JP6232235B2 - converter - Google Patents

Description

  The present invention relates to a converter that converts a transmission form of a high-frequency signal between a waveguide circuit and a planar circuit formed on a dielectric substrate, and in particular, can suppress spurious and widen the use band. Further, the present invention relates to a converter that can reduce design and manufacturing costs.

[Description of Prior Art: FIG. 9]
A conventional converter will be described with reference to FIG. 9A and 9B are configuration diagrams of a conventional converter, where FIG. 9A is a perspective view, FIG. 9B is a diagram viewed from the z-axis direction, FIG. 9C is a diagram viewed from the x-axis direction, and FIG. It is the figure seen from the axial direction.
As shown in FIG. 9A, the conventional converter includes a rectangular waveguide 51, a rectangular short-circuited waveguide 52, and a dielectric substrate 53. The waveguide 51 and the short-circuited waveguide are provided. 52 so that the dielectric substrate 53 is sandwiched between them.

A microstrip line 54 and a probe 55 that are planar circuits are formed on the surface of the dielectric substrate 53 (the surface on which the short-circuited waveguide 52 is formed). The tip of the probe 55 is disposed at a position protruding into the transmission space of the short-circuited waveguide 52.
Although not shown in the figure, a grounding conductor pattern connected to the opening end face of the short-circuited waveguide 52 is formed on the surface side of the dielectric substrate 53.
On the back surface side (waveguide 51 side) of the dielectric substrate 53, a ground pattern is formed on the entire surface except for the transmission surface of the waveguide 51, and the ground pattern is connected to the opening end face of the waveguide 51. doing.

The short-circuited waveguide 52 has the same inner dimension in the cross section perpendicular to the signal transmission direction of the waveguide 51 as the inner dimension of the waveguide 51. A wall surface perpendicular to the transmission direction is a short-circuit surface.
As a result, the waveguide 51 and the short-circuited waveguide 52 function as an integrated waveguide to prevent high-frequency leakage.

[Configuration of Short-Circuit Waveguide of Conventional Converter: FIG. 10]
The configuration of the short-circuit waveguide 52 in the conventional converter will be described with reference to FIG. 10A and 10B are bird's-eye views of the short-circuited waveguide 52 in the conventional converter, where FIG. 10A is a diagram viewed from the front surface side of the dielectric substrate 53, and FIG. 10B is a diagram viewed from the back surface side of the dielectric substrate 53. It is.
As shown in FIGS. 10A and 10B, the conventional short-circuited waveguide 52 includes an upper surface portion 521 that faces the dielectric substrate 53 and a side surface portion (flange portion) that surrounds the periphery of the upper surface portion 521. It has a substantially box shape.
The side surface portion includes long side flange portions 522 and 523 formed on the long side and short side flange portions 524 and 525 formed on the short side.

In the conventional short-circuited waveguide 52, an insertion port 526 through which the microstrip line 54 passes is formed at the center of one long side flange portion (here, the long side flange portion 522).
The inner wall surfaces of the long side flange portions 522 and 523 are short-circuit surfaces of the waveguide transmission path.
The short-circuited waveguide 52 is mounted such that the end face of the opening is in contact with the surface side of the dielectric substrate 53 with the box shape turned down.

[Characteristics of conventional converter: FIG. 11]
Next, the results of simulation of the conversion characteristics of the conventional converter shown in FIG. 9 will be described with reference to FIG. FIG. 11 is a characteristic diagram showing the conversion characteristics of a conventional converter, where (a) shows the conversion characteristics and (b) shows the pass characteristics in detail. In FIG. 11, the solid line indicates the pass characteristic, and the broken line indicates the return loss.

The simulation conditions will be described.
In the converter of FIG. 9, a dielectric substrate having a relative dielectric constant (er) of 8.6 and a thickness of 0.1 mm is used as the dielectric substrate 53, and the microstrip line 14 is 50Ω (ohms), a waveguide. The dimension of 11 is 1.55 mm × 3.1 mm. The band used was 60 GHz to 90 GHz.
The flange dimensions (thickness of the flange portion) of the short-circuited waveguide 52 are 0.5 mm, and the inner wall height (height inside the flange portion) is 0.5 mm.

