Chapter 7

Radiated emission

Introduction

The RadiMation^® package support three main radiated emission methods:

• Anechoic chamber method
• Fixed height method
• G-TEM method

These methods are described in the subsequent paragraphs.

Anechoic chamber

The test engineer can configure a complete radiated emission test in the Radiated Emission configuration menu.

Frequency window

In the frequency window, the operator can enter a frequency range to be measured or select a frequency list.

When the Frequency range is selected, the following items can be entered:

Start

Sets start frequency

Stop	Sets stop frequency

When the frequency list option is selected the operator can select a frequency list file by browsing to the file location. With the start-stop frequency the software searches for the peaks, while with a frequency list the frequencies on the list are measured.

Turntable window

In the turntable window, the following parameters can be configured:

Start position

Sets the start angle of the turntable.

Stop position

Sets the stop angle of the turntable.

#	Sets the number of steps for one turntable rotation.

Peak search

The software will automatically detect on which angle maximum emission will occur.

When peak search is selected, the user can configure the way a peak search is performed. In the peak search configuration window, the following configurations can be made:

Area	Range over which the peak search will be performed (0 to 360 degrees max.).

Step size

The angle step size.

Threshold

This value determines the acceptance criteria for a peak.

Mode	The mode setting determines the way a peak is detected.

The following modes are available:

• Intelligent
• Complete area

Intelligent

In this mode the software increases the angle of the turntable from the initial point with a step equal to “step size” as long as the field strength increases. As soon as lower field strength is detected the turntable angle is reversed till the initial point and from this point the turntable angle is decreased with a step equal to “step size” till lower field strength is detected.

Warning:

This might cause a measurement error if the number of steps is set to a low value.

Complete area

In this mode the complete area around the initial point and defined by “Area” is scanned for a peak.

Warning:

This might cause a measurement error if the “Area” is set to a low value relative to the area given by the stop position minus start position dived by number of steps.

Antenna tower window

In the antenna tower window, the following parameters can be configured:

Max. height

Sets maximum height of the antenna tower.

Min. height

Sets the minimum height of the antenna tower.

#	Sets the number of steps to go from min. height to max. height.

Peak search

The software will automatically detect on which antenna height maximum emission will occur.

When peak search is selected, the user can configure the way a peak search is performed. In the peak search configuration window, the following configurations can be made:

Area	Range over which the peak search will be performed (0 to n meter).

Step size

The distance for each step.

Threshold

This value determines the acceptance criteria for a peak.

Mode	The mode setting determines the way a peak is detected.

The following modes are available:

• Intelligent
• Complete area

Intelligent

In this mode the software increases the height of the antenna from the initial point with a step equal to “step size” as long as the field strength increases. As soon as lower field strength is detected the antenna is lowered till the initial point and from this point the antenna is lowered with a step equal to “step size” till lower field strength is detected.

Warning:

This might cause a measurement error if the number of steps is set to a low value.

Complete area

In this mode the complete area around the initial point and defined by “Area” is scanned for a peak.

Warning:

This might cause a measurement error if the “Area” is set to a low value relative to the area given by the max. height minus min. height dived by number of steps.

Antenna window

Polarisation

In the antenna window the user can select the antenna polarisation. The test engineer can select the following three options:

1. Horizontal
2. Vertical
3. Both

When Horizontal or Vertical is selected, the software will measure only one antenna polarisation. When the option “Both” is selected, the software will measure both Horizontal and Vertical polarisation (an antenna positioner is required for this option).

When this option is selected, all data will be displayed in one graph thus loosing some polarisation information. However the peak list table will show if a peak was measured in horizontal or vertical polarisation.

If the both emission graphs of horizontal and vertical polarisation are required, two separate tests must be configured. These tests can be put in a sequence, eliminating the need for a user intervention.

Distance

RadiMation^® uses the distance information for reference only.

Receiver settings

Reference level

Sets the reference level of the receiver

Attenuator

Sets the receiver attenuator level

RBW	Sets the Resolution BandWidth filter

VBW	Sets the Video BandWidth filter

Sweep

Sets the sweep time of the receiver

Pre-amp

Sets the pre-amp gain

Step frequency

Sets the frequency step size of the receiver

Measure time

Sets the measure time of the receiver

When a parameter is set to auto, RadiMation^® will determine the most optimum settings for this parameter. If the parameter is set to coupled, the parameter will be set to automatic internally in the receiver.

Max. hold measurements

In this window the number op peak hold sweeps for each measurement can be selected. If this value is set to, for example 10, the software will measure the frequency band 10 times for each turntable and antenna tower position. This value will normally be set to 1 for measurement receivers while a higher value is used for spectrum analysers. The amount of required peak sweeps is depending on the type of signal and the setting of the sweepspeed. For spectrum analysers and CW signals you can use a relatively low amount of peaksweeps, for example 10. But when you have discontinues signals like a spark bridge, you may need 100 peaksweeps or more. A good indication if you are using enough peak sweeps is to look at the envelope of the frequency spectrum. When it has gaps or jumps then you are not using enough sweeps to determine a correct signal envelope.

Traces window

In the traces window, the test engineer can select a maximum of four traces, which can be measured and displayed at the same time.

Detectors window

In the detectors window the test engineer can configure the detectors used during the emission measurements. The first value is the time constant of the detector while the second value is used for the measure time at each frequency point for this detector. The time constant is send to the receiver, to set the sample time of the detector. To select a detector, check the desired box.

