JP2007282025A - Waveguide splitter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a high performance waveguide splitter having a simple structure. <P>SOLUTION: The waveguide splitter contains a 4-port resin waveguide 10 having a magic T structure obtained by combining an E face T branch with an H face T branch. In the waveguide splitter, an input port into which an electromagnetic wave in 4 ports of the resin waveguide is inputted has a first matching structure 21 which matches a characteristic impedance of the resin waveguide. An end port in the 4 ports of the resin waveguide has a second matching structure which matches the characteristic impedance of the resin waveguide. The second matching structure comprises a carving part 31 which is not metal-plated, an absorber 32 which is fit to the carving part 31, thereby being coplanar with an end of the end port which is metal-plated, and a fixing tool 33 for fixing to the end port the absorber which is fit to the carving part 31. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a waveguide distributor, and more particularly to a waveguide distributor having a magic T structure used for microwaves.

  Currently, coaxial lines are widely used as transmission lines. However, at frequencies above microwaves, the conductor loss of the conductor in the coaxial line is large, and there is a loss of the support material, so there is a problem in using the coaxial line due to the characteristics of low loss and high power capacity. .

  On the other hand, the waveguide structure is a hollow tubular conductor (generally rectangular or circular in cross section), and microwaves propagate through it, so the conductor loss of the central conductor and the dielectric loss of the support material There is no loss. Therefore, a low-loss waveguide is widely used for a feeding circuit portion of an antenna and the like because low-loss characteristics are often required.

  Usually, a hollow waveguide distributor is an E-plane T-branch having a branch in the long side direction of a rectangular waveguide as a three-terminal circuit, an H-plane T-branch having a branch in the short-side direction, an H-plane Y-branch, etc. There is. Further, as a four-terminal circuit, there is a magic T structure in which an E-plane T branch and an H-plane T branch are combined and impedance matching is performed with a conical disk or rod later. And these methods are used in the wide range (for example, refer patent document 1, nonpatent literature 1, nonpatent literature 2).

JP 7-46011 A Antenna Engineering Handbook The Institute of Electronics, Information and Communication Engineers published by Ohm P264-P267 Microwave Engineering Masamitsu Nakajima Published by Morikita Publishing P123

  However, the prior art has the following problems. A distributor using a conventional metal hollow waveguide is constituted by a combination of a magic T and a hollow waveguide end, or a metal processed waveguide only (so-called E-plane T). There are two types: branching and H-plane T-branching.

  The former is used when high isolation is required between each distributed port, and the latter is often used when less high isolation is required. In both cases, it is necessary to assemble the hollow waveguide three-dimensionally, and the size is further increased because the hollow waveguide is used.

  In the former case, which is a combination of the magic T and the end of the hollow waveguide, the end is required. For this purpose, one end of the waveguide is short-circuited with a conductor, and a surface that is a quarter (λg / 4) away from the guide wavelength is an electrically open surface, and has a resistance value equal to the characteristic impedance of the propagation mode. The resistor is operated as a terminal by placing the resistor at a position where the electric field of the waveguide is maximized in parallel with the electric field.

  Here, usually, a resistor having a taper is formed so as not to give a sudden discontinuity to the waveguide. As a result, in addition to requiring a length of λg / 4 at the minimum, a flange is required to connect to other components.

  For this reason, the conventional termination is formed on the flange by aligning the metal-processed waveguide with the termination short-circuit surface, installing a notch in the short-circuit surface, and inserting a resistor that tapers from the notch. It can be assembled by fixing it with adhesive or screws in the position fixing holes. Therefore, when operating as a terminal, there is a problem that it is necessary to place the resistor on a surface (side surface or the like) other than the short-circuit surface in order to securely hold the resistor.

  Further, in a normal magic T configuration, an adjustment element such as an iris or a cone cone is usually essential in order to add a susceptance component to achieve impedance matching. Therefore, there are problems that it takes time and cost for such a configuration, and that the passage loss of the magic T increases due to the introduction of the adjusting element.

  The present invention has been made to solve the above-described problems, and an object thereof is to obtain a high-performance waveguide distributor having a simple configuration.

  A waveguide distributor according to the present invention includes a 4-port resin waveguide having a magic T structure in which an E-plane T-branch and an H-plane T-branch are combined. The input port to which electromagnetic waves are input among the 4 ports has a first matching structure that matches the characteristic impedance of the resin waveguide, and the termination port of the 4 ports of the resin waveguide is: The second matching structure has a matching with the characteristic impedance of the resin waveguide, and the second matching structure is terminated by being fitted into the engraved part not subjected to metal plating and the engraved part. It comprises an absorber that is flush with the end surface of the port that is plated with metal, and a fixture that fixes the absorber fitted to the engraved portion to the terminal port.