As shown in FIGS. 11 (a) and 11 (b), although the conventional converter has spurious, characteristics that can be used as a microstrip-waveguide converter in the vicinity of 60 GHz and 70 to 75 GHz were obtained.
However, as shown in FIG. 11, unnecessary resonance is in the immediate vicinity of the use band, and the passage loss is remarkably deteriorated.

  For this reason, when a wideband modulated wave is handled, the characteristics are deteriorated due to unnecessary resonance. Therefore, in order to avoid spuriousness, when the band to be used is determined, the design is performed by changing the dimensions each time, and the manufacturing is performed after the characteristics are confirmed.

[Related technologies]
In addition, as a prior art of a converter, Unexamined-Japanese-Patent No. 2002-100907 "High-frequency line converter" (New Japan Radio Co., Ltd., patent document 1), Unexamined-Japanese-Patent No. 2006-013868 "Waveguide-plane transmission" Line converter manufacturing method "(New Japan Radio Co., Ltd., Patent Document 2).

  In Patent Document 1, in the converter, when the effective wavelength of the high frequency in the dielectric substrate 13 is λ, the width of the ground conductor pattern on the surface side is set to a width in the vicinity of n · λ / 4 (n: odd number). In addition, it is described that the thickness of the wall of the short-circuited waveguide 12 is formed to be smaller than the width of the ground conductor, and the through hole for conducting the ground pattern formed on both surfaces of the dielectric substrate is unnecessary. .

  Further, in Patent Document 2, a mask material provided with opening patterning for forming a recess is formed on a base material that forms a short-circuited waveguide end, and a fine surface is formed on the surface of the base material exposed in the opening of the mask material. It is described that a recess is formed by spraying abrasive grains, and a short-circuited waveguide end having a bottom surface of the recess is formed as a short-circuit surface.

JP 2002-100907 A JP 2006-013868 A

However, the above-described conventional converter has a problem that a usable band is narrow because a spurious is generated, an application range of a product is limited, and time and cost required for the design are increased.
Further, in the conventional converter, since the shape of the short-circuited waveguide is complicated and fine, it is difficult to manufacture, and there is a problem that the manufacturing cost increases due to high processing cost of cutting.

  In Patent Document 1 and Patent Document 2, it is not described that the short-circuited waveguide is formed in a U-shaped groove without providing a short-side flange (side surface) in the short-circuited waveguide.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a converter that can suppress spurious and can be used in a wide band and can reduce the cost required for manufacturing and designing.

  The present invention for solving the problems of the above conventional example is to hold a dielectric substrate with a planar line formed between a waveguide and a short-circuited waveguide, and connect the planar line and the waveguide. The short-circuited waveguide has a rectangular shape having a long side in a direction perpendicular to the signal transmission direction of the planar line, and has an upper surface portion facing the dielectric substrate and one length of the upper surface portion. A substantially long U-side flange having a first long-side flange connected to the side and having an insertion port into which the planar line is introduced; and a second long-side flange connected to the other long side of the upper surface. It is characterized by being formed in a groove shape.

  According to the present invention, in the converter, the first long side flange portion includes a plurality of slits formed in parallel to the signal transmission direction of the planar line, and is divided into a plurality of blocks by the plurality of slits. It is characterized by being.

  Further, in the converter according to the present invention, the second long side flange portion includes a plurality of slits formed in parallel to the signal transmission direction of the planar line, and is divided into a plurality of blocks by the plurality of slits. It is characterized by being.

  In the converter, the width of the slit is 1/8 or less of the wavelength of the transmission signal of the waveguide.

  According to the present invention, in the converter, the width of the block is ¼ or less of the wavelength of the transmission signal of the waveguide.

