CONDUCTED RF:
Conducted RF immunity test is performed to check whether the EUT functionality is compromised or not, when a RF noise gets coupled to the EUT through its one or more ports. Some how I have not seen major issues with this test and that might be because I have worked more on digital circuits. There might be exceptions, but in general, digital circuits are less susceptible to continuous RF while analog circuits are more so.
The purpose of the test is to simulate the proximity of the EUT and its connected cables to radio transmitters and RF manufacturing equipment operating at low frequencies. These frequencies are not easy to test as it is hard to generate uniform fields in typical test facilities at frequencies much below 80MHz, but for typical sizes of apparatus the immunity problems at frequencies below 80MHz are normally associated with cable coupling, so conducted testing of the cables is seen as a reasonable alternative to radiated methods at such frequencies. Conducted RF immunity testing is also a lot less costly to do properly than radiated RF immunity. Please refer the link below and the IEC 61000-4-6 standard to learn about the conducted RF test procedures
http://www.compliance-club.com/archive/old_archive/011021.htm
The purpose of the test is to simulate the proximity of the EUT and its connected cables to radio transmitters and RF manufacturing equipment operating at low frequencies. These frequencies are not easy to test as it is hard to generate uniform fields in typical test facilities at frequencies much below 80MHz, but for typical sizes of apparatus the immunity problems at frequencies below 80MHz are normally associated with cable coupling, so conducted testing of the cables is seen as a reasonable alternative to radiated methods at such frequencies. Conducted RF immunity testing is also a lot less costly to do properly than radiated RF immunity. Please refer the link below and the IEC 61000-4-6 standard to learn about the conducted RF test procedures
http://www.compliance-club.com/archive/old_archive/011021.htm
The standard cable-coupled RF immunity test of IEC 61000-4-6 specifies an injected level, typically of 3V or 10V open circuit voltage from a source impedance of 150 ohm, in common mode into each interface to be tested. The test frequency range is 150kHz – 80MHz (expandable up to 230MHz). So, there are two principal parameters defined in conducted RF tests, the frequency range and the test level.
The exact frequency range used for a test is defined in the corresponding product standards. Frequency range is chosen defending on the size of cable and EUT. In general, if the cable and EUT length is λ/4, the upper frequency may be increased. This rule also holds true for the start frequency which may be higher than the specified 150 kHz. Start frequencies would be increased when the cable and EUT length is λ/4.
The exact frequency range used for a test is defined in the corresponding product standards. Frequency range is chosen defending on the size of cable and EUT. In general, if the cable and EUT length is λ/4, the upper frequency may be increased. This rule also holds true for the start frequency which may be higher than the specified 150 kHz. Start frequencies would be increased when the cable and EUT length is λ/4.
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