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UNIVERSITATEA TRANSILVANIA DIN BRAŞOV FACULTATEA INGINERIE ELECTRICA SI STIINTA CALCULATOARELOR

UNIVERSITATEA TRANSILVANIA DIN BRAŞOV FACULTATEA INGINERIE ELECTRICA SI STIINTA CALCULATOARELOR DEPARTAMENTUL DE INGINERIE ELECTRICA SI FIZICA APLICATA PROGRAMUL DE MASTER: SISTEME ELECTRICE AVANSATE Immunity to radio frequency fields. Project advisors: Prof. univ . Dr.Ing . Elena HELEREA

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UNIVERSITATEA TRANSILVANIA DIN BRAŞOV FACULTATEA INGINERIE ELECTRICA SI STIINTA CALCULATOARELOR

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  1. UNIVERSITATEA TRANSILVANIA DIN BRAŞOV • FACULTATEA INGINERIE ELECTRICA SI STIINTA CALCULATOARELOR • DEPARTAMENTUL DE INGINERIE ELECTRICA SI FIZICA APLICATA • PROGRAMUL DE MASTER: SISTEME ELECTRICE AVANSATE • Immunity to radio frequency fields • Project advisors: • Prof. univ. Dr.Ing. Elena HELEREA • drd.Ing. Cornel URSACHI • Absolvent: • Ing. Levente ERZSE BRAŞOV 2012

  2. Immunity to radio frequency fields Aim: Investigation of interference induced by RF field and experimental determination on some electronic devices degradation the RF testing. Objectives: O1. Investigation of radiofrequency radiation and sources of radiofrequency distorsions O2. Study of regulations regarding RF interference O3. Testing electrical and electronics device at RF interference using standard EM 61000-4-6 O4. Establishing the means for RF interference reduction

  3. Immunity to radio frequency fields Introduction • Passive receiving antenna networks • power supply cable • communication lines • cable interface • From these cable networks, becomed antennas, the equipment is exposed to currents flow through it. • Radio frequency interference or RFI is disturbance that affects an electrical circuit due to either electromagnetic induction or electromagnetic radiation emitted from an external source. The disturbance may interrupt, obstruct, or otherwise degrade or limit the effective performance of the circuit. • Conducted RF immunity refers to a product's immunity to unwanted 'noisy' RF voltages and currents carried by its external wires and cables.

  4. COMMUNICATION CHANNEL TRANSMITTER RECEIVER Immunity to radio frequency fields Radiofrequency radiation • Radiofrequency (RF) electromagnetic radiation (EMR) • Transfer of energy by radio waves. • Domane : 3 kHz to 300kHz • Transmitter- radiofrequency sources • Communication channel – air then all cables connected to equipment • Receiver- every electrical and electronic equipments and even human health

  5. Immunity to radio frequency fields Sources of radiofrequency disturbances Industrial scientific or medical equipment that use RF energy: -High Frequency Assembly Press Electronic components which operate at radio frequencies in an item of equipment also causes radiated electromagnetic fields. • Comunication: • Radio • Television • Radar transmitters • Celular phone • GPS

  6. Immunity to radio frequency fields Problems caused by conducted RF disturbances Sufficient levels of conducted RF noise can cause errors or malfunctions in the analogue or digital semiconductors These effects can range from a simple degradation of data to a total loss of data In analogue circuits, noise and signal distortion from interference can reduce the signal-to-noise ratio to negative values (more noise than signal).

  7. Regulations and test techniques Regulations andtest techniques: Immunity tests to perturbations induced by radio-frequency (RF) fields in the frequency range from 9 kHz to 80 MHz are covered by standard EN 61000-4-6:2009. This standard applies to the immunity requirements of electrical and electronic equipment to conducted electromagnetic disturbances coming from transmitters dedicated radio frequency (RF). Test methods defined are structured primarily to establish the reproducibility of the results corresponding to different testing laboratories in order to analyze qualitative effects.

  8. Regulations and test techniques Four different levels distinguishable from each other which reflects the perturbation intensity • Level 1: Enviroment with low electromagnetic fields • Level 2: Enviroment with media electromagnetic fields • Level 3: Enviroment with strong electromagnetic fields • Level x: Open test severity level, up to 30 V

  9. Regulations and test techniques For tests equipment, the signal is modulated 80% amplitude sine wave with a frequency of 1 kHz to simulate real threat.

