Abstract: Ceramic particles for use in a solar power tower and methods for making and using the ceramic particles are disclosed. The ceramic particle can include a sintered ceramic material formed from a mixture of a ceramic raw material and a darkening component comprising MnO as Mn2+. The ceramic particle can have a size from about 8 mesh to about 170 mesh and a density of less than 4 g/cc.

Abstract: A measuring assembly for detecting intermodulations which limits the source of the intermodulations includes a first measuring device including a signal generation device and a signal measuring device. The signal generation device is designed to generate test signals and to output the test signals at an output connection, and the signal measuring device is designed to measure signals that are applied at the output connection. The assembly further includes a second measuring device with an input connection and a signal measuring device. The signal measuring device of the second measuring device is designed to measure signals that are applied at the input connection. The assembly further includes a directional coupler coupled to the first measuring device and the second measuring device.

Abstract: The present application is directed to an electrical system including a housing configured to hold electrical components within an internal volume. In one aspect the electrical system is a power transformer. A sensor is mounted to the housing and is configured to sense a parameter associated with one or more electrical components during operation of the electrical system. A control system including a communication unit and a data processing unit is operable for analyzing the sensed parameter and comparing the sensed parameter to a predetermined minimum or maximum threshold value.

Abstract: A high-frequency 5 measurement method includes generating a test signal (TS), which is a sine-wave signal having a predetermined frequency, in which a period (?) during which the power level is at a first power level and a period (T-?) during which the power level is at a second power level lower than the first power level 10 are periodically repeated, inputting the test signal (TS) to a device under test (10) as an input signal, and measuring the difference between an output signal (OUT) of the device under test (10) and an ideal value of the output signal (OUT).

Abstract: In general, the subject matter described in this disclosure can be embodied in methods, systems, and program products for changing the manner in which an input signal is filtered based on a characteristic of an electronic test instrument. The method includes receiving, by the electronic test instrument, user input that modifies a characteristic of a channel of the electronic test instrument, and as a result changing the electronic test instrument from having the first digital filtering configuration to having a second digital filtering configuration, the first digital filtering configuration specifying that all or a majority of digital filtering occurs after the acquisition memory in the channel and the second digital filtering configuration specifying that all or a majority of digital filtering occurs before the acquisition memory in the channel.

Abstract: A spinal management system includes a stabilizing member adapted to extend substantially longitudinally along a target region of a spine tending to exhibit a defective curvature and a set of stabilizing anchors adapted for fixation to vertebrae and to receive the stabilizing member to secure the stabilizing member against substantial transverse translation relative to the vertebrae. The system also includes a first correction anchor adapted for fixation to a vertebra, a second correction anchor adapted for fixation to a vertebra, and a connection between the stabilizing member and the first correction anchor and between the first and second correction anchors adapted such that when the connection is tensioned a compressive force is selectively exerted between the first and second correction anchors.

Abstract: The description is of a circuit which, according to one example embodiment, comprises the following: an input circuit node for receiving an RF oscillator signal; a test signal generator circuit, which comprises at least one modulator and which is embodied to generate an RF test signal by modulating the RF oscillator signal. Further, the circuit comprises at least one receive channel with a receiver circuit and a coupler, which is embodied to feed the RF test signal into the receiver circuit.

Abstract: A method, system and computer program product are provided for implementing frequency spectrum analysis of noise in a device under test using causality (Hilbert Transform) results of Vector Network Analyzer (VNA) VNA-generated S-parameter model Information. A plurality of S-parameter samples are collected from the VNA generated S-parameter model Information. A Hilbert Transform of the collected plurality of S-parameter samples is used for error magnitude per frequency point analysis. An average error magnitude of predefined collected error magnitude samples is calculated to identify environmental noise in the device under test and used to identify acceptable environmental effects on the device under test.