Peak detection window

All peaks above “xx” below the limit lines

In the peak detection window, the test engineer can configure which signal peaks must be detected. If the operator selects a value of 6 dB, the software will detect all peaks, which are higher than 6 dB below the limit line.

Max. Peaks

With the max. peaks option, the user can limit the number of peak signals the software will detect and re-measure.

Test site window

Test equipment

In the test site window the test engineer can select which equipment list will be used during this test.

Test engineer

In the test engineer window, the test engineer can select its own name. The test engineer name will be stored by the test results.

Equipment icon

By clicking on the equipment icon, the equipment list can be viewed and edited.

Limit lines window

In the limit line window the operator select one or more limit lines to be used during the test.

Test options window

Record data

In the test options window the operator can select whether all RAW data must be stored or only the measurement results are stored. It should be noted that for full tracebility, all test data should be stored.

Narrow band / broad band discrimination

RadiMation® supports two types of narrow band / broad band determination.

The first one is called 'Generic'. During the determination of the peak, the so called ‘zooming’. RadiMation^® verifies if the peak is bigger or equal to twice the RBW filter. If so, the peak is determined broad band. Otherwise it is called narrow band. The second method is called 'Mil Standard'. This method is also based on the RBW filter. But now the filter is changed to determine the type of peak. First the peak is measured with the current RBW, then it is made 10 times bigger. If multiplying the current RBW gives a RBW that is bigger then 1 MHz the current RBW is divided by 10. A delta RBW is calculated according to the formula below.

${\displaystyle DeltaRBW=10*log({\frac {$RBW_{1}}{RBW_{2}}})}

Formula 7-1: Difference in a peak measurement, as a result of changing the used RBW

Where RBW1 is the RBW used in the first measurement and RBW2 is used in the second measurement. Also a Delta V is calculated, V1 is the dbuV measured during the first measurement and V2 is voltage measured during the second measurement.

$DeltaV={V_{1}}\ -\ {V_{2}}$

Formula 7-2: Difference in a peak amplitude

Determination the type of peak is done according to the table below.

Limits	Distortion type
Delta V <= 5 Delta RBW	Narrow band
Delta V is > than 5 Delta RBW and delta V is <= 15 delta RBW	Random noise
Delta V > 15 delta RBW	Broad band

Starting a Anechoic Chamber test

Loading a TSF file

To start a radiated emission test, an EUT file must be defined first. From the EUT file, select “Tests > Radiated emission > Anechoic chamber. A list of Technical Setup Files (TSF files) will be displayed. The test engineer can select one of these TSF files to load all parameters from a previously defined emission test or press cancel to define a new emission test.

The figure below shows the TSF window.

After the TSF file has been selected, the emission configuration window will appear.

When a TSF file is loaded, all test parameters will be already configured and pressing the start button on the right side of the screen can start the test.

When no TSF file is loaded (by pressing Cancel in the TSF selection window) all parameters will be at zero and can be configured by the operator.

Test initialisation and self test

When the start button is pressed, the software first runs a number of checks.

1. The presence of a valid software key is checked.
2. The software settings are checked (i.e. is all test equipment used within its parameters?)
3. The presence of all test equipment is checked.
4. All relevant equipment will be initialised.

When one or more of the tests mentioned above fail, an error message is displayed.

Test Procedure

The test procedure is better to understand with an example with a receiver, turntable and antenna tower.

Suppose you set 3 points on the turntable and 2 on the antenna. The angles of the turntable are 0, 45 and 90 degrees and the antenna positions are 1 and 4 meters. We start at 0 degrees and 1 meter.

1. The receiver takes the desired sweeps of the spectrum.
2. The antenna is moved to 4 meters.
3. The receiver takes the desired sweeps of the spectrum.
4. The turntable is moved to 45 degrees.
5. The receiver takes the desired sweeps of the spectrum.
6. The antenna tower is moved to 1 meter.
7. The receiver takes the desired sweeps of the spectrum.
8. The turntable is moved to 90 degrees.
9. The receiver takes the desired sweeps of the spectrum.
10. The antenna tower is moved to 4 meters
11. The receiver takes the desired sweeps of the spectrum.

RadiMation^® now performs a maxhold on all the sweeps and determines the peaks. Then it determines the position a peak was found. And changes the turntable and antenna to that current position to re-measure the peak. When multiple peaks have been detected, the most compact way is determined to measure these peaks.

Please note that the example above makes the assumption that there is an antenna tower and turntable controller. When either or neither of the controllers are available the test can still be performed except for the missing unit. When neither of the controllers are available the software performs the test on one point.

Info screen

Note:

The pass/fail criteria, shown in the tables do not take the measure uncertainty of the test setup into account.

You can access the info screen by selecting the test you whish to see and then press the info button. A window like below here will appear.

Settings

In the settings window all the used settings are displayed.

Graph control

In the graph control window the scale of the graph can be changed. You can show or hide the table by selecting or deselecting the show table checkbox.

Trace

In the trace window you can control the traces that are shown in the graph by selecting or deselecting the checkbox. If during a measurement a trace is not used then the check box is grayed out.

Detector

The detector window gives you the possibility to show and hide the values measured on the peaks. If during a measurement a type of detector is not used for determining the value on the peak the checkbox is grayed out.

