DE977511C - Directional antenna for very short electromagnetic waves - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

ISSUED NOVEMBER 3, 1966

GERMAN PATENT OFFICE

PATENT LETTERING

CLASS 21a ⁴ GROUP 46 02 INTERNAT. CLASS H 01 q

T10382 IXd j 2Ia *

. Gerhard Koch, Ulm / Danube

has been named as the inventor

Telefunken Patentverwertungsgesellschaft m.b.H., Ulm / Donau

Directional antenna for very short electromagnetic waves

Addendum to patent 975 274

Patented in the territory of the Federal Republic of Germany on December 25, 1954

The main patent started on October 5th, 1954

Patent application published November 8, 1956

Patent issued September 29, 1966

The invention relates to a directional antenna for very short electromagnetic waves, consisting of a surface radiator, the height of which decreases from the center towards the sides.

In the main patent, such a directional antenna has the limiting function

y = ± - Λ ( ^χ )

in the case of an inhomogeneous occupancy α (χ, y) of the aperture of the surface emitter as a function of this

electrical occupancy α (χ, y) chosen such that for

a {x, y) dy = df _h {x)

■ v'iW

results in a bell-like function, where y is the coordinate of the aperture plane that is perpendicular to the transmission plane, χ the coordinate of the aperture plane lying in the transmission plane, f _t (x)

609 714/3

the limiting function of the inhomogeneously occupied aperture, //, {x) the limiting function of the homogeneously occupied substitute aperture and ei mean the maximum extent of the aperture perpendicular to the transmission plane.

In practice it has been shown that for surface radiators with such limiting functions theoretically determined secondary maxima when the surface radiator is designed as a parabolic mirror antenna

ίο exceeded with the exciter antenna in the center will.

Starting from a directional antenna for very short electromagnetic waves, consisting of a Surface radiator, the height of which decreases from the center towards the sides and which has the limiting function

in the case of an inhomogeneous occupancy α (χ, y) of the aperture of the surface radiator as a function of this electrical occupancy α (χ, y) is chosen such that for

Y a (x, y) dy = if _h {x)

3- = --Ii (X)

results in a bell-like function, where y is the coordinate of the aperture plane that is perpendicular to the transmission plane, χ the coordinate of the aperture plane lying in the transmission plane, f _t (x) the limiting function of the inhomogeneously occupied aperture, f _h (x) the limiting function of the homogeneously occupied Substitute aperture and d denote the maximum extent of the aperture perpendicular to the transmission plane, according to patent 975 274, the surface emitter being designed as an at least approximate rotational or cylindrical paraboloid, in whose focal point or focal line an excitation emitter is arranged, it is proposed according to the invention that in an As is known, a section of the paraboloid is provided as the radiating surface, which is eccentric to the axis of rotation or plane of symmetry. The eccentricity and the size of the paraboloid section are chosen so that the exciter is so far removed from the adjacent paraboloid edge in the direction of the aperture plane that the disturbing influence of the exciter on the radiation diagram is largely avoided (Fig. 1).

The invention is based on the knowledge that the behavior described above on the disruptive Influence of the exciter antenna is based, which lies in the field of the wave reflected on the parabolic mirror. These reflected waves cause additional secondary diffraction maxima at the exciter antenna, which are superimposed on the secondary maximum values theoretically determined for the surface radiator as such.

The invention is explained in more detail below using an exemplary embodiment.

Fig. 1 shows a cross section through an inventive trained directional antenna. In the focal point ι one eccentric to the axis of rotation 2 one Rotation paraboloids 3 lying dome 4, an excitation antenna S is arranged such that the dome is illuminated according to a predetermined relationship. For example, this relationship can consist in the fact that maximum area utilization is achieved in a manner known per se. It however, any other type of occupancy that is customary for parabolic mirror antennas of this type can also be used.

The invention can also be applied to the so-called horn parabolic, as shown in FIG. These The type of antenna is known per se. Fig. 2 shows a cross section and a front view of a such antenna, the aperture 7 according to the main patent according to a cosine function is chosen. The shape of the aperture, which can be clearly seen in the front view of Fig. 2 corresponds approximately to the shape of the parabolic dome in Fig. 1, if you look at its aperture. The so-called horn parabolic antennas differ from normal parabolic mirror antennas essentially due to the fact that an excitation radiator serving as a feed is missing as such and a normal hollow pipe 8 is widened slowly and steadily, an eccentric one Parabolic dome 9 is excited by the hollow tubular shaft. The parabolic dome can be a cylindrical parabolic or a parabolic of revolution.

The limiting function of the parabolic dome is selected depending on the occupancy in such a way that that the aperture 6 - which is shown in phantom in Fig. 1 with - in their Shape and assignment corresponds to a surface heater according to the main patent.

In the exemplary embodiments shown in the figures, the excerpt from the Paraboloid of revolution chosen in such a way that in the case of the highly inhomogeneous one given by the horn antenna Allocation of the aperture 6 in relation to the radiation diagram in the transmission plane homogeneously covered surface radiator with a bell-like limiting function.

The invention can be applied to all of the embodiments of 1x0 Surface emitters are used to advantage.

The eccentricity and the size of the parabolic section is expediently selected according to structural and electrical requirements. The eccentricity is chosen so that the exciter antenna in the direction of the aperture plane as possible is far from the adjacent (lower) mirror edge, which simultaneously causes the mirror reflection decreased more and more. The opposite requirement is by striving for Given the lowest possible bulkiness of the antenna, so that an intermediate value exists which is in the Practice best meets the opposing demands. Under mirror reflection, the from Mirror on the exciter antenna understood radiation reflected.

Claims (1)

PATENT CLAIM: Directional antenna for very short electromagnetic waves, consisting of a surface radiator, whose height decreases from the center towards the sides and in which the limiting function y = ± ~ fi ( ^x ) in the case of an inhomogeneous occupancy α (χ, y) of the aperture of the surface radiator as a function of this electrical occupancy α {χ, y) is chosen such that for a (x, y) dy = d -f _n (x) results in a bell-like function, where y is the coordinate of the aperture plane that is perpendicular to the transmission plane, χ the coordinate of the aperture plane lying in the transmission plane, fi (x) the limiting function of the inhomogeneously occupied aperture, f _h (x) the limiting function of the homogeneously occupied substitute aperture and d mean the maximum extent of the aperture perpendicular to the transmission plane, according to patent 975 274, the surface radiator being designed as an at least approximate rotational or cylindrical paraboloid, in whose focal point or focal line an excitation radiator is arranged, characterized in that known per se Way, a section of the paraboloid is provided as the radiating surface, which is eccentric to the axis of rotation or the plane of symmetry, and that the eccentricity and the size of the paraboloid section are chosen such that the exciter in the direction of the aperture plane is so far away from the adjacent paraboloid edge that the annoying one The influence of the exciter on the radiation diagram is largely avoided (Fig. i). Considered publications:
German patent specifications No. 470222, 480933, 669549, 827810; Silver Samuel, Microwave Antenna Theory and Design, 1st edition, New York, 1949, p. 169 to 199 and 451 to 457; Proceedings of the LR.E., November 1947, Pp. 1284 to 1294. Please refer to the sheet of drawings 15 609 706/278 10.56 (609 71473 10.66)