JPS5829607Y2 - horn antenna - Google Patents

Description

[Detailed explanation of the invention] This invention relates to the improvement of a horn antenna.
More specifically, the present invention relates to an improvement in the airtight window necessary for filling the inside of the horn antenna with dry air.

Conventional horn antennas often have a flat or conical dielectric thin plate attached to their opening to make the inside airtight.

In this case, in order to reduce electrical reflection from this dielectric thin plate, it was necessary to make it sufficiently thin compared to the wavelength.

On the other hand, mechanically, it must have sufficient strength not to break under the stress caused by the pressurization of dry air.

This has the disadvantage that the electrical and mechanical requirements are opposite, usually at the expense of electrical performance.

In addition, a sandwich plate or a half-wave plate is sometimes used instead of a dielectric thin plate as a material with low reflection and high mechanical strength, but in this case, the frequency range where reflection is low is very large. It had the disadvantage of being narrow.

In order to solve the above-mentioned conventional drawbacks, this idea provides a dielectric plate in the small-diameter waveguide section to provide strength against the pressure applied by dry air filling, and provides broadband matching using a matching element electrically. A thin dielectric plate is installed at the opening of the horn to reduce electrical reflection, and a thin dielectric plate is installed at the opening of the horn to prevent condensation of moisture in the space between them. By placing the desiccant material through the small holes, a horn antenna with sufficient mechanical strength and less electrical reflection can be realized.

The horn antenna of this invention will be described below with reference to the drawings.

Figures 1 and 2 show an example of a conventional horn antenna. In the figures, 1 is a horn, 2a is a flat dielectric thin plate, 2b is a conical dielectric thin plate, and 3 is a rubber backing. , 4 is a pressed frame, and 5 is a waveguide.

In this case, as mentioned above, in order to reduce electrical reflection, it is necessary to use dielectric plates 2a and 2b that are sufficiently thin compared to the wavelength, and on the other hand, when dry air is filled inside the horn 1, the pressing force As a result, the dielectric thin plates 2a and 2b are deformed or destroyed.

FIG. 3 shows an embodiment of this invention. In the figure, 2c is a dielectric thin plate, 6 is a dielectric, 7a and 7b are rubber backings, 8 is an impedance matching element, and 9 is a desiccant ( For example, silica gel), and the rest is the same as in FIGS. 1 and 2.

In this case, since the dielectric plate 6 is inside the waveguide 5, which normally has a medium inner diameter so as not to transmit any higher-order mode waves within the frequency range used, the dielectric plate 6 at the opening of the hole 71 Even if it is thinner than the thin plate 2c of the body, it can withstand the pressure applied by the dog.

On the other hand, a dielectric thin plate 2C is provided at the opening of the horn 1 with a rubber backing 3 interposed therebetween to prevent outside air from entering therein.

As a result, the reflection by the dielectric plate 6 in the waveguide 5 can be matched over a wide band by the impedance matching element 8, and the inner diameter of the deep waveguide 5 is such that high-order mode waves cannot be transmitted. Therefore, there are no adverse effects such as delay distortion caused by higher-order mode waves.

Is the dielectric thin plate 2C in the opening part rubber backing for the horn 1?
Since it is shielded from the waveguide 5 by a and 7b, there is no pressurization of dry air or the like from inside, and it can be constructed of a very thin material, and electrical reflection can be made very small.

When the air in horn 1 is exhausted, this will cause rubber backing 3.
Since the horn 1 is isolated from the outside air by the horn 1 and 7b, when the outside temperature becomes low, moisture condenses and has an adverse electrical effect. , and prevents condensation.

As described above, according to this invention, the reflections from the dielectric plate 60 can be matched by the matching element 8, and the reflections from the thin dielectric plate 2C can be made thinner, resulting in less reflections, and the reflections as a whole can be reduced.

Furthermore, the dielectric 6 of the waveguide 5 having a small inner diameter can provide sufficient strength against the pressure applied by dry air filling.

As a result, a horn antenna with excellent electrical performance and mechanical strength can be realized.

However, this invention can be implemented regardless of the shape of the horn, such as a cone or a pyramid, and it goes without saying that the shape of the dielectric thin plate 2C may be concave or convex in addition to the flat shape.

[Brief explanation of drawings]

1 and 2 are cross-sectional views showing an example of a conventional horn antenna, and FIG. 3 is a cross-sectional view showing an example of a horn antenna based on this invention.
a, 2b, 2c, and 6 are dielectric plates, 3.7a, 7bi4 rubber backing, 4 is a stamping frame, 5 is a waveguide, 8 is a joining element, and 9 is a desiccant. Note that the same or corresponding parts in the figures are denoted by the same reference numerals.

Claims (1)

[Scope of utility model registration request] A dielectric plate is provided at the connection between the horn and the waveguide whose inner diameter is large enough not to transmit higher-order mode waves, and a dielectric plate is also provided at the opening of the horn to make the space between the two dielectrics airtight. A horn antenna characterized in that the above-mentioned horn is further provided with Ii [rlJ] to prevent air between the two dielectric bodies from condensing.