Table

In the table all the measured peaks are showed. The table also shows the limit values for that frequency point when a limit was given at the beginning of the test.

Test site information

Device name	Tab in Radimation configuration window
Spectrum analyser	Standard 2
Pre amplifier	Standard 2
Antenna	Standard 1

Cables

#	Device name	Tab in Radimation configuration window
1	Pre amp->Spectrum	Cables
2	Ant->Pre amp	Cables

Note:

Usage of cable correction factors is not mandatory. However, using correction factors will increase measurement accuracy during emission measurements. When in doubt contact your reseller.

Measurement of peak amplitude and peak frequency

When using a spectrum analyser for emission measurements, RadiMation^® first performs a full span max. hold measurement with the configured trace detector. The number of max. hold peak sweeps can be defined by the user. From the obtained max hold graph, RadiMation^® determines a number of peaks, which will be further investigated. The number of peak signals to be measured can be defined by the user. For each peak from the graph, RadiMation^® will zoom in, by reducing the span in several steps. This must be done while span inaccuracy of the analyser in large frequency spans will give slightly incorrect frequency information. After the exact peak frequency is determined, RadiMation^® will perform the configured Peak,Quasi peak, Average and / or RMS measurements. Due to the above, the finally measured frequency and amplitude of a peak can slightly differ from the max hold graph. This is not an error, but merely an indication that the final measurements are more accurate. The peak table always shows the final measured values (most accurate).

Fixed height test method

Introduction

The “fixed height” test method is intended to increase measurement speed of radiated emission tests. Instead of measuring the radiated emission of an EUT under all turntable positions and for all antenna tower positions, this method uses a fixed antenna height to measure the radiated emission level for all turn table positions. The software then determines the maximum emission peaks from the measured data and re- measures the emission levels on these frequencies (and corresponding turntable positions). During these final measurements the antenna tower is scanned in height to find the maximum emission level on these frequencies. This method decreases measurement time dramatically. A trade-off for this method is a slight decrease in measurement accuracy.

Frequency window

In the frequency window, the operator can enter a frequency range to be measured or select a frequency list.

When the Frequency range is selected, the following items can be entered:

Start

Sets start frequency

Stop	Sets stop frequency

When the frequency list is selected the operator can select a frequency list file by browsing to the file location.

Turntable window

In the turn table window, the following parameters can be configured:

Start position

Sets the start angle of the turntable.

Stop position

Sets the stop angle of the turntable.

#	Sets the number of steps for one turntable rotation.

Peak search

The software will automatically detect on which angle maximum emission will occur.

When peak search is selected, the user can configure the way a peak search is performed. In the peak search configuration window, the following configurations can be made:

Area	Range over which the peak search will be performed (0 to 360 degrees max.).

Step size

The angle step size.

Threshold

This value determines the acceptance criteria for a peak.

Mode	The mode setting determines the way a peak is detected.

The following modes are available:

• Intelligent
• Complete area

Intelligent

In this mode the software increases the height of the antenna from the initial point with a step equal to “step size” as long as the field strength increases. As soon as lower field strength is detected the antenna is lowered till the initial point and from this point the antenna is lowered with a step equal to “step size” till lower field strength is detected.

Warning:

This might cause a measurement error if the number of steps is set to a low value.

Complete area

In this mode the complete area around the initial point and defined by “Area” is scanned for a peak.

Warning:

This might cause a measurement error if the “Area” is set to a low value relative to the area given by the max. height minus min. height dived by number of steps.

Antenna tower window

In the antenna tower window, the following parameters can be configured:

Max. height

Sets maximum height of the antenna tower.

Min. Height

Sets the minimum height of the antenna tower.

#	Sets the number of steps to go from min. height to max. height.

Peak search

The software will automatically detect on which antenna height maximum emission will occur.

When peak search is selected, the user can configure the way a peak search is performed. In the peak search configuration window, the following configurations can be made:

Area	Range over which the peak search will be performed (0 to n meter).

Step size

The distance for each step.

Threshold

This value determines the acceptance criteria for a peak.

Mode	The mode setting determines the way a peak is detected.

The following modes are available

• Intelligent
• Complete area

Intelligent

In this mode the software increases the height of the antenna from the initial point with a step equal to “step size” as long as the field strength increases. As soon as lower field strength is detected the antenna is lowered till the initial point and from this point the antenna is lowered with a step equal to “step size” till lower field strength is detected.

Warning:

This might cause a measurement error if the number of steps is set to a low value.

Complete area

In this mode the complete area around the initial point and defined by “Area” is scanned for a peak.

Warning:

This might cause a measurement error if the “Area” is set to a low value relative to the area given by the max. height minus min. height dived by number of steps.

Antenna window

Polarisation

In the antenna window the user can select the antenna polarisation. The test engineer can select the following three options:

1. Horizontal
2. Vertical
3. Both

When Horizontal or Vertical is selected, the software will measure only one antenna polarisation. When the option “Both” is selected, the software will measure both Horizontal and Vertical polarisation (an antenna positioner is required for this option).

When this option is selected, all data will be displayed in one graph thus loosing some polarisation information. However the peak list table will show if a peak was measured in horizontal or vertical polarisation.

If the both emission graphs of horizontal and vertical polarisation are required, two separate tests must be configured. These tests can be put in a sequence, eliminating the need for a user intervention.

