Designing of double negative media based low pass microstrip filter using stepped impedance

摘要

This paper presents the use of double negative media for improving the response of microstrip low pass filter using FR4 as a substrate of dielectric constant of 4.4. Initially, this paper presents the discussion of designing a simple low pass microstrip filter using stepped impedance with cut off frequency 2.1GHz and the results are simulated by using CST software. The results did not match with the ideal characteristics. Next, 4 SRR are designed on the positive plate of this filter then the response was close to the ideal one. Further, with 4 SRR a rectangular shaped CSRR is implemented on the filter. The results were improved drastically with the high attenuation in the stop band, improved quality factor, high roll off rate low insertion loss and cut off frequency of 1.99GHz.