Modes of a metal horn with a hyperbolic profile lateral surface 

V. V. Serov, N. O. Strelkov, V. V. Shtykov
National Research University "Moscow Power Engineering Institute", Krasnokazarmennaya 14, Moscow 111250,  Russia

The paper is received on December 9, 2016

 

Abstract. In open horns the main contribution to the overall reflection coefficient makes the reflection from the aperture. Also, there is a reflection at the transition from the waveguide to the horn. In junction of a waveguide with a sectorial horn, matching of phase front does not occur, which leads to the formation of higher modes. In order to reduce the reflection coefficient of the aperture, it is necessary to increase its geometrical dimensions. However, with increasing of horn’s angle, the reflection of the transition increases. Reflection from the transition can be minimized by applying a smooth transition form. This paper presents specifications of a metal horn with a hyperbolic profile lateral surface. Using a horn with a hyperbolic profile lateral surface allows us to minimize the reflection from the transition of waveguide with a horn. The main reason of decreasing this reflection may be matching phase of the wave front in junction of a waveguide with a horn. This is an advantage of this form of lateral surface compared to others (exponential, parabolic, etc.). In this paper field patterns of a metal sectorial horn and a horn with a hyperbolic profile lateral surface are obtained and investigated. Experimental results on a horn with a hyperbolic profile lateral surface are presented. A comparison of the characteristics of a metal sectorial horn, a horn with a hyperbolic profile lateral surface and a horn with a parabolic profile lateral surface has been performed.

Keywords: metal horn, hyperbolic profile, modes, elliptic coordinate system, periodic Mathieu functions.

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