Abstract: A testing method or apparatus utilizes filter banks to measure time varying or dynamic harmonic distortion or intermodulation distortion from a device. With a stairstep or arbitrary signal and filter banks, Nth order harmonic and or intermodulation distortion is measured via the filter banks at different offsets provided by an arbitrary low frequency signal. An amplifier with crossover distortion will show increased harmonic and or intermodulation distortion near the zero crossing while providing less distortion in other portions of the transfer curve of the amplifier. One or more distortion signals from the device (e.g., audio device) may be measured for a phase and or frequency modulation effect.

Abstract: A testing method or apparatus utilizes filter banks to measure time varying or dynamic harmonic distortion or intermodulation distortion. With a stairstep signal and filter banks, Nth order harmonic and or intermodulation distortion is measured via the filter banks at different offsets provided by an arbitrary low frequency signal. An amplifier with crossover distortion will show increased harmonic and or intermodulation distortion near the zero crossing while providing less distortion in other portions of the transfer curve of the amplifier.

Abstract: Certain aspects of the present disclosure provide methods and apparatus for generating a two-tone signal for performing linearity calibration of a radio frequency (RF) circuit. One example apparatus generally includes a tone generating circuit configured to generate a first single-tone signal from a digital clock signal and a mixer connected with the tone generating circuit and configured to mix the first single-tone signal with a second single-tone signal to provide a two-tone signal having frequencies at a sum and a difference of frequencies of the first and second single-tone signals.

Abstract: A system for measuring passive intermodulation (PIM) comprises a port connectable with a load and a PIM source, a test signal source providing a test signal having components of two or more frequencies, and a receiver including a phase-coherent detector to receive a reflected signal obtained at the port in response to the provided test signal. The phase-coherent detector has an output that provides a signal indicative of PIM. A reference signal source connected with the phase-coherent detector provides a reference signal derived from the test signal. A signal combiner having a first input connected with the output of the phase-coherent detector, a second input connectable with storing a measurement of residual PIM generated by the apparatus, and removes the residual PIM from the signal indicative of PIM and provides measured PIM of the PIM source at the output.

Abstract: An embodiment of a system for determining a distance and magnitude to one or more unknown passive intermodulation (PIM) sources associated with a network under test comprises a scalar PIM measuring instrument and a reference PIM source. The scalar PIM measuring instrument has an output frequency that is systematically changeable to produce a series of response signals of varying frequency and the reference PIM source is configured to introduce a reflected signal to the scalar PIM measuring instrument in response to the output frequency. The scalar PIM measuring instrument can perform data processing algorithms allowing the extraction of distance and magnitude information about the unknown PIM sources located along the network under test from scalar data received by the scalar PIM measuring instrument. The scalar data received by the scalar PIM measuring instrument represents a combination of signals from the unknown PIM sources and the reference PIM source.

Abstract: A passive intermodulation test device includes a first signal generator that generates a first signal and a second signal generator that generates a second signal. A combiner combines the first signal and the second signal to generate a combined signal. A duplexer receives a test signal based, at least in part, on the combined signal and filters the first signal and the second signal from the test signal to generate an intermodulation signal. A variable low-noise amplifier amplifies the intermodulation signal in accordance with a variable gain based at least in part on a selected power level. A receiver, upon receipt of the intermodulation signal, measures intermodulation generated by a device under test.

Abstract: A testing method or apparatus utilizes multiple frequencies applied to a device under test for measuring newly discovered frequency modulation effects. An embodiment may include a lower frequency signal with a smaller amplitude higher frequency signal to test a dynamic change in frequency response, gain, and or phase. This dynamic test can reveal frequency modulation effects. Another embodiment may include the use of a multiple frequency signal or a modulated signal such as an amplitude modulated to dynamically induce a time varying phase or frequency distortion for the device that has differential phase distortion.

