SU1358708A1 - Cassegrainian aerial - Google Patents

Abstract

The invention relates to radio engineering and provides a reduction in the level of lateral radiation in the H-plane. The irradiator 3 emits an inhomogeneous spherical wave, reflects it from the auxiliary mirror (VZ), focuses into the focal ring, transforms into a diverging toroidal wave, and illuminates the main mirror (03) I. The main field reflected from the VZ 2 and transmits through the focal ring, it reaches 03 1 without phase distortion with a slight attenuation of the amplitude due to scattering on the metallic junction. ca (MK) 4. A field passing through the focal ring excites cuttings from MK 4 and induces an antiphase Mrff) t -.-. The field is spread uniformly in space. A reduction in the level of lateral radiation in the bone is achieved by the excitation, at the edges of the VZ 2, two edge waves, the floor of which is antiphasic and of equal amplitude. 3 il. sl 00 el 00

Description

The equipment is related to the field of radio engineering, namely to antenna technology.

The aim of the invention is to reduce the level of lateral radiation in the H-plane.

Fig. I shows a structural scheme of a two-beam antenna (side view); in Fig.2 the element of the structural scheme of the antenna; fig.Z - the same, axonometric projection.

A two-mirror antenna consists on an axisymmetric primary mirror 1 having a parabolic generator,

1358708. 2

 they have an antiphase field that is dispersed in space almost uniformly. Since the field exciting the cuts from the metal-ring, on its surface the singing is phase in directions to the edge of the auxiliary mirror 2 and the center of the main mirror I, the scattered field is focused and excites the edge wave on the edge of the auxiliary mirror 2 that folds to the edge wave, the irradiator 3 excited on this edge by the direct field, about l. teaching auxiliary - the mirror 2

fO

focal1) On the axis of which the parallel is shifted from the phase center O,. parallel to the axis of symmetry of the antenna, in particular, the reduction of the leveling mirror 2, which has an elliptical pattern, the first focus of which is aligned with the focus of the parabolic array of the primary mirror

lateral radiation in the H-plane is fused due to excitation of two edge waves on the edges of the auxiliary mirror 2 Sch

1, and the second is located on the axis of symmetry of the antenna, the irradiator 3, whose phase center is aligned with the second focus of the auxiliary mirror 2, and two C1mmetric cutouts from the metal ring 4, coaxial with the focal ring. The chords of these cuts are parallel to the electromagnetic field vector E, the diameter of the metal ring A is equal to p; and the diameter of the focal ring. In this case, the length L of the chord of each out of the metal ring 4 is selected from the ratio L - 2,

 their d is from the ratio 0,, 2, and the distance 1 from the plane of the metal ring 4 to the edge of the auxiliary mirror 2

- (2p + 1)

2a 4a

The antenna works as follows. (,

The radiator 3 / emits a non-uniform spherical wave, which is reflected from the auxiliary mirror 2, is focused into the focal ring, converted into a diverging toroidal wave and illuminates the main mirror 1. The main field reflected from the auxiliary mirror 2 and flowing through the focal the ring reaches the main mirror 1 without phase distortions with a slight attenuation of the amplitude due to scattering on the cuts from the metal ring 4. A field passing through the focal ring excites metal cuts 4 and ring leads

-

8708. 2

they have an antiphase field that is dispersed in space almost uniformly. Since the field exciting the cuts from the metal ring, on its surface the singing is phase in directions to the edge of the auxiliary mirror 2 and the center of the primary mirror I, the scattered field is focused and excites the edge wave on the edge of the auxiliary mirror 2 that folds to the edge wave excited by on this edge is a direct field of the irradiator 3 about the auxiliary one - mirror 2

fO

  from the phase center Oh,. In this way, a decrease in

from the phase center Oh,. In this way, a decrease in

lateral radiation in the H-plane is achieved by exciting two edge waves at the edges of the auxiliary mirror 2, the floor of which is anti-phase and equal in amplitude. i Lormula invention

A two-mirror antenna, containing an axisymmetric primary mirror having a parabolic shape, whose focal axis is shifted parallel to the axis of symmetry of the antenna,. an axially symmetric auxiliary mirror that has an elliptic -generative formation, the first focus, which is aligned with the focus of the parabolic generator, and the second located on the axis of symmetry

antennas, and an irradiator whose phase center is aligned with the second focus of the elliptical generatrix, characterized in that, in order to reduce the level of lateral radiation in the H-plane, in the focal ring region of the antenna, there are two symmetrical cuts from a metal ring coaxial with the focal ring, chords of metal

the rings are parallel to the vector E of the electromagnetic field, while the diameter of the metal ring is equal to the diameter of the focal ring, the length L of the chord of each cut from the metal ring

selected from the ratio L 2l, where is the wavelength, the thickness of the cutouts from the metal ring d is from the ratio 0.01 d / L 0.2, and the distance 1 from the plane of the metal ring

to the edge of the auxiliary mirror

1 ha

() | + 1 -,

where 2a is the p (tf) -H constant of the ellipse;

n 0,1,2 ...; b - the eccentricity of the ellipse.

Fi9.g

FIG. one

ig.-W

Claims (2)

Claims je A two-mirror antenna containing an axisymmetric main mirror having a parabolic generatrix, the focal axis of which is offset parallel to the axis of symmetry of the antenna, 3® axisymmetric auxiliary mirror having an elliptic generatrix, the first focus that is aligned with the focus of the parabolic generatrix, and the second is located on the symmetry axis 35 of the antenna, and an irradiator, the phase center of which is aligned with the second focus of the elliptical generatrix, 'characterized in that, in order to reduce the level of side radiation 40 in the H-plane, In the area of the antenna focal ring there are two symmetrical cuts from a metal ring coaxial with the focal ring, chords of cuts from a metal `` 5 ring are parallel to the electromagnetic field vector E, while the diameter of the metal ring is equal to the diameter of the focal ring, the length L of the chord of each cut from the metal ring 50 is selected from the relation L? r ^. where'X is the wavelength, the thickness of the cutouts from the metal ring d is from the ratio 0.01 <<ί / Ά <0.2, and the distance is 1 from the plane of the metal ring to the edge of the auxiliary mirror 2Г- ^{(2η + Ι,} 4Ϊ ^{+ 1} - ^£ · η = 0,1,2.,.; b - eccentricity of the ellipse. where 2a p (<f _t ) +1 is the constant of the ellipse; Editor B. Fedotov