JP4854622B2 - Connection structure of rectangular waveguide section and differential line section - Google Patents

Description

  The present invention relates to a connection structure between a rectangular waveguide frequently used in a high frequency band such as a millimeter wave and a strip line, and more particularly to a connection structure between a differential line through which a differential signal is transmitted and the waveguide. It is about.

Various structures have been proposed for connecting a rectangular waveguide, which is often used in a high frequency band such as a millimeter wave, and a strip line. For example, in a slot formed on a tube wall of a rectangular waveguide. The microstrip lines are arranged so as to face each other and perpendicular to the long side of the slot so that the magnetic field generated around the microstrip line enters the inside of the rectangular waveguide through the slot. A structure for connecting a waveguide and a waveguide has been proposed (see, for example, Patent Document 1).
JP 2004-180032 A

  However, in the conventionally proposed connection structure between the rectangular waveguide and the stripline, the lines such as the stripline connected to the rectangular waveguide are all unbalanced lines, and a differential signal is transmitted. A differential line composed of a pair of line conductors and a rectangular waveguide cannot be directly connected and a differential signal cannot be directly input to the rectangular waveguide. For this reason, even when connecting a differential line that is less affected by external noise and that emits less external noise to a rectangular waveguide, connect the differential line to a rat race circuit, etc. It is necessary to connect to a rectangular waveguide after converting to an unbalanced line, and there is a problem that conversion loss from the differential line to the unbalanced line occurs. There was a problem that radiation of noise occurred.

  The present invention has been devised in view of such problems in the prior art, and an object of the present invention is to provide a rectangular waveguide section that enables direct connection between a rectangular waveguide and a differential line. And providing a connection structure between the differential line section and the differential line section.

The connection structure between the rectangular waveguide portion and the differential line portion according to the present invention includes a rectangular waveguide portion and a ground conductor on the lower surface of the dielectric layer disposed on the upper tube wall of the rectangular waveguide portion. And a differential line portion having a pair of line conductors through which differential signals are transmitted on the upper surface or inside, and a rectangular slot penetrating the upper tube wall of the rectangular waveguide portion and the ground conductor. And a pair of through conductors connecting the respective end portions of the pair of line conductors to the ground conductors adjacent to the center portions of the pair of long sides of the slot, respectively , The line conductors are formed in parallel to the pair of long sides of the slot .

  Furthermore, in the connection structure between the rectangular waveguide portion and the differential line portion according to the present invention, in each of the above configurations, the slot has the pair of long sides at the center in the width direction of the rectangular waveguide portion. It is formed so as to be parallel to the width direction of the rectangular waveguide portion.

  Still further, according to the connection structure of the rectangular waveguide portion and the differential line portion of the present invention, in the above configuration, the slot is located at a position adjacent to an end surface in the longitudinal direction of the rectangular waveguide portion or from the end surface. It is characterized in that it is formed at a position separated by an integral multiple of ½ of the wavelength of the high-frequency signal transmitted through the rectangular waveguide portion.

  Furthermore, in the connection structure between the rectangular waveguide portion and the differential line portion of the present invention, the ground conductor and the upper tube wall of the rectangular waveguide portion are integrally formed in each of the above configurations. It is characterized by that.

  Furthermore, the connection structure between the rectangular waveguide portion and the differential line portion according to the present invention is characterized in that, in each of the above configurations, the rectangular waveguide portion is a metal waveguide.

  Furthermore, in the connection structure between the rectangular waveguide portion and the differential line portion according to the present invention, the rectangular waveguide portion is arranged on the upper surface of the dielectric layer for the waveguide in each of the above-described configurations. An upper main conductor layer serving as a tube wall; a lower main conductor layer serving as a lower tube wall disposed on the lower surface of the waveguide dielectric layer; and a wavelength of the high-frequency signal in the transmission direction of the high-frequency signal. The upper main conductor layer and the lower main conductor layer are arranged so as to be electrically connected at a repetition interval of less than 1/2 and at a predetermined interval in a direction orthogonal to the transmission direction. A high-frequency signal is transmitted by a region surrounded by the upper main conductor layer, the lower main conductor layer, and the two rows of through-hole conductor groups. It is characterized by being a dielectric waveguide.

