JP3269683B2 - Leak wave NRD guide - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a leaky wave NRD guide capable of efficiently radiating radio waves.

[0002]

2. Description of the Related Art NRD guides (Non-radiative dielectric lines, non-radiative dielectric lines) are used as new dielectric lines for millimeter-wave integrated circuits.
ielectric Waveguide) is known. This NRD guide has a structure in which a dielectric strip is sandwiched between upper and lower metal plates. Then, a discontinuous element such as a concave portion is provided on the dielectric strip, and by exciting the dielectric strip, a radio wave is generated between the upper and lower metals.

[0003]

Conventionally, a dielectric strip is provided with a concave portion for each radio wave propagation wavelength λg, and a leaky wave NRD guide is used as a discontinuous element. Since the electric power of the radio wave radiated from one concave portion is small, a large number of concave portions must be provided in order to radiate the radio wave efficiently. For this reason, there is a problem that the length of the leaky wave NRD guide must be increased. The present invention has been made in view of the above points, and an object of the present invention is to provide a leaky wave NRD guide that can efficiently radiate radio waves even if it is short.

[0004]

According to a first aspect of the present invention, there is provided a leaky wave NRD guide, wherein a concave discontinuous element is provided on a dielectric strip of the NRD guide for each propagation wavelength λg, and the discontinuous element is provided with a dielectric strip. It is characterized in that a dielectric having a dielectric constant higher than the dielectric constant is added.

[0005] The leaky wave NRD guide according to claim 2 is:
Providing a discontinuous element on the dielectric strip of the NRD guide,
It is characterized in that the dielectric constant of the discontinuous element is made larger than that of the dielectric strip.

[0006] leaky wave NRD guide according to claim 3, and the dielectric strip sandwiched disposed dielectric strip or the metal plate between two metal plates which were vertically parallel
It is characterized in that a concave discontinuous element is provided for each of the propagation wavelengths λg on the contacting main surface, and a dielectric having a dielectric constant larger than the dielectric constant of the dielectric strip is added to the discontinuous element.

[0007] leaky wave NRD guide according to claim 4, and the dielectric strip sandwiched disposed dielectric strip or the metal plate between two metal plates which were vertically parallel
A discontinuous element is provided on a contacting main surface, and the dielectric constant of the discontinuous element is made larger than the dielectric constant of the dielectric strip.

[0008] leaky wave NRD guide according to claim 6, the dielectric strip of the upper or the upper metal plate of the dielectric strip which is sandwiched disposed between the upper metal plate and lower metal plate having vertically parallel A concave discontinuous element is provided for each propagation wavelength λg on the main surface in contact with the lower surface of the dielectric strip or in contact with the dielectric strip on the lower metal plate.
A concave discontinuous element is provided on the main surface at every propagation wavelength λg by λg / 2 from the above discontinuous element, and a dielectric substance having a dielectric constant larger than the dielectric strip is added to each discontinuous element. I do.

[0009]

The leakage NRD guide according to any one of claims 1 to 5,
Since a discontinuous element is provided on the dielectric strip or metal plate of the guide, and a dielectric constant greater than the dielectric constant of the dielectric strip is added to this discontinuous element, radio waves can be efficiently radiated from the discontinuous element. it can.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view of a basic NRD guide,
FIG. 2 is a cross-sectional view of the leaky wave NRD guide according to the first embodiment of the present invention, and FIG. 3 is a diagram showing a relationship between a depth of a cut provided in a dielectric strip and a radio wave radiation amount.

First, the configuration of a basic NRD guide will be described with reference to FIG. A waveguide using a dielectric such as an NRD guide is advantageous in reducing a conductor loss due to a metal wall in a microwave or millimeter wave band.

As shown in FIG. 1, the NRD guide is parallel
The structure has a structure in which a dielectric strip 13 is sandwiched between an upper metal plate 11 and a lower metal plate 12 arranged in the same manner. The dimensions of the dielectric strip 13 are the height a. A material having a width b and a size represented by Formulas 1 and 2 is used (λ is a free space wavelength, ε _r is a dielectric constant of a dielectric strip), and the material is a high frequency such as Teflon, polyethylene, or polystyrene. Low-loss materials are used.