Abstract: The present invention is directed to an apparatus and methodology for performing spurious-free dynamic range (SFDR) measurements on an RF circuit, such as a mixer, using a single analog input port. The present invention is designed for use when access to the intermediate frequency (IF) port in a radio frequency (RF) front-end circuit is not available, when the traditional two-port method for making an SFDR measurement is inadequate. Passing the analog input through a directional coupler between the RF combiner and the mixer facilitates the performance of the traditional third order intermodulation (IMD) test. Key differences between the single-port and traditional two-port setups are considered and examined, and experimental data obtained using the single-port setup is compared to data obtained using the traditional two-port set-up for different mixer models. Comparison of similar results yields confirmation and a calibration to account for the additional losses introduced by the directional coupler.

Abstract: A variable displacement axial piston machine. The variable displacement axial piston machine includes a cylinder block with at least one main cylinder and main piston, a swash plate, a plunger arrangement with a plunger and auxiliary cylinder, and a sensor. The swash plate is arranged to effect movement of the main piston in the main cylinder upon rotation of the swash plate relative to the cylinder arrangement. The plunger is arranged to tilt the swash plate relative to the cylinder arrangement and to control a stroke of the main cylinder in the main piston. To provide a simple and reliable measurement of displacement of the main piston in the main cylinder, the invention provides a sensor element which is fixed in the auxiliary cylinder and which is adapted to sense movement of the plunger therein.

Abstract: A method and system for digital spur cancellation may include removing a spur in a left channel minus right channel (L?R) baseband signal generated from a FM signal. The L?R baseband signal may be generated by demodulating a sub-carrier, for example, by using CORDIC algorithm, in a signal demodulated from the FM signal. An orthogonal signal may also be generated by demodulating a sub-carrier, for example, by using CORDIC algorithm, in a signal demodulated from the FM signal. The phase of the orthogonal signal may be further adjusted to introduce a substantially ?90° phase shift to spurs at a specific frequency. Accordingly, the spurs in the L?R baseband signal may be cancelled when the first L?R baseband signal is combined with the phase adjusted orthogonal signal.

Abstract: A testing method or apparatus utilizes multiple frequencies applied to a device under test for measuring newly discovered frequency modulation effects. An embodiment may include a lower frequency signal with a smaller amplitude higher frequency signal to test a dynamic change in frequency response, gain, and or phase. This dynamic test can reveal frequency modulation effects. Another embodiment may include the use of a multiple frequency signal to dynamically induce a time varying phase or frequency distortion for the device that has differential phase distortion. The device's output is then measured with an FM detector to measure a shift in one of the frequencies used in the test signal or to measure frequency modulation effects of any signals, including distortion products, from the device.

Abstract: A portable test apparatus for conducting a plurality of tests on a communications device is provided. The unit can include a control panel, which can include at least one display for displaying test information from the device under test. The apparatus can also include a frequency mixing assembly, an amplifier module, a voltage regulator module, and a frequency module. The apparatus can allow a user to measure a number of parameters including, but not limited to, power, return loss and passive intermodulation products.

Abstract: An apparatus for measuring spectral components of a signal is described. The apparatus comprises a measurement acquisition unit configured to receive an input signal and to provide a measurement trace. The apparatus also comprises a model module configured to model one or more of a phase noise from the apparatus, a broadband noise from the apparatus, and a third order intermodulation (TOI) product from the apparatus. The apparatus also comprises a display configured to show one or more of the phase noise from the apparatus, the broadband noise from the apparatus, and the TOI product from the apparatus.

Abstract: A method for determining input tones required to produce a desired output includes the step of extracting a linearization of a spectral map representing a device under test (DUT) that i) is under drive of a large signal having one or more fundamental frequencies with associated amplitudes and phases, and ii) produces an approximation of a desired output having at least one unwanted spectral component. The method includes the further step of using an inverse of the extracted linearization to determine the input tones required to produce the desired output under a given load condition.

Abstract: A method and system for remotely affecting electronics within a conductive enclosure are disclosed. The method can comprise transmitting electromagnetic radiation of two different frequencies to the enclosure. The two different frequencies can be selected such that they penetrate the enclosure and therein form electromagnetic radiation of a third frequency that resonates within the enclosure. The third frequency can interact with the electronics, such as to disrupt operation thereof.