  According to the connecting structure of the rectangular waveguide portion and the differential line portion of the present invention, the rectangular waveguide portion and the lower surface of the dielectric layer disposed on the upper tube wall of the rectangular waveguide portion are grounded. The conductor is provided with a differential line part having a pair of line conductors through which differential signals are transmitted on the upper surface or inside, and a rectangular slot penetrating the upper wall of the rectangular waveguide part and the ground conductor. The differential line section and the rectangular waveguide are connected by providing a pair of through conductors that connect the end portions of the pair of line conductors to the ground conductors adjacent to the center portions of the pair of long sides of the slot. The differential signal can be directly input to the rectangular waveguide unit without converting the differential signal into an unbalanced signal. As a result, when connecting a differential line consisting of a pair of line conductors that transmit differential signals to a rectangular waveguide, the differential line is connected to a rat race circuit or the like and converted to a single unbalanced line. Since there is no need to connect to the rectangular waveguide after the operation, there is a problem of loss due to the conversion from the differential line to the unbalanced line. The problem of generation of radiation can be solved.

  In addition, as a mechanism in which the rectangular waveguide portion and the differential line portion are electrically connected by the connection structure between the rectangular waveguide portion and the differential line portion of the present invention, a pair of lines of the differential line portion is used. The differential signal flowing through the conductor is supplied to the ground conductor adjacent to the center portion of the pair of long sides of the slot through the pair of through conductors, so that an oscillating electric field is generated between the center portions of the pair of long sides of the slot. It is thought that the electromagnetic wave generated and generated by this oscillating electric field is transmitted to the inside of the rectangular waveguide portion.

  Further, according to the connection structure of the rectangular waveguide portion and the differential line portion of the present invention, since the pair of line conductors of the differential line portion are formed in parallel to the pair of long sides of the slot, Since the magnetic field generated around the pair of line conductors can be suppressed to the minimum through the slot and enter the rectangular waveguide section, it is possible to prevent disturbance of the electromagnetic field inside the rectangular waveguide section. Can do.

Furthermore, according to the connection structure of the rectangular waveguide portion and the differential line portion of the present invention, the slot has a pair of long sides at the center portion in the width direction of the rectangular waveguide portion and the width of the rectangular waveguide portion. Therefore, the oscillating electric field generated between the center portions of the pair of long sides of the slot is formed in the fundamental mode (TE ₁₀ mode) of the rectangular waveguide in the width direction of the waveguide portion. ) Is generated at the position where the electric field strength is the highest, the direction of the oscillating electric field coincides with the longitudinal direction of the waveguide section, and is orthogonal to the direction of the magnetic field at the position where the slot of the fundamental mode is formed. Loss in the connection between and the differential line portion can be reduced.

Still further, according to the connection structure of the rectangular waveguide portion and the differential line portion of the present invention, the slot is transmitted from the position adjacent to or in the longitudinal direction of the rectangular waveguide portion to the rectangular waveguide portion. The slot is formed at a position where the electric field intensity of the fundamental mode (TE ₁₀ mode) is the highest in the longitudinal direction of the waveguide portion because it is formed at a position separated by an integral multiple of 1/2 of the wavelength of the high-frequency signal to be transmitted. Therefore, the loss in the connection between the rectangular waveguide portion and the differential line portion can be further reduced. The end face in the longitudinal direction of the rectangular waveguide portion means the inner wall surface of the tube wall forming the end face in the longitudinal direction of the rectangular waveguide portion, and the slot position means the position of the center of the slot. To do. Of course, the wavelength of the high-frequency signal transmitted through the rectangular waveguide section is the wavelength within the rectangular waveguide section, and when the rectangular waveguide section is filled with a dielectric. Becomes shorter than the wavelength in air.

  Furthermore, according to the connection structure between the rectangular waveguide portion and the differential line portion of the present invention, since the ground conductor and the upper tube wall of the rectangular waveguide portion are integrally formed, Since it is possible to prevent variation in the shape of the slot due to the displacement between the conductor and the upper tube wall of the rectangular waveguide portion, the rectangular waveguide portion and differential line portion excellent in mass productivity Connection structure can be obtained. Note that the ground conductor and the upper tube wall of the rectangular waveguide portion are integrally formed. One conductor has the functions of both the ground conductor and the upper tube wall of the rectangular waveguide portion. Means that

  Furthermore, according to the connection structure between the rectangular waveguide portion and the differential line portion of the present invention, since the rectangular waveguide portion is a metal waveguide, there is a dielectric inside the waveguide portion. Therefore, the dielectric loss of the dielectric does not occur, and the transmission loss in the rectangular waveguide portion can be reduced.

