designing and manufacturing of wideband band-pass microstrip filter by using of series of filters and out of band rejection improvement

in this paper, a bandpass filter with cutoff frequencies 1.7-11.5ghz have been implemented. for construction of this filter, the first two lowpass and highpass filters with cutoff frequencies 1.7 ghz and 11.5ghz respectively have been designed and then they use in series. we design cutoff frequencies independently, consequently, designing cutoff frequencies doesn’t interfere with each other. the end, combination of two filters is fabricated on the ro4003 dielectric substrate with thickness of 32mil and ε_r=3.38. the simulation and measurement results agree each other.