RadiMation Application Note 145

How to perform a MIL-STD-461 RE102 Radiated Emission test

This application note explains how the MIL-STD-461 RE102 Radiated Emission test can be performed with RadiMation^®.

The "RE102, radiated emissions, electrical field" test is applicable to equipment, subsystem enclosures and all interconnecting cables and is used to verify that the electrical field emissions from the EUT and cabling do not exceed the specified requirements. Other standards are based on this test (for example DO160) and those tests are very comparable to this test.

The exact requirements and test methods for the RE102 are specified in the MIL-STD-461. Depending on the tested product, the complete or a partial frequency range should be tested.

Necessary equipment

The following devices should be configured:

• Receiver
• One or more antennas
• Cables

Depending on the frequency range that should be measured, up to four different antennas may be needed.

Antenna	Frequency range
Rod antenna	10 kHz to 30 MHz
Biconical antenna	30 MHz to 200 MHz
Double ridge horn	200 MHz to 1 GHz
Double ridge horn	1 GHz to 18 GHz

Optionally

• Antenna polarizer / tower, because above 30 MHz both vertical and horizontal polarizations should be measured.

Configuration of the testsites

The configuration of the equipment is an antenna connected with a cable to a receiver.

The configuration of the testsite should thus contain the following devices:

Device name	Tab in testsite configuration window	note
Antenna	Devices 1	Antenna for the required frequency range
Antenna tower	Devices 1	Optional antenna tower
Spectrum Analyser	Devices 2	The receiver used for the test
Cable preamp -> analyser	Cables	Cable with a correction file specified for the loss

As different antennas are used for each frequency range, it is best to also create and configure multiple separate testsites. Each testsite will use a different antenna, and to make the distinction between the testsites, it is best to give them different names. For example like:

Testsite	Antenna
MIL-STD RE102 10 kHz - 30 MHz	Rod antenna
MIL-STD RE102 30 MHz - 200 MHz	Biconical antenna
MIL-STD RE102 200 MHz - 1 GHz	Horn antenna
MIL-STD RE102 1 GHz - 18 GHz	Horn antenna

Perform the test

To perform the actual RE102 test, start a Radiated Emission Multiband test:

    Tests

       Radiated Emission

          Multiband

The complete test from 10 kHz up to 18 GHz has different settings for different frequency bands. All these different bands can be configured. The test can be configured with 6 bands each using their applicable frequency range, bandwidth, polarization and used testsite (antenna).

When it is not possible to automatically switch and or position the antenna, multiple tests can be created and executed separately.

Band	Frequency range	RBW	Step size	Measure time receiver	Measure time FFT receiver	Polarization	Testsite	Antenna
Band 1	10 kHz - 150 kHz	1 kHz	500 Hz	0.15 s	1 s	Vertical	MIL-STD RE102 (10 kHz - 30 MHz)	Rod antenna
Band 2	150 kHz - 10 MHz	10 kHz	5 kHz	0.015 s	1 s	Vertical	MIL-STD RE102 (150 kHz - 30 MHz)	Rod antenna
Band 3	10 MHz - 30 MHz	10 kHz	5 kHz	0.015 s	0.15 s	Vertical	MIL-STD RE102 (150 kHz - 30 MHz)	Rod antenna
Band 4	30 MHz - 200 MHz	100 kHz	50 kHz	0.015 s	0.15 s	Both	MIL-STD RE102 (30 MHz - 200 MHz)	Biconical antenna
Band 5	200 MHz - 1 GHz	100 kHz	50 kHz	0.015 s	0.15 s	Both	MIL-STD RE102 (200 MHz - 1 GHz)	Horn antenna
Band 6	1 GHz - 18 GHz	1 MHz	500 kHz	0.015 s	0.015 s	Both	MIL-STD RE102 (1 GHz - 18 GHz)	Horn antenna

For more information regarding required antenna positions refer to section 5.18.3.3 c. EUT testing, of the MIL-STD-461 RE102 standard. To automatically change the antenna position, an antenna tower could be used. When no antenna tower is available, multiple positions (heights) could be tested using a "Manual Controlled Antenna Tower", the "Manual Controlled Antenna Tower" will prompt the end-user to move the antenna manually when applicable.

In the following test setup, an EUT for "Ground applications, Navy Mobile & Army" is tested. This limit line starts at 2 MHz and ends at 18 GHz, therefore this test does not include the test site for "Band 1 (10 kHz - 150 kHz)"

Start

The start frequency of the test. For example 2 MHz.

Stop	The stop frequency of the test. For example 10 MHz.

Reference Level

The reference level set in an analyser, not used in a receiver

Attenuation

The attenuation set in the receiver

RBW	The RBW set in the receiver, see table with different bands for possible values

Step size

The step size set in the receiver, see table with different bands for possible values

Measure time

The measure time set in the receiver, see table with different bands for possible values

Preamplifier

The preamplifier setting set in the receiver

Traces

The type of trace set in the receiver, for MIL-STD-461 RE102 a peak detector is used

Test Equipment

The equipment used for the measurement, see table with different bands for possible values

Location type

Set this to "Antenna height, distance, polararization and angle"

Max Height

The maximum height for the antenna tower, configuration is depending on how many positions should be measured

Min Height

The minimal height for the antenna tower, configuration is depending on how many positions should be measured

Steps

The number of height positions to measure, configuration is depending on how many positions should be measured

Move during measurement

If the antenna tower can move during the measurement, not used during MIL-STD-461 RE102 measurement

Optimize Height

Find the optimal emission around a certain height, not used during MIL-STD-461 RE102 measurement

Distance

The used antenna distance, 1 Meter for MIL-STD-461 RE102

Antenna Polarization

Which polarization is used, Vertical, Horizontal or Both, above 30 MHz both polarization should be tested

Start Angle

The minimal turn table angle

End Angle

The maximum turn table angle

Steps

The number of angles to measure

Turn during measurement

If the turn table can move during the measurement, not applicable for MIL-STD-461 RE102

Optimize Angle

Find the optimal emission around a certain angle, not applicable for MIL-STD-461 RE102

EUT Angle Offset

The offset of the EUT on the table, not applicable for MIL-STD-461 RE102

Limit Lines

The applicable limit line can be added, in this case "MIL-STD-461G RE102 Ground Applications, Navy Mobile & Army"

All peaks above x dB below the limit line

Which level above x dB below the limit line should detect peaks, no peaks should be measured in MIL-STD-461 RE102

Peak detection

How many peaks should be detected automatically, no peaks should be measured for MIL-STD-461 RE102

Final peak measurement

It is possible to perform a final measurement on a peak with a specific detector, no final peak measurement is needed for RE102

When all parameters are configured for the RE102 test, press Start Test to perform the emission measurement.

Review the test result

Once the test is finished, the results of this test is stored in the EUT file, and available as one of the performed Tests in the EUT file. Selecting the corresponding test result and pressing on Info will show the test results again.

Conclusion

The MIL-STD-461 RE102 test has to use multiple antennas and depending on the frequency band, different settings are configured. All these settings can be easily configured in a "Test Setup File" and tested with RadiMation^®.

Equipment Under Test

Resolution BandWidth

Decibel