  Furthermore, according to the connection structure between the rectangular waveguide portion and the differential line portion of the present invention, the rectangular waveguide portion is disposed on the upper surface of the waveguide dielectric layer and becomes the upper tube wall. A main conductor layer, a lower main conductor layer which is disposed on the lower surface of the waveguide dielectric layer and serves as a lower tube wall, and a repetition interval of less than half of the wavelength of the high frequency signal in the transmission direction of the high frequency signal And two rows of through conductors for side walls in the longitudinal direction arranged so as to electrically connect the upper main conductor layer and the lower main conductor layer with a predetermined interval in a direction orthogonal to the transmission direction A dielectric waveguide that transmits a high-frequency signal by a region surrounded by an upper main conductor layer, a lower main conductor layer, and two rows of through conductor groups for side walls. Since the waveguide section can be easily formed inside the laminated body, rectangular guides with excellent mass productivity It is possible to obtain a connection structure between the tube portion and the differential line portion.

  Hereinafter, a connection structure between a rectangular waveguide portion and a differential line portion according to the present invention will be described in detail with reference to the accompanying drawings.

(First example of embodiment)
FIG. 1 is a perspective view schematically showing an example of an embodiment of a connection structure between a rectangular waveguide portion and a differential line portion of the present invention. FIG. 2 is a top perspective view schematically showing a connection structure between the rectangular waveguide portion and the differential line portion shown in FIG. 3 is a cross-sectional view taken along line XX ′ of FIG.

  As shown in FIG. 1 to FIG. 3, the connection structure between the rectangular waveguide portion and the differential line portion in this example is formed on the rectangular waveguide portion 10 and the tube wall 11 on the upper side of the rectangular waveguide portion 10. The grounding conductor 22 is disposed on the lower surface of the dielectric layer 21, and the differential line portion 20 having a pair of line conductors 23a and 23b through which a differential signal is transmitted is disposed on the upper side of the rectangular waveguide portion 10. A rectangular slot 30 penetrating the tube wall 11 and the ground conductor 22 is provided, and each end of the pair of line conductors 23a and 23b is adjacent to the center of the pair of long sides 31a and 31b. A pair of through conductors 24a and 24b connected to the conductor 22 are provided and connected.

  The pair of line conductors 23 a and 23 b of the differential line section 20 are formed in parallel to the pair of long sides 31 a and 31 b of the slot 30, respectively. The slot 30 is formed at the center in the width direction of the rectangular waveguide portion 10 so that a pair of long sides 31a and 31b are parallel to the width direction of the rectangular waveguide portion 10, and the rectangular waveguide. It is formed at a position separated from the inner wall surface of the end face 12 in the longitudinal direction of the portion 10 by ½ times the wavelength λg of the high-frequency signal transmitted through the rectangular waveguide portion 10. Note that the rectangular waveguide portion 10 in this example is a metal waveguide.

  In the connection structure between the rectangular waveguide portion 10 and the differential line portion 20 of the present example having such a structure, the differential signal flowing through the pair of line conductors 23a and 23b of the differential line portion 20 passes through a pair of through holes. By being supplied to the ground conductor 22 adjacent to the central portion of the pair of long sides 31a and 31b of the slot 30 through the conductors 24a and 24b, vibration is generated between the central portions of the pair of long sides 31a and 31b of the slot 30. An electric field is generated, and an electromagnetic wave propagating in the rectangular waveguide portion 10 can be generated by the oscillating electric field.

  According to the connection structure of the rectangular waveguide portion 10 and the differential line portion 20 in this example, the differential line portion 20 and the rectangular waveguide portion 10 are directly connected to each other, and the rectangular guide is maintained without changing the differential signal. Since it can be input to the wave tube section, it is not necessary to connect the differential line section 20 to a rat race circuit or the like and convert it to a single unbalanced line, and then connect it to the rectangular waveguide section 10. It is possible to solve the problem that a loss due to conversion to an unbalanced line occurs, and the problem that noise from outside and noise emission to the outside occur in the unbalanced line.

