JP2002344210A - Conversion circuit between non-radiative dielectric line and waveguide - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a conversion circuit that enables a non-radiative dielectric line to utilize a lower-order mode, and at the same time, satisfactorily conducts mode transformation between the dielectric line and a waveguide. SOLUTION: The non-radiative dielectric line 10 is connected to the waveguide 14, having a short-circuiting plate 16 at its end section, by arranging a dielectric strip 13 in a direction, which is almost parallel with the direction of the high-frequency electric field of the waveguide 14. Then the probe 18 of a conductive member, installed to the end section of the strip 13, is inserted into and arranged in the waveguide 14 from an opening 14Q of the waveguide 14. In addition, the LSE01 mode is used as the transmission mode of the dielectric line 10, and when the probe 18 is used, the transformation between the LSE01 mode and the TE10 mode of the waveguide 14 and high-frequency transmission are made smoother, by making transmitted high-frequency electric fields concentrate. Moreover, an impedance converting section which performs impedance matching can be provided on the wall of the waveguide 14 of this conversion circuit.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a conversion circuit between a nonradiative dielectric line and a waveguide for efficiently transmitting a high frequency such as a millimeter wave band between the nonradiative dielectric line and the waveguide. .

[0002]

2. Description of the Related Art In recent years, non-radiative dielectric lines have been used because of their excellent transmission characteristics in ultra-high frequencies, especially in the millimeter wave band.
Various products using (NRD) are manufactured and used, and as a transmission mode of the non-radiative dielectric line, the LSM ₀₁ mode is predominant because of low transmission loss. Then, a conversion circuit is used in order to satisfactorily transmit a high frequency between the non-radiative dielectric line and the waveguide.

FIG. 7 shows a configuration of a conventional nonradiative dielectric line / waveguide conversion circuit. As shown in FIG. 7, nonradiative dielectric lines 1 are arranged at predetermined intervals. The dielectric strip 3 is formed between two metal plates 2A and 2B. A rectangular waveguide 5 having, for example, a flange 4 is connected to the non-radiative dielectric line 1, and the tip of the dielectric strip 3 is inserted into the waveguide 5 at the connection portion. The portion 3a is formed in a tapered shape such that the width in the high-frequency electric field direction is reduced.

According to such a converter, in the portion of the dielectric strip 3 in the non-radiative dielectric line 1, the electric field distribution of the LSM ₀₁ mode is obtained as shown in FIG. It becomes the electric field of TE ₁₀ mode as shown in FIG. 9, both the electric field direction coincides (waveguide 5 in FIG. 7 is in a state of being rotated 90 degrees to that of Figure 9). Also,
Due to the tapered shape of the dielectric strip 3 (tip portion 3a), the reflection of the transmission wave at the connection portion is suppressed low, and the LSM ₀₁ mode of the non-radiative dielectric line 1 is gradually changed to the T-mode of the waveguide 5.
It is converted to the E ₁₀ mode.

[0005]

However, the conversion circuit of the non-radiative dielectric line 1 and the waveguide 5 has good characteristics such as transmission loss, but the LSM ₀₁ mode has a higher mode. Therefore, there is a problem that a mode suppressor is required to prevent mode conflict. By the way, in order to prevent the mode competition and secure the operation stability, it is conceivable to use an LSE mode which is a lower-order mode, for example, an LSE ₀₁ mode. It has been found that even in the ₀₁ mode, the loss per effective wavelength is not inferior to that of the LSM ₀₁ mode. Therefore, if the non-radiative dielectric line 1 can use the LSE ₀₁ mode, there is no need for a means for preventing mode competition.

However, when the non-radiative dielectric line 1 of the LSE ₀₁ mode transmission is used for various applications, a conversion circuit between the LSE ₀₁ mode transmission and the waveguide 5 is required.
The conventional conversion circuit using the LSM ₀₁ mode shown in FIG. 7 has a problem that it cannot support the LSE ₀₁ mode having a different high-frequency electromagnetic field.

