RadiMation Error: 536872031
IF overload is detected
When a test is started or while a test is running, an IF overload (or RF overload) indication is generated by the scanning receiver or spectrum analyser. This error notifies you that the IF circuit in the spectrum analyser/receiver has been overloaded. A RF overload indicates that a signal is to hard for the input of the receiver or spectrum analyser. An IF overload indicates that a signal is to hard on some point in the electrical measurement circuit of the receiver.
The measured signal can for example be too hard to be measured, due to short duration pulses. It can for example be caused by ESD discharges that are generated by moving components in the anechoic chamber, like a not correctly grounded turntable.
A RF/IF overload is not caused by a wrong command or instruction that is transmitted by software to a receiver. It actually is a too hard signal in the electrical measurement circuit of the receiver itself. Manual configuration (without using software or a PC) of the measurement settings on the receiver itself, using the same settings as is configured in the software, will also with the manual configuration cause RF/IF overload messages.
Solution
The solution is to reduce the amplitude of the signal provided on the input of the receiver or spectrum analyser.
It is a task of the EMC test engineer to identify the cause of the (temporarily short duration) pulses, and to take precautions to prevent that the pulses are causing a too high amplitude on the receiver.
This can be achieved in multiple ways, also depending on the actual test configuration that is used, and the cause of the actual signal triggering the IF overload:
- Identify the cause, and remove the actual source that is generating the high signal.
- Sometimes IF overload situations are caused by unintentional discharges or spikes. It is possible that with repeating the measurement it is possible to perform the measurement. By clicking on 'Automatic' again in the multiband emission test, the test will repeat the last sweeps with the spectrum analyser, and will continue to perform the measurement from where it was interrupted.
- Increase the reference level (in most analyzers this also increases the attenuation level) by specifying a higher reference level in the test configuration.
- Use a fixed and increased value of the internal attenuator instead of the auto attenuator setting in the test configuration.
- Use fixed value for the reference level instead of auto. An auto setting is not always available on the actually used spectrum analyser, and setting a fixed value for the reference level ensures that the value that you have set is actually the value used during measurement. When fixed settings can be used this is always advised.
- Turn off the internal preamplifier in the used spectrum analyser. In the test configuration this can be done by specifying a value of 0 dB for the Preamp.
- If the signal level is still to high after raising the reference level and/or the attenuator value, you are possibly dealing with a signal that is to high for the input. In this case you need to bring the level down by using a physical external attenuator before the input of the receiver. Be aware that adding an additional attenuator in front of the receiver also requires that a correction is applied in software for that attenuator to maintain correct measurement results.
- Remove any physical external preamplifier in front of the input of the spectrum analyser. Be aware that removing the external preamplifier also requires that the external preamplifier is removed from the testsite in RadiMation, and that possibly applied corrections should be removed to maintain correct measurement results.
The RadiMation® software can of course help in activating the correct attenuator and reference levels as they are configured by the EMC test engineer in the test configuration. It remains a task of the EMC test engineer to identify the cause and problem, and to decide for the correct measurement settings that should be used to configure the receiver, related to the signal that is being measured.
If you remain having issues with RF/IF overloads please get in touch with our software support team for further assistance so that we can further help and advise.
