Compact Quad-Band Bandpass Filter for DCS/WLAN/WiMAX/5G Wi-Fi Application

This letter presents a compact quad-band bandpass filter for DCS/WLAN/WiMAX/5G Wi-Fi applications. It utilizes two resonators. One is a multi-stub-loaded resonator operating at the first, second and fourth passband frequencies. The other one is a short-end stub-loaded resonator used to yield the third passband. Among the four passbands, the highest one is designed to cover a wide bandwidth (5.15-5.85 GHz) for 5G Wi-Fi applications. The design procedures are discussed in detail and the simulated and measured results are presented.