EMI receivers used for EMC testing are difficult to operate or understand at a deeper level without software. EUTTEST has compiled the following early R&S ESRP receiver webinar, which focuses on the operation of R&S EMI test receivers and on-site Q&A recordings in the hope that it will be helpful to all EMC test engineers. The following is an early R&S webinar on ESRP receivers.
EMI Test Receiver Operating Guide and Field Q&A Record:
Netflix:In what ways do pre-certified and certified receivers differ, and can't the test results of pre-certified receivers be used as final test results? Are the test results of pre-certified receivers only for reference purposes?
R&S Expert Answer:Pre-certified and certified receivers are positioned differently. ESRP pre-certified receivers have the same results as certified receivers when the interference repetition frequency is not less than 10 Hz, but rigorous certification testing still requires certified meters because the type of interference is unknown and the judgment is very complex.
Netflix:ESPI is calibrated punctually given a fixed value of the signal, you must adjust the attenuation of the receiver to get the corresponding size of the signal (provided that we already know the size of the signal to adjust the attenuator), but we do not know the size of the test signal when we are actually testing it, so it will be inaccurate in the test? What is the reason for this?
R&S Expert Answer:ESPI receiver in the self-calibration (Cal total), will automatically open the internal 128MHz known calibration signal, the signal is not required to adjust the attenuator settings can be measured to the exact level; in addition to adjusting the attenuator will not affect the amplitude of the external input signal size, the actual use of a signal because of the adjustment of the amplitude of the attenuation and the change, it can basically be determined that the signal is receiver overload caused by the receiver, so in the actual test will not be inaccurate.
Netflix:When the instrument is on, if I want to connect VGA or other ports, do I need to turn off the power before connecting?
R&S Expert Answer:Generally speaking, good grounding environment, GPIB, LAN interface, VGA interface can be directly connected, but pay attention to the electrostatic protection; however, if the working environment of the grounding is not good, the shell may be electrically charged, but also in the moment of contact may cause discharge.
Netflix:My teacher has just talked about pre-testing, I would like to ask what is the importance of pre-testing for electronic design engineers?
R&S Expert Answer:Pre-testing can be done before the product is sent to the certification laboratory, greatly reducing the probability and cost of repeated testing, is very necessary.
Netflix:The biggest headache I usually have when performing EMI rectification is port radiation. Is there much difference in test results for radiation and conduction between different test equipment?
R&S Expert Answer:Thanks for the concern, ESRP is perfect for rectification testing, whether it be radiated or conducted. Test equipment that complies with the standard should give the same results, which is one of the purposes of the standard. However, in actual testing, the results may vary depending on equipment accuracy, accessories, site layout, and personnel operating factors.
Netflix:What are the differences between ESRP and a spectrometer or oscilloscope for pre-testing?
R&S Expert Answer:ESRP is a pre-certified receiver with a preselector. For interference signals with pulse repetition frequencies above 10Hz, the results are consistent with the certified receiver, which cannot be achieved by spectrometers and oscilloscopes, and is the most important reason for users to select the pre-certified receiver ESRP.
Netflix:When we measure RE, we usually measure 30MHz to 1GHz, if we use a fast FFT in the time domain, wouldn't the sampling frequency be at least 2GHz?CISPR 22 goes up to 6GHz, and the sampling frequency needs to be at least 12GHz, will the highest sampling frequency of the new receiver ESRP be that high?
R&S Expert Answer:The ESRP combines a conventional receiver with an FFT time-domain scan. The FFT is implemented at IF, so it doesn't need such a high sampling rate.
Netflix:For ESCI or ESPI in spectrum mode, what is the meaning of OV TRC appearing on the left side, OV TRC is OVLD appearing, IFOVL appearing and then appearing again, what if it is canceled out?
R&S Expert Answer:OV TRC means the mixer is temporarily overloaded. overload state is harmful to the receiver, it is recommended to increase the attenuator or set to "AUTO".
Netflix:For the receiver to have OV TRC, the product has a preselector that is turned on and the attenuator is set to AUTO, what else should be set to make it eliminate OV TRC?
R&S Expert Answer:In case of ESU, Port2, AC coupling is selected; if the pre-test receiver is predicted, there may be pulsed signals below 10Hz, it is recommended to manually set up an increased attenuator in the Receiver Mode, Scan Table.
Netflix:My setup has the attenuator set to AUTO, but if I read points in the 150KHz-260KHz range, I get OV TRC How should I set it?
