JPH0432801Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The present invention is a corner waveguide circuit used in a bent part of an oversized transmission waveguide for transmitting electromagnetic waves in the microwave band or millimeter wave band. It is related to.

[Conventional technology]

In order to reduce loss in the transmission of electromagnetic waves in the microwave band or millimeter wave band, oversized transmission waveguides are often used.

However, in oversized transmission waveguides,
If a corner waveguide is inserted directly into the bend, the amplitude frequency characteristics will deteriorate due to impedance mismatch and generation of unnecessary electromagnetic field modes.

For example, Figure 4 shows the amplitude frequency characteristics of around 136 GHz when tapered waveguides are connected to both ends of a corner waveguide with a rectangular diameter of 22.9 mm in major axis and 12.7 mm in minor axis to transmit electromagnetic waves. be. As can be seen from this figure, ripples occur in the amplitude frequency characteristics.

Therefore, when bending an oversized transmission waveguide, conventionally a corner waveguide circuit is used in which tapered waveguides 5 and 6 are connected to both ends of a corner waveguide 4 in the fundamental mode, as shown in FIG. was. That is,
The oversized transmission waveguide is once converted to the fundamental wave mode using the tapered waveguide 5, and the corner waveguide 4 of the fundamental mode forms a bent part, and then the tapered waveguide 6 is used again to convert the oversized transmission waveguide into the fundamental wave mode. It was converted into a transmission waveguide.

[Problem that the invention attempts to solve]

However, since this conventional corner waveguide has a complicated circuit configuration in which a tapered waveguide and a fundamental wave corner waveguide are connected, the amount of attenuation of transmitted electromagnetic waves is large. Furthermore, the tapered waveguides provided at both ends of the corner waveguide are difficult to manufacture and are therefore very expensive.

[Means for solving problems]

The present invention has been developed in view of the above problems, and is a straight line oversized transmission with a length of more than 1,000 times the wavelength of the input electromagnetic wave at both ends of a corner waveguide having the same diameter as the oversized transmission waveguide. A waveguide is connected to the waveguide.

[Effect]

The generation of unnecessary electromagnetic field modes and impedance mismatch can be suppressed without increasing the amount of attenuation.

〔Example〕

Hereinafter, the present invention will be described in detail along with examples.

FIG. 1 is a longitudinal sectional view showing an embodiment of the present invention. The corner waveguide circuit of this embodiment is an oversized transmission waveguide whose diameter is rectangular with a major diameter of 22.9 mm and a minor diameter of 12.7 mm. It is used for curved parts.

The corner waveguide 1 has a reflection plate at the corner, and the diameter at both ends is the same as the oversized transmission waveguide.
It is rectangular with a width of 22.9 mm and a short axis of 12.7 mm. Straight oversized transmission waveguides 2 and 3 having the same diameter as the corner waveguide 1 are connected to both ends of the corner waveguide 1 . Both straight oversized transmission waveguides 2 and 3 have a length of 2 m,
This length corresponds to approximately 1,000 times the wavelength of the input electromagnetic wave.

FIG. 2 is a diagram showing the amplitude frequency characteristics of the corner waveguide circuit of the present example. Specifically, tapered waveguides that convert between the oversize mode and the fundamental mode are connected to both ends of straight oversized transmission waveguides 2 and 3, and a rectangular waveguide with a major axis of 2.032 mm and a minor axis of 1.016 mm is used. This shows the amplitude frequency characteristics around 136 GHz when electromagnetic waves are transmitted from a certain fundamental mode transmission waveguide.
It can be seen that compared to the amplitude frequency characteristics shown in FIG. 4, ripples are very small and good characteristics are shown.

FIG. 3 is a characteristic diagram showing the relationship between the length of the linear oversized transmission waveguides 2 and 3 and the ripple size of this embodiment. When the length of the straight oversized transmission waveguides 2 and 3 is 2 m, that is, approximately 1,000 times the wavelength of the electromagnetic wave, the amount of ripple is approximately 10 minutes compared to when the straight oversized transmission waveguides 2 and 3 are not connected. 1, at which point it is almost saturated.

Note that straight oversized transmission waveguides include, of course, oversized transmission waveguides that have no bends in the length direction in appearance, but also broadly refer to those that do not cause mode changes in electromagnetic waves. Yes, the oversized waveguide in this range is a straight oversized transmission waveguide.

[Effect of idea]

As explained above, according to the corner waveguide circuit of the present invention, a straight line oversized transmission with a length of more than 1000 times the wavelength of the input electromagnetic wave is provided at both ends of the corner waveguide having the same diameter as the oversized transmission waveguide. Since a waveguide is connected, it is possible to suppress the generation of unnecessary electromagnetic field modes and impedance mismatch without increasing the amount of attenuation, and it is possible to have extremely good amplitude frequency characteristics. Furthermore, since a tapered waveguide is not required, it has the advantage that it can be provided at low cost.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional view showing an embodiment of the present invention, Fig. 2 is an amplitude frequency characteristic diagram of the embodiment of Fig. 1, and Fig. 3 is the length of the straight oversized transmission waveguide of the embodiment of Fig. 1. Figure 4 is an amplitude-frequency characteristic diagram of a conventional corner waveguide with the same diameter as the oversized transmission waveguide.
FIG. 5 is a longitudinal sectional view showing an example of a corner waveguide circuit used in a conventional oversized transmission waveguide. 1... Oversized corner waveguide, 2, 3...
Straight oversized transmission waveguide.

Claims (1)

[Scope of utility model registration request] In a corner waveguide circuit used for the curved part of an oversized transmission waveguide, a straight line with a length of at least 1,000 times the wavelength of the input electromagnetic wave is installed at both ends of the corner waveguide that has the same diameter as the oversized transmission waveguide. Corner waveguide circuit with oversized transmission waveguides connected.