The article presents the results of a study of a modal filter (MF) based on a microstrip line (MSL) with two side conductors grounded at both ends. For the first time, the quasi-static simulation and measurements of the filter are conducted with two devices, and the results are compared. Frequency dependences of |S11| and |S21| are measured and calculated in the range from 0 to 10 GHz. At the MF output, the time response to an ultrashort pulse (USP) was analyzed. It was experimentally proved that the performed quasi-static simulation was correct. The simulation and measurement results showed remarkable consistency. The proposed MF provides the protection of electrical circuits from USP by decomposing it into two pulses with the amplitudes that are more than three times smaller. This confirms that such MF obtained simply by adding to a MSL two passive conductors grounded at both ends can be used to create simple and cheap protection, for example, of critical radioelectronics against powerful intentional USP created by electromagnetic weapons.
Cite this article as: I. Y. Sagiyeva and T. R. Gazizov, “Simple modal filter based on microstrip line,” Electrica, 23(3), 516-521, 2023.