The present invention has been made in view of the above problems, and an object of the present invention is to make it possible to use a low-order mode in a nonradiative dielectric line and to combine the nonradiative dielectric line with a waveguide. An object of the present invention is to provide a nonradiative dielectric line / waveguide conversion circuit capable of favorably performing mode conversion between modes.

[0008]

In order to achieve the above object, the invention according to claim 1 is directed to a waveguide provided with a short-circuit plate at an end, and a direction of a high-frequency electric field with respect to the waveguide. A non-radiative dielectric line in which a dielectric strip is arranged and connected in a substantially parallel direction; and a non-radiative dielectric line provided at an end of the dielectric strip and inserted into the waveguide from an opening formed in a wall of the waveguide. And a conductive member probe. According to a second aspect of the present invention, in the probe,
A conductive member is provided so as to protrude from the waveguide wall facing the opening of the waveguide toward the opening, and the conductive member is formed by being coupled to the dielectric strip. I do. The invention according to claim 3 is characterized in that a waveguide wall facing the opening of the waveguide is provided with an impedance conversion section made of a conductive member protruding from the wall and for achieving impedance matching. And

According to the above configuration, the LSE mode, particularly the LSE ₀₁ mode, is used as the transmission mode of the non-radiative dielectric line. The non-radiative dielectric line and the waveguide have their electric field directions. Connected to match. Then, a probe such as a metal film, a metal rod, or a conductive paste film is attached to the tip of the dielectric strip provided on the non-radiative dielectric line, and the probe is inserted into the inside from the waveguide opening. This conductive probe
The high-frequency electric field transmitted through the dielectric strip is concentrated, whereby the non-radiative dielectric line LSE ₀₁
It serves to facilitate conversion and high-frequency transmission between the TE ₁₀ mode of the mode and the waveguide.

According to the second aspect of the present invention, the probe is firmly fixed to the dielectric strip and the waveguide wall, and the operation is stabilized. Further, according to the third aspect of the present invention, high-frequency transmission can be performed satisfactorily by achieving impedance matching by adjusting the height of the ridge of the converter.

[0011]

1 to 3 show a first embodiment of the present invention.
FIG. 1A shows a configuration of a conversion circuit between a non-radiative dielectric line and a waveguide according to an embodiment. FIG. 1A is a diagram in which a waveguide flange is viewed from the front, and FIG. Sectional view taken along line II ′ of FIG.
FIG. 2 is a perspective view, and FIG. 3 is a view of an electric field direction viewed from each direction. In the figure, a non-radiative dielectric line 10 is composed of two metal plates 12A and 12B arranged at a predetermined interval, and a prismatic dielectric material arranged at the center between the two metal plates 12A and 12B. The non-radiative dielectric line 10 is composed of a strip 13 and an LSE ₀₁ mode, which is a fundamental mode of the LSE mode, is applied. On the other hand, the rectangular waveguide 14 is provided with a flange 15 having a rectangular opening at one end, and a short-circuit plate 16 at the other end. The transmission mode of the waveguide 14 is a TE ₁₀ mode. Become.

The above-mentioned non-radiative dielectric line 10 and waveguide 1
4 are connected such that their electric field directions coincide.
That is, the electric field of the LSE ₀₁ mode in the non-radiative dielectric line 10 is as shown in FIG. 3A when viewed from the front, and as shown in FIG. 3B when viewed from the side. Become
An electric field distribution follows the high-frequency transmission direction. On the other hand, FIG.
As shown (C), the in TE ₁₀ mode of the waveguide 14 has an electric field distribution oriented vertically. Therefore,
If the vertical direction of the waveguide 14 (the direction perpendicular to the high-frequency transmission direction in the waveguide) and the transmission direction in the non-radiative dielectric line 10 are matched, both electric field directions match.

In such a connection state, a rectangular opening 14Q is opened in the upper wall of the waveguide 14 in the drawing, and the tip of the dielectric strip 13 is introduced into the waveguide 14 from the opening 14Q. Part is inserted. In the first embodiment, a probe 18 of a copper thin film (conductor pattern) is formed on the tip of the dielectric strip 13 in the first embodiment. The probe 18 may be a thick film or the like using another conductive paste instead of the copper thin film.

