Measurement and Simulation of Time Response of Printed Modal Filters with Broad-Side Coupling

A principle of modal filtering and an asymmetric modal filter with broad-side coupling are presented. Prototypes with different parameters are developed and fabricated. Experimental measurements and computer simulation are performed for the time response to a pulse with a duration of about 1 ns. It is shown that the simulated results are in agreement with the experimental data. Attenuation of the input pulse by a factor of 5 is demonstrated for the modal filter with optimal parameters for a 50-Ω circuit.