  Further, according to the connection structure between the rectangular waveguide portion 10 and the differential line portion 20 of the present example, the pair of line conductors 23 a and 23 b of the differential line portion 20 are connected to the pair of long sides 31 a and 31 b of the slot 30. Since they are formed in parallel with each other, the magnetic field generated around the pair of line conductors 23a, 23b can be suppressed from entering the inside of the rectangular waveguide portion 10 via the slot 30 to the minimum. 30 inside the rectangular waveguide section 10 due to interference between the magnetic field that has entered the rectangular waveguide section 10 through 30 and the electromagnetic field generated inside the rectangular waveguide section 10 due to the oscillating electric field generated in the slot 30. The disturbance of the electromagnetic field can be prevented.

Furthermore, according to the connection structure between the rectangular waveguide portion 10 and the differential line portion 20 of this example, the slot 30 has a pair of long sides 31a and 31b at the center in the width direction of the rectangular waveguide portion 10. Since it is formed so as to be parallel to the width direction of the rectangular waveguide portion 10, an oscillating electric field generated between the center portions of the pair of long sides 31a and 31b of the slot 30 is generated in the width direction of the waveguide portion. At the position where the electric field strength of the fundamental mode (TE ₁₀ mode) of the rectangular waveguide is highest, the direction of the oscillating electric field coincides with the longitudinal direction of the waveguide portion, and the slot where the fundamental mode slot 30 is formed Since it is orthogonal to the direction of the magnetic field, the loss in the connection between the rectangular waveguide portion 10 and the differential line portion 20 can be reduced.

Furthermore, according to the connection structure between the rectangular waveguide portion 10 and the differential line portion 20 of this example, the slot 30 is squarely guided from the inner wall surface of one end face 12 in the longitudinal direction of the rectangular waveguide portion 10. Since the slot 30 is formed at a position separated by ½ times the wavelength λg of the high-frequency signal transmitted through the wave tube section ₁₀ , the slot 30 has an electric field strength of the fundamental mode (TE ₁₀ mode) in the longitudinal direction of the waveguide section. Is formed at the highest position, the loss in connection between the rectangular waveguide portion 10 and the differential line portion 20 can be further reduced.

  Furthermore, according to the connection structure of the rectangular waveguide portion 10 and the differential line portion 20 of this example, since the rectangular waveguide portion 10 is a metal waveguide, there is a dielectric inside the waveguide portion. Since no body is present, dielectric loss of the dielectric does not occur, so that transmission loss in the rectangular waveguide portion 10 can be reduced.

(Second example of embodiment)
FIG. 4 is a perspective view schematically showing another example of the embodiment of the connection structure between the rectangular waveguide portion and the differential line portion of the present invention. Note that in this example, only differences from the first example described above will be described, and the same components will be denoted by the same reference numerals, and redundant description will be omitted.

  As shown in FIG. 4, in the connection structure of the rectangular waveguide portion 10 and the differential line portion 20 in this example, the rectangular waveguide portion 10 is disposed on the upper surface of a waveguide dielectric layer (not shown). An upper main conductor layer 14a disposed as an upper tube wall 11; a lower main conductor layer 14b disposed on a lower surface of a waveguide dielectric layer (not shown) as a lower tube wall; Between the upper main conductor layer 14a and the lower main conductor layer 14b with a repetition interval less than ½ of the wavelength λg of the high-frequency signal in the signal transmission direction and a predetermined interval in the direction orthogonal to the transmission direction. 2 side-row through-hole conductor groups 15a and 15b arranged in the longitudinal direction so as to be electrically connected to each other, the upper main conductor layer 14a, the lower main conductor layer 14b and the two rows of side-wall through conductors It is a dielectric waveguide that transmits a high-frequency signal by a region surrounded by the conductor groups 15a and 15b. In FIG. 4, in order to facilitate understanding of the internal structure of the rectangular waveguide portion 10, the illustration of the dielectric layer for the waveguide is omitted, and the upper side leading to the tube wall 11 on the upper side of the rectangular waveguide portion 10 is omitted. The state which removed the body layer 14a partially is shown.

  In the connection structure of the rectangular waveguide portion 10 and the differential line portion 20 in this example, the upper main conductor layer 14a constitutes the upper tube wall 11 of the rectangular waveguide portion 10, and the lower main conductor. The layer 14 b constitutes the lower tube wall of the rectangular waveguide portion 10, and the pair of side wall through conductor groups 15 a and 15 b constitute the tube walls on both sides of the rectangular waveguide portion 10.