  According to the present invention, in a waveguide distributor using a four-port rectangular resin waveguide having a magic T structure, the input port has the first matching structure, and the terminal port has an engraved portion and an absorber. By having the second matching structure including the fixing member, a high-performance waveguide distributor having a simple configuration can be obtained.

  Hereinafter, preferred embodiments of the waveguide distributor of the present invention will be described with reference to the drawings.

Embodiment 1 FIG.
FIG. 1 is a diagram showing an upper oblique surface of a connection portion of a waveguide distributor according to Embodiment 1 of the present invention. The waveguide distributor shown in FIG. 1 has a magic T structure in which an H-plane T branch of a rectangular resin waveguide 10 is combined with an E-plane T branch, and includes four ports. In the following description, the four ports at the respective waveguide ends are referred to as port 1, port 2, port 3, and port 4, as shown in FIG.

  Here, in the rectangular resin waveguide 10, the port 1 corresponds to an input port, and an impedance adjustment structure 21 that is an example of the first matching structure 20 is provided. Further, the end surfaces of the ports 1 to 4 with respect to the tube axis direction are exposed without metal plating except for the port 4 (corresponding to the end surface of the shaded portion in FIG. 1), and other than the end surfaces such as the side surfaces of the waveguide. About, the metal plating is given.

  1 to 7 used in the following description, the shaded portion indicates that metal plating is not performed, and the non-shaded portion indicates that metal plating is performed. Shall.

  Here, the port 4 corresponding to the termination port is referred to as a termination section. A cylindrical engraved portion 31 that is not subjected to metal plating is formed on the end face of the end portion. The cylindrical engraving portion 31 is fitted with the cylindrical absorbent body 32 inserted into the cylindrical engraving portion 31 and is dimensioned to be flush with the end face of the port 4 after assembly. And after inserting the cylindrical absorber 32 in the cylindrical engraving part 31, a terminal part is fixed using conductor fixing tools 33, such as a metal. The cylindrical engraving 31, the cylindrical absorber 32, and the conductor fixture 33 configured as described above correspond to the second alignment structure 30.

Next, the operation of the waveguide distributor having the configuration shown in FIG. 1 will be described.
Consider the case where electromagnetic waves (microwaves) are input from port 1 which is an input port in the structure shown in FIG. In this case, it is considered that electromagnetic waves (microwaves) are input from the port 1 and distributed in opposite phases to the ports 2 and 3, and the port 4 corresponding to the terminal port is the terminal part.

This structure can be expressed by an equivalent circuit as a four-opening element. In this case, when the characteristic impedance of the waveguide is Z _n and the impedances of the ports 1 to 4 are Z ₁ , Z ₂ , Z ₃ , and Z ₄ , respectively, Z ₁ , Z ₂ , and Z ₃ are usually since waveguide end face becomes pure resistance, in _particular, Z 2, _{Z 3} is assumed to be a _{Z n.}

It can be seen that this structure is provided with port 1 and port 4 between the straight waveguides of port 2 to port 3. For this reason, susceptance components X ₁ and X ₂ are generated by the ports 1 and 4. Therefore, the impedance Z _{4 of the} port 4 can be expressed as Z ₄ = R ₄ + jX ₄ using the susceptance component X ₄ for matching with X ₁ and X ₂ .

From this, contact equations and closed-circuit equations related to ports 1 to 4 are derived, and impedance values at each port are calculated. Here, when the matching condition and non-bonding property of magic T (S ₁₁ = S ₂₂ = S ₃₃ = S ₄₄ = S ₂₃ = S ₃₂ = 0) are solved as conditions, the results of the following expressions (1) to (5) are obtained. Is obtained.

X ₁ = −X ₂ (1)
Z ₁ = 2Z _n (2)
^{_{R 4 = X 1 2/2}} (1 + X 1 2) (3)
X ₄ = X ₁ ^3/2 (1 + X ₁ ² ) (4)
0 <R ₄ <Z _n / 2 (5)

Here, from the equation (2), the impedance Z _{1 of the} port 1 is twice the waveguide characteristic impedance Z _n . Further, Equation (3), since the result and │R ₄ │»│X ₄ │ _(4), and _{Z 4 = R 4 + jX 4} ≒ R 4. When considered together with the results of the formula (5), port 1 is twice the characteristic impedance Z _n of the waveguide, the port 4 is ideally by half the characteristic impedance Z _n of the waveguide It can be seen that a characteristic as a magic T can be obtained.

Here, the port 1 realizes twice the waveguide characteristic impedance Z _n by providing an impedance adjustment structure 21 as a first matching structure 20. Further, the non-reflective terminal corresponding to the port 4 has the second matching structure 30 described above. The non-reflective terminal is provided with a resistor (cylindrical absorber 32) in the waveguide so that it becomes half the characteristic impedance of the transmission wave at a point approximately λg / 4 or less away from the short-circuited surface by the conductor fixture 33. Equivalent). Furthermore, a non-reflective termination is realized at a wide frequency by giving the resistor a certain length.