  In the converter according to the present invention, the first long side flange portion and the second long side flange portion each include a plurality of slits formed in parallel to the signal transmission direction of the planar line, The width of each slit is 1/8 or less of the wavelength of the transmission signal of the waveguide, and the width of each block is 1 of the wavelength of the transmission signal of the waveguide. / 4 or less.

  According to the converter of the present invention, a dielectric substrate on which a planar line is formed is held between a waveguide and a short-circuited waveguide, and the converter connects the planar line and the waveguide. The short-circuited waveguide has a rectangular shape having a long side in a direction orthogonal to the signal transmission direction of the planar line, and is connected to the upper surface portion facing the dielectric substrate and one long side of the upper surface portion. It is formed in a substantially U-shaped groove shape including a first long side flange portion having an insertion port into which a line is introduced and a second long side flange portion connected to the other long side of the upper surface portion. Therefore, it is possible to simplify the configuration as compared with the conventional box type, reduce the cost of design and manufacture, suppress spurious, and widen the use band.

  According to the present invention, the first long side flange portion and the second long side flange portion each include a plurality of slits formed in parallel to the signal transmission direction of the planar line, and the plurality of slits Divided into a plurality of blocks, the width of each slit is ８ or less of the wavelength of the transmission signal of the waveguide, and the width of each block is ¼ or less of the wavelength of the transmission signal of the waveguide Therefore, the spurious can be further reduced and a wider band can be achieved.

It is a block diagram of the converter which concerns on the 1st Embodiment of this invention. It is a bird's-eye view which shows the structure of the short circuiting waveguide 12 of a 1st converter. It is a characteristic view which shows the conversion characteristic of a 1st converter. It is a characteristic view which compared the passage characteristic of the 1st converter and the conventional converter. It is a block diagram of the converter which concerns on the 2nd Embodiment of this invention. It is a bird's-eye view which shows the structure of the short circuiting waveguide 22 in a 2nd converter. It is a characteristic view which shows the conversion characteristic of a 2nd converter. It is a characteristic view which compared the passage characteristic of the 2nd converter and the conventional converter. It is a block diagram of the conventional converter. It is a bird's-eye view of the short circuiting waveguide 52 in the conventional converter. It is a characteristic view which shows the conversion characteristic of the conventional converter.

Embodiments of the present invention will be described with reference to the drawings.
[Outline of the embodiment]
A converter according to an embodiment of the present invention holds a dielectric substrate on which a planar line is formed, sandwiched between a waveguide and a short-circuited waveguide, and connects the planar transmission line and the waveguide transmission line. A short-circuited waveguide facing the dielectric substrate and connected to a rectangular upper surface portion having a long side in a direction perpendicular to the signal transmission direction of the planar line and one long side of the upper surface portion As a substantially U-shaped groove shape including a first long side flange portion having an insertion port into which a planar line is introduced and a second long side flange portion connected to the other long side of the upper surface portion This eliminates the flange on the short side of the short-circuited waveguide, simplifies the configuration compared to the box type, reduces manufacturing and design costs, suppresses spurious, and can be used in a wide band. It can be made possible.

  The converter according to the embodiment of the present invention includes a plurality of slits in the long-side flange portion of the U-shaped groove-shaped short-circuited waveguide, and the long-side flange portion is divided into a plurality of blocks by the slits. When the wavelength of the transmission signal of the waveguide is λ, the slit width is λ / 8 or less and the width of each block is λ / 4 or less. It can be used and the characteristics can be improved.

[First Embodiment: FIG. 1]
A converter according to a first embodiment of the present invention will be described with reference to FIG. FIG. 1 is a configuration diagram of a converter according to a first embodiment of the present invention, in which (a) is a perspective view, (b) is a diagram viewed from a z-axis direction, and (c) is a diagram from an x-axis direction. FIG. 3D is a diagram viewed from the y-axis direction.
As shown in FIGS. 1 (a) to 1 (d), the converter (first converter) according to the first embodiment of the present invention is rectangular in the same manner as the conventional converter shown in FIG. The waveguide 11, the short-circuited waveguide 12, and the dielectric substrate 13 are arranged so that the dielectric substrate 13 is sandwiched between the waveguide 11 and the short-circuited waveguide 12.

