Research on the Fast Rising Edge of Square Wave Pulse Protection Based on Impedance Mismatching

For the fast rising edge square wave electromagnetic pulse protection problem, by analyzing the effect of different semiconductor protection devices’impedance variation on the response time for the electromagnetic pulse and port transmission power, this paper draws a conclusion that impedance mismatch has the character of good suppression of square wave electromagnetic pulse and fast response speed. In order to improve the power capacity, a micro-strip filter is used in this paper. By the principle of wavelength 1/4, the 1/4 wavelength microstrip band-pass filter is designed and fabricated. The passband is 3. 2-6. 2 GHz, insertion loss is less than 1.8 dB, the impedance is matched to 50 W,the out of band rejection is 30 dB at 1 GHz. The fast edge in this paper is generated by the high frequency square wave pulse noise generator (INS-4040), the microstrip bandpass filter has a good suppressing effect for the fast rising edge square wave, also has a response time of subnanosecond.