JP6276567B2 - Non-waveguide line-waveguide converter - Google Patents

Description

  The present invention is used for non-waveguide line-waveguide converters, particularly for conversion between non-waveguide lines and waveguides, such as distributed constant lines or coaxial lines used in microwave circuits, and high input The present invention relates to a configuration of a converter having power tolerance.

  Conventionally, amplifiers, frequency converters, and the like have been used as microwave circuits, and waveguides with low transmission loss are often used for transmission of microwave signals from these circuits to external circuits. In this microwave circuit, a distributed constant transmission line and a coaxial line typified by a microstrip line are used because of the circuit configuration and parts used. A non-waveguide line-waveguide converter for converting the above is required, and examples of the converter include techniques disclosed in Patent Documents 1 and 2 below.

  FIG. 3 shows a general structure in which a microstrip line, which is a transmission line from a front circuit, is inserted into a waveguide and used as an open-ended probe, as in Patent Document 1. That is, as shown in FIG. 3, the waveguide 1 is provided with a short-circuit surface (short surface) 2. From the H surface of the waveguide 1 (surface parallel to the magnetic field in the upper surface of the figure), a dielectric is formed. The substrate 3 and the microstrip line 4 formed on the substrate 3 are extended and inserted into the waveguide, and the tip of this line becomes the probe 4a. According to such a structure, there is an advantage that a non-waveguide line-waveguide converter can be realized simply and inexpensively.

  On the other hand, as shown in Patent Document 2 (FIG. 5), there is also a coaxial waveguide converter having a special structure in which a ridge having a stepped protrusion is provided in a conversion portion.

Japanese Utility Model Publication No. 61-93005 Japanese Utility Model Publication No. 62-77903

  However, in the conventional non-waveguide line-waveguide converter, there is a transmission loss due to the material constituting the circuit and the surface state of the material. However, there is a problem that heat generation at the part increases, and depending on the constituent material, the material may be damaged such as melting, deformation, and carbonization. In addition, there may be a problem such as discharge due to emission of thermoelectrons generated due to a high temperature due to heat generation or generation of a high electric field site due to a significant change in matching conditions.

  As described above, a general, simple, and easy insertion of a tip end portion (4a: open portion) of a microstrip line (4) serving as a distributed constant transmission line or a tip end open portion of a central conductor of a coaxial line into a waveguide as a probe. In a converter with a structure that can be realized at low cost, because the equivalent thermal resistance increases due to the structure such as the arrangement of thin linear probes in the space, the above-mentioned problems are likely to occur and high power cannot be handled. There was a problem.

  Moreover, although the said patent document 2 as a prior art example can hold down the thermal resistance of a probe part low unlike patent document 1, on the other hand, the structure of the conversion part with a stepped ridge becomes complicated, There is a problem that the production cost is high.

  The present invention has been made in view of the above problems, and its object is to reduce the thermal resistance of the probe inserted in the waveguide and its peripheral portion while maintaining a simple and inexpensive structure, and to achieve high power. It is an object to provide a non-waveguide line-waveguide converter capable of handling the above.

In order to achieve the above object, the invention according to claim 1 is directed to a waveguide provided with a short-circuit surface, and an opposing H surface facing the probe insertion H surface (surface parallel to the magnetic field) into the waveguide. anda probe non waveguide line inserted toward the non-waveguide line for transmitting mode conversion between the unguided pipe line and the waveguide - waveguide converter , The short-circuiting conductor is formed from the tip of the probe toward the E-plane (surface parallel to the electric field) of the waveguide, and the end of the short-circuiting conductor is close to the opposite H-plane of the E-plane. The shape of the shorting conductor on the probe insertion H surface side has a stepped portion, and the shape of the opposing H surface side of the shorting conductor has no stepped portion except for the joining surface with the E surface, It is characterized by being linear in parallel with the opposing H surface .
According to a second aspect of the present invention, the corner of the connecting portion between the shorting conductor and the probe, the corner of the connecting portion between the shorting conductor and the waveguide E surface, or the corner of the shorting conductor itself is gentle. It is formed so as to have a curved line (arc shape).