A microstrip line 14 and a probe 15 are formed on the surface side of the dielectric substrate 13 (short-circuit waveguide 12 side). The probe 15 protrudes into the transmission space of the short-circuited waveguide 12. In addition, a ground conductor and a ground pattern are formed on the dielectric substrate 13 as in the prior art.
In the first converter, the configurations of the waveguide 11 and the dielectric substrate 13 are the same as the conventional one, but the configuration of the short-circuited waveguide 12 is different from the conventional one.

[Configuration of Short Waveguide 12 in First Converter: FIG. 2]
The configuration of the short-circuit waveguide 12 in the first converter will be specifically described with reference to FIG. 2A and 2B are bird's-eye views showing the configuration of the short-circuit waveguide 12 of the first converter, where FIG. 2A is a diagram viewed from the front surface side of the dielectric substrate 13 and FIG. It is the figure seen from.
As shown in FIGS. 2 (a) and 2 (b), the short-circuit waveguide 12 (first short-circuit waveguide 12) of the first converter is a characteristic part of the first converter and has two lengths. A rectangular upper surface portion 121 composed of a side and two short sides, a long side flange portion 122 connected to one long side of the upper surface portion 121, and a long side flange portion 123 connected to the other long side. ing.

The long side of the upper surface 121 coincides with the direction orthogonal to the signal transmission direction.
An insertion port 124 for introducing a microstrip line is provided at the center of one long side flange portion (here, the long side flange portion 122).
The long side flange portion 122 corresponds to the first long side flange portion described in the claims, and the long side surface portion 123 corresponds to the second long side flange portion.

Since the first converter is a fundamental mode (TE01) converter, the inner wall on the short side of the short-circuited waveguide is essentially unnecessary.
Therefore, in the first converter, the short-circuited waveguide 12 is composed of only the upper surface portion 121, the long side flange portion 122, and the long side flange portion 123, and is connected to the short side of the upper surface portion 121. Is not provided.
Thereby, the 1st short circuiting waveguide 12 is formed in the substantially U-shaped groove shape which the short side opened.
By adopting a substantially U-shaped groove shape, the first waveguide can be manufactured and designed more easily and the manufacturing cost can be reduced as compared with the conventional box-type short-circuited waveguide.

[Conversion characteristics of the first converter: FIG. 3]
The result of having performed the simulation of the conversion characteristic about the 1st converter is shown.
The simulation conditions are the same as in the prior art. The dielectric substrate 13 has a relative dielectric constant (er) of 8.6 and a thickness of 0.1 mm, the microstrip line 14 has a resistance of 50Ω (ohms), and the dimensions of the waveguide 11. Is 1.55 mm × 3.1 mm. The band used was 60 GHz to 90 GHz.
The thickness of the long side surface portions 122 and 123 of the short-circuited waveguide 12 is 0.5 mm, and the inner wall height (the height inside the side surface portion) is 0.5 mm.

The conversion characteristics of the first converter will be described with reference to FIG. FIG. 3 is a characteristic diagram showing the conversion characteristics of the first converter, where (a) shows the conversion characteristics and (b) shows the pass characteristics in detail. In FIG. 3, the solid line indicates the pass characteristic, and the broken line indicates the return loss.
As shown in FIG. 3, the conversion characteristic of the first converter is similar to that of the conventional converter shown in FIG. 11, and can confine electromagnetic waves with less radiation, and good characteristics can be obtained. ing.
Further, unnecessary resonance that occurs at the length of the long side is also eliminated.

[Comparison of pass characteristics (1): Fig. 4]
The pass characteristic of the first converter shown in FIG. 3B and the pass characteristic of the conventional converter shown in FIG. 11 are compared using FIG. FIG. 4 is a characteristic diagram comparing the pass characteristics of the first converter and the conventional converter.
In FIG. 4, the pass characteristic of the first converter is indicated by a solid line, and the pass characteristic of a conventional converter is indicated by a broken line.
As shown in FIG. 4, the pass characteristics of the first converter can be used in the entire band of 60 to 75 GHz, and can cope with a wider band than in the past.

