A Design and Realization of Miniaturized Low Pass Filter Using Defected Ground Structure Technique with Wide Stop band

A novel fifth order Chebyshev stepped impedance low pass filter is designed, simulated and fabricated. Parameters of circuit are extracted from the EM design equations and then values are optimized. Defected ground structures (DGS) have been developed to enhance different characteristics like wide stop band, frequency response, flat pass band and minimum ripples etc. of many microwave devices. In this paper we designed and fabricated fifth order low pass filter and the characteristic of this low pass filter is improved when this filter is designed with dumbbell Shaped Slot Defected Ground Structure (DGS). The response of the filter is analyzed with respect to variation in dimension of the GS unit. The variation of dimensions of defects studied with their corresponding change in capacitance, inductance as well as frequency response. The defects dimensions are modeled with respect to the frequency. Chebyshev stepped impedance five pole DGS is adopted to increase the bandwidth of stopband and decrease the size of the filter. This proposed low pass filter achieves a wide stop band with overall 38-dB attenuation up-to 10 GHz. The frequency response of the micro strip filter is modeled with respect to the variation in dimension of DGS also using CST microwave studio