Abstract: There is an increasing demand for microwave systems to meet the emerging telecommunication challenges with respect to size, performance and cost. This project describes a general design technique for micro strip low pass filters that are used to convey microwave frequency signals. The parasitic problems of X- band can be adjusted through impedance ratio K, which can enhance the performance of harmonic suppression. The ADS simulation tool is used to design an X-band stepped impedance low pass filter of range 8-12 GHz. This simulation results show that the filter works on 10GHz at the center frequency and achieves attenuation of 60dB, which effectively suppresses the parasitic bands. To attain the filter with these characteristics, Insertion Loss Method is performed. Compared to other filter types, this design works very well with excellent harmonic suppression performance.