According to the first aspect of the present invention, the equivalent thermal resistance from the probe part to the peripheral part is greatly reduced by the short-circuiting conductor connecting the probe and the waveguide E surface, and the heat generated from the probe part is released. The
According to the configuration of claim 2, since the connecting portion between the shorting conductor and the probe, the connecting portion between the shorting conductor and the waveguide E surface, or the corner portion of the shorting conductor itself is not a sharp corner, It is possible to avoid the concentration of the electric field in

  According to the non-waveguide line-waveguide converter of the present invention, the equivalent thermal resistance from the probe part to the peripheral part can be greatly reduced, and as a result, the heat generated in the probe part is efficiently released. No primary damage such as melting, deformation, or carbonization of the material, or secondary damage such as discharge triggered by these, and the incident power that causes these damages is relatively improved and simple. In addition, there is an effect that a large amount of electric power can be handled while being an inexpensive structure.

  In addition, even if a shorting conductor is provided by connecting the shorting conductor to each part and the corners of the shorting conductor itself, it has the effect of reducing the concentration of the electric field. It becomes possible to improve electric power tolerance.

1 shows a configuration of a non-waveguide line (microstrip line) -waveguide converter according to a first embodiment of the present invention, in which FIG. (A) is a front view seen from the waveguide opening side, and FIG. These are the center sectional views of Drawing (A). The structure of the non-waveguide line (coaxial line)-waveguide converter of 2nd Example is shown, A figure (A) is the front view seen from the waveguide opening side, A figure (B) is a figure (A). FIG. 4C is a diagram showing the upper side from inside the waveguide. The structure of the conventional non-waveguide line (microstrip line) -waveguide converter is shown, FIG. (A) is a front view seen from the waveguide opening side, and FIG. (B) is the center of FIG. (A). It is sectional drawing.

1A and 1B show the configuration of a non-waveguide line-waveguide converter according to a first embodiment of the present invention. This first embodiment is a non-waveguide. A microstrip line is used as the tube line.
In FIG. 1, as described in FIG. 3, 1 is a waveguide, 2 is a shorted surface (short surface), 3 is a dielectric substrate, and 4 is a microstrip line from a pre-circuit formed on the substrate 3. (Distributed constant line) 4a is a probe at the tip of the microstrip line 4 projectingly inserted into the waveguide 1, and 5 is a through hole.

  In the embodiment, a short-circuit (heat-dissipating) conductor 10 is integrally formed on the distal end side of the probe 4a, and the short-circuit conductor 10 is elongated in the direction in which the probe 4a is inserted, that is, in the direction orthogonal to the electric field direction. The left and right ends of the waveguide 1 are in contact with the left and right E planes (surfaces parallel to the electric field direction on the left and right wall surfaces in the figure) and short-circuited.

  Further, as indicated by the arrow (g), the corner of the connecting portion between the shorting conductor 10 and the probe 4a, the corner of the connecting portion between the shorting conductor 10 and the left and right E surfaces of the waveguide 1, and The corners of the short-circuiting conductor 10 itself are rounded with sharp corners so as to have a gentle curve (arc shape).

  According to the configuration of the first embodiment, since the probe 4a and the left and right E surfaces of the waveguide 1 are connected by the short-circuiting conductor 10, the equivalent thermal resistance from the portion of the probe 4a to the peripheral portion is greatly increased. As a result, the heat generated from the probe portion is released well. Since the short-circuiting conductor 10 is orthogonal to the insertion direction (electric field E direction) of the probe 4 a and is disposed in parallel with the direction of the magnetic field (H) of the transmission wave in the waveguide, the probe 4 a is located with respect to the waveguide 1. Even in the short-circuit state, the transmission wave in the waveguide is not affected.