  Further, at one end in the longitudinal direction of the rectangular waveguide portion 10, the upper main conductor layer 14 a and the lower side are led at a repetition interval less than ½ of the wavelength λg of the high frequency signal in a direction orthogonal to the transmission direction of the high frequency signal. An end face through conductor group 16 is disposed so as to electrically connect the body layers 14b, and the end face through conductor group 16 forms a tube wall of the end face 12 of the rectangular waveguide portion 10. .

  Further, in the connection structure between the rectangular waveguide portion 10 and the differential line portion 20 of the present example, since the waveguide dielectric layer 13 exists inside the rectangular waveguide portion 10, the rectangular waveguide is provided. The wavelength λg of the high-frequency signal transmitted through the tube portion 10 is different from that of the first example described above. However, in the connection structure between the rectangular waveguide portion 10 and the differential line portion 20 in this example of this example, the slot 30 is The pair of long sides 31 a and 31 b are formed in the center of the rectangular waveguide portion 10 in the width direction so as to be parallel to the width direction of the rectangular waveguide portion 10. It is formed at a position separated from the inner wall surface of one end face 12 in the longitudinal direction by ½ times the wavelength λg of the high-frequency signal transmitted through the rectangular waveguide portion 10.

  According to the connection structure of the rectangular waveguide portion 10 and the differential line portion 20 in this example, since the rectangular waveguide portion 10 is a dielectric waveguide, it can be easily placed inside a dielectric ceramic laminate. Since the waveguide portion can be formed on the substrate, a connection structure between the rectangular waveguide portion 10 and the differential line portion 20 excellent in mass productivity can be obtained.

In the connection structure between the rectangular waveguide portion 10 and the differential line portion 20 of the present invention, the dielectric layer 21 and the waveguide dielectric layer 13 have characteristics that do not hinder the transmission of high-frequency signals. It is not particularly limited as long as it is possible to use a resin such as glass epoxy, but it is desirable to use dielectric ceramics from the viewpoint of accuracy and ease of manufacturing when forming a transmission line. The relative dielectric constant is, for example, about 2 to 20. Such dielectric layer 21 and waveguide dielectric layer 13 are made into a slurry by adding and mixing an appropriate organic solvent / solvent with ceramic raw material powders such as glass ceramics, alumina ceramics and aluminum nitride ceramics. After that, a plurality of ceramic green sheets are produced by making a sheet by a doctor blade method, a calender roll method, etc., and thereafter, these ceramic green sheets are appropriately punched and laminated together, In the case of glass ceramics, it is fabricated by firing at a peak temperature of about 850 ° C. to 1000 ° C., in the case of alumina ceramics, about 1500 ° C. to 1700 ° C., and in the case of aluminum nitride ceramics, it is fired at a peak temperature of about 1600 ° C. to 1900 ° C. The thickness of the dielectric layer 21 is, for example, about 0.02 mm to 1 mm. The thickness of the waveguide dielectric layer 13 matches the height inside the tube wall of the rectangular waveguide portion 10. For example, when the fundamental mode (TE ₁₀ mode) is used, the rectangular waveguide portion 10 is used. Is set to about ½ of the inner width of the tube wall in the cross section orthogonal to the longitudinal direction (transmission direction of the high frequency signal), and is ¼ to 1 of the wavelength λg of the high frequency signal transmitted through the rectangular waveguide portion 10. / 2 or so.

  The pair of line conductors 23a and 23b, the ground conductor 22, the upper main conductor layer 14a and the lower main conductor layer 14b are made of a highly conductive metal, and have a thickness of, for example, about 3 μm to 50 μm. The pair of line conductors 23a and 23b, the ground conductor 22, the upper main conductor layer 14a, and the lower main conductor layer 14b are made of, for example, an oxide such as alumina, silica, or magnesia suitable for metal powder, an organic solvent, or the like. A paste formed by adding and mixing can be formed by printing on a ceramic green sheet by a thick film printing method and then firing at a temperature of about 1600 ° C. As the metal powder, copper, gold or silver is suitable when the dielectric layer 21 is glass ceramic, and tungsten or molybdenum is suitable when the dielectric layer 21 is alumina ceramic or aluminum nitride ceramic. In addition, the width | variety of each line of a pair of line conductors 23a and 23b shall be 0.05 mm-about 1 mm, for example, and the space | interval between lines will be set to about 0.05 mm-0.5 mm, for example.