Abstract: An apparatus for measuring spectral components of a signal is described. The apparatus comprises a measurement acquisition unit configured to receive an input signal and to provide a measurement trace. The apparatus also comprises a model module configured to model one or more of a phase noise from the apparatus, a broadband noise from the apparatus, and a third order intermodulation (TOI) product from the apparatus. The apparatus also comprises a display configured to show one or more of the phase noise from the apparatus, the broadband noise from the apparatus, and the TOI product from the apparatus.

Abstract: Parametric measurement of first- and second-generation telecommunications equipment has been relatively straightforward. The evolution to more complex transmission schemes such as those proposed for third-generation (3G) telecommunications devices can employ the subject methods and apparatus and apply AM-PM test procedures to a multicarrier amplifier RF environment to properly characterize the parametric performance of these transmission systems, particularly those operating in a multicarrier environment.

Abstract: There is disclosed a knitted transducer device comprising a knitted structure having at least one transduction zone, in which the transduction zone is knitted with electrically conductive fibres so that deformation of the knitted structure results in a variation of an electrical property of the transduction zone.

Abstract: An arrangement is for measuring characteristic parameters of intermodulation distortion of a device under test. The arrangement may include a generator of at least two tones at different test frequencies, and an attenuation path feeding the device with a replica of the two tones attenuated of a factor equal to the gain of the device. The arrangement may also include a circuit for generating a difference signal between the signal output by the device and the two tones, and a circuit input with the difference signal and measuring the characteristic parameters as a function thereof.

Abstract: A measuring device is provided for measuring intermodulation distortion of a measuring object. The measuring device includes a first signal generator which produces a first signal that is supplied to an input of a measuring object, a signal combining device having a first input which is connected to the output of the measuring object, and a signal analyzing device which is connected to the output of the signal combining device. According to the disclosure, a second signal generator which is synchronized with the first signal generator is provided, and second signal generator producing a second signal that is supplied to a second input of the signal combining device.

Abstract: A technique for measuring spectral components, such as noise and distortion, of a non-coherently sampled test signal containing at least one tone of known frequency includes modeling the spectral components of the at least one tone, including the effects of leakage, based upon frequency of the at least one tone and a plurality of known sampling parameters. A DFT is taken of the sampled test signal, and the DFT is adjusted based on the modeled spectral components. The adjusted DFT is substantially leakage-free and directly reveals spectral components of the test signal, including low-power components that would ordinarily be lost in the leakage errors.

Abstract: A signal generator controls power output on the basis of the output from a &Dgr;-&Sgr; modulator or oscillator. That output may be generated in real time by the modulator or oscillator and fed to a switch control logic unit which controls a power switching stage to output switchably switched power from a power supply to an output, preferably via a filter. Alternatively the output of a &Dgr;-&Sgr; oscillator or modulator may be stored in a switchable memory to be retrieved when needed. A further alternative is to control the power switching stage by a processor with a program which reproduces the control effect of the &Dgr;-&Sgr; oscillator/modulator. Feedback from the output may be used to control the &Dgr;-&Sgr; modulator/oscillator and/or the power supply.

Abstract: In the process of estimating attributes of a transmission line from reflectometry measurements, small yet important reflections may be drowned in the immediate reflected signal owing to the mismatch between the reference impedance with respect to which the 1-port scattering parameter of the line has been determined and the characteristic impedance of the line.

Abstract: A signal generator controls power output on the basis of the output from a &Dgr;-&Sgr; modulator or oscillator. That output may be generated in real time by the modulator or oscillator and fed to a switch control logic unit which controls a power switching stage to output switchably switched power from a power supply to an output, preferably via a filter. Alternatively the output of a &Dgr;-&Sgr; oscillator or modulator may be stored in a switchable memory to be retrieved when needed. A further alternative is to control the power switching stage by a processor with a program which reproduces the control effect of the &Dgr;-&Sgr; oscillator/modulator Feedback from the output may be used to control the &Dgr;-&Sgr; modulator/oscillator and/or the power supply.

