Filter design using the substrate integrated waveguide (YGDK) technology on X band

Planer band-pass filters are considered as a major part of any RF/Microwave device. The increasing demands on communications and radar systems require filters are that provide all of compactness and lightweight with superior performance and easy to integrate with other circuits. In this thesis, we look at new planer technology called substrate integrated waveguides (YGDK), developed recently with characteristics mixes the affirmative characteristics of the metallic waveguides and microstrip technologies, has opened the horizons in microwave filter design to provide new designs to match the high requirements of the increased demand. In this thesis, we have designed two 3rd order compact filters using the Substrate integrated waveguide (YGDK) technology and the Defected ground structure (ÇTY). Both of the designs are using the YGDK -microstrip taper transition to ensure wideband adaption with microstrip technology. The first filter is a Wideband bandpass filter designed for X-band application has a center frequency at 10 GHz, with fractional bandwidth (FBW 40%), the structure composed by YGDK and two types of defected ground structures (ÇTY) loaded in both of the Top and bottom plane of the YGDK and its characterized by the wide free of spurious upper stopband, while the second filter is a broadband filter designed for C-band Space communications has a center frequency at 6.175 GHz, with 500 MHz bandwidth (FBW=8.3%), the structure composed by YGDK and 3-ÇTY cells on the top plane of the YGDK. The filters were built on a single-layer Rogers DiClad 880 substrate, and they were designed and optimized using the time domain solver "the Finite-difference time-domain method (FDTD) numerical method" in CST MW studio.