When the rectangular waveguide section 10 has a rectangular cross section and uses the fundamental mode (TE ₁₀ mode), for example, the width is 1 / wavelength λg of the high-frequency signal transmitted through the rectangular waveguide section 10. The height is 2 or more and less than 1, and the height is about ½ of the width. In the case where the rectangular waveguide portion 10 is a metal waveguide, for example, it can be formed using a highly conductive metal such as aluminum or brass, and depending on the frequency of the high-frequency signal to be transmitted, the width is For example, the height is about 2 mm to 8 mm, and the height is about 1 mm to 4 mm, for example. Moreover, the thickness of the tube wall of a metal waveguide shall be about 0.1 mm-1 mm, for example.

The slot 30 is formed in a rectangular shape so as to penetrate the ground conductor 22 and the tube wall 11 on the upper side of the rectangular waveguide portion 10. Further, the slot 30 is located at a position or end surface adjacent to the end surface 12 in the longitudinal direction of the rectangular waveguide portion 10 in order to reduce the loss when the rectangular waveguide portion 10 and the differential line portion 20 are connected. It is desirable to form at a position away from 12 by an integral multiple of ½ of the wavelength λg of the high-frequency signal transmitted through the rectangular waveguide section 10, and when using the fundamental mode (TE ₁₀ mode), the rectangular shape is used. It is desirable to form it at the center in the width direction of the waveguide portion 10. The pair of long sides 31 a and 31 b of the slot 30 is preferably formed so as to be parallel to the width direction of the rectangular waveguide portion 10. Such a slot 30 is formed in a rectangular shape having a width of about 0.05 mm to 0.5 mm and a length of about 0.3 mm to 4 mm, for example, according to the frequency of the high-frequency signal transmitted through the rectangular waveguide portion 10. .

  The pair of through conductors 24a, 24b is preferably connected to a portion as close as possible to the center of the pair of long sides 31a, 31b of the slot 30, and the distance from the end of the slot 30 is, for example, 0.02 mm to 0.5 It is about mm.

  The pair of side wall through conductor groups 15 a and 15 b function as tube walls on both sides of the rectangular waveguide portion 10, and the end surface through conductor group 16 functions as a tube wall of the end surface 12 of the rectangular waveguide portion 10. Each repetition interval needs to be a repetition interval less than ½ of the wavelength λg of the high-frequency signal transmitted through the rectangular waveguide unit 10 from the viewpoint of preventing leakage of the high-frequency signal. It is preferable that it is less than 1/4.

  Such a pair of through conductors 24a and 24b and a pair of side wall through conductor groups 15a and 15b are similar to the pair of line conductors 23a and 23b, the ground conductor 22, the upper main conductor layer 14a and the lower main conductor layer 14b. A via hole or a through hole made of the above metal material can be used, and its diameter is, for example, about 0.05 mm to 0.5 mm. Further, the pair of through conductors 24a and 24b and the pair of side wall through conductor groups 15a and 15b, for example, perform appropriate punching processing on each of the ceramic green sheets to be the dielectric layer 21 and the waveguide dielectric layer 13. After that, it is possible to form by filling a paste-like metal material by a thick film printing method or the like and then firing it at a temperature of about 1600 ° C. with a ceramic green sheet.

(Modification)
The present invention is not limited to the first and second examples of the embodiments described above, and various modifications and improvements can be made without departing from the scope of the present invention.

  For example, in the example of the embodiment described above, an example in which the slot 30 is formed so that the pair of long sides 31a and 31b are parallel to the width direction of the rectangular waveguide portion 10 has been described. When an increase in loss when connecting the tube portion 10 and the differential line portion 20 can be allowed, the pair of long sides 31a and 31b is inclined so as to be inclined with respect to the width direction of the rectangular waveguide portion 10. 30 may be formed, and even when the pair of line conductors 23a and 23b is formed to be inclined with respect to the width direction of the rectangular waveguide portion 10, the pair of line conductors 23a is formed. , 23b can be connected to the pair of through conductors 24a, 24b without bending. In some cases, the slot 30 may be formed so that the pair of long sides 31a and 31b are parallel to the longitudinal direction of the rectangular waveguide portion 10. In this case, the slot 30 is formed in the rectangular waveguide. It is desirable to form it so as to be adjacent to one tube wall on both sides of the portion 10.