Abstract: An intermodulation detector (11) that operates standalone or in parallel with a radio receiver (10) of a radio receiver system (100) including a receiver tuning logic module (12), and, in the case of operating standalone, provides signals conveying information about intermodulation power in the receiver frequency band, and in case of operating in parallel with a radio receiver (10), provides to the receiver tuning logic module signals conveying information about power aliasing into the frequency band to which the radio receiver is tuned.

Abstract: In connection with blind source separation, proposed herein, inter alia, are: expectation-maximization equations to iteratively estimate unmixing filters and source density parameters in the context of convolutive independent component analysis where the sources are modeled with mixtures of Gaussians; a scheme to estimate the length of unmixing filters; and two alternative initialization schemes.

Abstract: A spectrum analyzer in which automatic setting of parameters such as band width is done by the analyzer without manual operator input and noise measurements are determined and displayed to the operator. This is accomplished by an input signal being supplied to a frequency mixer via an input variable attenuator. The frequency of the input signal is mixed with the frequency of a local signal from a frequency sweep generator. The mixed signal is then supplied to a band pass filter and the output of the filter is amplified by an amplifier. The frequency of the amplified output is mixed with the frequency of a local signal from a local oscillator by a frequency mixer. The intermediate frequency signal is taken out by a band pass filter and the output is detected by a detector. The detected output is converted into a digital signal by an A/D converter after passing through a low pass filter and the digital signal is stored in a buffer memory. A CPU sets an attenuation amount.

Abstract: A method and apparatus for fast response and distortion measurement of a signal transfer device. A computer processor generates a multitone test signal of predetermined duration and stores it in a memory. The test signal is read out, converted to analog form, if necessary, and applied to the input of a device under test. The output produced by the device under test in response to the test signal is acquired and digitized, if necessary, and a Fast Fourier Transform is performed on the acquired data to determine its spectral characteristics. Frequency response, harmonic distortion, intermodulation distortion, phase distortion, wow and flutter and other signal transfer characteristics are measured by the CPU by analysis of the output signal.

Abstract: A method and apparatus for fast response and distortion measurement of a signal transfer device. A computer processor generates a multitone test signal of predetermined duration and stores it in a memory. The test signal is read out, converted to analog form, if necessary, and applied to the input of a device under test. The output produced by the device under test in response to the test signal is acquired and digitized, if necessary, and a Fast Fourier Transform is performed on the acquired data to determine its spectral characteristics. Frequency response, harmonic distortion, intermodulation distortion, phase distortion, wow and flutter and other signal transfer characteristics are measured by the CPU by analysis of the output signal.

Abstract: A method and apparatus for fast response and distortion measurement of a signal transfer device. A computer processor generates a multitone test signal of predetermined duration and stores it in a memory. The test signal is read out, converted to analog form, if necessary, and applied to the input of a device under test. The output produced by the device under test in response to the test signal is acquired and digitized, if necessary, and a Fast Fourier Transform is performed on the acquired data to determine its spectral characteristics. Frequency response, harmonic distortion, intermodulation distortion, phase distortion, wow and flutter and other signal transfer characteristics are measured by the CPU by analysis of the output signal.

Abstract: A fluid level sensor for determining the amount of liquid in a container. Thin metal plates are placed parallely adjacent each other to form a capacitor cell coated with a non-hygroscopic film. The plates are mounted on the walls of the container containing fluid. As the fluid covers more surface area of the capacitor plates, the dielectric properties of the fluid increase the capacitance of the cell proportionally. The plates are connected to an oscillator whose output frequency varies with the change in container fluid levels. By monitoring these frequency changes, the container fluid levels of the fluid in the container can be controlled.