JPS6340485B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a splitter that splits electromagnetic waves of the same polarization in two frequency bands into electromagnetic waves of each frequency band.

Here, for convenience, the frequencies of the two frequency bands are respectively referred to as _H and _L ( _H > _L ), and the frequency bands are distinguished by subscripts H and L.

First, a conventional duplexer shown in FIGS. 1 and 2 will be explained.

In Fig. 1, 1 is a main waveguide consisting of a rectangular waveguide 2 through which _{the H} and _L waves propagate, and a tapered waveguide 3 which completely reflects _{the L} wave and through which _{the H} wave passes; is a branch waveguide provided on a wide surface of the rectangular waveguide 2 of the main waveguide 1, 5 is a rectangular waveguide dedicated to _{the H} frequency band, 6 is a coupling hole provided in the rectangular waveguide 2, and 7 is a low-pass filter provided in the branch waveguide 4 that passes _{the L} wave and cuts off _{the H} wave, and this figure shows the case of a series resonant element.

FIG. 2 is a diagram showing a case where a branch waveguide 4 is provided on a narrow surface of the rectangular waveguide 2 of the main waveguide 1.

Now, the frequency _L ,
When _{the H} wave is introduced, _{the H} wave is passed through the low pass filter 7 without being coupled to the branch waveguide 4.
The signal propagates to the rectangular waveguide 5 dedicated to _{the H} frequency band. On the other hand, _{the L} wave forms an equivalent reflecting surface due to the shearing characteristics of the tapered waveguide 3, so it is completely reflected, and the position of the coupling hole 6 is reflected by the reflection formed by the tapered waveguide 3. By selecting an appropriate distance from the plane, the wave is branched into the branch waveguide 4 via the coupling hole 6.

In the conventional duplexer shown in FIG. 1, the coupling hole 6 produces a coupled wave with the transverse component of the magnetic field in the main waveguide 1. The coupled wave caused by the coupling hole 6 branches the current flowing in the axial direction across the wide surface of the main waveguide 1 . Therefore, even if the position of the coupling hole 6 is selected at an appropriate distance from the equivalent reflection surface of the tapered waveguide 3, there will be little reflection between the rectangular waveguide 2 and the branch waveguide 4 for the _L wave. The drawback was that the frequency band in which high-speed transmission was possible was narrow.

Further, in the conventional duplexer shown in FIG. 2, the coupling hole 6 generates a coupled wave using the component of the magnetic field in the main wave tube 1 in the direction of the tube axis. The voltage of the wave coupled by the coupling hole 6 is constant at the branch point, and current flows into the branch waveguide 4.
Therefore, if the position of the coupling hole 6 is selected at an appropriate distance from the equivalent reflection surface of the tapered waveguide 3, _{the L} wave can be transmitted between the rectangular waveguide 2 and the branched waveguide 4 with less reflection. The possible frequency bands are becoming wider.

However, it has the disadvantage that it cannot be constructed as a primary radiation system of an antenna, which requires multiple branching filters to be arranged side by side so that they touch each other on the narrow surface of the main wave tube 1 of the branching filter, due to space constraints. It was hot.

The present invention has been made to solve these drawbacks, and is to straddle the rectangular waveguide 2 and the tapered waveguide 3 of the main waveguide 1 in the tube axis direction, and to approach the narrow tube wall surface. Broadband demultiplexing characteristics can be obtained by providing coupling holes 6 on a wide tube wall surface, and a plurality of demultiplexers can be connected to each other on the narrow surface of the main wave tube 1 of the duplexer. The present invention provides a duplexer that can be configured by arranging them side by side.

An embodiment of the present invention shown in FIG. 3 will be described below.

In Figure 3, 1 is a main waveguide, 2 is a rectangular waveguide that propagates _H and _L waves, 3 is a tapered waveguide, and 4 is a rectangular waveguide that propagates H and L waves.
and 6 are branch waveguides provided on the wide tube wall surface, close to the narrow tube wall surface, straddling the rectangular waveguide 2 and the tapered waveguide 3 of the main waveguide 1 in the tube axis direction. A tube and a coupling hole, 5 is a rectangular waveguide dedicated to _{the H} frequency band, and 7 is a low-pass filter.

Now, passing through the center of the cross section of the rectangular waveguide 2,
The long side of the rectangular waveguide 2 is taken as 2a, and the short side is taken as 2b, and x and y coordinate axes are taken parallel to the long side and the short side, respectively.

The magnetic field component in the tube axis direction in TE ₁₀ mode is However, λg is expressed by the guide wavelength of the rectangular waveguide. In other words, the magnetic field in the tube axis direction is x=
It is minimum at 0 (i.e., the center of the long side), and x
= a (i.e., the short side tube wall surface). Therefore, by providing the coupling hole 6 long in the tube axis direction and close to the narrow tube wall surface, the main wave is transmitted to the branch waveguide 4. Coupling can be achieved by a magnetic field component in the tube axis direction of the tube 1.

Here, when _L and _H waves are introduced into the rectangular waveguide 2 of the main waveguide 1, the operating principle for _{the H} wave is the same as the conventional one. For _{the L} wave,
The position of the coupling hole 6 is between the rectangular waveguide 2 and the tapered waveguide 3.
Since it is provided astride the tapered waveguide 3, it can be shortened to an appropriate distance from the equivalent reflection surface formed by the tapered waveguide 3, so it can be connected to the branch waveguide 4 via the coupling hole 6 over a wide band with little reflection. transmission can be carried out.

As described above, according to the present invention, _{the L} wave can be transmitted over a wide band with little reflection between the rectangular waveguide 2 and the branch waveguide 4, and a plurality of splitters can be connected to the branch waveguide 4. It has the advantage that it can be arranged side by side so as to touch each other on the narrow surface of the main wave tube 1 of the wave device.

[Brief explanation of the drawing]

Figures 1 and 2 are diagrams showing conventional duplexers;
The figure shows an embodiment according to the present invention. In the figure, 1 is a main waveguide, 2 is a rectangular waveguide, 3 is a tapered waveguide, 4 is a branched waveguide, 5 is a waveguide dedicated to high frequency bands, 6 is a coupling hole, and 7 is a low-pass waveguide. It's a filter. In the drawings, the same or corresponding parts are designated by the same reference numerals.

Claims (1)

[Claims] 1. From electromagnetic waves of the same polarization in two frequency bands propagating through a main wave tube having a straight section and a tapered section, electromagnetic waves in a low frequency band are transferred to a branch guide connected through a coupling hole provided in the main wave tube. In a duplexer that separates waves into a wave tube section, the cross-sectional shape of the main wave tube is rectangular, and the main wave tube is straddled in the tube axis direction of the straight section and the tapered section, and approaches the narrower tube wall surface. The coupling hole and the branch waveguide section are provided on the wider tube wall surface, and the long side direction of the opening surface of the branch waveguide section is located between the straight section and the tapered section of the main waveguide. A duplexer characterized by being aligned with the tube axis direction.