Comparative Analysis of an LC-Filter and a Reflection Symmetric Modal Filter

The paper presents a comparative analysis of two devices protecting against ultra-short pulses: a reflection symmetric modal filter and an LC-filter. The filters with the same bandwidth of 255 MHz are studied experimentally, and their measurement results are compared in the frequency and time domains when the devices are affected by an ultra-short pulse with a total duration of 150 and 300 ps. The results show that as the duration of the input excitation decreases, the attenuation of the ultra-short pulse for the modal filter increases, whereas the maximum interference amplitude increases for the LC-filter. The insertion loss characteristic is presented. It shows that with the same bandwidth of the protection devices the insertion loss of the reflection symmetric MF increases after 1.5 GHz. The insertion loss of the LC-filter decreases. The parasitic parameters are shown to have an influence on the protective performance of the LC-filter. This work is important for further development of ultra-short pulse protection devices with modal decomposition and develops an important direction in designing passive filtering devices.