11 results about "Time-domain reflectometry" patented technology

The application discloses an optical time domain reflectometry (OTDR) method, system and OTDR equipment for avoiding event blind area, and relates to the technical field of OTDR. The OTDR method adds a second detector to the ground end of a first detector, and detects the optical signal emitted by a second light source by using the second detector. Then, when measuring the OTDR curve of a to-be-measured optical fiber, the second driver is controlled to drive the second light source to emit a compensation optical signal within a pre-determined saturation time interval, so that the photocurrent detected by the second detector offsets and compensates the photocurrent detected by the first detector, and the current input to the amplification circuit is lower than the saturation threshold, thereby eliminating the event blind area caused by saturation, enabling the blind area event to be detected, and without adding a selection switch, thereby avoiding introducing additional noise, improving the optical fiber OTDR test accuracy and having better noise performance.

The invention provides an electronic wire harness anti-interference optimization method and system, and the method comprises the steps: S2, blocking a DC component and low-frequency interference through employing a band elimination filter according to the initial spectrum distribution, and extracting a core frequency band of high-frequency signal transmission from a filtered signal; s4, acquiring demand data of voltage grade separation from the signal output, designing an electrical isolation layer through a multi-layer shielding structure, and determining isolation boundaries among different voltage grades; s5, according to the isolation boundary, a space optimization algorithm is adopted to adjust wire harness arrangement in the compact layout, and structural parameters considering isolation and coupling balance are obtained; and S8, according to the final scheme, a time domain reflection method is adopted to detect the distortion rate in signal transmission, the actual effect of improving the anti-interference capability is judged from the detection result, and optimized operation parameters are obtained. The anti-interference capability and the signal transmission quality of the electronic wire harness in a complex electromagnetic environment are effectively improved.

The present disclosure relates to techniques for visualizing multiple time domain reflectometry waveforms. Various embodiments include a TDR viewer for visualizing a large number of reflected TDR signals on a 3D display system. The TDR system captures waveforms of reflected TDR signals associated with signal propagation and delay. The TDR viewer displays waveforms of signals as they propagate through a transmission line. These waveforms can show changes in the reflected TDR signals due to transmission between various printed circuit board layers, through printed circuit board component connectors and vias, and across interconnects and socket pins. The 3D visualization of the reflected TDR signals can be rotated, zoomed in or out, and filtered to display a subset of signals in the 3D space. The 3D visualization enables a test engineer to more quickly identify TDR signals of interest, including signals with longer or shorter delay times relative to other TDR signals and signals exhibiting undesirable signal properties.

A time domain reflectometry (TDR) controlled-impedance testing system includes one or more ultra-low impedance testing channels (e.g., having a characteristic impedance of less than 10 ohms, or less than 5 ohms, or less than 2 ohms) to couple a test signal to a test target ("device under test"). In one example, the TDR testing system includes one or more printed circuit boards (PCBs) on which at least a portion of the testing channel is implemented. The PCB includes an ultra-wide impedance-controlled trace and one or more return conductors constituting at least a portion of an ultra-low impedance PCB RF transmission line having a characteristic impedance of less than 10 ohms (or less than 5 ohms, or less than 2 ohms).

An ultrasound system for measuring the dimensions of a structure, the system including a flexible body elongated along a longitudinal axis for insertion into the structure. At least one ultrasound transducer arranged on the flexible body and configured to transmit and receive ultrasound signals to and from the structure. The system is configured to calculate distances between each transducer and the structure based on the received ultrasound signals and to calculate multiple cross-sectional shapes of the structure based on the distances. The flexible body includes one or more electrical waveguides. The system causes electrical pulses to travel through the one or more wave-guides and a conductive element through which the flexible body moves to make time domain reflectometry (TDR) distance measurements based on responsive impedance signals created by the conductive element. The system is configured so that the TDR distance measurements correspond to relative longitudinal positions of the flexible body.

A coexistence module usable at secondary locations within a routing optical network is disclosed, which accommodates OTDR testing on the optical network without requiring a separate, dedicated fiber connected between secondary locations for such testing. Rather, a filter arrangement is used in which OTDR wavelengths are separated from transmission wavelengths and optically connected to bypass router equipment at the secondary location.

The present invention relates generally to moisture sensors, in particular to moisture sensors using Time Domain Reflectometry (TDR). In particular, the present invention relates to a sensor device which is charged using wireless power transfer and subsequently performs a moisture measurement using Time Domain Reflectometry. The present invention also provides a measurement method using such a sensor device as well as a use or application method employing such a sensor device.

Real equivalent time oscilloscope with time domain reflectometer. A test and measurement device includes one or more ports configured to connect to a device under test (DUT), a time domain reflectometer (TDR) source configured to receive a source control signal and generate an incident signal to be applied to the DUT, one or more analog-to-digital converters (ADCs) configured to receive a sampling clock and sample the incident signal from the TDR source and a time domain reflectometry (TDR) signal or a time domain transmission (TDT) signal from the DUT to generate an incident waveform and a TDR / TDT waveform, one or more processors configured to execute code to cause the one or more processors to control a clock synthesizer to generate the sampling clock and the source control signal and determine time positions of samples in the incident waveform and the TDR / TDT waveform using a period of the TDR source, a period of the sampling clock, and a number of samples, and a display configured to display the incident waveform and the TDR / TDT waveform.

The present application relates to a method for performing optical time domain reflectometry (OTDR) on an optical fibre. The method comprises transmitting a first signal into an optical fibre, wherein the first signal comprises a sequence of optical radiation pulses based on a coded sequence, wherein each of the sequence of optical radiation pulses are separated by a fill pattern controlled by a binary sequence of high and low values.

Various embodiments include a TDR viewer for visualizing a large number of reflected TDR signals on a 3D display system. The TDR system captures the waveforms for reflected TDR signals that are associated with signal propagation and delay. The TDR viewer displays the signal waveforms as the signals propagate through the transmission lines. The waveforms can display changes in the reflected TDR signals due to transmission between various printed circuit board layers, through component connectors and vias of the printed circuit board, and across the interconnects and socket pins. The 3D visualization of the reflected TDR signals can be rotated in 3D space, zoomed in or out, and filtered to display a subset of signals. The 3D visualization enables a test engineer to more quickly identify TDR signals of interest, including signals with longer or shorter delay times relative to other TDR signals and signals that exhibit undesirable signal attributes.

The present application relates to the field of optical time domain reflectometry, in particular to a distributed optical fiber acoustic wave sensing system based on double acousto-optic difference frequency modulation. The present application introduces a frequency shift device in the local reference light of the system, reduces the signal detection bandwidth: in the signal acquisition part, the difference frequency of two signal frequencies is used to complete the phase modulation of the probe light signal, which reduces the cost of the acquisition equipment required for signal restoration and reduces the burden of the data storage equipment; in the realization of frequency conversion, the frequency modulation is carried out on the optical signal 1 and 2, and the optical signal 2 is combined with the optical signal 1 to realize the frequency conversion together, and the frequency shift driving control of the optical signal 2 only needs to provide a driving signal alone, without considering the problem of whether the trigger is synchronous, in the case of ensuring the system restoration ability and spatial resolution unchanged, the signal acquisition pressure is greatly relieved, the hardware requirement is reduced, the system real-time performance is improved, and the distributed optical fiber sensing system with high signal-to-noise ratio is realized.