Design, Simulation and Fabrication of the Compact Narrow Notch-Band and Band-Pass Filters Based on the Metamaterials Concept

In this paper, a novel microwave narrow notch-band and band-pass filters using composite right-left handed (CRLH) structure for WLAN application are proposed. The proposed filters have been designed by using a unit-cell which is called z-shaped unit-cell. By using the z-shaped unit-cell near the microstrip line, a narrow notch-band at 5.7 GHz has been occurred while by utilizing a series interdigital capacitor, a narrow band-pass filter at 5.7 GHz has been occurred. According to the Metamaterial concept, the proposed one- and two-stage narrow notch-band and band-pass filters have been designed and simulated. The equivalent circuit model and full-wave simulation results of the proposed band-pass filters are developed. To validate the design concept, the designed two-stage band-pass filter has been fabricated and tested. Experimental verification is provided and a good agreement has been found between the simulation and measurement. The proposed filters have many advantages in terms of compact size, high selectivity, low insertion loss, and easy integration with other planar technologies. The total size of the proposed one- and two-stage filters are 0.40 λg × 0.17 λg and 0.40 λg × 0.35 λg respectively.