However, this conversion unit is a part in which the quasi-TEM wave transmitted through the microstrip line 4 is mode-converted into a TE wave that is a waveguide transmission mode, and therefore is not a complete TE wave. The influence of the conductor 10 cannot be completely ignored. Therefore, in the implementation, it is preferable to pay attention to the following conditions and set the optimal shape of the probe 4a and the short-circuiting conductor 10 using an electromagnetic field simulator or the like.
1. The width of the short-circuiting conductor 10 to the surface of the waveguide E is desirably as thick as possible from the viewpoint of efficiently releasing the heat generated by the probe 4a.
2. In order to obtain higher power resistance, the conductor shapes of the probe 4a and the short-circuiting conductor 10 are made to avoid the sharp corner where the electric field tends to concentrate.
In the above description, a signal is input from the microstrip line 4 side and transmitted toward the waveguide 1. However, since this conversion circuit has reversibility, the signal is guided. The above description is valid even when input from the tube 1 side and proceed toward the microstrip line 4.

  In the embodiment, as described above, the connecting portion (g) between the shorting conductor 10 and the probe 4a, the corner portion (g) of the connecting portion between the shorting conductor 10 and the right and left E surfaces of the waveguide 1, Since the corner (g) of the short-circuiting conductor 10 itself is not a sharp curve but a gentle curve, there is an advantage that the concentration of the electric field at each corner is reduced and the resistance to high power input is improved.

FIG. 2 shows a configuration of a non-waveguide line-waveguide converter according to the second embodiment. This second embodiment uses a coaxial line as the non-waveguide line. is there.
As shown in FIG. 2, a coaxial line 8 is arranged via a coaxial dielectric 7 toward the H plane of the waveguide 1 provided with the short-circuit plane 2, and this central conductor serves as a probe 9 from the H plane. It is inserted into the waveguide.

  The probe 9 is connected to (attached to) the short-circuiting conductor 12 that is elongated in a direction orthogonal to the insertion direction (electric field direction). The left and right E side surfaces (surfaces parallel to the electric field direction) are contacted and short-circuited. Further, the corner portion (g) of the connecting portion between the short-circuit conductor 12 and the right and left E side surfaces of the probe 9 and the waveguide 1 and the corner portion of the short-circuit conductor 12 itself are formed in a gentle curve.

  Also in the second embodiment of such a coaxial line, as in the first embodiment, the equivalent thermal resistance from the probe 9 portion to the peripheral portion is greatly reduced, and the generated heat from the probe portion is released well. Also, there is an advantage that the concentration of the electric field at each corner (g) is alleviated.

  As described above, in the first and second embodiments, primary damage such as melting, deformation, or carbonization of the material, secondary damage such as discharge triggered by these does not occur, and high input power resistance is achieved. Use in equipment that handles high power is useful.

  In each of the above-described embodiments, the configuration of the rectangular waveguide has been described. However, the present invention can be similarly applied to a circular waveguide, and a short circuit similar to that of the above-described embodiment can be applied to a probe inserted and arranged in the electric field (E) direction. What is necessary is just to comprise so that a conductor may be connected and this shorting conductor may be short-circuited to the side surface substantially parallel to the electric field (E).

DESCRIPTION OF SYMBOLS 1 ... Waveguide, 2 ... Short-circuit surface (short surface),
3 ... Dielectric substrate, 4 ... Microstrip line,
4a, 9 ... probe, 8 ... coaxial line,
10, 12 ... Short-circuiting conductor.

Claims (2)

A waveguide having a short-circuited surface, and a probe of a non-waveguide line that is inserted into the waveguide from the probe insertion H surface toward the opposing H surface. In a non-waveguide line-waveguide converter that performs transmission mode conversion between the tube line and the waveguide,
Forming a short-circuiting conductor from the tip of the probe toward the E-plane of the waveguide, and joining the end of the short-circuiting conductor closer to the opposite H-plane of the E-plane; and
The shape on the probe insertion H surface side of the shorting conductor has a stepped portion, and the shape on the facing H surface side of the shorting conductor has no stepped portion except for the joint surface with the E surface, A non-waveguide line-waveguide converter characterized by being linear in parallel . The corner portion of the connecting portion between the shorting conductor and the probe, the corner portion of the connecting portion between the shorting conductor and the waveguide E surface, or the corner portion of the shorting conductor itself is formed to have a gentle curve. The non-waveguide line-waveguide converter according to claim 1.

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