Tunable dual-band bandpass filter for WLAN applications

DAVID GIRBAU; ANTONIO LAZARO; ESTHER MARTINEZ; DIEGO MASONE; LLUIS PRADELL

MICROWAVE AND OPTICAL TECHNOLOGY LETTERS

JOHN WILEY & SONS INC

Lugar: New York; Año: 2009 vol. 51 p. 2025 - 2028

0895-2477

This article proposes the design of tunable dual-band filters for multiband multistandard systems, specifically for wireless local-area network applications. The two main goals are to provide frequency tunability in the second band while maintaining the first band fixed and to obtain a structure capable of offering a ratio between the second and first passband center frequencies larger than 2. To this end, a capacitively loaded stepped-impedance resonator is proposed for integration in dual-band filters. A detailed analysis of the resonator is provided. A filter has been designed to validate the concept. It demonstrates operability in wireless local-area network frequency bands, with a fixed first band at 2.45 GHz and a second band which can be tuned between 5.75 GHz and 5.25 GHz.