According to one embodiment, a communication device is described comprising an antenna, a signal path for supplying a signal to the antenna, two directional couplers arranged within the signal path, wherein each directional coupler is coupled to an adjustable impedance defining the characteristic impedance of the directional coupler, a controller configured to set, for each of a plurality of impedances, the adjustable impedances of the directional couplers to the impedance, a return loss measurement circuit configured to determine, for each of the plurality of impedances, a return loss of the signal path when the adjustable impedances of the directional couplers are set to the impedance and a load impedance determination circuit configured to determine a load impedance of the signal path based on the determined return losses.

A method and system of a method of measuring complex dielectric constant and permeability includes directing two polarizations onto a material under test and measuring one or more values of reflection coefficients. Further, the method includes integrating a p-wave reflection coefficient and a s-wave reflection coefficient and calculating, based on the measured one or more values of the reflection coefficients in association with a Brewster's angle, one or more of a complex dielectric constant and permeability.

A circuit assembly is provided for producing a test voltage for testing a test object, comprising two high voltage sources for producing a positive and negative high voltage of variable amplitude at respective outputs thereof and a high voltage switch assembly, which is arranged between the outputs of the two high voltage sources and the test object and which can be switched suitably in order to successively charge and discharge the test object, wherein furthermore a closed-loop controller is provided, which measures the present test voltage on the test object and acts on the high-voltage switch assembly in order to charge and discharge the test object in a defined manner in dependence on the measured test voltage.

The present invention relates to a method and monitoring device, for monitoring N number of transformer bushings operating in substantially the same environment. N being any number more than 1. The method comprises estimating an absolute value for the capacitances of each of the bushings, the absolute values for the capacitances being denoted C.sub.x, and estimating an absolute value for the loss factor or the power factor of each of the bushings, the absolute values for the loss factors or the power factors being denoted F.sub.x. X is a number representing which bushing the value is associated to and X larger than 1. The method further comprises calculating Δ-values for all C values and Δ-values for all F values, according to:

ΔC.sub.X=C.sub.X−C.sub.X+1, for all values up to, and including, ΔC.sub.N−1,

ΔC.sub.N=C.sub.N−C.sub.1, for ΔC.sub.N,

ΔF.sub.X=F.sub.X−F.sub.X+1, for all values up to, and including, ΔF.sub.N−1,

ΔF.sub.N=F.sub.N−F.sub.1, for ΔF.sub.N,

and determining whether the Δ-values are within predefined ranges.

The present disclosure relates to a detection circuit, an appliance, and a control method. The detection circuit includes at least a first capacitive component, a second capacitive component, a load to be detected and a detection component, where the first capacitive component is connected in series with the load to be detected to form a first branch, and the first branch is connected in parallel with a second branch including the second capacitive component. The detection component is configured to detect a first alternating current (AC) signal of the first branch and a second AC signal of the second branch, determine a first direction of the first AC signal and a second direction of the second AC signal, and determine a type of the load to be detected based on the first direction and the second direction.

A process includes reading a measurement result of a sum of a conductor loss and a dielectric loss for a signal at a predetermined frequency in each of first wiring-boards, respective wiring-widths and insulating-layer-thicknesses of the first wiring-boards being different, and an analysis result by three-dimensional electromagnetic field analysis of conductivity dependence of the conductor loss and the dielectric loss in each of second wiring-boards including same wiring-widths and insulating-layer-thicknesses as the wiring-widths and the insulating-layer-thicknesses of the first wiring-boards, obtaining a first ratio of conductor losses and a second ratio of dielectric losses between two second wiring-boards among the second wiring-boards, based on the analysis result, and obtaining a value of the conductor loss and a value of the dielectric loss for each of two first wiring-boards corresponding to the two second wiring-boards among the first wiring-boards, based on the first ratio, the second ratio, and the measurement result.

The present invention relates to diagnostic device for the characterization of electromagnetic material properties and a method of making and using same. Unlike current diagnostic devices, the disclosed diagnostic device comprises a novel waveguide system and is suitable for the characterization of electromagnetic material properties such as permittivity, permeability, and the loss tangent of materials over a broad temperature and pressure range.

Provided is a live measurement method for three-winding transformer loss based on windowed frequency shift. The method includes: step 1: providing an improved live calculation equation of a three-winding transformer loss; step 2: processing a collected x(t) signal by windowed frequency shift calculation; step 3: solving an amplitude and a phase of the collected x(t) signal via discrete Fourier transform of a frequency shift signal; and step 4: calculating a no-load loss and a load loss of a three-winding transformer.

An electrical measurement contacting system for use with a component testing system operable to convey devices includes: a first module including a test contact module having a test contact adapted to electrically contact devices conveyed by the component testing system, and a second module including circuitry electrically coupled to the test contact module and operative to perform an electrical measurement on devices conveyed to the test contact. The circuitry is connected, within the second module, to a first conductive path and a second conductive path. The first conductive path and the second conductive path extend into the first module. The first conductive path and the second conductive path are electrically connected to each other and to the test contact module in the first module.

Provided is a live measurement method for three-winding transformer loss based on windowed frequency shift. The method includes: step 1: providing an improved live calculation equation of a three-winding transformer loss; step 2: processing a collected x(t) signal by windowed frequency shift calculation; step 3: solving an amplitude and a phase of the collected x(t) signal via discrete Fourier transform of a frequency shift signal; and step 4: calculating a no-load loss and a load loss of a three-winding transformer.