R&S Expert Answer:The signal under test may be broadband, if it is a receiver with a preselector, this will be avoided to the greatest extent possible.
Netflix:For ESCI scanning modes, what is the difference between PEAK and SAMP?
R&S Expert Answer:Each display point on the spectrum curve corresponds to multiple sample values, with PEAK corresponding to the largest of these and SAMPLE to the first.
Netflix:For ESPI, if the wheel fails and there is no way to rotate the cursor to move it, can there be another way to move the cursor? Will this problem affect the test performance of ESPI?
R&S Expert Answer:It can also be moved by pressing the up and down buttons, which does not affect the accuracy of the test, but is less convenient.
Netflix:When doing a Bluetooth test there will be a situation where the average exceeds the peak, what is the reason for this?
R&S Expert Answer:receiver state, which is not normally the case with single frequency point readings.
Netflix:How does the speed of the ESPR test QP values compare to the ESR?
R&S Expert Answer:Looking at the detector alone, there is no difference in speed between the QPK detector of the ESRP and the QPK detector of the ESR, and both test times have to meet the requirement of greater than the signal period. But the time domain scan mode speed of ESR receiver is much faster than ESRP. So, for example, ESR is much faster than ESRP for direct QPK detector for final test in CISPR B band.
Netflix:The analysis bandwidth (demodulation bandwidth) of a spectrometer refers specifically to the bandwidth of which component of the spectrometer?
R&S Expert Answer:Filter bandwidth for I/Q analysis.
Netflix:What is the ESRP test frequency range to?
R&S Expert Answer:The maximum frequency range is from 10Hz to 7GHz.
Netflix:What is the reasonable number of sweep points to choose for EMI pre-scan, such as 1-18GHz Span scan? How many sweep points should I choose so that I won't miss any signal points? I understand that frequency\ step should not be greater than 0.5RBW to be more reasonable, what is your understanding? Thanks for your understanding!
R&S Expert Answer:When pre-scanning, it is recommended to use the receiver mode, set the STEP SIZE in the scanning table to be less than one-half of the IF bandwidth, and the number of points is set automatically, at this time, it can be guaranteed that there is no leakage of points.
Netflix:May I ask why VBW=10Hz, the measured value can be the AV value, what is the relationship between this and Detector AV value?
R&S Expert Answer:VBW is a low-pass filter that filters the signal after the envelope detector, in some cases the effect is similar to multiple trace averaging, but with the average value detector is a different concept.
Netflix:Will there be a difference between self-calibrated and non-self-calibrated tests?
R&S Expert Answer:Instruments that have not been self-calibrated for a long period of time (e.g., six months) have large differences before and after calibration.
Netflix:What are the advantages of using R&S ESRP to perform conducted interference testing with a quasi-peak detector according to CISPR band B in time-domain scanning mode over using conventional testing methods? For example, in terms of time, how much time can be shortened? Also, just checking the information it seems to say that it comes with a spectrum meter.
R&S Expert Answer:The time domain scan mode of the ESRP receiver can greatly increase the speed of the test, the time must be much shorter, about thousands of times faster. Yes, comes with a spectrum meter function.
Netflix: Yeah, if it's faster and shorter there's no need for shifts. Kind of a one-stop shop.
Netflix:We are testing a microwave oven, a pulsed signal, and the ESU is cut to spectrum mode. What we have is:When RBW=1MHz, VBW=10Hz test Peak value above 1GHz, the result with ESU will be quite high, is it because ESU is more sensitive? These two devices should be the same in terms of testing peak value theoretically! The ESU also uses the spectrum function when testing, please ask the experts to help analyze it, thank you!
R&S Expert Answer:The pulsed signal is broadband and the receiver has a preselector to filter the signal below 1 GHz entering the receiver to improve the dynamic range when the microwave oven is tested above 1 GHz, while the spectrometer does not have a preselector. In addition, for a pulsed signal like a microwave oven, it needs a preliminary + final test, and after the preliminary test selects the frequency point, the final test is performed at a smaller SPAN, and the measurement time is much larger than the pulse period. It is recommended that the receiver mode selected frequency point for final test, the test time is greater than the pulse period This should be a broadband signal, ESU receiver state no VBW, no video filtering, while the spectrometer RBW for 1M, video filtering 10Hz. therefore, the receiver peak readings will be higher than the spectrometer readings. Do a comparison test: use a signal source to generate a sine wave signal, respectively, into the ESU and the spectrometer, the instrument settings are the same, the spectrometer mode, set the SPAN to 5 times the RBW, look at the peak reading. It should be the same.
