This paper presents a filtering power divider (PD)/power combiner (PC) using substrate integrated waveguide (SIW)-based 180 hybrid. The utilized 180 hybrid includes a standard H-plane 3-dB coupler and a broadband 90 phase shifter. The phase shifter is composed of non-radiating longitudinal slots patterned on the top conducting surface of the SIW. We have added the filtering property to the stru...

local scouring around bridge piers is a natural phenomenon caused by the erosive process of flowing stream on alluvial beds. the 3d flow field around bridge piers interacting with the bed materials increases complexity of local scour process. the local scour depth develops in accelerated flows and if it is not predicted correctly, the bottom level of local scour hole will exceed the original le...

A method is presented to investigate diffraction of an electromagnetic plane wave by an infinitely thin infinitely conducting circular cylinder with longitudinal slots. It is based on the use of the combined boundary conditions method that consists on expressing the continuity of the tangential components of both the electric and the magnetic fields in a single equation. This method proves to b...

A design procedure is developed for slotted-waveguide antennas with probe-fed slots. Radiation into a gyrotropic, plane-stratified medium is considered, nonzero waveguide wall thickness is assumed, and noncosinusoidal slot fields and arbitrary slot length up to about one free-space wavelength are allowed. External mutual coupling is taken into account by matching the tangential fields at the an...

Possibilities for the extension of the operational frequency band of slotted waveguide antennas are studied. It is shown that by using both conventional longitudinal slots and subarraying techniques it is possible to reach the relative bandwidth of about 15%. This result is illustrated by the development of a novel slotted waveguide antenna for high-resolution SAR applications. The antenna oper...

An effective development of a dual composite right/lefthanded (D-CRLH) leaky-wave (LW) structure for dual-polarized antenna application is presented. The dual-polarized antenna consists of a two-section 3-dB rat-race hybrid and two symmetrical substrate integrated waveguide lines. Each of the waveguide lines is periodically loaded with 15 transverse slots and 15 longitudinal slots. The dualpola...

This paper shows a comparative study of Multi U–shaped slot antenna with the substrate integrated waveguide(SIW) fed patch antenna. By cutting four asymmetrical U-slots, we can make U-shaped patch antenna. Advantages of this structure are the simple feed, single layer structure, simple structure of antenna, one more degree of freedom can be achieved by the asymmetry of U-slot arm. The design gu...

A method is presented for calculating the real part of the longitudinal impedance for both a small hole and a long slot in a beam vacuum chamber with a circular cross section. The length of the slot can be arbitrarily large, the only requirement on the dimensions of the slots is that its width be much smaller than c/w. Regular . arrays of N slots periodically distributed along the pipe are also...

A novel idea of conformal corrugated edges (CCE) is put forward in this paper for tapered slot antennas to obtain improved low-frequency characteristics. The CCE is realized using conformal slots whose two longitudinal boundary lines are modelled using curvilinear function of the curves that form the tapered slots. So the conformal slots can sufficiently corrugate edges of the tapered slot ante...