Distance

In this box, the operator can enter the distance between antenna and EUT. RadiMation^® uses the distance information for reference only.

Receiver settings

Reference level

Sets the reference level of the receiver

Attenuator

Sets the receiver attenuator level

RBW	Sets the Resolution BandWidth filter

VBW	Sets the Video BandWidth filter

Sweep

Sets the sweep time of the receiver

Pre-amp

Sets the pre-amp gain

Step frequency

Sets the frequency step size of the receiver

Measure time

Sets the measure time of the receiver

When a parameter is set to auto, RadiMation^® will determine the most optimum settings for this parameter. If the parameter is set to coupled, the parameter will be set to automatic internally in the receiver.

Max. hold measurements

In this window the number op peak hold sweeps for each measurement can be selected. If this value is set to, for example 10, the software will measure the frequency band 10 times for each turntable and antenna tower position. This value will normally be set to 1 for measurement receivers while a higher value is used for spectrum analysers. The amount of required peak sweeps is depending on the type of signal and the setting of the sweepspeed. For spectrum analysers and CW signals you can use a relatively low amount of peaksweeps, for example 10. But when you have discontinues signals like a spark bridge, you may need 100 peaksweeps or more. A good indication if you are using enough peak sweeps is to look at the envelope of the frequency spectrum. When it has gaps or jumps then you are not using enough sweeps to determine a correct signal envelope.

Traces window

In the traces window, the test engineer can select a maximum of four traces which can be measured and displayed at the same time.

Detectors window

In the detectors window the test engineer can configure the detectors used during the emission measurements. The first value is the time constant of the detector while the second value is used for the measure time at each frequency point for this detector.

Peak detection window

All peaks above “xx” below the limit lines

In the peak detection window, the test engineer can configure which signal peaks must be detected. If the operator selects a value of 6 dB, the software will detect all peaks, which are higher than 6 dB below the limit line.

Max. Peaks

With the ‘max. peaks” option, the user can limit the number of peak signals the software will detect and re-measure.

Test site window

Test equipment

In the test site window the test engineer can select which equipment list will be used during this test.

Test engineer

In the test engineer window, the test engineer can select its own name. The test engineer name will be stored by the test results.

Equipment icon

By clicking on the equipment icon, the equipment list can be viewed and edited.

Limit lines window

In the limit line window the operator select one or more limit lines to be used during the test.

Test options window

In the test options window the operator can select whether all RAW data must be stored or only the measurement results are stored. It should be noted that for full tracebility, all test data should be stored.

Starting a fixed height test

Loading a TSF file

To start a fixed height - radiated emission test, an EUT file must be defined first. From the EUT file, select “Tests > Radiated emission > Fixed height. A list of Technical Setup Files (TSF files) will be displayed. The test engineer can select one of these TSF files to load all parameters from a previously defined emission test or press cancel to define a new emission test.

After the TSF file has been selected, the emission configuration window will appear.

When a TSF file is loaded, all test parameters will be already configured and pressing the start button on the right side of the screen can start the test.

When no TSF file is loaded (by pressing Cancel in the TSF selection window) all parameters will be at zero and can be configured by the operator.

Test initialisation and self test

When the start button is pressed, the software first runs a number of checks.

5. The presence of a valid software key is checked. 6. The software settings are checked (i.e. is all test equipment used within its parameters?) 7. The presence of all test equipment is checked. 8. All relevant equipment will be initialised.

When one or more of the above tests fail, an error message is displayed as shown in de picture below.

Test Procedure

The test procedure is better to understand with an example with a receiver, turntable and antenna tower.

Suppose you set 3 points on the turntable. The points of the turntable are 0, 45 and 90 degrees. We start at 0 degrees and 1 meter.

1. The receiver takes the desired sweeps of the Spectrum.
2. The turntable is moved to 45 degrees.
3. The receiver takes the desired sweeps of the Spectrum.
4. The turntable is moved to 90 degrees.
5. The receiver takes the desired sweeps of the Spectrum.

RadiMation^® now performs a maxhold on all the sweeps and determines the peaks. Then it determines the position a peak was found. The turntable position is changes to that position to re-measure the peak. The antenna tower is changed in height according to the settings.

Please note that the example above makes the assumption that there is an antenna tower and turntable controller. When either or neither of the controllers are available the test can still be performed except for the missing unit. When neither of the controllers are available the software performs the test on one point.

Test site information

Device name	Tab in Radimation configuration window
Spectrum analyser	Standard 2
Pre amplifier	Standard 2
Antenna	Standard 1

Cables

#	Device name	Tab in Radimation configuration window
1	Pre amp->Spectrum	Cables
2	Ant->Pre amp	Cables

Note:

Usage of cable correction factors is not mandatory. However, using correction factors will increase measurement accuracy during emission measurements. When in doubt contact your reseller.

G-TEM Method

Correlation method

In order to use a G-TEM cell for radiated emission measurements, a good correlation has to be found between emissions measurements on an Open Area Test Site (OATS) and emission measurements in a G-TEM cell.

For this purpose the following method can be used:

When radiated emission measurements are made in the G-TEM cell in three directions (i.e. X-Y-Z axis), the total radiated power for each frequency can be calculated by:

${{P_{tr}}^{2}}=X^{2}+Y^{2}+Z^{2}$

When this total radiated power would be fed into an isotrope antenna on an OATS, one would measure a value equal to the radiated power, minus the site attenuation of the open area test site for this specific frequency.

