Compact high selective DGS band-pass filters for WLAN applications

摘要

In this paper, compact size band pass filters are proposed and designed for WLAN applications. The coupled DGS resonators are considered the main block of proposed band pass filters. The three proposed filters are designed by using the same defected ground structure shape, but with different feed line configurations. The feed line configuration affects the presence of transmission zeros in the rejection band to enhance the filter selectivity. So, we proposed three designs based on the different feed line configuration. The first design is band pass without transmission zero, the second is with one transmission zero, and the last one is band pass with two transmission zeros. In general, the three band pass filters are designed to operate from 5 GHZ to 6 GHZ with a central frequency of 5.5 GHZ, return loss higher than 25 dB and a wide stop band rejection up to 10 GHz with level lower than 30 dB, and an insertion loss lower than 0.5 dB is achieved within pass band. The simulated results are presented to show the performance of these filters.