JPH0126562B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a waveguide-TEM mode converter that can be used in simple microwave communication devices such as SHF broadcast receiving converters.

Conventional configuration and its problems In recent years, satellite broadcasting in the SHF band has been planned.
Even in the field of microwaves, circuit technology with excellent mass productivity has come to be required. The price of microwave semiconductors is rapidly decreasing due to the development of technology, and the mass production of microwave equipment is increasingly dependent on the circuit configuration.

Conventional waveguide - TEM with reference to the drawings below
The mode converter will be explained.

Figure 1 is a cross-sectional view of the main part of a waveguide-stripline converter, which is a conventional waveguide-TEM mode converter, taken parallel to the E plane in the direction of propagation of the electromagnetic field. In the waveguide, 1' is a flange, 2 is a probe, and 3 is an insulator for holding the probe 2 within the waveguide 1. 4 is an output end of the probe 2, which is connected to a microstrip line 6 formed on the surface of a dielectric substrate 5 constituting a microwave integrated circuit (hereinafter simply referred to as MIC). probe 2
is connected to the microstrip line 6, and also operates as a center conductor in a coaxial line section 7 with the waveguide 1 as the outer conductor. Therefore, in the example of Fig. 1, the waveguide-TEM mode converter and the coaxial-
It has a composite structure of stripline transducers.

However, in the above configuration, in converting the coaxial mode to the microstrip line 6, the ground electrode 8 provided on the back surface of the dielectric substrate 5 is used as the conductor of the waveguide 1, especially in the coaxial portion 7.
It is difficult to ensure electrical connection at the position where the outer conductor of the wire is formed, and it is difficult to obtain reliable and stable performance.

OBJECT OF THE INVENTION The object of the present invention is to provide a waveguide which enables converting a microwave signal in a waveguide into a stripline mode with a simple structure, high reliability, and high stability.
Our purpose is to provide a TEM mode converter.

Structure of the Invention The waveguide-TEM mode converter of the present invention includes a groove provided on the outer surface of a conductor constituting the waveguide, and a lid body having a groove opposite to the groove, and the waveguide. The conductor is part or all of the outer conductor of the TEM transmission line, the conductor connected to the probe that extracts the electromagnetic field in the waveguide is the center conductor of the TEM transmission line, and the insulation filled in the TEM transmission line is The central conductor is held by the body, which allows connection to the stripline with less disturbance in the TEM mode.

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 2a shows a waveguide in an embodiment of the present invention.
A cross-sectional view of the main part of a waveguide-stripline converter, which is one of the TEM mode converters, taken parallel to the E plane in the direction of propagation of the electromagnetic field. Figure 2b is similar to Figure 2a.
FIG. 2 is an external view when looking from the A-A' plane to the left side.

In Figures 2a and b, 21 is a waveguide, 21'
22 is a flange, 22 is a probe, 22' is a center conductor of the coaxial line, 23 is an insulator that fixes the probe 22 in the waveguide 21, and 24 is an insulator that is filled in the coaxial line and fixes the center conductor 22'. , 25 has a groove 25' facing the groove 26 on the outer surface of the waveguide 21, and together with the waveguide 21, forms the outer conductor of the coaxial line, and at the same time is a lid for fixing the insulator 24. , 27a, 27b are screws for fixing the lid 25, 28 is a dielectric substrate of the MIC, and the center conductor 2
The output end of 2' is the conductor 2 of the microstrip line.
9 is connected. A ground electrode 30 on the back surface of the dielectric substrate 28 is electrically connected to a chassis portion 21'' integrated with the waveguide 21.
To correct for TEM propagation having reflections at corners,
This is a metal piece or dielectric piece that is practically provided for matching.

The waveguide of this embodiment configured as above-
According to the TEM mode converter, the output end of the signal converted to the coaxial mode can be easily taken out in any direction. In the embodiment shown in FIG. 2, the signal is output in the same direction as the signal propagation direction within the waveguide. As a result, the dielectric substrate 28 of the MIC can be positioned in any direction with respect to the waveguide 21, providing a high degree of freedom in designing the device configuration. The parts necessary for this purpose are simple, consisting of the insulator 24 that supports the center conductor 22' and the lid 25 that presses it down, and no special electrical consideration or precise machining precision is required. Nevertheless, there are no large propagation discontinuities in TEM propagation, and very excellent propagation performance can be expected. Furthermore, since the output end of the coaxial line can be separated from the conductor of the waveguide 21 portion, the grounding of the dielectric substrate 28 of the MIC can be ensured. That is, in the case of the conventional example shown in FIG. 1, the method of connecting the outer conductor to the ground electrode and the coaxial portion is generally by pressure bonding or by using a conductive adhesive, which is not a reliable method. However, in the case of FIG. 2a, for example, a hole is made in the chassis 21'' below the connection between the center conductor 22' and the microstrip line 29, and the ground electrode 30 and the chassis, that is, the coaxial outer conductor 26 are connected by soldering or the like. The output end can be reliably connected.

Next, other embodiments of the present invention will be described with reference to the drawings.

FIG. 3 shows a waveguide in another embodiment of the present invention.
FIG. 3 is a cross-sectional view of the main parts of the stripline converter. In FIG. 3, parts given the same numbers as in FIG. 2 are parts having the same functions as in FIG. 2. In FIG. 3, 40 is a cylindrical conductor inserted closely between the insulator 24 and the coaxial outer conductor portion, and this cylindrical conductor 40 acts as the outer conductor of the coaxial line. A ground electrode 30 of the dielectric substrate 28 of the MIC is connected to the output end. The connection between the ground electrode 30 of the MIC and the outer conductor 40 can be made very easy and reliable by using solder 41 or the like. Practically speaking, the MIC is held from a waveguide or another housing using a separate support fitting. By changing the length of the cylindrical outer conductor 40, the position of the output end can be easily adjusted. Also, the dielectric substrate 2 of the MIC
8 can be connected at any angle rotated about the axis of the coaxial line.

Effects of the Invention Because the present invention has a structure of the outer surface of the waveguide conductor and a TEM transmission line consisting of the lid of the conductor,
A waveguide-stripline converter that can minimize TEM mode discontinuities can be realized by very simple means. Further, the output end of the coaxial portion can be easily provided in any direction and position along the external shape of the waveguide. This effect provides a high degree of freedom in the design of devices, and when connected to a MIC, excellent connection performance can be easily obtained, resulting in extremely excellent effects such as ease of mass production of microwave devices.

[Brief explanation of drawings]

FIG. 1 is a sectional view of the main part of a conventional waveguide-stripline converter, and FIGS. 2a and 2b are cross-sections of the main part of a waveguide-stripline converter according to an embodiment of the present invention. FIG. 3 is a sectional view of the main part of another embodiment of the present invention. 21... Waveguide, 22... Probe, 24...
Insulator, 25... conductor lid, 22'... center conductor, 40... cylindrical conductor, 28... dielectric substrate.

Claims (1)

[Claims] 1. A groove is provided on the outer surface of a conductor constituting a waveguide, and a TEM transmission line is formed by a cover body of the conductor having a groove opposite to the groove and the conductor constituting the waveguide. The above conductor is part or all of the outer conductor and is connected to the probe that extracts the electromagnetic field inside the waveguide.
A waveguide characterized in that the center conductor is a TEM transmission line, and the center conductor is held by an insulator filled in the TEM transmission line.
TEM mode converter. 2. The waveguide-TEM mode converter according to claim 1, characterized in that a cylindrical conductor is provided between the outer conductor and the insulator of the TEM transmission line.