the notch band and UWB passband are 2.4 dB and 2.6 dB, respectively. For the notch band, MAR of the transmission skirt is 32.94 dB/GHz calculated from 5.34 GHz with À3 dB to 6.24 GHz with À14.6 dB. The inevitable insertion loss observed in operation frequency higher than 5 GHz can be improved by replacing the substrate with other materials having a smaller loss tangent than that of FR4. Table 2 lists the performance comparison among the fabricated UWB-BPF and other filters in previous publications. It is shown that the proposed UWB-BPF adopting C-shaped DGS structure has the advantage of miniaturization. CONCLUSIONSA compact structure of a reconfigurable UWB-BPF with embedded notch band has been presented. The notched band is introduced by two open-loop resonators on the top layer whose length is equal to half-wavelength at 5.8 GHz. The C-shaped slot on the bottom layer provides a full bandwidth of UWB systems. The desired specifications can be easily achieved by tuning the sizes of both the resonators and C-shaped slot, which can be further applied to other communication systems. The design is successfully realized in theory and verified by fullwave EM simulation and measurement. The proposed UWB-BPF is promising for using in UWB wireless technologies due to the advantages of simple structure and compact size. ABSTRACT: We propose a new system of the multiplexed sensors using a series of fiber Bragg gratings (FBGs), where the gratings separation lengths, Bragg wavelength, dip length, and birefringence can be configured as the sensing information. The transmission spectrum of a dual fiber Bragg gratings has been derived. Value of separation length between two FBGs, dL, is varied from 0.5 to 5.5 cm. The dip of separation length affects the transmission spectrum, which is indicated by the numbers of minimum dip values. Results show that the increasing in the separation length (dip length) between two FBGs leads to the formation of phase shift and increases the number of minimum transmission dip. For the dual FBGs to be used as a Fabry-Perot interferometer, it must have the smallest possible separation length. The multiplexed sensing application of more than two physical parameters can be operated by using such effects, for instance, strain, temperature, and gas sensor is plausible, while the self calibration between them is also available.

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