RadiMation Application Note 112
How to perform Audio Break Through measurements[edit]
This application note explains on how RadiMation can be used to perform Audio Break Through measurements, as it is described in for example CISPR 35 (Annex G of the CISPR 35).
Specific audio breakthrough measurement not available[edit]
In RadiMation we currently do not have native support for the control of specific audio breakthrough devices. This however doesn’t mean that it is not possible to integrate an Audio Break Through measurement in RadiMation by using such a device. The difficulty of the setup is that the configuration of the audio breakthrough device can be depending on the characteristics and requirements of the EUT that is being measured. This very often results in a large amount of settings of the audio breakthrough device that should be set correctly by RadiMation to perform the correct type of measurement. And these settings and parameters are very often different for different models of the EUT being tested. The control of the audio breakthrough device including the configuration and setting of all these settings is a complex program on its own, and thus normally a lot of work to integrate this in RadiMation. To correctly integrate this amount of functionality in RadiMation we first need to create a functional specification that clearly states all the settings, possible values, limitations and internal measurement procedures. After all parties agree to the functional specification, the integration of the audio breakthrough device inside our RadiMation according to the functional specification will probably then take an additional several weeks of work.
If we take for example a R&S UPV to perform such a measurement, it becomes clear that it is a very versatile device that has the capability to measure a lot of different audio signal parameters. For example:
- Level or S/N measurement
- Selective level measurement
- SINAD or THD+N measurement
- Measurement of total harmonic distortion (THD)
- Modulation distoration analysis in line with IEC 60268-3
- Intermodulation measurement
- Dynamic intermodulation measurement
- DC voltage measurement
- Frequency, phase and group delay measurement
- Polarity test
- Crosstalk measurement
- Waveform function
- Measurement of time difference
- UPV-K6 expanded analysis function
- Psycho-acoustic measurement methods
- Speech and audio quality measurements (PESQ, PEAQ and POLQA)
- PDM bitstream analysis
These are just some of the measurements that are described in the R&S UPV Brochure and Datasheet. This example strengthens us in the fact that it is extremely complex to correctly integrate the needed functionalities from the equipment into a dedicated device driver.
Manually configuration, automated testing[edit]
There is however an easier and more flexible solution to integrate the measurement results of the audio breakthrough device in RadiMation. This is also the method that we suggest to use. During the setup of the EUT in the chamber, the EUT will be connected to the Audio Break Through measurement setup that also includes the audio breakthrough device. The test engineer will then also configure the audio breakthrough device to correctly measure the signal, and set all the settings of the audio breakthrough device manually to their correct and corresponding values. This allows the test engineer to configure the audio breakthrough device manually in such a way that the desired signal is measured with optimal settings. After this setup the test-engineer can start the EMC test in our RadiMation software. The RadiMation software will then request one or more of the needed measurement values of the audio breakthrough device for each tested RF frequency, and will plot these measurement values in the graphs within the RadiMation software. This is then the including the results of the Audio Break Through measurement.
Configurable AD Converted as Audio breakthrough device driver[edit]
In RadiMation we provide a ‘Configurable AD Convertor’ device driver, which can be used to retrieve a measurement value from another device (the audio breakthrough device). This device driver can be configured to send a GPIB command, wait for the response, and interpret the response to convert it to a number that is shown in the graph. This device driver allows to use multiple ‘channels’, so multiple values can be retrieved from the audio breakthrough device, and be reported in RadiMation as different graphs/values. We only need to determine the correct commands for the audio breakthrough device once, and specify them once in the ‘Configurable AD Convertor’ device driver. After this ‘Configurable AD Convertor’ device driver is configured, it can be reused during all the EMC tests that use the audio breakthrough device to perform the Audio Break Through measurement.
The big advantage of using the ‘Configurable AD Convertor’ device driver is that you have a lot of flexibility to control the setup and the measurement parameters, while it is very easy to use in RadiMation This ‘Configurable AD Convertor’ device driver’ is already available in the current RadiMation release.
As an example there is a forum topic which explains how it can be configured using a R&S UPV: [1]
Our reference to related items: #7568 and #7565.