RadiMation® uses the above method to correlate the radiated emission measurements performed in a G-TEM to the emission levels on an OATS.

Measurement procedure

To start a Radiated emission test, the operator must (as for all tests) first define a EUT window. To start a Radiated emission measurement in a G-TEM cell, please select:

    Tests

       Radiated emission

          G-TEM

The TSF window will appear. If tests are configured previously, select the required test configuration and press “START” to start the emission test.

The software will ask the operator to place the EUT in the X direction. After pressing “OK”, the software will perform all measurements on this axis. When the X-axis measurements are finished, the software will ask the operator to place the EUT in the Y- direction. After pressing “OK”, the software will perform all measurements on the Y-axis. When the Y-axis measurements are finished, the software will ask the operator to place the EUT in the Z-direction. After pressing “OK”, the software will perform all measurements on this axis. When the Z-axis measurements are finished, the software will ask the operator to place the EUT again in the (X,Y and Z) direction . This is required to perform the automatic peak measurements on the peaks found during the first three measurements.

When a new test has to be configured please press the “Cancel” button. A blank test configuration screen will appear. The chapter below will explain all settings for this test configuration screen.

Test configuration

Frequency range selection

In the frequency window, the operator can enter a frequency range to be measured or select a frequency list.

When the Frequency range is selected, the following items can be entered:

Start

Sets start frequency

Stop	Sets stop frequency

When the frequency list is selected the operator can select a frequency list file by browsing to the file location.

Frequency list selection

In stead of measuring a defined frequency band, emission measurements can also be performed using a pre-defined frequency list. When the check box before “frequency list” is checked, the operator can browse to the required frequency list file.

OATS settings

In this window the operator has to define to which kind of OATS the correlation measurements will be made.

The operator can enter the antenna tower height and the measurement distance on the OATS (i.e. 3, 10 or 30 meters).

G-TEM settings

The operator has to define the Height of the septum of the G-TEM cell used for the radiated emission measurements.

Receiver settings

Reference level

Sets the reference level of the receiver.

Attenuator

Sets the receiver attenuator level.

RBW	Sets the Resolution BandWidth filter.

VBW	Sets the Video BandWidth filter.

Sweep

Sets the sweep time of the receiver.

Pre-amp

Sets the pre-amp gain.

Step frequency

Sets the frequency step size of the receiver.

Measure time

Sets the measure time of the receiver.

When a parameter is set to auto, RadiMation^® will determine the most optimum settings for this parameter. If the parameter is set to coupled, the parameter will be set to automatic internally in the receiver.

Max. hold measurements

In this window the number op peak hold sweeps for each measurement can be selected. If this value is set to, for example 10, the software will measure the frequency band 10 times for each turntable and antenna tower position. This value will normally be set to 1 for measurement receivers while a higher value is used for spectrum analysers. The amount of required peak sweeps is depending on the type of signal and the setting of the sweepspeed. For spectrum analysers and CW signals you can use a relatively low amount of peaksweeps, for example 10. But when you have discontinues signals like a spark bridge, you may need 100 peaksweeps or more. A good indication if you are using enough peak sweeps is to look at the envelope of the frequency spectrum. When it has gaps or jumps then you are not using enough sweeps to determine a correct signal envelope.

Traces window

In the traces window, the test engineer can select a maximum of four traces which can be measured and displayed at the same time.

Detectors window

In the detectors window the test engineer can configure the detectors used during the emission measurements. The first value is the time constant of the detector while the second value is used for the measure time at each frequency point for this detector.

Peak detection window

All peaks above “xx” below the limit lines

In the peak detection window, the test engineer can configure which signal peaks must be detected. If the operator selects a value of 6 dB, the software will detect all peaks, which are higher than 6 dB below the limit line.

Max. Peaks

Under max. peaks, the user can limit the number of peak signals the software will detect and re-measure.

Test site window

Test equipment

In the test site window the test engineer can select which equipment list will be used during this test.

Test engineer

In the test engineer window, the test engineer can select its own name. The test engineer name will be stored by the test results.

Equipment icon

By clicking on the equipment icon, the equipment list can be viewed and edited.

Limit lines window

In the limit line window the operator can add or remove one or more limit lines to be used during the test.

Test options window

In the test options window the operator can select whether all RAW data must be stored or only the measurement results are stored. It should be noted that for full tracebility, all test data should be stored.

Starting a G-TEM test

Loading a TSF file

To start a radiated emission test in the G-TEM cell, an EUT file must be defined first. From the EUT file, select “Tests > Radiated emission > G-TEM. A list of Technical Setup Files (TSF files) will be displayed. The test engineer can select one of these TSF files to load all parameters from a previously defined emission test or press cancel to define a new emission test.

After the TSF file has been selected, the emission configuration window will appear.

When a TSF file is loaded, all test parameters will be already configured and pressing the start button on the right side of the screen can start the test.

When no TSF file is loaded (by pressing Cancel in the TSF selection window) all parameters will be at zero and can be configured by the operator.

Test initialisation and self test

When the start button is pressed, the software first runs a number of checks.

1. The presence of a valid software key is checked.
2. The software settings are checked (i.e. is all test equipment used within its parameters?)
3. The presence of all test equipment is checked.
4. All relevant equipment will be initialised.

When one or more of the above tests fail, an error message is displayed.

