| Electrostatic discharge (ESD) is a kind of common electromagnetic disturbance. It will bring serious interference to the electronic devices, and even cause the equipment damage. So the electrostatic immunity test of electronic equipment is necessary. The traditional electrostatic discharge generator based on IEC61000-4-2 standard has some problems. For example, according to this standard, the discharge generator produced by different manufactures can get different results. And these generators have poor repeatability. The IEC standard is obviously insufficient to carry on the immunity test. Therefore, transmission line pulse (TLP) generator has been applied in the electrostatic immunity test, which is used to simulate the interference of electrostatic discharge to the device under test. So the study of transmission line pulse generator and the coupling between TLP and the device under test is important.According to the principle of transmission line, this paper analyzes the process of transmission line pulse and its influencing factors were studied. An actual TLP generator was built and different excitation probes of TLP test were used to simulate different coupling mode of ESD. This paper consists three parts. The principle of transmission line pulse generator was analyzed in the first part. And based on the principle of the transmission line and wave reflection and refraction, this part analyzed the process of transmission line pulse square wave. According to the structure and principle of TLP generator, the influence factors may affect the pulse width or rise time and so on of the square wave were discussed. A simulation model using Simulink software was built to simulate the influence of these influencing factors. In the second part, an actual TLP generator was built and the square wave pulse was produced. The wave was a relatively ideal one. And the rise time of TLP can be controlled in 800ps. The overshoot phenomenon had been suppressed. Finally, a brief introduction to the excitation probes used in the TLP test was briefly introduced. S parameters and the conversion of the S parameter and Y parameter and Z parameter were expounded. And an equivalent model of a two port network Y parameter was presented. In this paper, the vector network analyzer was used to test the S parameters of the homemade electric field probe, horizontal magnetic field probe, vertical magnetic field probe and injection probe used in TLP test. And according to the conversions of S parameter and Y, and Z parameter, the â…¡ type and T type parameters of two port network equivalent circuit of these probes were gotten. Based on the equivalent model of Y parameter, the coupling relationship between these probes and simple electronic circuits was analyzed. |