  In the above-described embodiment, the ground conductor 22 is disposed on the lower surface of the dielectric layer 21, and the pair of line conductors 23a and 23b is disposed on the upper surface. However, the pair of line conductors 23a is illustrated. , 23b may be arranged inside the dielectric layer 21, and another ground conductor may be arranged on the upper surface of the dielectric layer 21. Thereby, the influence by the unnecessary electromagnetic waves from the outside can be prevented more reliably.

  Furthermore, in the example of the above-described embodiment, an example in which the ground conductor 22 and the upper tube wall 11 of the rectangular waveguide portion 10 exist separately is shown. However, the ground conductor 22 and the rectangular waveguide portion 10 The upper tube wall 11 may be integrally formed. As a result, it is possible to prevent variation in the shape of the slot 30 due to the positional deviation between the ground conductor 22 and the upper tube wall 11 of the rectangular waveguide portion 10, and therefore, it is possible to prevent the rectangular conductor having excellent mass productivity. A connection structure between the wave tube portion 10 and the differential line portion 20 can be obtained.

  Furthermore, in the second example of the above-described embodiment, an example is shown in which the tube walls on both sides of the rectangular waveguide portion 10 are configured by only a pair of side wall through conductor groups 15a and 15b. A pair of side wall sub-conductor layers formed in parallel to the upper main conductor layer 14a and the lower main conductor layer 14b and electrically connecting the pair of side wall through conductor groups 15a and 15b, respectively, include the upper main conductor layer 14a and the side main conductor layer 14a. Tube walls on both sides of the rectangular waveguide portion 10 are formed in a lattice pattern by the pair of side wall sub-conductor layers and the pair of side wall through conductor groups 15a and 15b, which are arranged between the lower main conductor layers 14b. It does not matter if it is made. Thereby, leakage of high frequency signals from both side surfaces of the rectangular waveguide portion 10 can be prevented more reliably.

  Furthermore, in the example of the embodiment described above, the slot 30 is ½ times the wavelength λg of the high-frequency signal transmitted from the one end face 12 in the longitudinal direction of the rectangular waveguide portion 10 through the rectangular waveguide portion 10. However, it may be an integral multiple of ½ of the wavelength λg of the high-frequency signal transmitted through the rectangular waveguide unit 10. It may be formed so as to be adjacent to one end face 12 in the longitudinal direction. Usually, the slot 30 is formed at a position that is 1/2 or 1 times the wavelength λg of the high-frequency signal transmitted through the rectangular waveguide portion 10 from one end face 12 in the longitudinal direction of the rectangular waveguide portion 10. However, when a high-frequency signal is transmitted to both sides in the longitudinal direction of the rectangular waveguide portion 10 and the transmission loss of the rectangular waveguide portion 10 is small, for example, the slot 30 is formed in the rectangular waveguide portion 10. You may make it form in the position about 100 times as long as 1/2 of wavelength (lambda) g of the high frequency signal which transmits the rectangular waveguide part 10 from the one end surface 12 in a longitudinal direction.

  Next, a specific example of the connection structure between the rectangular waveguide portion and the differential line portion of the present invention will be described.

  In the connection structure between the rectangular waveguide portion 10 and the differential line portion 20 of the first example of the embodiment shown in FIGS. 1 to 3, the relative dielectric constant is placed inside the metal waveguide for miniaturization. The electrical characteristics in the structure with 9.75 dielectric were simulated by electromagnetic field analysis using finite element method. Specifically, the thickness of the dielectric layer 21 was 0.15 mm, and the thickness of the ground conductor 22 disposed on the lower surface of the dielectric layer 21 was 0.1 mm. The distance between the pair of line conductors 23a and 23b disposed on the upper surface of the dielectric layer 21 was 0.2 mm, the width was 0.12 mm, and the thickness was 0.01 mm. Each of the pair of through conductors 24a and 24b connected to one end of the pair of line conductors 23a and 23b has a diameter of 0.1 mm and a length of 0.15 mm. The width inside the tube wall of the rectangular waveguide portion 10 disposed on the lower surface of the ground conductor 22 was 1.2 mm, and the height was 0.45 mm. A slot 30 having a width of 0.17 mm and a length of 0.636 mm around the position of 0.847 mm from the inner side of the tube wall in one end face 12 in the longitudinal direction of the rectangular waveguide portion 10 is formed in the rectangular waveguide portion 10. A pair of long sides 31 a and 31 b are formed in the center in the width direction so as to be parallel to the width direction of the rectangular waveguide portion 10. The pair of through conductors 24a and 24b are connected to positions spaced 0.025 mm on both sides from the center of the pair of long sides 31a and 31b of the slot 30.

