EMSCAN EMxpert EHX User Manual Download

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1. How can I correlate the scan results to PCB design?

EMxpert support three types of file formats: Gerber file format RS-274x, HPGL and JPG. On rare

occasions, a Gerber file may not be in a pure RS-274x format and cannot be read by EMxpert software.

This file can often be read by a third party Gerber reader such as GerbView and converted to an RS-

274x format that can be used. GerbView can be obtained at

http://www.softwarecompanions.com/

2. Does the system require annual calibration?

The EMxpert EHX does not require calibration after shipment. The scanner elements are passive and
will not require further calibration. If you believe that one or more of the probes have been damaged,

the unit can be returned to EMSCAN for verification and repair.

3. What is the frequency and amplitude accuracy of the EMxpert measurements?

Frequency Accuracy: Marked Peaks – Typically accurate to 1 kHz

A calibrated spectrum analyzer or EMC analyzer normally has a frequency error of between 1% and

2% of span. During the process of marking peaks, EMxpert conducts several rescans of identified

peaks after the initial scan is completed. The final accuracy is 1-2% of the final scan bandwidth shown

on the spectrum analyzer display.

Some supported models of spectrum analyzer provide higher accuracy frequency measurements

using an internal counter. For these spectrum analyzers the final accuracy is the specified accuracy

of the counter.

Amplitude Accuracy: Spectral or Spatial Scans: approxi/- 3 dB

This is a combination of spectrum analyzer accuracy and probe factor responses from cell to cell
across all frequencies from scanner to scanner.

4. How do I achieve higher frequency accuracy?

Frequency accuracy is compromised by the spectrum analyzer frequency measurement accuracy
of 1% to 2% of span, unless the spectrum analyzer is equipped with a higher accuracy frequency
counter. Therefore, by decreasing the span, the user can increase the frequency accuracy. Since

EMxpert final rescan for peak detection is set at a span of 5 x RBW, reducing the RBW has the effect

of improving the frequency accuracy.

5. I have a spectrum analyzer that is not on the list of supported analyzers. Can it be

supported?

If your spectrum analyzer is not on the supported spectrum analyzer list, please contact your local
representative or EMSCAN at

support@emscan.com

to discuss the development of a custom driver.

Spectrum Analyzer must be configured with the following options to be supported: gated sweep, pre-

amplifier, LAN or USB port, external trigger port with BNC connector and VISA support.

6. How do I make sure that I see all the peaks that might cause me problems in the far-

field?

There are instances where components of the DUT are some distance away from EMSCAN’s patented

scanner, and signals from these devices may be mixed with the noise floor. We recommend that a low

noise amplifier be placed in series between the scanner and the spectrum analyzer to differentiate

the signal from the noise floor. We also recommend that you reduce the RBW to improve the signal to

noise ratio. It is important to recognize that some of the emissions may originate within the DUT, and
then couple onto the connectors and cables (which may act as an antenna). The signals, at the DUT

EMxpert Software

Appendix - FAQ