1. Study of Electromagnetic Radiation from Microwave oven using Mathematical Model Presented by Kiran Phalak ID : 6514081

2. Exactly What?  Characteristics and shape of signal generated in microwave oven  Different components possessed by signal  Mathematical modeling of microwave oven signal

3. What is mathematical model?  Mathematical Equation which represents the signal response accurately  It contains all the parameter which affects the behaviour or value of signal

4. Why to study Interference?  Acts as unintentional antenna for ISM band technologies  Interference and noise is more due to very high power  EM radiation are harmful for health of units working in vicinity

5. Microwave oven signal FM SWEEP TRANSIENT PULSES

6. Microwave oven signal Amplitude Modulation

7. Characteristics of Microwave signal  Carrier frequency of 2.455 GHz  Turns ON during positive half cycle of power signal  Frequency modulated signal having frequency sweep proportional to 60 Hz power signal  FM signal has varying power which follows envelope of 60 Hz power signal  Transient signals which are sinc pulses are at the start and end of ON period

8. 6 step approach for MWO model 1. Effective MWO Signal  Periodic signal  C(t) is signal in one single period

9. 6 step approach for MWO model 2. Signal during ON time Transient Pulse at the START of ON period Transient Pulse at the END of ON period FM Sweep signal

10. 6 step approach for MWO model 3. Transient Pulse signal  Transient pulse can be represented as summation of N sinc pulses having bandwidth parameter b  transient pulses are located at ± Td from centre of pulse  Pulse has energy is given by function E(fn)

11. 6 step approach for MWO model 4. Energy function of each pulse  Modified Rayleigh function [1]  N sinc pulses are situated from f1 to fN  These pulses are separated uniformly with frequency fn  fpk is that sub carrier at which maximum energy is situated  Fh = fN - fpk

12. 6 step approach for MWO model 5. AM-FM signal  Ax(t) is instantaneous amplitude of AM-FM signal  cosine part gives frequency modulation effect as deviation is proportional to power line frequency fac

13. 6 step approach for MWO model 6. Amplitude modulation effect  x(t) shows that amplitude of AM-FM signal is varying with power line frequency fac  Therefore envelope of signal follows 60 Hz power signal

14. MWO model = 13 variables In short, Microwave oven signal can be represented by 13 independent variable model 1. fac 2. F1 3. fN 4. Fpk 5. fa 6. fb 7. Tp 8. Ts 9. Td 10. β 11. b 12. E 0 13. A

15. Simulation Results After scaling down to MHz range and considering all the variable values of lab experimental case, Software simulation gives : Effect of FM sweep Effect of transient pulses

16. Conclusion  Microwave oven signal is mathematically modeled through AM-FM model  Maximum radiation frequency from Microwave oven signal  Simulation results are useful for designing material for microwave oven  This result is also useful in data communication technology at ISM to make system less susceptible to these frequencies

17. References [1] J. Proakis, M. Salehi, Communication Systems Engineering, 2nd ed. Upper Saddle River, NJ: Prentice Hall, 1994. [2] T.M. Taher, M.J. Misurac, J.L. LoCicero, and D.R. Ucci, “Microwave Oven Signal Interference Mitigation For Wi-Fi Communication systems,” accepted for publication at Proc. IEEE Consumer Communications and Networking Conference, Jan. 2008. [3] http://www.math.ufl.edu/help/matlab-tutorial/http://www.math.ufl.edu/help/matlab-tutorial/ [4] T.M. Taher, A.Z. Al-Banna, J.L. LoCicero, and D.R. Ucci, “Characteristics of an Unintentional Wi-Fi Interference Device – The Residential Microwave Oven,” in Proc. IEEE Military Communications Conference, Oct. 2006.

18. Questions