JP4103330B2 - NRD guide L type antenna element - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an antenna element used in a high frequency band such as a millimeter wave band or a microwave band, and more particularly to an NRD guide L-type antenna element.
[0002]
[Prior art]
As a dielectric line for an integrated circuit in the millimeter wave band, a nonradiative dielectric waveguide (hereinafter referred to as “NRD guide”) in which a dielectric strip is disposed between a pair of parallel metal plates is known. Yes.
[0003]
FIG. 4 is an exploded perspective view of a basic NRD guide antenna element.
[0004]
This NRD guide antenna element 1 is provided with a dielectric strip 4 having a high dielectric constant between two metal plates (or on one metal plate) 2 and 3, and the dielectric strip 4 is excited to excite the metal plate. A radio wave is transmitted between two and three, and a radio wave is radiated from the tapered portion 4a at the tip, and the conductor loss due to the inner walls of the metal plates 2 and 3 is reduced in the microwave band and the millimeter wave band. Can do.
[0005]
As antenna elements of this type of NRD guide, the antennas shown in FIGS. 5 and 6 below are known.
(1) FIG. 5 is a perspective view showing a conventional example of an NRD guide antenna element.
[0006]
The antenna element 10 shown in FIG. 1 is obtained by exposing a prismatic dielectric strip 11 having a taper in an electric field direction from a metal plate 12 to the outside. In the antenna element 10, the NRD guide uses parallelism of the electric field component of the main transmission mode with respect to the metal plate 12. Reference numeral 13 is a millimeter wave oscillator, 14 is a metal strip resonator, 15 is a high dielectric constant sheet, 16 is a frequency modulator, 17a and 17b are waveguides, and 18 is a circulator (Japanese Patent No. 2855246).
(2) FIG. 6 is an exploded perspective view showing another conventional example of an NRD guide antenna element.
[0007]
The antenna element 20 shown in the figure is provided with a collar 21 a on the dielectric resonator 21 having a size larger than that of the opening 22 a provided on the second planar conductor 22 than the dielectric resonator 21 side. The dielectric resonator 21 is inserted into the fixing hole 23 a of the conductor 23.
[0008]
Here, the radio wave propagates through the dielectric strip 24 in an LSM mode that generates an electric field having an XY plane component and a magnetic field having an XZ plane component, and is electromagnetically coupled to the dielectric resonator 21 at its end. The dielectric resonator 21 radiates as electromagnetic waves in the normal direction from the opening 22a formed in the second planar conductor 22 through the slot 25a formed in the third planar conductor 25. (See JP-A-11-27034).
[0009]
[Problems to be solved by the invention]
However, in the prior art shown in FIG. 5, the dielectric strip is exposed to the outside of the metal so that it is easily damaged mechanically. Further, the prior art shown in FIG. 6 has a problem in that the number of parts increases, so that the material cost becomes high and the assembling takes time.
[0010]
SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to solve the above-described problems, and to provide an NRD guide L-type antenna element that is hardly damaged mechanically and has a small number of parts.
[0011]
[Means for Solving the Problems]
In order to achieve the above object, the NRD guide L-type antenna element of the present invention includes a first metal plate and a long portion on the first metal plate so that the short portion is perpendicular to the first metal plate. And an L-shaped dielectric strip having a tapered portion with a tapered tip and an inclined surface formed outside the bent portion, and an opening so that the tip of the dielectric strip is exposed. And a second metal plate arranged in parallel with the first metal plate so as to sandwich a long portion of the dielectric strip.
[0012]
In addition to the above configuration, the NRD guide L-type antenna element of the present invention is provided at the opening of the second metal plate so that the central axis of the horn antenna or the dielectric lens or both is along the normal direction of the second metal plate. It may be done.
[0013]
According to the present invention, when a high frequency is input to a long portion of the L-shaped dielectric strip, the high frequency propagates from a long portion to a short portion, is reflected by an inclined surface, and is reflected from the opening of the second metal plate. Radiated in the normal direction of the second metal plate. For this reason, since the front-end | tip part 32aa exposed to the exterior of a dielectric strip can be decreased, it can reduce in size and mechanical strength improves. Further, since the shape of the dielectric strip 32 is as simple as an L shape, it is easy to manufacture at a low cost. Accordingly, it is possible to provide an NRD guide L-type antenna element that is not easily damaged mechanically and has a small number of components.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
[0015]
FIG. 1 is an exploded perspective view showing an embodiment of an NRD guide L-type antenna element of the present invention. FIG. 2 is a side view of the NRD guide L-type antenna element shown in FIG. 1 after assembly. In this embodiment, the case of an NRD guide L-type antenna element for millimeter waves will be described.
[0016]
