensor pads, respectively, is provided. The touch detection apparatus comprises a parasitic capacitance control unit for controlling the parasitic capacitance generated between a specific sensor pad which is to be an object of touch detection from among the plurality of sensor pads and another adjacent sensor pad. The parasitic capacitance control unit enables the output voltage of the specific sensor pad to be applied to another sensor pad connected to the signal wire that is adjacent to the signal wire of the specific sensor pad.

A detecting device includes a reading coil configured to read a magnetic flux generated by a detecting coil for detecting a magnetic field of an electromagnetic wave output from an exciting coil according to the magnetic field. The detecting device further includes a Q-value measuring section configured to measure a Q-value of the detecting coil on a basis of a temporal transition of oscillation of a voltage obtained in the reading coil according to the magnetic flux generated by the detecting coil.

Methods and apparatus for detecting the presence of undesirable foreign matter in a region between a wireless power transmission apparatus and a power reception apparatus are described. First and second detection methods, based on different detection schemes, may be used to detect and distinguish the presence of foreign matter from misalignment during power transfer operation. A first detection method may be used before power is transferred to a load in a power reception apparatus, and a second detection method may be used while power is supplied to the load.

The invention relates to the technical field of microwave testing, and particularly relates to a material dielectric constant testing system and a testing method based on the same. The material dielectric constant testing system comprises a coaxial resonant cavity and a control system, wherein the coaxial resonant cavity comprises a cavity body and a probe reaching out of the cavity body; the control system is used for providing microwave input signals for the coaxial resonant cavity, the probe forms an electromagnetic field outside the cavity body, and a to-be-tested sample changes microwave output signals for the coaxial resonant cavity through interference with the electromagnetic field; and the control system analyzes and calculates the microwave output signals before and after the to-be-tested sample is placed to obtain the dielectric constant of the to-be-tested sample. The material dielectric constant testing system has the advantages that the data processing is simple; the testing efficiency is high; and the probe reaching out of the cavity body carried out scanning-type detection on the to-be-tested sample, and the testing speed is quick. The invention also provides a testing method based on the above material dielectric constant testing system. The testing efficiency is high, and the testing speed is quick.

An apparatus for measuring component performance including a feed line having an input port and an output port, a first resonator connected to the feed line, and a first Josephson junction device connected to the first resonator and to ground.

The invention relates to a detecting device, power receiving device, contactless power transmission system, and detecting method. Disclosed herein is the detecting device including a coil electromagnetically coupled to the external coil, a resonant circuit that includes at least the coil, and a detecting section that superimposes a measurement signal for measuring the Q-factor of the resonant circuit on a power transmission signal transmitted to the coil in a contactless manner and removes the power transmission signal from an alternating-current signal obtained by superimposing the measurement signal on the power transmission signal. The detecting section measures the Q-factor by using the alternating-current signal from which the power transmission signal is removed.

A coil detection circuit thereof for an electromagnetic input device including a plurality of first loop coils and second loop coils includes a first detection unit, a second detection unit and a selection unit. When the selection unit selects one the first loop coils to emit an electromagnetic signal for each one of the second loop coils, each one of the second loop coils forms a second closed loop for receiving the electromagnetic signal, and the second detection unit detects a second signal. When one of the second loop coils forms an open circuit or short circuit, the second detection unit detects an open-circuit signal or a short-circuit signal.

The invention provides a system and method of testing complex dielectric constant of a material based on a gradient coaxial resonator. The system comprises the gradient coaxial resonator and a coupling device. The method comprises the steps: 1) testing and recording resonant frequency f0 and quality factor Q0 in a corresponding cavity working mode when no sample is loaded; 2) measuring diameter DSand thickness dS of a sample under test, placing the sample in a sample area, and testing and recording resonant frequency fS and quality factor QS in the corresponding cavity working mode when the sample is loaded; 3) using resonator perturbation theory to calculate complex dielectric constant of the material under test. The system and method have the advantages that high-precision testing of complex dielectric constant at normal temperature is achieved for a microwave dielectric material, required cavity size and sample size for low frequency testing can be reduced, a sealed-bottom tube clamp can also be used to test the complex dielectric constant of liquid and powdery materials.

A method for evaluation of cable aging degradation based on slice sampling is revealed. An insulation layer of a cable is aged or degraded from the outside in under influence of high temperature, liquid immersion, radiation exposure, or other factors. The present invention gets slices as samples of the cable by cutting from the outside in. Then related tests including dielectric withstand test, insulation resistance measurement, elongation test, etc. are carried out. Besides the state of cable aging degradation being of the slice being found out, different positions in the insulation layer such as an outer layer, a middle layer and an inner layer can also be evaluated.

Film thickness measurement systems and methods are provided that utilize a signal generator having a Gunnplexer design and a resonant frequency detector to correlate the shift in resonant frequency experienced by a resonant cavity having one face abutting a test object. The shift is resonant frequency is determinative of a linear or near linear correlation between film thickness and the resonant frequency shift.

The invention discloses an insulation aging evaluation method for a 110kV XLPE high-voltage cable. The method comprises the following steps: testing polarization current and depolarization current ofthe high-voltage cable in a polarization process and a depolarization process through polarization-depolarization current (PDC); obtaining a low-frequency dielectric loss factor under the corresponding polarization voltage according to the obtained polarization current and depolarization current; and evaluating the insulation performance of the high-voltage cable by taking variation of the low-frequency dielectric loss factor under different polarization voltages as a characteristic quantity for representing the insulation aging of the cable. Thus, the insulation aging state of the high-voltage cable can be diagnosed efficiently, and reflected more accurately, the sensitivity is high, and the method can be widely applied in the field of cable insulation aging diagnosis in future.