JPH02260703A - Corrugate horn - Google Patents

Abstract

PURPOSE:To alighn the beam width of an E plane with that of an H plane extending over a broad band area by forming the depth of a groove in the neighborhood of an aperture deeper than that of the groove of a flare intermediate part. CONSTITUTION:The depth of the groove in the neighborhood of an aperture part is formed deeper than that (around lambda/4) of the groove in the neighborhood of an intermediate part. In other words, the depth d2 of the groove 12 in the neighborhood of the intermediate part is around lambda/4, and the depth d1 of the groove 12 in the neighborhood of the aperture part is formed in dimension shallower than lambda/2 and deeper than lambda/4(lambda/2<d1<lambda/4). Figure (a) shows the pattern of the minor axis plane of an elliptic corrugate horn at frequency 12GHz, and figure (b) shows the pattern of the minor axis plane of the same elliptic corrugate horn at frequency 14GHz. In such a way, satisfactory alignment can be obtained with the beam width 10dB rather than that in an on-going pattern.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a corrugated horn suitable for a primary radiator of a mirror antenna.

(Prior Art) Corrugated horns have excellent characteristics such as extremely low cross-polarized components and sidelobe levels. Therefore, corrugated horns have been conventionally used as primary radiators such as parabolic mirror antennas.

In conventional corrugated horns, the groove depth at the neck is approximately λ/
2 (λ is the free space wavelength), and thereafter it is gradually made shallower to near the middle of the flare, and a balanced hybrid mode is generated from near the middle of the flare. The depth of the clearing from the middle part to the opening was approximately λ/4.

Figures 4 and 5 show a conventional elliptical corrugated horn, Figure 4 is a side view of the elliptical corrugated horn (however, the part below the center line is a sectional view), and Figure 5 is the elliptical corrugated horn of Figure 4. shows a front view.

(Problem to be Solved by the Invention) In the conventional corrugated horn described above, the depth of the groove from the middle part to the opening is approximately λ/4, so there is a band where the beam widths of the E plane and the E plane are the same. If the aperture cannot be made very wide, especially if the aperture shape is elliptical or rectangular, the band where the beam widths of the E-plane and E-plane match will be narrow, worsening the elliptical polarization coefficient, and further increasing spillover loss, reducing the efficiency of the antenna. let

FIG. 6 is a diagram showing an actually measured pattern using a conventional elliptical corrugated horn. Figure 6(a) shows the short axis pattern of an elliptical corrugated horn at a frequency of 12 GHz, and Figure 6(b) shows the short axis pattern of the same elliptical corrugated horn at 14 GHz. )as well as(
From b), it can be seen that the 10 dB beam widths of conventional corrugated horns do not match very well. As described above, conventional corrugated horns have problems to be solved.

(Means for Solving the Problems) In the corrugated horn of the present invention, the depth of the groove near the opening is made deeper than the depth (about λ/4) of the groove near the middle part, thereby improving the corrugated horn as described above. Solved the problem.

(Example) Next, the present invention will be explained with reference to the drawings.

Fig. 1 is a side view of one embodiment of the present invention (however, the half below the center line is a sectional view), and Fig. 2 is a front view of the embodiment of Fig. 1. In Fig. 0, 1 is an elliptical corrugated gate. 1 with horn
1 is a tooth, 12 is a hole, and 13 is a feeding waveguide connected to the elliptical corrugated horn 1. The depth d2 of the basin 12 near the middle part is approximately λ/4, and the depth dl of the basin 12 near the opening is approximately λ/4.
is shallower than λ/2 and deeper than λ/4 (λ/2
<dl <λ/4).

3(a) and 3(b) are actually measured radiation patterns of the embodiment of FIG. 1. FIG. 3(a) shows a short-axis pattern of an elliptical corrugated horn at a frequency of 12 GHz, and FIG. 3(b) shows a short-axis pattern of the same elliptical corrugated horn at 14 GHz. In the patterns shown in Figures 3(a) and (b), the beam width is 10 dB.
It is clear that there is better agreement than in the pattern shown in b).

(Effects of the Invention) As explained above, in the corrugated horn of the present invention, by making the depth of the groove near the opening deeper than λ/4, the beam width in the E plane and the H plane can be increased compared to the conventional one. It is also possible to match over a wide band.

[Brief explanation of drawings]

FIG. 1 is a perspective view of an elliptical corrugated horn which is an embodiment of the present invention, FIG. 2 is a front view of the embodiment of FIG. 1, and FIG. 3 is a diagram showing an actually measured radiation pattern of the embodiment of FIG. , the same figure (
Figure a) shows the radiation pattern at 12 GH2, and figure (b) shows the radiation pattern at 14 GHz. In addition, Fig. 4 is a perspective view of a conventional elliptical corrugated horn, Fig. 5 is a front view of the elliptical corrugated horn shown in Fig. 4, and Fig. 6 shows an actually measured radiation pattern of the conventional elliptical corrugated horn shown in Fig. 4. 12 GHz in the figure (a) and 1 GHz in the figure (b).
It is a figure which shows the radiation pattern in 4GHz, respectively. 1...Oval corrugated horn, 11...Tooth tip, 12
...Groove, 13...Feeding waveguide, 2...Oval corrugated horn, 21...Tooth tip, 22...Elimination, 23...
・Feeding waveguide. Figure 2

Claims (1)

[Claims] A corrugated horn characterized in that the depth of the groove near the opening is deeper than the depth of the groove in the middle of the flare.