The NRD guide L-type antenna element 30 has a first metal plate 31 and a long portion 32 b arranged on the first metal plate 31 so that the short portion 32 a is perpendicular to the first metal plate 31. In addition, the tip 32aa of the short portion 32a is formed in a pyramid shape (may be conical or tapered, or tapered), and an L-shaped side surface having an inclined surface 32cc formed outside the bent portion 32c (see FIG. Alternatively, the dielectric strip 32 having a circular cross-sectional shape) and a rectangular (circular, polygonal, or elliptical) opening 33a may be formed so that the tip 32aa of the dielectric strip 32 is exposed. It comprises a second metal plate 33 arranged in parallel with the first metal plate 31 so as to sandwich the long portion 32b of the strip 32.
[0017]
The first metal plate 31 and the second metal plate 33 are made of, for example, a copper plate, and the dielectric strip 32 is made of, for example, alumina.
[0018]
Here, the dielectric strip 32 has a structure sandwiched between the first metal plate 31 and the second metal plate 33 and functions as an NRD guide.
[0019]
Now, a millimeter wave transmitted from the outside of a waveguide, a transmission circuit (not shown) or the like into the dielectric strip 32 has an electric field having an XY plane component and an XZ plane component in the dielectric strip 32. It propagates in the LSM (Longitudinal Section Magnetic) mode that generates a magnetic field. Since the dielectric strip 32 has a 45 ° inclined surface 32cc formed outside the bent portion 32c, the electromagnetic wave propagating in parallel to the metal plates 31 and 33 in the LSM mode is transmitted through the inclined surface 32cc to the metal plates 31 and 33. And is radiated to the outside from the tip end portion 32aa as the radiation surface.
[0020]
Since the antenna element 30 has a short tip portion 32aa exposed from the second metal plate 33, the exposed portion is reduced, and as a result, the antenna element 30 can be reduced in size and mechanical strength is improved. Further, since the shape of the dielectric strip 32 is as simple as an L shape, it is easy to manufacture at a low cost. Accordingly, it is possible to provide an NRD guide L-type antenna element that is not easily damaged mechanically and has a small number of components.
[0021]
FIG. 3 is a side view showing another embodiment of the NRD guide L-type antenna element of the present invention.
[0022]
The difference from the embodiment shown in FIG. 1 is that the opening 33a of the second metal plate 33 is such that the central axes of the horn antenna 41 and the dielectric lens 42 are along the normal direction of the second metal plate 33. It is a point provided in.
[0023]
In such an antenna element 40, the same effect as that of the antenna element 30 shown in FIG. 1 can be obtained, and the directivity of the radiated radio wave can be adjusted.
[0024]
As described above, according to the present invention, the dielectric strip line (none of which is shown) for propagating a signal from the millimeter wave transmitter, and the L-shaped dielectric strip 32 are connected to the first metal plate 31 and the first metal plate 31. Since the opening 33a is formed in the second metal plate 33 so as to be sandwiched between the two metal plates 32 and to expose the tip end portion 32aa of the dielectric strip 32 to the outside, the radiation portion exposed to the outside is reduced. Can be downsized and mechanically strong. The shape of the dielectric strip 32 is simple and can be reduced in price because it is integrated. In this embodiment, the case of millimeter waves has been described, but the present invention can also be applied to high frequencies such as microwaves and submillimeter waves.
[0025]
【The invention's effect】
In short, according to the present invention, the following excellent effects are exhibited.
[0026]
It is possible to provide an NRD guide L-type antenna element that is not easily damaged mechanically and has a small number of parts.
[Brief description of the drawings]
FIG. 1 is an exploded perspective view showing an embodiment of an NRD guide L-type antenna element of the present invention.
FIG. 2 is a side view after assembly of the NRD guide L-type antenna element shown in FIG. 1;
FIG. 3 is a side view showing another embodiment of the NRD guide L-type antenna element of the present invention.
FIG. 4 is an exploded perspective view of a basic NRD guide antenna element.
FIG. 5 is a perspective view showing a conventional example of an NRD guide antenna element.
FIG. 6 is an exploded perspective view showing another conventional example of an NRD guide antenna element.
[Explanation of symbols]
31 First metal plate 32 Dielectric strip 32aa Tip portion 32cc Inclined surface 33 Second metal plate 33a Opening portion

Claims (2)

The first metal plate and the long part are arranged on the first metal plate so that the short part is perpendicular to the first metal plate, and the tip of the short part is formed in a tapered shape and bent. An L-shaped dielectric strip having an inclined surface formed on the outer side of the portion, and an opening formed so as to expose a tip of the dielectric strip, and a first portion so as to sandwich a long portion of the dielectric strip. An NRD guide L-type antenna element, comprising: a second metal plate arranged in parallel with the metal plate. 2. The NRD guide L-type antenna element according to claim 1, wherein the central axis of the horn antenna or the dielectric lens or both is provided in the opening of the second metal plate so as to be along the normal direction of the second metal plate. .

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