Compact structure of band-pass filter integrated with Defected Microstrip Structure (DMS) for wideband applications

This paper presents compact structure of bandpass filter integrated with Defected Microstrip Structure (DMS) to produce band-pass and band reject response simultaneously. The filter design based upon λ_g0 short-circuited stubs structures of 7^th degree. The narrow notch responses produced by DMS was introduced at a frequency of 5.2 GHz in order to reject any undesired signals which may interfere with the wideband communication systems. The design was simulated and fabricated on a Roger Duroid RO4350 with a thickness of 0.508 mm and dielectric constant, ε_r of 3.48. The group delay in the passband was lower than 0.74 ns. This type of filter is useful in any RF/ microwave communication systems particularly to eliminate any undesired signals in wideband spectrum. While maintaining its excellent performance, the overall physical and cost reduction can also be achieved using this technique.