[0013]

(Equation 1)

[0014]

(Equation 2)

In general, the line does not radiate in the transmission mode (hybrid mode) of the homogeneous NRD guide. In the present invention, however, a discontinuous element is provided in the dielectric strip so that the upper metal plate 11 and the lower metal plate 12 are provided. The present invention relates to a leaky wave NRD guide that radiates radio waves and is used for an antenna or a coupling line.

FIG. 2 is a cross-sectional view of the leaky wave NRD guide according to the first embodiment of the present invention. FIG. 2A is a cross-sectional view along the center in the longitudinal direction, and FIG. A) AA
It is sectional drawing along the line. As shown in FIG. 2, a dielectric strip 14 is provided between an upper metal plate 11 and a lower metal plate 12.
Has a structure in which it is disposed. This dielectric strip 1
4 for each 1λg the dielectric strip 13 of FIG. 1, an incision having a width narrower, are added to the dielectric constant epsilon ₁ is greater than the dielectric constant epsilon ₂ of the dielectric of the dielectric strip in the cut. The discontinuous element 15 to which the dielectric is added is provided above the dielectric strip 14, and below the dielectric strip 14 is provided above the dielectric strip 14 and is shifted from the discontinuous element 15 by λg / 2. discontinuous elements 16 the dielectric is added dielectric constant epsilon ₂ is provided. FIG. 2 shows a structure in which a leak wave is generated in a direction perpendicular to the guide, and this is not limited as long as the interval between the discontinuous elements is arbitrary.

Referring to FIG. 3, discontinuous element 15 in FIG.
The measurement results of the characteristics in two cases are shown. Dielectric strip 1
4 is a Teflon of a = 5.9, b = 5.4 mm (ε ₁ = 2.
04), a cut having a width w = 1.3 mm and a depth d is made, and a dielectric having a high dielectric constant (ε ₂ = 10.2) is added thereto. Here, the frequency of the experiment was set to the 24 GHz band, and the depth d of the dielectric having a high dielectric constant was changed to show the radiation amount and the standing wave ratio characteristics.

Here, radiation amount = input power−output power−mismatch loss. The lower curve A in the graph is air (ε ₀ =
1.0), and the upper curve A is a case where a dielectric having a high dielectric constant (ε ₂ = 10.2) is added to the discontinuous element.

As is clear from the gram in the figure, the lower curve B has a small radio wave radiation amount and the standing wave ratio does not change.
Curve A above changes significantly, with about 3 dB or about 50% of power emanating from one discontinuous element at a depth d = 2 mm. Thus, by providing the dielectric strip 14 with the discontinuous element having a dielectric constant larger than that of the dielectric strip 14, radio waves can be efficiently radiated.

Next, a leaky wave NRD guide according to a second embodiment of the present invention will be described with reference to FIG. FIG.
4A is a cross-sectional view of the leak wave NRD guide, and FIG. 4B is a cross-sectional view along the line BB of FIG. 4A.

As shown in FIG. 4, cuts 24, which are discontinuous elements, are provided for each λg on the main surface of the upper metal plate 21 of the NRD guide which is in contact with the dielectric strip 23. inserting a dielectric having a dielectric constant epsilon ₁ is greater than the dielectric constant epsilon ₂ of the dielectric strip 23.

Further, the dielectric strip of the lower metal plate 22 is formed.
Cuts 25... Which are discontinuous elements are provided for each λg on the main surface in contact with the step 23, and a dielectric having a dielectric constant ε ₂ larger than the dielectric constant ε ₁ of the dielectric strip 23 is inserted into the cut 25. It is arranged to be shifted by λg / 2 from the notch 24 as a discontinuous element provided in the upper metal plate 22. With this configuration, it is possible to radiate radio waves efficiently as in the first embodiment.

Next, a planar antenna using a leaky wave NRD guide according to the present invention will be described with reference to FIG. As shown in FIG. 5, a dielectric strip 33 having the structure shown in FIG. 2 is sandwiched between two upper and lower metal plates 31 and 32, and this dielectric strip 33 is excited by a coaxial line 34. The periphery of the upper and lower two metal plates 31 and 32 is short-circuited by a metal wall 35. The upper metal plate 31 is provided with a slot 36 for each wavelength, and the end of the dielectric strip 33 is open.