  In general, in a hollow waveguide, it is very difficult to hold the absorber in a floating state in the central portion. Usually, the absorber is tapered to have two or more surfaces such as a bottom surface and a side surface. Holding the resistor.

  On the other hand, in the structure as shown in the first embodiment, the cylindrical absorber 32 can be disposed at the most effective place on the short-circuit surface. As a result, it is not necessary to terminate with a characteristic impedance, and fixing is easy, so that a high-performance termination can be easily manufactured.

  Further, the magic T structure of the hollow waveguide is complicated and expensive due to the provision of adjusting elements such as an iris and a cone cone. On the other hand, in the first embodiment, since it is a resin waveguide, it can be configured relatively easily and inexpensively. Therefore, there is an effect that a small distributor with high isolation between the distribution ports can be obtained inexpensively and easily.

  Furthermore, as the shape of the resistor, in addition to the cylindrical absorber 32 as shown in FIG. 1, when an absorber changed to a shape such as a square column resistor, a cone resistor, a triangular column, or a wedge shape is used. In addition, the same effect as in the case of FIG. 1 can be obtained.

  Further, in FIG. 1, the fixing of the resistor and the leakage of electromagnetic waves are suppressed using a conductor fixture 33 using a conductor such as metal. However, even when a fixture that is not a conductor is used, it can be seen that there is no leakage of electromagnetic waves because the gap is sufficiently small with respect to the guide wavelength. Therefore, since what fixes a resistor does not ask | require a conductor and a nonconductor, the effect that it can manufacture still more cheaply is acquired.

  Moreover, in this structure, since the termination | terminus part can also be manufactured integrally, the effect that the dimension of a divider | distributor can be made small as a whole is also acquired.

  As described above, according to the first embodiment, in the waveguide distributor using the 4-port rectangular resin waveguide having the magic T structure in which the E-plane T-branch and the H-plane T-branch are combined. A high-performance waveguide distributor is realized with a simple configuration by having a first matching structure at the port and a second matching structure including the engraved part, the absorber and the fixture at the terminal port. can do.

Embodiment 2. FIG.
FIG. 2 is a diagram showing an upper oblique surface of the connection portion of the waveguide distributor in the second embodiment of the present invention. FIG. 2 is different from the first embodiment in that a capacitive iris 22 is provided in the port 1 as the first matching structure 20 instead of the impedance adjustment structure 21.

  Next, the operation of the waveguide distributor having the configuration of FIG. 2 will be described. The waveguide distributor in FIG. 2 adds impedance to the impedance by using a capacitive iris 22. From this, the same effect as in the first embodiment can be obtained. Further, the same effect can be obtained when the dimension of the iris portion is widened and reversed.

Embodiment 3 FIG.
FIG. 3 is a diagram showing an upper oblique surface of the connection portion of the waveguide distributor in the third embodiment of the present invention. FIG. 3 is different from the first embodiment in that an inductive iris 23 is provided in the port 1 as the first matching structure 20 instead of the impedance adjustment structure 21.

  Next, the operation of the waveguide distributor having the configuration shown in FIG. 3 will be described. The waveguide distributor in FIG. 3 adds impedance to the susceptance component by the inductive iris 23 to achieve impedance matching. From this, the same effect as in the first embodiment can be obtained. Further, the same effect can be obtained when the dimension of the iris portion is widened and reversed.

Embodiment 4 FIG.
FIG. 4 is a diagram showing an upper oblique surface of the connection portion of the waveguide distributor according to the fourth embodiment of the present invention. FIG. 4 shows that the port 1 is provided with a taper 24 as the first matching structure 20 instead of the impedance adjustment structure 21 in which the short side dimension of the port 1 is changed to a tapered shape. Different from 1.

  Next, the operation of the waveguide distributor having the configuration of FIG. 4 will be described. The waveguide distributor in FIG. 4 adds impedance to the susceptance component by a taper 24 that changes the dimension in the short direction. From this, the same effect as in the first embodiment can be obtained. The same effect can be obtained when the taper shape is reversed.

Embodiment 5 FIG.
FIG. 5 is a diagram showing an upper oblique surface of the connection portion of the waveguide distributor in the fifth embodiment of the present invention. FIG. 5 shows that the port 1 is provided with a taper 24 in which the longitudinal dimension of the port 1 is changed to a taper instead of the impedance adjustment structure 21 as the first matching structure 20 in the first embodiment. And different.

  Subsequently, the operation of the waveguide distributor having the configuration of FIG. 5 will be described. The waveguide distributor in FIG. 5 is impedance matched by adding a susceptance component by a taper 24 that changes the dimension in the longitudinal direction. From this, the same effect as in the first embodiment can be obtained. The same effect can be obtained when the taper shape is reversed.

