H-Shaped Fractal Slots Based Highly Miniaturized Substrate Integrated Waveguide Metamaterial Bandpass Filters for C-Band Applications

Abstract

A new family of substrate integrated waveguide SIW-metamaterial bandpass filters is proposed which support backward and forward wave propagations with two adjacent passbands under the cutoff frequency of the conventional SIW structure. Through varying the fractal slots sizes etched over SIW structures, different frequency transmission responses were realized. Extraction of the metamaterial parameters was achieved via scattering parameters. The equivalent electrical length of a fractal slot is larger than the conventional slot, making it suitable to design highly miniaturized filters. The equivalent circuit model was analyzed in detail to provide comprehension on the SIW-metamaterial unit cells. Three filters using the 3rd iteration H-shaped SIW-metamaterial unit cells were designed and tested using subwavelength resonators. Filter design was used to extract the coupling coefficient and external quality factor to obtain the filters' optimized physical dimensions. The out-of-band rejection can be enhanced by reconfiguring the fractal slots or the SIW. A wide upper out-of-band rejection with attenuation > 30 dB with the range 5.5 GHz to 8 GHz was realized. The proposed filters offer advantages through low insertion loss, easy fabrication, high selectivity, small size, and low cost. The measured scattering parameters S 21 and S 11 were in good agreement with the simulated ones.

Investigation and Implementation of Integrated SIW System for Hexagonal Diamond of Lamda Shape Slots Fractal Array Antenna for X and KU-Band Applications

“…The proposed full SIW integrated system structure which consists of the basic SIW with tapering transition structure, the SIW rhombic divider/combiner, the SIW phase shifter and two arrays of the final SIW hybrid of hexagonal diamond and lamda array on the two output ports with phase shifter in one of them is shown in figure 19. Simulation results for the full integrated system and its antenna parameters for about eleven operating frequencies have been presented from (5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18) GHz in figure 20 and tables 11 respectively. Comparing these results with slot SIW slot antenna in [51] indicates that the proposed antenna has more enhancements in antenna parameters such as the return loss in [51] reaches -20 dB compared with -43 dB in the proposed structure in addition to the multiple operating frequency.…”

Low profile Substrate Integrated Waveguide (SIW) wideband antenna for Ku-band Applications

“…Later The SIW technique has been used for designing and fabrication filters and slot antennas [14,15,16,17]. low profile designs antenna are achieved by using SIW technique for high gain and wideband [18,19,20,21]. Impedance bandwidth was improved to up to 13.89% with moderate gain and unidirectional radiation characteristics in [22].…”