Netflix:Is there any difference between ESU and FSP30 when testing PEAK values above 1GHz?
R&S Expert Answer:Spectrometers are prone to overloading for EMI testing due to the lack of a preselector, and as long as they are not overloaded, the results are consistent with a standards-compliant peak detector.
Netflix:What is the difference between FFT time domain scanning and the sweep function of a spectrum analyzer?
R&S Expert Answer:FFT time-domain scanning is still in the receiver mode, where the signal, after passing through the preselector, is frequency-converted to the IF, where an FFT is performed on a segment of frequencies to obtain the desired result; whereas in the spectrometer mode, the principal oscillator is continuously tuned to vary.
Netflix:I would like to ask why the receiver has a self-calibration that does not pass? Occasionally the self-calibration CAL RESULT all PASS, but after connecting to the system to test, the test result will be 2 to 3dB worse than the previous normal test result. what is the possible reason for this?
R&S Expert Answer:Check the "CAL result", you will find which one is not, to determine whether the hardware failure. Self-calibration is a known standard signal test, get the filter, frequency response, oscilloscope and all other components of the error, if out of the permissible value, the self-calibration is not, at this time it is necessary to send to the maintenance center for adjustment. It is recommended to warm up for more than 40 minutes before self-calibration, if the self-calibration is not recommended to send to the maintenance center for testing. Use the signal source and power meter to check if the level measurement is really inaccurate, if not, please send it to the repair center. It is not possible to self-calibrate frequently, it is recommended to save the calibration results of FAIL and feedback to our maintenance center.
Netflix:What is the difference between ESRP and ESPR? Are they replacing the original ESPI? So now the new generation of R&S products come with the time domain scanning option, does the ESU series come with this option?
R&S Expert Answer:ESR is the next generation of certified-grade receivers, while ESRP is pre-certified-grade. esrp is the next generation of espi. esu receivers are the highest-end receivers, and were the first to come with the time-domain scanning option, which was available many years ago.
Netflix:ESRP should be very sensitive as an EMI receiver, what is the bottom noise? Does it have modulation domain analysis function? What kind of signals can be analyzed? What kind of signal can be analyzed in the modulation domain? How fast is the frequency sweeping required to detect unknown interference signals?
R&S Expert Answer:1MHz-6GHz, with pre-amplifier can be below -160dBm/Hz, you need to check the manual for details.ESRP is mainly for EMI test application, currently there is no modulation domain analysis function, but it can analyze pulses, AM and other signals by using spectral patterns. The specific test time is related to the test setup, but compared to ordinary receivers or competitors' products, it is much faster.
Netflix:Can it be used to test the hopping time of a frequency synthesizer?
R&S Expert Answer:For this test it is recommended to use another instrument R&S FSUP signal source analyzer or R&S FSW real time spectrum analyzer.
The above is the content of this EMC test receiver Q&A, if you are interested in R&S receiver, you can contact EUTTEST through the right side of the consulting quote module for more information.
EMI test receiver product recommendations:
EUTTEST Shenzhen EUTTEST Technology Co., Ltd. agent of the German R & S receiver in the EMC test industry occupies a pivotal position, most of the EMC laboratories are using the German R & S receiver to carry out EMC in the EMI-RE, EMI-CE test, the test standard covers civil products, industrial products, power tools, automotive, aerospace, military equipment, wireless communication equipment and other fields. The test standards cover civil products, industrial products, power tools, automotive, aerospace, military equipment, wireless communication equipment and other fields. According to the above EMI test receiver operation guide and on-site Q&A record, you can choose the EMI test receiver products for yourself.
The most popular EMC test receiver models in China are as follows:
The following two models are EUTTEST's representative certified EMC-EMI test receivers
R&S®ESR3: 10 Hz to 3.6 GHz
R&S®ESR7: 10 Hz to 7 GHz
R&S®ESR26: 10 Hz to 26.5 GHz
R&S®ESW8: 2 Hz to 8 GHz
R&S®ESW26: 2 Hz to 26.5 GHz
R&S®ESW44: 2 Hz to 44 GHz
The following two models are pre-certified EMC-EMI test receivers sold by EUTTEST, contact EUTTEST for specific technical parameters.
R&S ESL
R&S®ESL6: 9 kHz to 6 GHz
R&S®ESL3: 9 kHz to 3 GHz
R&S®ESRP3: 9 kHz to 3.6 GHz
R&S®ESRP7: 9 kHz to 7 GHz