FSS-based planar filter with capacitor chips for antenna frequency selection

In this paper, the design of planar filter based on FSS structure workable at three different frequency allocations is proposed. The FSS structure which is constructed using inductive and capacitive grids is designed to have frequency selection feature for incoming waves from antenna at operating frequency of 1.575GHz and 1.8GHz. Meanwhile at operating frequency of 2.4GHz, the incoming waves will be always passed. Some capacitor chips are incorporated into the grids to obtain the tuning frequency of selection. From the measured results, it shows that the FSS-based planar filter which is implemented on a 0.8mm thick FR4 Epoxy dielectric substrate with the dimension of 135mm × 60mm are not affected by the capacitance values for operating frequency of 2.4GHz. Whilst for operating frequency around 1.8GHz, the different capacitance values have shifted frequency response which is larger than for operating frequency of 1.575GHz.