Embodiment 6 FIG.
FIG. 6 is a diagram showing an upper oblique surface of the connection portion of the waveguide distributor in the sixth embodiment of the present invention. In FIG. 6, a hole 25 that is not plated in the longitudinal direction of the port 1 of the rectangular resin waveguide 10 is provided in the port 1 as the first matching structure 20 instead of the impedance adjustment structure 21. The difference from the first embodiment is that a rod 26 made of a conductor or a metal-plated dielectric is inserted so as to fit into the hole 25.

  Next, the operation of the waveguide distributor having the configuration of FIG. 6 will be described. The waveguide distributor in FIG. 6 can add a susceptance component due to the conductive rod 26 to the port 1 of the rectangular resin waveguide 10. By using this to perform impedance matching, unnecessary reflection due to impedance mismatch can be further suppressed. From this, in addition to the effect obtained in the first embodiment, the electrical characteristics are improved, and the effect that adjustment is possible after assembly is obtained.

Embodiment 7 FIG.
FIG. 7 is a diagram showing an upper oblique surface of the connection portion of the waveguide distributor in the seventh embodiment of the present invention. In FIG. 7, a hole 25 that is not plated in the short direction of the port 1 of the rectangular resin waveguide 10 is provided in the port 1 as the first matching structure 20 instead of the impedance adjustment structure 21. The difference from the first embodiment is that a rod 26 made of a conductor or a metal-plated dielectric is inserted so as to fit into the hole 25.

  Subsequently, the operation of the waveguide distributor having the configuration of FIG. 7 will be described. The waveguide distributor in FIG. 7 can add a susceptance component due to the conductor rod 26 to the port 1 of the rectangular resin waveguide 10. By using this to perform impedance matching, unnecessary reflection due to impedance mismatch can be further suppressed. From this, in addition to the effect obtained in the first embodiment, the electrical characteristics are improved, and the effect that adjustment is possible after assembly is obtained.

It is a figure which shows the upper oblique surface of the connection part of the waveguide distributor in Embodiment 1 of this invention. It is a figure which shows the upper oblique surface of the connection part of the waveguide distributor in Embodiment 2 of this invention. It is a figure which shows the upper oblique surface of the connection part of the waveguide distributor in Embodiment 3 of this invention. It is a figure which shows the upper oblique surface of the connection part of the waveguide distributor in Embodiment 4 of this invention. It is a figure which shows the upper oblique surface of the connection part of the waveguide distributor in Embodiment 5 of this invention. It is a figure which shows the upper oblique surface of the connection part of the waveguide distributor in Embodiment 6 of this invention. It is a figure which shows the upper oblique surface of the connection part of the waveguide distributor in Embodiment 7 of this invention.

Explanation of symbols

  10 rectangular resin waveguide (resin waveguide), 20 first matching structure, 21 impedance adjustment structure, 22 capacitive iris, 23 inductive iris, 24 taper, 25 hole, 26 rod, 30 second Structure for alignment, 31 cylindrical engraved portion (engraved portion), 32 cylindrical absorber (absorber), 33 conductor fixture (fixer).

Claims (7)

In a waveguide distributor including a 4-port resin waveguide having a magic T structure combining an E-plane T-branch and an H-plane T-branch,
The input port to which an electromagnetic wave among the four ports of the resin waveguide is input has a first matching structure that matches with the characteristic impedance of the resin waveguide,
The termination port of the four ports of the resin waveguide has a second matching structure for matching with the characteristic impedance of the resin waveguide,
The second alignment structure is:
Engraved parts that are not plated with metal,
An absorber that is flush with the end surface of the end port that has been subjected to metal plating by being fitted into the engraved portion;
A waveguide distributor comprising: a fixing member that fixes the absorber fitted to the engraved portion to the terminal port. The waveguide distributor of claim 1, wherein
The waveguide distributor according to claim 1, wherein the first matching structure is made of a capacitive iris. The waveguide distributor of claim 1, wherein
The waveguide distributor according to claim 1, wherein the first matching structure is formed of an inductive iris. The waveguide distributor of claim 1, wherein
The waveguide distributor according to claim 1, wherein the first matching structure is configured by providing a taper in a longitudinal direction of the input port. The waveguide distributor of claim 1, wherein
The waveguide distributor according to claim 1, wherein the first matching structure is configured by providing a taper in a short direction of the input port. The waveguide distributor of claim 1, wherein
The first alignment structure is composed of a hole provided in the longitudinal direction of the input port and not provided with metal plating, and a rod inserted into the hole. vessel. The waveguide distributor of claim 1, wherein
The first alignment structure includes a hole portion provided in a short direction of the input port and not subjected to metal plating, and a rod inserted into the hole portion. Distributor.

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