Design and Fabrication of Band Pass Filter (BPF) Based onSubstrate Integrated Waveguide (SIW) Technology forCommunication Applications

n this paper a new filter is constructed by embedding two semi-circular slots havebeen in the SIW structure for use in X-band applications. The insertion of these slots hassuccessfully led to the compact size and the wide bandwidth. The cavity dimensions are9.94×13.09 mm2 while the overall filter dimensions are 26.6×14 mm2 using a substratewith relative permittivity of 2.2 and thickness of 0.245 mm. The resulting structureexhibits a return loss less than -15 dB and insertion loss approaching to -0.26 dB overthe passband, while a fractional bandwidth of about 68.4% centered at 11.7 GHz. Anacceptable agreement between the experimental and simulation results. The compactsize offered by this filter makes it a suitable for use in designing microwave circuits. Thesimulation and performance evaluation of the proposed filter have been carried out usingMicrowave Studio Suite of Computer Simulation Technology (CST).