The figure below shows the TSF window.

Test site information

Device name	Tab in Radimation configuration window
Spectrum analyser	Standard 2
Pre amplifier	Standard 2
Antenna	Standard 1

Cables

#	Device name	Tab in Radimation configuration window
1	Pre amp->Spectrum	Cables
2	Ant->Pre amp	Cables

Note:

Usage of cable correction factors is not mandatory. However, using correction factors will increase measurement accuracy during emission measurements. When in doubt contact your reseller.

Manual mode

For product improvements, it quit often is required to operate the test set-up in manual mode. This can be done either by operating the measurement receiver (or spectrum analyser) manually or by the RadiMation^® software. In our opinion it is no use to take over the buttons of the receiver without adding any extra functionality. For this reason a number of handsome futures are included in manual mode.

Receiver settings

The receiver setting menu allows the operator to configure the measurement receiver. The following parameters can be configured:

Start

Sets start frequency

Stop	Sets stop frequency

Reference

Sets the reference level of the receiver

Attenuator

Sets the receiver attenuator level

RBW	Sets the Resoution Band Width filter

VBW	Sets the Video BandWidth filter

Sweep

Sets the sweep time of the receiver

Pre-amp

Sets the pre-amp gain

When a parameter is set to auto, RadiMation^® will determine the most optimum settings for this parameter. If the parameter is set to coupled, the parameter will be set to automatic internally in the receiver.

The left column in the receiver setting menu shows the parameters as configured by the test engineer while the right column shows the actual receiver configuration.

The figure shows the receiver settings menu.

Data correction

The semi- manual mode of RadiMation^® uses the PC screen to display the emission data real time on the computer screen. However the measured data is corrected for antenna factors and cable losses.

Peak menu

Search peak

RadiMation® can detect peaks automatically. From the “peaks” TAB, choose “Search peak” to detect the maximum signal. The software will measure the detected peak.

Add peak

The measured values can be added to the peak list by pressing the “Add Peak” button.

Search angle

By pressing the “Search Angle” button, the software starts a turntable scan to determine at which turn table angle maximum emission takes place.

Search Height

By pressing the “Search Height” button, the software starts an antenna height scan to determine at which antenna height maximum emission takes place.

The picture below shows the “manual mode” peak list option

Traces Menu

Traces

In the “traces” menu, a maximum off four traces can be switched on. Each trace can be appointed to be a Max hold trace, Average trace, Write trace or be switched either to View mode or just left Blank.

The figure below shows the traces menu:

Detectors

In the traces menu, The following detectors can be switched on and off:

• Peak detector
• Average detector
• Quasi peak detector
• RMS detector

Turntable and antenna tower position

The turntable position and antenna height can be entered. The manual mode measurements will be carried out on the entered antenna height and turntable position.

Zoom function

RadiMation^® features a live zoom function. When the operator wants to “zoom in” on a certain signal just use the mouse to drag a box around the signal of interest. The RadiMation^® software will fully automatic zoom in to this signal. The screen, as well as the measurement receiver will be zoomed. This reduces the number of actions of the operator significantly.

The figures on the next page show how to drag a box to zoom into a graph, while the second graph shows the zoomed graph.

The following options are possible for the automatic zooming function:

X-axis

When this option is switched on, the frequency settings of the receiver and the graph will be automatically adjusted when the user zooms in to the graph.

Y-axis

When this option is switched on, the amplitude settings of the receiver and the graph will be automatically adjusted when the user zooms in to the graph.

Under the “traces” TAB, the user can select two different ways of zooming:

X-axis

When this option is switched on, the frequency settings of the receiver and the graph will be automatically adjusted when the user zooms in to the graph.

Y-axis

When this option is switched on, the amplitude settings of the receiver and the graph will be automatically adjusted when the user zooms in to the graph.

Limit lines

Under the TAB “limit lines”, limit lines can be added to and removed from graphs. The limit lines must be previously defined (See also creating new limit line files).

Export menu

Data from the graphs and peak list can be exported to the clipboard by pressing the corresponding icons in the export menu. From the clipboard, the graph (or table) can be pasted in to any Windows application.

Merge function

The merge function is used to merge separate emission graphs to one graph.

The figure below shows the merge window. All emission tests, carried out on the Equipment Under Test, will be shown in this menu. The operator can select which emission measurements have to be merged together.

The results of the merge action will be stored in the EUT window, together with all other test results.

X+k*S Calculations

The X+k*S function is a statistic calculation method used when a number of the same measurements are made to the same type of EUT.

The figure below shows the X+k*S function window. All emission tests, carried out on the Equipment Under Test, will be shown in this menu. The operator can select on which emission measurements the calculations have to be performed.

The results of the X+k*S function will be stored in the EUT window, together with all other test results.

Anechoic chamber (Multi band)

The test engineer can configure a complete radiated emission test in the Radiated Emission configuration menu. The test engineer can change the frequency range from one frequency band or the RBW of several bands. It all depends on the selection of bands. When several bands are selected and some options are blank, this means that these settings in bands are different. For example if the test engineer selects both frequency band in de window above, the frequency range will be blank. If the engineer sets the start and stop frequency, all the selected bands will have the same frequency setting. One of the advantages of this feature is the quick settings of several settings like the RBW or the peak detection.

