Electromagnetic harassment is electromagnetic noise, useless signal, or changes in the propagation medium. The frequency range is 0Hz ~ 400GHz.
Electromagnetic harass characteristics
1. The spectrum of unit pulse is the widest;
2. The low frequency content in the spectrum depends on the area of the pulse, the high frequency component depends on The steepness of the front and rear edge of the pulse;
3. The crystal oscillation level must satisfy a certain amplitude, the digital circuit can operate in a certain timing, and the harassment of the crystal oscillator exhibits coverage bandwidth, the characteristics of high harassment level;
4. When the antenna polarization, the direction characteristics are the same, EMI radiation and acceptance are the most serious; the larger the transmission and reception antenna area, EMI is more harmful;
5. Harassment: Radiation , Conduction, coupling, radiation, conduction, coupling combination;
6. The power cord conduction harass is mainly generated by common mode current;
7. Radiation harass is mainly formed by differential current The loop generation.
Electromagnetic harassment waveform
1. Transient () Transient (Adjective and Nou) physical quantity or physical phenomenon between two adjacent stabilization states, the change time is less than The time scale of attention.
2. The pulse Pulse mutated in a short time, and then quickly returned to its initial value of the physical quantity.
3. Fujian pulse Impulse For a given purpose, it is similar to a pulse of a unit pulse or Dirac function.
4. One-way pulse of a short duration of spike pulse SPIKE.
5. (pulse) Rising time RISE TIME (OF A PLUSE) pulse instantaneous time The time experienced from a given lower limit to a given upper limit (Note: except for special specification The outer lower limit and the upper limit are set to 10% and 90% of the pulse amplitude, respectively.
6. Rising Rate Rate of Rise One amount from 10% to 90% from the peak value within a specified numerical range, with time to change the average rate.
7. Radiant (pulse or oscillation) Burst (of pluth or oscillaions) a string of a string of clear pulses or a limited duration of duration.
8. Pulse Noise Impulsive Noise appears on a particular device as a series of clear pulses or transient noise.
9. Pulse harassment ImpulSive Disturbance appears in a particular device or device as a series of clear pulses or transient electromagnetic harassment.
10. Continuous noise Continuous Noise's effect on a particular device cannot be decomposed into a cyclic-changing effect of noise.
11. Continuous harassment of Continuous Disturbance The effect of a particular device cannot be decomposed into an electromagnetic harassment of a stroke clearly identical effect.
12. Quasi-Impulsive Noise is equivalent to superimposed noise of pulse noise and continuous noise.
13. Discharge Discontinuous Interference appears in an electromagnetic interference within a certain period of time being intermittently separated by no interference.
14. Random noise RADOM Noise is a given instantaneous value unpredictable noise.
15. When the 呖 呖 呖 Click is measured by a predetermined method, its duration does not exceed the electromagnetic harassment of a certain specified value.
16. 呖 呖 Click Rate unit time (usually per minute) exceeds a certain level of 呖.
17. Based on the Fundamental (Component) a cycle of the volume of Barley Level.
18. Harmonic (component) Harmonic (Component) One cycle of Fourier-level number is higher than one component.
19. Harmonic number of Harmonic Number integer ratio of the harmonic frequency and the fundamental frequency. Harmonic number is also called Harmonic ORDER.
20. The ratio of Nth Harmonic Ratio Nth Harmonic Ratio Nature and Base Wave Root Root Value.
21. Harmonic content Harmonic Content subtracted from an alternating variable to the amount obtained after the fundamental component.
22. Based wave coefficient Fundamental Factor Base Wave Meter The mean square between the alone is worth more than the alone.
23. (Total) Harmonic Factor The ratio of the harmonic content between the harmonic content and its alone.
24. Pulsating pulsating is used to express a periodic quantity having a non-zero average.
25. The amount of ALTERNATING Component is removed from the pulsating amount (Note: AC components sometimes referred to as ripple content).
26. The ratio of the difference between the PEAK-RIPPLE FACTOR pulse quantity pattern and the absolute value of the DC component.
27. The root factor of ripple wave is R. m. The ratio of the mean squares of the S-Ripple Factor pulsating content and the absolute value of the DC component.