Abstract
In this paper, a compact microstrip low-pass filter (LPF) for radar applications is proposed. The microstrip filter configuration consists of a transmission line with a pair of S-shaped stub with radial stub loaded resonators (RSLRs), and a ground plane with triple array modified stairwell defected ground structures (DGSs). Operation frequencies of the filter can be easily controlled by changing the sizes of RSLR structures. The DGS slots evolved from photonic band gap (PBG) is embedded to achieve a good impedance matching and the required filter’s characteristics. The proposed LPF has a flat rejected-band characteristic around of 3-15 GHz with an insertion loss which is larger than 27dB and a return loss less than 0.5dB at the centre of the band-stop frequency range. An excellent agreement between measured and simulated was obtained. The proposed microstrip filter is fabricated on a Rogers RT/Duroid 5880 substrate with a relative dielectric constant of 2.2 and has a very small size of 10×15×0.635 mm3. The proposed filter configuration is simple, easy to fabricate and can be integrated into any radar system.

Keywords
DGS, low-pass filter, radar application, RSLR.

Cite this paper
Nasser Ojaroudi, A Novel Design of Compact Microstrip Low-Pass Filter with Large Band-Stop Characteristic , SCIREA Journal of Physics. Volume 1, Issue 2, December 2016 | PP. 101-107.

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