A low-profile wideband CONICAL BEAM antenna which uses two concentric annular ring slots in substrate integrated waveguide (SIW) technology is presented. First, a single ring antenna is considered and then the effect of introducing the second slot on bandwidth is investigated and high bandwidth is achieved. A brief parametric study for different slot width is presented. A prototype of the proposed antenna is fabricated and measured. The measured reflection coefficient is in good agreement with simulation. The theoretical result is also provided for S11 to validate the simulation and measurement results. The proposed antenna shows 30% bandwidth in 17 GHz center frequency (|S11<-10 dB). Radiation pattern was measured in three different frequencies in the entire frequency bandwidth. Maximum measured radiation efficiency is 93%. The antenna is very simple and low profile with a planar structure. Electrical dimensions are (1. 76𝜆 𝜆 0×1. 76𝜆 𝜆 0×0. 08𝜆 𝜆 0) with very simple feeding network which could be a suitable choice in many practical applications from anti-collision radars to WLAN applications.

In this paper, an exact closed-form solution is presented for free vibration analysis of Euler-Bernoulli CONICAL and tapered BEAMs carrying any desired number of attached masses. The concentrated masses are modeled by Dirac’s delta functions which creates no need for implementation of compatibility conditions. The proposed technique explicitly provides frequency equation and corresponding mode as functions with only two integration constants which leads to solution of a two by two eigenvalue problem for any number of attached masses. Using Basic functions which are made of the appropriate linear composition of Bessel functions leads to make implementation of boundary conditions much easier. The proposed technique is employed to study effect of quantity, position and translational inertia of the concentrated masses on the natural frequencies and corresponding modes of CONICAL and tapered BEAMs for all standard boundary conditions. Unlike many of previous exact approaches, presented solution has no limitation in number of concentrated masses. In other words, by increase in number of attached masses, there is no considerable increase in computational effort.

this article presents the coupled thermoelasticity of a truncated functionally graded CONICAL shell under thermal shock load. The classical coupled thermoelasticity theory is employed to set the partial differential equations of motion of the CONICAL shell. The shell governing equations are based on the fi, rst-order shear deformation shell theory that accounts for the transverse shear strains and rotations. The solution is obtained by transforming the governing equations into the Laplace domain and using the Galerkin fi, nite element method in the Laplace domain to calculate the displacement components. The physical displacement components in real time domain are obtained by the numerical inversion of the Laplace transform. Temperature distribution is assumed to be linear across the shell thickness. Radial displacement, axial stress, axial force, and temperature versus time are calculated and the effect of relaxation time and power law index are examined. Comparison indicates that an increase in the radial vibration amplitude and a decrease of vibration frequency occur when changing the material from ceramic to metal. The results are validated with the known data in the literature.

A finite element analysis is presented for sloshing and impulsive motion of liquid-filled CONICAL tanks during lateral anti-symmetric excitation. The performed analyses led to the development of a number of charts which can be used to identify the natural frequency, the mode shapes of CONICAL tanks for both fundamental and the cos (q) -modes of vibration. CONICAL tank geometry was described with several parameters namely, bottom radius (Rb) total height of liquid (h), angle of inclination of the tanks (qi), as variables. Numerical result of the free vibration was obtained for the cases of CONICAL tanks with qi=0 and compared with existing experiments and other predicated results, showing a good agreement between the experiment and numerical results.