  10. Regulations and test techniques CDN Coupling/ Decoupling Network • Coupling: • devices shall be used to ensure adequate coupling for disturbing signal (in whole frequency range with a defined common mode impedance at port EUT). • Decoupling: • devices shall be used to ensure adequate decoupling forthe various cables connected to the EUT and in order to prevent damage to other devices, equipment or systems that are not tested, by the signal test applied. • Coupling and decoupling network should ensure: • coupling signal disturbing the EUT; • stable impedance, seen from the EUT, independent of the common mode impedance auxiliary equipment (AE); • decoupling AE disruptive signal to avoid any interference from AE • transparency for the useful signal

  11. Regulations and test techniques CDN Coupling/ Decoupling Network Different type are specified in the standard •CDN-M1/2/3/4/5 (M=Mains) •CDNS-S9/15/25/38 (S=Shielded) •CDN-T2/4 (T=Telecom, symmetrical) •CDN-AF2/3/4/8 (AF, asymmetrical) •EM clamp •BCI Clamp (Bulk current injection) Coupling and decoupling for mains , asymmetric unshielded lines. R,C1 is the coupling part L, C2 is the decoupling part Injection by clamp - Current clamp: a transformer, whose secondary winding is made up of cable that is injected; - Electromagnetic field clamp (EM clamp) injection coupled device combined capacitive and inductive

  12. Regulations and test techniques Test mounting diagram for immunity to conducted radio interference. AE - Auxiliary equipment T - load resistor (terminal), 50 EUT – Equipment under test T2 - Power attenuator (6 dB) CDN: network coupling / decoupling RF generator – Radiofrequency generator

  13. Immunity to radio frequency fields • Experimental determination • Tree type of EUT have been investigated: • -PC power supply • -Mouse • Memory stick

  14. AC connector 3 EUT Disturbance Generator 1 3 CDN AE T2 T Immunity testing to radiofrequency fields on a PC Power Supply Structure of the FR immunity testing banch EUT – 250W PC power supply Disturbance - Frequencyapplied by the generatorwasfrom 150kHz to 250MHz modulatedwith 1 kHz and amplitude of 1V whichislevel 1 T2 - Attenuator 6dB CDN – Coupling network type CDN-M5 T – Load resistor with 100 Ω impedance,to realise the 150 ohm common mode impedance of the system AE – 200Mhz osciloscope for measuring

  15. AC connector 3 EUT Disturbance Generator 1 3 CDN AE T2 T Immunity testing to radiofrequency fields on a PC Power Supply Structure of the FR immunity testing bench Testing procedure EUT preparation disturbances generator calibration choseing CDN and T(load resistor) placing all equipment on a reference ground plane connecting cables according to the scheme running the test to a certain frequency from 150kHz to 250MHz modulatedwith 1 kHz and with amplitude of 1V read all outputs of the EUT on the oscilloscope increasing the test frequency and then take step 6

  16. Immunity testing to radiofrequency fields on a PC Power Supply The output variation of the EUT voltage, on frequency range from 150 kHz to 250 MHz It is the same for all of the 6 outputs (3.3V,5V,-5V,12V, -12V,5VSB) The output variation of the EUT voltage, on frequency range from 10 MHz to 39 MHz with smaller steps

  17. Immunity testing to radiofrequency fields on a PC Power Supply Schema block EUT (PC power supply) • The reason of the disturbanceesshod : • Input filter (primary circuit LC filter) • Output filter (secondary circuit LC filter) • Feedback circuit control • The commutation frequency and his harmonics interference with the disturbing signal • it is possible to say that the perturbance value is under 7% of the output value (12V)

  18. EUT AE Disturbance Generator CDN T2 Immunity testing to radiofrequency fields on a Mouse Structure of the FR immunity testing bench EUT – Logitecusb mouse Disturbance - Frequencyapplied by the generatorfrom 150kHz to 250MHz modulatedwith 1 kHz and amplitude of 1V whichislevel 1 T2 - Attenuator 6dB CDN – EM clamp AE – laptop mouse movement was normal in all frequency range of perturbation applied on it

  19. Immunity testing to radiofrequency fields on a Memory Stick Structure of the FR immunity testing bench DUT – memory stick Disturbance - Frequencyapplied by the generatorwasfrom 150kHz to 250MHz modulatedwith 1 kHz and amplitude of 1V whichislevel 1 T2 - Attenuator 6dB CDN – EM clamp AE – laptop Fistwe copy a file on the flash and for everytestedfrequencywe copy back to the laptop and verify the content, but itworkscorectlyin all frequency range of perturbation applied on it

  20. Immunity to radio frequency fields Conclusions • In dissertation paper have been developed • Investigation of radiofrequency radiation and Sources of radiofrequency distorsions • Study of regulations regarding RF interference • Testing electrical and electronics device at RF interference using standard EM 61000-4-6 • Establishing the means for RF interference reduction

  21. Immunity to radio frequency fields THANK YOU for your attention

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