Bandpass filter using direct-coupled grounded patch resonator for wireless LAN applications

In this paper, a new compact bandpass microstrip filter based on grounded patch resonators is proposed. The coupling model of the filter is established and the coupling coefficients of coupled pair of resonators and the external quality factors of basic feeding configuration are investigated using full-wave electromagnetic simulations. As an example, a third order direct-coupled Chebyshev filter that operates according IEEE 802.11b/g/n standard is designed.