Next, an example of a more specific configuration of the first embodiment will be described. That is, in the case of a converter in the millimeter wave band of about 60 GHz, the non-radiative dielectric line 10 is used.
The dimensions of the dielectric strip 13 are 1.52 mm ×
0.6 mm and a relative dielectric constant of 9.2 are used, and the rectangular waveguide 14 has an inner size of 3.76 mm according to WR15 standard.
X 1.88 mm. In addition, this waveguide 14
Is set so that the high-frequency electric field is maximized at the position of the dielectric strip 13, and is set at a position 1.8 mm from the end of the dielectric strip 13.

Further, the insertion amount of the dielectric strip 13 into the waveguide 14 is approximately one-fourth of the effective wavelength in the non-radiative dielectric line 10, and is 0.6 m in this case.
m is inserted. And this dielectric strip 1
3 is 0.6 mm ×
The length of the probe 18 in the vertical direction is equal to the insertion length of the dielectric strip 13 into the waveguide 14. The probe 18 is connected to the non-radiative dielectric line 1.
0, the LSE ₀₁ mode is disturbed and the reflection loss increases.
It is preferable that the structure 8 has a structure stopped at a boundary between the waveguide 14 and the non-radiative dielectric line 10.

According to the configuration of the first embodiment as described above,
As shown in FIG. 3C, the direction of the electric field in the LSE ₀₁ mode of the non-radiative dielectric line 10 matches the direction of the electric field in the TE ₁₀ mode of the waveguide 14, and the insertion of the dielectric strip 13 into the waveguide 14 is performed. Since the probe 18 is provided in the portion, the high-frequency electric field concentrates on the probe 18 and the transmission of the high frequency through the dielectric strip 13, that is, the LSE ₀₁ mode and the TSE ₀₁ mode
Conversion between E ₁₀ mode is satisfactorily performed.

FIG. 4 shows the configuration of a conversion circuit according to a second embodiment of the present invention. This second embodiment is provided with a probe made of a metal bar. That is, as shown in FIG. 4, the basic configuration of the non-radiative dielectric line 10 and the waveguide 14 is the same as that of the first embodiment, but the dielectric provided on the non-radiative dielectric line 10 A metal bar made of copper or the like (or a bar made of another conductive member) at the tip of the strip 20
Probe 21 is embedded. The probe 21 is formed by inserting and fixing a metal rod into a hole provided in the dielectric strip 20, or by casting a metal member.
The settings are made in the same manner as in the embodiment. According to the second embodiment as well, the high-frequency electric field is concentrated on the probe 20, so that the high-frequency transmission is favorably performed.

FIG. 5 shows a configuration of a conversion circuit according to a third embodiment of the present invention. In the third embodiment, a probe is provided from a waveguide wall opposite to an opening. It is.
That is, as shown in FIG. 5, this conversion circuit attaches a metal rod to be the probe 23 to the bottom of the waveguide 14 with a screw or the like while directing the metal rod toward the opening 14Q. It is manufactured by inserting and fixing in a hole provided in the strip 22. Other configurations are the same as those of the first embodiment. Also in the third embodiment, the electric field is concentrated on the probe 23 and the high-frequency transmission via the dielectric strip 22 is favorably performed.

FIG. 6 shows a configuration of a conversion circuit according to a fourth embodiment of the present invention. This fourth embodiment is provided with an impedance conversion unit. That is, as shown in FIG. 6, in this conversion circuit, on the bottom side of the waveguide 25,
An impedance conversion section 25D raised to reduce the vertical width of the internal space is formed. A metal rod serving as a probe 26 is attached to the impedance conversion section 25D with a screw or the like, and the upper side thereof is provided on the dielectric strip 22. Into the hole provided. Also, this impedance conversion unit 25D
Is set to such a size that a high-frequency reflection loss is small and a transmission characteristic is good at a connection portion between the waveguide 25 and the non-radiative dielectric line 10.

