Signal integrity analysis for the four-layer reflection symmetric modal filter

Abstract

The article presents the results of signal integrity analysis for a four-layer reflection symmetric modal filter and determines a potential field of application for such devices. The authors performed a simulation and experimental study in the range from 0 to 1.5 GHz. The results show that the average level of insertion loss in the passband does not exceed -18 dB, which demonstrates good agreement. The insertion loss does not significantly attenuate the useful signal. After the modal filter was defined in the frequency domain, the authors used the Advanced Design System to analyze the time characteristics. Pseudorandom binary sequences with bitrates from 0.125 to 0.5 Gb/s were excited to the input of the device in the Advanced Design System. The eye diagrams show that the modal filter has an excellent performance in terms of signal integrity. Thus, at the fastest data rate, the jitter does not exceed 39.5 ps. The maximum value of amplitude noise was 71 mV. It is possible to achieve significantly lower values of jitter and amplitude noise for the modal filter using its optimal geometric and electrical parameters. The results of the electrodynamic simulation are in good agreement with the experimental results.