Frequency window

In the frequency window, the test engineer can enter a frequency range to be measured. Pressing Add a new frequency band to the test, Remove will remove all selected bands and Duplicate will duplicate all selected bands.

Turntable window

In the turntable window, the following parameters can be configured:

Start position

Sets the start angle of the turntable.

Stop position

Sets the stop angle of the turntable.

Steps

Sets the number of steps for one turntable rotation.

EUT angle offset

The offset of the EUT compared to the zero angle of the table.

Optimize Angle

Optimized settings for searching the correct angle.

Turntable window optimize angle settings

When optimize angle is selected, the user can configure the way a peak search is performed. In the optimize angle configuration window, the following configurations can be made:

Area	Range over which the peak search will be performed (0 to 360 degrees max.).

Step size

The angle step size.

The area is defined 50% left of the starting position and 50% right. So if the area is 30 degrees, RadiMation will scan between starting position plus and minus 15 degrees.

In the detector window the test engineer can select which detectors to use for measuring the optimal angle. After selecting the detectors the measure time and observation time of the selected detector are enabled. It is possible to use other settings for finding the peak then the settings on the main configuration window.

Antenna tower window

In the antenna tower window, the following parameters can be configured:

Max. height

Sets maximum height of the antenna tower.

Min. height

Sets the minimum height of the antenna tower.

Steps

Sets the number of steps to go from min. height to max. height.

Optimize height

The software will automatically detect on which antenna height maximum emission will occur.

When Optimize height is selected, the user can configure the way a peak search is performed.

Optimize height settings

When optimize height is selected, the user can configure the way a peak search is performed. In the optimize height configuration window, the following configurations can be made:

Area	Range over which the peak search will be performed (0 to Max height).

Step size

The height step size.

The area is defined 50% above of the starting position and 50% below. So if the area is 1 meter, RadiMation will scan between starting position plus and minus 50 cm.

In the detector window the test engineer can select which detectors to use for measuring the optimal height. After selecting the detectors the measure time and observation time of the selected detector are enabled. It is possible to use other settings for finding the peak then the settings on the main configuration window.

Antenna window

Polarisation

In the antenna window the user can select the antenna polarisation. The test engineer can select the following three options:

1. Horizontal
2. Vertical
3. Both

When Horizontal or Vertical is selected, the software will measure only one antenna polarisation. When the option “Both” is selected, the software will measure both Horizontal and Vertical polarisation (an antenna positioner is required for this option).

When this option is selected, all data will be displayed in one graph thus loosing some polarisation information. However the peak list table will show if a peak was measured in horizontal or vertical polarisation.

If the both emission graphs of horizontal and vertical polarisation are required, two separate tests must be configured. These tests can be put in a sequence, eliminating the need for a user intervention.

Distance

RadiMation uses the distance information for reference only.

Receiver settings

Reference level

Sets the reference level of the receiver.

Attenuator

Sets the receiver attenuator level.

RBW	Sets the Resolution Band Width filter.

VBW	Sets the Video Band Width filter.

Sweep

Sets the sweep time of the receiver.

Step frequency

Sets the frequency step size of the receiver.

Measure time

Sets the measure time of the receiver.

Pre-amp

Sets the pre-amp gain.

When a parameter is set to auto, RadiMation® will determine the most optimum settings for this parameter. If the parameter is set to coupled, the parameter will be set to automatic internally in the receiver.

Traces window

In the traces window, the test engineer can select a maximum of four traces, which can be measured and displayed at the same time.

Number of sweeps

The number op peak hold sweeps for each measurement can be selected. If this value is set to, for example 10, the software will measure the frequency band 10 times for each turntable and antenna tower position. This value will normally be set to 1 for measurement receivers while a higher value is used for spectrum analysers. The amount of required peak sweeps is depending on the type of signal and the setting of the sweep speed. For spectrum analysers and CW signals you can use a relatively low amount of peak sweeps, for example 10. But when you have discontinues signals like a spark bridge, you may need 100 peak sweeps or more. A good indication if you are using enough peak sweeps is to look at the envelope of the frequency spectrum. When it has gaps or jumps then you are not using enough sweeps to determine a correct signal envelope.

Final peak measurement

In the final peak measurement window the test engineer can configure the detectors used during the final emission measurements of the peaks. The first value is the time constant of the detector while the second value is used for the measure time at each frequency point for this detector. The time constant is send to the receiver, to set the sample time of the detector. To select a detector, check the desired button.

Peak detection window

No peaks

When no final peak measurements are required select the option no peaks.

Max. Peaks

With the max. peaks option, the user can limit the number of peak signals the software will detect and re-measure.

Test site window

Test equipment

In the test site window the test engineer can select which equipment list will be used during this test.

It is possible to use different test equipment for every configured frequency band.

Equipment icon

By clicking on the equipment icon, the equipment list can be viewed and edited.

Limit lines window

In the limit line window the operator select one or more limit lines to be used during the test.

All peaks above “xx” below the limit lines

In the peak detection window, the test engineer can configure which signal peaks must be detected. If the operator selects a value of 6 dB, the software will detect all peaks, which are higher than 6 dB below the limit line.

Change Order window

In some case you want to switch for example the antenna height scan before the turn table scan because this will decrease the total measuring time. With the change order the test engineer can control the way RadiMation® performs the testing sequence. Read the list from top to bottom to see what changes first. The best way explain the change order window is by example.

