Design and Optimization of New Compact Tunable 2.4-GHz Band Pass Filter Using Coupled λ/2 Microstrip Open-Loop Resonators and Mems-Switch Technique

A new compact WLAN-band pass filters are proposed using a half wavelength microstrip open-loop and lambda/2 microstrip resonators based on direct-cross coupling method and micro electronic mechanical system (MEMS) technology. The filter is not only compact in size due to the slow-wave effect, but also has multitransmission zeros at both low and high rejection bands, as well as low insertion loss in the pass band. A demonstration filter has been designed and tested. Simulation results almost agree with the measured results. Some discrepancy between them can still be observed, which can be attributed to the unexpected tolerance of fabrication. Due to the simplicity of the design and its fabrication, it shows that this type of band pass filter has great potential for actual applications in communication and other systems. By applying the MEMS technology, a switchable band pass filter based on the quadruplet filter is able to be designed. (C) 2013 Wiley Periodicals, Inc.