چكيده به لاتين
Abstract:
The new gap waveguide technology has been recently introduced as a promising candidate to address some of the problems faced at millimeter waves with conventional technologies. The key idea behind this circuit is based on the possibility to guide the electromagnetic field along desired directions in the gap between metal plates and to avoid any propagation along undesired directions. In this way, any leakage occurring in between the split blocks of a circuit with poor quality metal contacts as well as unwanted radiations are avoided. This condition is achieved by surrounding a metal ridge/strip, or groove, with a so-called Artificial Magnetic Conductor (AMC). When this textured layer is placed below an upper metal lid, all parallel-plate modes will be in cut-off, thus letting the propagation only in the air gap between the ridge/strip and the upper plate. the main performance of the gap waveguide is determined by its ability to create cut-off or stop band for the wave propagation in undesired directions. This is achieved by using a texture in the form of a periodic structure (AMC), located around the metal strips or ridges. The AMC or EBG surface plays a key role in the design of gap waveguides. Consequently, an extensive study of the behaviour of different periodic structures (the simpler, the better) in one of the surfaces of a parallel plate waveguide is of interest. In this sense, this work explores the possibilities of creating parallel-plate cut-offs, i.e. stop bands in parallel plate waveguides, by using textured surface made of metal pins also referred to as a bed of nails EBG surface. Then presents a new type of narrow band filter with good electrical performance and manufacturing flexibility, based on the newly introduced groove gap waveguide technology. The designed third order filters work at X band with 0.4% fractional bandwidth and it’s structures are manufactured with an allowable gap between two metal blocks, in such a way that there is no requirement for electrical contact and alignment between the blocks that is a major manufacturing advantage compared to normal rectangular waveguide filters.
Keywords: Lowloss Transmission line, Gapwaveguide Filter, Narrowband Filters, High Impedance Surface, Electromagnetic Bandgap Surface