[Effect of the first embodiment]
According to the converter of the first embodiment of the present invention, the dielectric substrate 13 on which the microstrip line 14 and the probe 15 are formed is sandwiched and held between the waveguide 11 and the short-circuited waveguide 12, A converter for connecting a planar transmission line and a waveguide transmission line, wherein the short-circuited waveguide 12 has a rectangular upper surface 121 having a long side in a direction orthogonal to the signal transmission direction of the planar line, and an upper surface A long side flange portion 122 having an insertion port 124 into which the microstrip line 14 is inserted, and a long side flange portion 123 connected to the other long side of the upper surface portion 121. Therefore, it is possible to simplify the configuration of the short-circuited waveguide 12 compared to the conventional box shape, reduce the cost required for manufacturing and design, and reduce spurious. Suppress and use a wider bandwidth There is an effect that that.

[Second Embodiment: FIG. 5]
A converter according to a second embodiment of the present invention will be described with reference to FIG. FIG. 5 is a configuration diagram of a converter according to a second embodiment of the present invention, where (a) is a perspective view, (b) is a view seen from the z-axis direction, and (c) is a view taken from the x-axis direction. FIG. 3D is a diagram viewed from the y-axis direction.
As shown in FIGS. 5A to 5D, the converter (second converter) according to the second embodiment of the present invention is similar to the waveguide 21 in the same manner as the first converter. The configuration includes a short-circuit waveguide 22 and a dielectric substrate 23.
In the second converter, the configuration of the short-circuited waveguide 22 is different from that of the first converter, and is a characteristic part of the second converter.

[Configuration of the Short-Circuit Waveguide 22 in the Second Converter: FIG. 6]
The configuration of the short-circuit waveguide 22 in the second converter will be specifically described with reference to FIG. 6A and 6B are bird's-eye views showing the configuration of the short-circuited waveguide 22 in the second converter. FIG. 6A is a view seen from the front surface side of the dielectric substrate 23, and FIG. It is the figure seen from.
As shown in FIGS. 6 (a) and 6 (b), the short-circuit waveguide 22 of the second converter is basically composed of two long sides orthogonal to the signal transmission direction and long sides. A rectangular upper surface portion 221 having two orthogonal short sides, a long side flange portion 222 connected to one long side of the upper surface portion 221, and a long side flange portion 223 connected to the other long side It is comprised only from these three parts like the 1st short circuiting waveguide.

The long side flange portion 222 is provided with an insertion port 224 into which the microstrip line 14 is inserted.
As a feature of the second short-circuited waveguide 22, a plurality of slits 225 parallel to the signal transmission direction of the planar line are formed in the long side flange portion 222 and the long side flange portion 223. Thus, the long side flange portions 222 and 223 are divided into a plurality of blocks 225.
By adopting such a shape, spurious is reduced.

In particular, in the second short-circuited waveguide 22, the width (d1) of an arbitrary slit 225 is set to 1/8 or less (d1 ≦ λ / 8) of the wavelength (λ) of the transmission signal of the waveguide, and an arbitrary block The width (d2) of 226 is set to ¼ or less of the wavelength (d2 ≦ λ / 4). Here, the “width” is the length of the upper surface portion 221 in the long side direction.
In the example of FIG. 6, the width of the block 226 is different depending on the location, but all are formed to be ¼ or less of the wavelength.
By limiting the size of the slit 225 and the size of the block 226, spurious can be effectively reduced.

Further, the numbers of the slits 225 and the blocks 226 are determined so that the respective widths are within the above-described range and optimum characteristics are obtained.
In addition, although the structure which formed the slit 225 and the block 226 in both the long side flange parts 222 and 223 was shown here, the slit 225 and the block 226 were formed only in one of the long side flange parts 222 and 223. May be.