You need to perform a test as shown but you have 2 test sites. One with an antenna with the frequency range that is equal to the total band. The second test site you have 2 antennas, one for every frequency band. For test site one you want the RBW filter to change as little as possible to prevent the old analyzer from breaking down.

So for Site 1 you want:

• Band A RBW 9 kHz
• Band B RBW 9 kHz
• Band A RBW 120 kHz
• Band B RBW 120 kHz

And for test site 2:

• Band A RBW 9 kHz
• Band A RBW 120 kHz
• Band B RBW 9 kHz
• Band B RBW 120 kHz

For test site one, we do not have to change the order. Why? you may wonder. The explanation is quite easy. Look at the frequency change list, first change frequency band then change RBW. That is exactly what you want. Let check what the software is going to do:

• Band A RBW 9 kHz
• Band B RBW 9 kHz
• Band B RBW 120 kHz
• Band A RBW 120 kHz

This is even better then we had hoped for, the amount of switching has been decrees due to the fact that RadiMation® detected that it had to measure the same frequency twice.

For test site two, it is a bit more complicated. You might wonder why? It looks easy just put the RBW in front the Frequency band and you are done. So far you are correct, but a different antenna also means a different test site. So changing the test site should also be above frequency band. When doing so, lets check it again. The top three settings:

• RBW
• Testsite
• Frequency band

In words again, first change the RBW then the test site and then the frequency band.

• Band A RBW 9 kHz
• Band A RBW 120 kHz
• Band B RBW 120 kHz
• Band B RBW 9 kHz

This is also better then we had hoped for, the amount of switching has been decrees due to the fact that RadiMation® detected that it had to measure the same RBW twice.

Note:

If you have any questions regarding the setting of the change order please contact your reseller.

Starting a Anechoic Chamber test

Loading a TSF file

To start a radiated emission test, an EUT file must be defined first. From the EUT file, select “Tests > Radiated emission > Anechoic chamber. A list of Technical Setup Files (TSF files) will be displayed. The test engineer can select one of these TSF files to load all parameters from a previously defined emission test or press cancel to define a new emission test.

The figure below shows the TSF window.

After the TSF file has been selected, the emission configuration window will appear.

When a TSF file is loaded, all test parameters will be already configured and pressing the start button on the right side of the screen can start the test.

When no TSF file is loaded (by pressing Cancel in the TSF selection window) all parameters will be at zero and can be configured by the operator.

Test initialisation and self test

When the start button is pressed, the software first runs a number of checks.

1. The presence of a valid software key is checked.
2. The software settings are checked (i.e. is all test equipment used within its parameters?)
3. The presence of all test equipment is checked.
4. All relevant equipment will be initialised.

When one or more of the tests mentioned above fail, an error message is displayed.

Info screen

Note:

The pass/fail criteria, shown in the tables do not take the measure uncertainty of the test setup into account.

You can access the info screen by selecting the test you whish to see and then press the info button. The window appearing looks a lot like the manual mode screen, the reason that it looks the same is because it is. You can continue testing after you finished a test, just select the test site you want to use and you can continue testing.

Note:

Continuing the test is only possible with the selected test site. RadiMation will not select the correct test site for you. All measurements are done with the selected test site. If you want automatic changes of the test site, restart the configured TSF file.

Test site information

Device name	Tab in Radimation configuration window
Spectrum analyser	Standard 2
Pre amplifier	Standard 2
Antenna	Standard 1

Cables

#	Device name	Tab in Radimation configuration window
1	Pre amp->Spectrum	Cables
2	Ant->Pre amp	Cables

Note:

Usage of cable correction factors is not mandatory. However, using correction factors will increase measurement accuracy during emission measurements. When in doubt contact your reseller.

Manual Mode (Multi band)

Receiver settings

With receiver settings the test engineer has full control over the analyzer/receiver. Depending on the personal taste the frequency range can be set using in Center/span or start/stop mode. The rest of the settings speak for themselves except the buttons on the bottom. The test engineer can use them to select which type traces should be used to measure the spectrum. For configuring the detectors used during final measurement see chapter “Final measurement”.

Turn table

The turn table settings are directly linked to the turn table. Meaning that when a test engineer changes one of the settings then RadiMation® will apply this setting directly.

Antenna tower

The antenna tower settings are directly linked to the antenna tower. Meaning that when a test engineer changes one of the settings then RadiMation® will apply this setting directly.

Test site

Before manual mode can be used the test site needs to be selected so that Radimation® knows which devices to use.

Final measurement

In the final peak measurement window the test engineer can configure the detectors used during the final emission measurements of the peaks. The first value is the time constant of the detector while the second value is used for the measure time at each frequency point for this detector. The time constant is send to the receiver, to set the sample time of the detector. To select a detector, check the desired button.

Peaks window

Take sweeps

Triggers the receiver of analyzer to take the configured amount of sweeps.

Detect peaks

Detects the configured amount of sweeps in the measured spectrum.

Measure Peaks

Measures all selected peaks with the configured settings in the final measurement window.

Delete Peaks

Delete the selected peaks from the list.

Peak actions

Allows several actions to be performed on the detected peaks, like select all and deselect all.

Resolution BandWidth

Video BandWidth

Carrier Wave: An unmodulated RF signal

Continuous wave: An unmodulated RF signal

Decibel

Test Setup File

Equipment Under Test

Root Mean Square

Open Area Test Site

Personal Computer