According to the fourth embodiment, impedance matching in the coupled line is achieved by the impedance conversion unit 25D, and the nonradiative dielectric line 10
High frequency transmission with a small reflection loss between the waveguide and the waveguide. In the fourth embodiment,
In place of the probe 26, the probe 18 of a copper thin film (conductor pattern) and the probe 21 of a metal bar (or a bar made of another conductive member) as described in the first and second embodiments may be used. Similar effects can be obtained.

[0021]

As described above, according to the present invention,
For a waveguide provided with a short-circuit plate at the end, a dielectric strip is arranged in a direction substantially parallel to the direction of the high-frequency electric field, and a non-radiative dielectric line is connected to the end of the dielectric strip. Since the conductive probe inserted from the opening into the waveguide is provided, mode conversion between the non-radiative dielectric line and the waveguide using the lower-order mode can be performed smoothly and favorably. There is an advantage that a mode suppressor is not required.

According to the second aspect of the present invention, the probe can be arranged in a structurally stable state, and the operation can be stabilized. Furthermore, according to the third aspect of the present invention, impedance matching is achieved by the impedance converter, and mode conversion and high-frequency transmission with reduced reflection loss can be achieved.

[Brief description of the drawings]

FIG. 1 shows a configuration of a conversion circuit for a non-radiative dielectric line and a waveguide according to a first embodiment of the present invention. FIG. 1 (A) is a front view from the flange side, and FIG. FIG. 2A is a sectional view taken along line II ′.

FIG. 2 is a perspective view of a conversion circuit according to the first embodiment.

3A and 3B show an electric field distribution in the first embodiment, where FIG. 3A is a view of the non-radiative dielectric line viewed from the front (high-frequency transmission direction), and FIG. (C) is a diagram viewed from the same direction as FIG. 1 (A).

4A and 4B show the configuration of a nonradiative dielectric line and waveguide conversion circuit according to a second embodiment, wherein FIG. 4A is a front view, and FIG.
FIG. 2A is a sectional view taken along line II-II ′ of FIG.

5A and 5B show a configuration of a nonradiative dielectric line and waveguide conversion circuit according to a third embodiment. FIG. 5A is a front view, and FIG.
FIG. 3A is a sectional view taken along line III-III ′ of FIG.

6A and 6B show the configuration of a nonradiative dielectric line and waveguide conversion circuit according to a fourth embodiment, where FIG. 6A is a front view, and FIG.
FIG. 4A is a sectional view taken along line IV-IV ′ of FIG.

FIG. 7 is a perspective view showing an example of a conventional nonradiative dielectric line / waveguide conversion circuit.

8 is a diagram showing the electric field distribution in the non-radiative dielectric line of the conversion circuit of FIG. 7 as viewed from the front.

FIG. 9 is a perspective view showing an electric field distribution in the waveguide.

[Explanation of symbols]

 1,10 ... non-radiative dielectric line, 3, 13, 20, 22 ... dielectric strip, 5, 14, 25 ... waveguide, 16 ... short-circuit plate, 18, 21, 23, 26 ... probe, 25D ... impedance Conversion unit.

Continued on the front page F-term (reference) 5J014 HA06

Claims (3)

[Claims] A non-radiative dielectric line connected to a waveguide having a short-circuit plate provided at an end thereof, and a dielectric strip disposed in the waveguide in a direction substantially parallel to the direction of the high-frequency electric field. A non-radiative dielectric line and a waveguide, which are provided at an end of the dielectric strip and are made of a conductive member inserted into the waveguide through an opening formed in the wall of the waveguide. Conversion circuit. 2. The probe according to claim 1, wherein the probe includes a conductive member protruding from the waveguide wall facing the opening of the waveguide toward the opening, and the conductive member is attached to the dielectric strip. 2. The non-radiative dielectric line / waveguide conversion circuit according to claim 1, wherein the conversion circuit is formed by coupling. 3. The waveguide according to claim 1, wherein said waveguide wall is provided with an impedance conversion section for conducting impedance matching on a waveguide wall facing said opening of said waveguide. A non-radiative dielectric line / waveguide conversion circuit according to claim 1 or 2.