[Conversion characteristics of second converter: FIG. 7]
FIG. 7 shows the simulation result of the conversion characteristics for the second converter. FIG. 7 is a characteristic diagram showing the conversion characteristics of the second converter, where (a) shows the conversion characteristics and (b) shows the pass characteristics in detail. In FIG. 7, the solid line indicates the pass characteristic, and the broken line indicates the return loss.
The simulation conditions are the same as the simulation of the first converter shown in FIGS.
As shown in FIGS. 7A and 7B, it can be seen that the conversion characteristics of the second converter are good, and in particular, there is no spurious in (b).

[Comparison of pass characteristics (2): Fig. 8]
The pass characteristic of the second converter shown in FIG. 7B and the pass characteristic of the conventional converter shown in FIG. 11 are compared using FIG. FIG. 8 is a characteristic diagram comparing the pass characteristics of the second converter and the conventional converter. In FIG. 8, the pass characteristic of the second converter is indicated by a solid line, and the pass characteristic of a conventional converter is indicated by a broken line.
As shown in FIG. 8, the pass characteristic of the second converter has no spurious and can be used in a wide band as compared with the conventional pass characteristic.
Furthermore, it can be seen that the second converter spurious is suppressed and the characteristics are further improved compared to the pass characteristics of the first converter shown in FIGS. 3B and 4.

[Effect of the second embodiment]
According to the converter of the second embodiment of the present invention, the short-circuit waveguide 22 has a rectangular upper surface portion 221 having a long side in the direction orthogonal to the signal transmission direction of the planar line, and the upper surface portion 221. A long-side flange portion 222 having an insertion port 224 into which the microstrip line 14 is inserted, and a second long-side flange portion connected to the other long side of the upper surface portion 221. Since the long side flange portions 222 and 223 are formed by being divided into a plurality of blocks 226 by a plurality of slits 225, the spurious is suppressed and the use band is widened. There is an effect that can.

  INDUSTRIAL APPLICABILITY The present invention is suitable for a converter that can suppress the spurious and widen the use band and further reduce the design and manufacturing cost.

  11, 21, 51 ... waveguide, 12, 22, 52 ... short-circuited waveguide, 13, 23, 53 ... dielectric substrate, 14, 54 ... microstrip line, 15, 55 ... probes, 121,221,521 ... upper surface parts, 122,123,222,223,522,523 ... long side flange parts, 124,224 ... insertion holes, 225 ... slits , 226 ... Block, 524, 525 ... Short side flange

Claims (6)

A dielectric substrate on which a planar line is formed is held between a waveguide and a short-circuited waveguide, and is a converter for connecting the planar line and the waveguide,
The short-circuited waveguide has a rectangular shape having a long side in a direction orthogonal to the signal transmission direction of the planar line, and is connected to the upper surface portion facing the dielectric substrate and one long side of the upper surface portion. Formed in a substantially U-shaped groove shape having a first long side flange portion having an insertion port into which a planar line is introduced and a second long side flange portion connected to the other long side of the upper surface portion The converter characterized by being made.   2. The first long side flange portion includes a plurality of slits formed in parallel to a signal transmission direction of a planar line, and is divided into a plurality of blocks by the plurality of slits. Converter.   2. The second long side flange portion includes a plurality of slits formed in parallel to a signal transmission direction of a planar line, and is divided into a plurality of blocks by the plurality of slits. Converter.   4. The converter according to claim 2, wherein the width of the slit is 1/8 or less of the wavelength of the transmission signal of the waveguide.   5. The converter according to claim 2, wherein the width of the block is ¼ or less of the wavelength of the transmission signal of the waveguide. Each of the first long side flange portion and the second long side flange portion includes a plurality of slits formed in parallel to the signal transmission direction of the planar line, and is divided into a plurality of blocks by the plurality of slits. And
The width of each slit is 1/8 or less of the wavelength of the transmission signal of the waveguide,
2. The converter according to claim 1, wherein the width of each block is ¼ or less of the wavelength of the transmission signal of the waveguide.

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