With the above configuration, the leaky wave radiated from the dielectric strip 33 travels to the broad side, propagates in the lower space of the row of slots 36, and is reflected by the metal wall 35 at the right end. A standing wave distribution is formed between the metal plates 31 and 32.

Each slot 36 of the upper metal plate 31
Since the magnetic field is at the maximum position at one wavelength interval of the standing wave, each slot 36 is excited in phase,
Are also in phase in the longitudinal direction, so that linearly polarized waves are radiated in the direction perpendicular to the antenna plane.

As described above, radio waves can be efficiently radiated by the discontinuous elements having a high dielectric constant provided on the dielectric strip of the leaky wave NRD guide.
The planar antenna using the D guide can be reduced in size. The leak wave NRD guide according to the present invention has a 3 dB
It can also be used for devices with strong coupling, such as directional matching devices.

[0027]

As described above in detail, according to the present invention, a leaky wave NR capable of efficiently radiating radio waves even if it is short.
A D guide can be provided.

[Brief description of the drawings]

FIG. 1 is a sectional view of a basic NRD guide.

FIG. 2 is a sectional view of a leaky wave NRD guide according to the first embodiment of the present invention.

FIG. 3 is a diagram showing a relationship between a depth of a cut provided in the dielectric strip and a radiation amount of a radio wave.

4A and 4B show a leaky wave NRD guide according to a second embodiment of the present invention. FIG. 4A is a cross-sectional view of the leaky wave NRD guide, and FIG. Sectional drawing along the B line.

FIG. 5 is a perspective view of a planar antenna using a leaky wave NRD guide according to the present invention.

[Explanation of symbols]

11 upper metal plate, 12 lower metal plate, 13, 14 dielectric strip, 15, 16 discontinuous element.

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Jun Minase 1406 Hasunuma, Omiya City, Saitama Prefecture Inside the Omiya Plant, Yagi Antenna Co., Ltd. Inventor Toshihiko Agatsuma 4-16-20 Tsurugaoka, Izumi-ku, Sendai City, Miyagi Prefecture (56) Reference IEICE Technical Report, A. P91-124 (58) Fields investigated (Int. Cl. ⁷ , DB name) ) H01Q 13/20 H01P 3/16 H01Q 21/06

Claims (5)

(57) [Claims] 1. A dielectric strip of an NRD guide, wherein a concave discontinuous element is provided for each propagation wavelength λg, and a dielectric having a dielectric constant larger than that of the dielectric strip is added to the discontinuous element. Leakage wave NRD guide. 2. The leaky wave N according to claim 1, wherein a discontinuous element is provided on the dielectric strip of the NRD guide, and the dielectric constant of the discontinuous element is made larger than the dielectric constant of the dielectric strip.
RD guide. Wherein said induction of upper and lower is sandwiched disposed between two metal plates which are parallel dielectric strip or the metal plate
A leaky wave characterized in that a concave discontinuous element is provided for each of the propagation wavelengths λg on the main surface in contact with the electric strip, and a dielectric having a dielectric constant larger than the dielectric constant of the dielectric strip is added to the discontinuous element. NRD guide. Wherein said induction of upper and lower is sandwiched disposed between two metal plates which are parallel dielectric strip or the metal plate
A leaky wave NRD guide, wherein a discontinuous element is provided on a main surface in contact with an electric strip, and the dielectric constant of the discontinuous element is made larger than the dielectric constant of the dielectric strip. 5. An upper metal plate and a lower metal plate which are vertically parallel.
A concave discontinuous element is provided for each propagation wavelength λg on the upper surface of the dielectric strip sandwiched and disposed between the dielectric strips or on the main surface of the upper metal plate in contact with the dielectric strip. Above the dielectric strip of the lower or lower metal plate
For each propagation wavelength lambda] g to the main surface in contact with the trip shifted from the discontinuous elements only lambda] g / 2 is provided a discontinuous element concave,
A leaky wave NRD guide characterized in that a dielectric material having a dielectric constant larger than the dielectric strip is added to each discontinuous element.