A Traveling Wave Calibration Method for Spatial Resolution of Near-field Probe Based on Transmission Line

Abstract

The invention relates to a traveling wave calibration method based on near-field probe spatial resolution of a transmission line. The method comprises step 1, design of a near-field probe spatial resolution calibration scale; and step 2, calibration measurement of the near-field probe spatial resolution. The method constructs a spatial resolution calibration scale having resolvable field distribution features and the calibration precision adjustable within a certain range, in combination with amplitude precision given by a receiver or a spectrometer in a near-field EMI (Electro-Magnetic Interference) test system, based on the theory of the transmission line, using the multi-conductor planar transmission line as a construction platform.

Description

technical field [0001] The invention relates to a traveling wave calibration method based on the spatial resolution of a transmission line near-field probe, which belongs to the field of antenna measurement. Background technique [0002] When analyzing and rectifying board-level electromagnetic interference (EMI: Electromagnetic Interference) problems, near-field probes are often used to locate the radiation source on the board. As an important technical parameter of the near-field probe, the spatial resolution has a very important impact on the accuracy of positioning. [0003] Currently, the available calibration method for the spatial resolution of the near-field probe is to excite a microstrip line, and then move the near-field probe from left to right in a direction perpendicular to the direction in which the microstrip line extends longitudinally (that is, laterally). Then a field distribution curve similar to the normal distribution is obtained through the measuremen...

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Problems solved by technology

However, this method is not scientific from the perspective of metrology, and it is relatively easy to introduce large calibration measurement errors

First of all, for this calibration method, taking the magnetic field probe as an example, the distribution of the field quantity on the moving path of the probe is not always orthogonal to the induction coil plane of the near-field probe, and under the corresponding test conditions, the field distribution on the moving path of the probe It also has high complexity, which makes the electromagnetic wave field used to calibrate the spatial resolution of the near-field probe not plastic and resolvable

Secondly, on the moving path of the near-field probe, the change of the field with the moving distance of the probe is not linear no matter in the logarithmic domain or in the linear domain. At the same time, if the moving path of the probe is divided into many sub-sections with the same distance, the field quantity changes corresponding to different sub-sections are different. The description is not uniform and linear, and it is unscientific to use this scale to describe the spatial resolution of the near-field probe

In addition, the current calibration method will also cause calibration errors caused by non-uniform coupling ratios

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