  Then, the other end of the pair of line conductors 23a and 23b is defined as port 1, the other end in the longitudinal direction of the rectangular waveguide portion 10 is defined as port 2, and the passing characteristics when a differential signal is input from port 1 (S21). The reflection characteristics (S11) were examined. FIG. 5 is a graph showing the results, with the horizontal axis representing frequency and the vertical axis representing gain.

  According to the graph shown in FIG. 5, since S21 is -0.91 dB and S11 is -18.29 dB at 76.5 GHz, the impedance is well matched and good connection characteristics with little conversion loss are obtained. I understand that. This confirmed the effectiveness of the present invention.

It is a perspective view which shows typically an example of embodiment of the connection structure of the rectangular waveguide part and differential line | wire part of this invention. It is the see-through | perspective view seen from the top which shows typically the connection structure of the rectangular waveguide part shown in FIG. 1, and a differential line part. FIG. 2 is a sectional view taken along line X-X ′ in FIG. 1. It is a perspective view which shows typically the other example of embodiment of the connection structure of the rectangular waveguide part and differential line | wire part of this invention. It is a figure which shows the simulation result of the electrical property of the connection structure of the rectangular waveguide part of this invention, and a differential line part.

Explanation of symbols

10: Rectangular waveguide
11: Upper pipe wall
12: End face
13: Dielectric layer for waveguide
14a: Upper main conductor layer
14b: Lower main conductor layer
15a, 15b: Side wall through conductor group
21: Dielectric layer
22: Ground conductor
23a, 23b: a pair of line conductors
24a, 24b: a pair of through conductors
30: Slot
31a, 31b: a pair of long sides

Claims (6)

A rectangular waveguide section;
A differential line section disposed on the upper wall of the rectangular waveguide section, having a ground conductor on the lower surface of the dielectric layer, and a pair of line conductors through which a differential signal is transmitted on the upper surface or inside;
A rectangular slot penetrating the tube wall on the upper side of the rectangular waveguide portion and the ground conductor is provided, and each end of the pair of line conductors is adjacent to a central portion of a pair of long sides of the slot. A rectangular conductor characterized by comprising a pair of through conductors connected to the ground conductor, respectively , wherein the pair of line conductors are formed in parallel to the pair of long sides of the slot, respectively. Connection structure between wave tube and differential line. The slot claim 1, wherein the pair of long sides in a central portion in the width direction of the rectangular waveguide portion is formed so as to be parallel to the width direction of the rectangular waveguide section The connection structure of the rectangular waveguide part and differential line part as described in 2. The slot is formed at a position adjacent to the end face in the longitudinal direction of the rectangular waveguide section or a position away from the end face by an integral multiple of 1/2 of the wavelength of the high-frequency signal transmitted through the rectangular waveguide section. The connection structure between the rectangular waveguide portion and the differential line portion according to claim 2 . The difference between the grounded conductor and the rectangular waveguide portion according to any one of claims 1 to 3 , wherein the ground conductor and the upper tube wall of the rectangular waveguide portion are integrally formed. Connection structure with the moving line section. The connection structure between the rectangular waveguide portion and the differential line portion according to any one of claims 1 to 4 , wherein the rectangular waveguide portion is a metal waveguide. The rectangular waveguide portion is disposed on the upper surface of the waveguide dielectric layer and serves as the upper tube wall, and the lower tube is disposed on the lower surface of the waveguide dielectric layer. A lower main conductor layer serving as a wall, and the upper side with a predetermined interval in a direction orthogonal to the transmission direction at a repetition interval of less than ½ of the wavelength of the high frequency signal in the transmission direction of the high frequency signal The upper main conductor layer, the lower side conductor group, and the lower main conductor layer. square according to any one of claims 1 to 4, characterized in that the area surrounded by the side-wall through conductor group of the main conductor layer and the second column is a dielectric waveguide for transmitting a high-frequency signal Connection structure between the waveguide section and the differential line section.

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