JPS6013563B2 - variable power divider - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a variable power divider mainly used in the microwave band to the millimeter wave band, and in particular, the present invention relates to a variable power divider that is used mainly in the microwave band to the millimeter wave band. This invention relates to a variable power divider that can be divided into two output terminals.

Recently, phased array antennas, which can achieve desired directivity or change directivity by changing the excitation amplitude and excitation phase of some radiating elements, are often used.

In this case, a variable power divider capable of dividing electromagnetic wave power (hereinafter simply referred to as power) to each radiating element at an arbitrary ratio is required as a feeding system element. An example of a conventional variable power divider using a waveguide in the microwave band or millimeter wave band is shown in FIG. In the figure, 1 is a circular waveguide, 2 is an input terminal, 3A, 38
are output terminals orthogonal to each other, 4, 4A, 4B are coupling holes,
5 is a dielectric plate phase shifter, 6 is the central axis of the circular waveguide, and arrow 7 is
and 8 and 9 indicate the direction and magnitude of polarization of input and output waves, respectively.

Here, the portion where the rectangular waveguide input and output terminals are attached to the circular waveguide via the coupling hole is usually called a polarization splitter, OMT, or the like. Briefly explaining its operating principle, an input wave input from the input terminal 2 with polarization shown by the arrow 7 passes through the circular waveguide 1 and passes through the dielectric plate phase shifter 5. Here, the dielectric constant and dimensions of this compact plate phase shifter are determined so that the phase changes by 1800 degrees at the operating frequency. Therefore, by rotating this dielectric plate phase shifter 5 around the central axis 6, the polarization direction of the input wave can be freely changed. The polarized wave component (tentatively assumed to be the x-direction component in FIG. 1) of the wave whose polarization direction has been changed in this way, shown by the arrow 8, is transmitted to the output terminal 3A via the coupling hole 4A, and the polarized wave component shown by the arrow 9, All wave components (referred to as y-direction components) can be taken out to the output terminal 3B' via 4B. In other words, due to the rotation of the dielectric plate phase shifter 5, the output terminal 3
The power ratio of the output waves A and 38 can be changed arbitrarily. Although the case where a dielectric plate phase shifter is used has been described here, a variable power divider can be similarly realized by using a phase shifter using ferrite instead. However, these variable power dividers have the following drawbacks.

{1} Since there is a dielectric or ferrite in the waveguide 1 through which radio waves pass, loss is large and the matching part for improving reflection characteristics becomes complicated. ■Dielectrics, ferrites, etc. have frequency characteristics, and power distribution characteristics vary greatly depending on frequency. t3} derivatives and ferrites have characteristics that change depending on temperature, so the usable temperature range is narrow. Therefore, in order to rotate the polarization of the input wave without using these dielectric plates or ferrite, the input terminals 2 shown in FIG. It is conceivable to rotate it around, but this also has the following disadvantages.

In other words, when configuring an array antenna feeding system using waveguides, etc., the waveguide systems on the input terminal side (assuming the antenna is a transmitting antenna, the transmitter side) and the output terminal side (also on the antenna element side) are complete. is fixed. Therefore, as described above, it is not possible to change the polarization direction by simply rotating the input terminal 2. In order to solve these drawbacks, the present invention does not use a phase shifter using a dielectric plate or ferrite, and it is necessary to move the waveguide system on the input terminal side (transmission device side) and output terminal side (antenna element side). The drawings will be described in detail below.

FIG. 2 shows an embodiment of the present invention, in which 10 is a connecting waveguide, 11 is a rotary joint (usually referred to as a rotary coupler), 12 is an input waveguide, and 13 is a rotary gap. , circular waveguide 1, input mode 2, and connection waveguide 1
It constitutes a Kawama Kusunoki wave excitation circuit.

Next, the operating principle of the present invention will be explained. Now, the rotary joint 11, the polarization splitter including the circular waveguide 1 and its input terminal 2, and the polarization splitter including the output terminals 3A and 38 are arranged so as to share the central axis 6, In addition, the input waveguide 12 is connected to a transmitting device (temporarily considered here as a variable power divider of a transmitting antenna system), and to an output terminal 3.
It is assumed that A and 3B are each fixed to the antenna element. Therefore, the polarization excitation circuit consisting of the circular waveguide 1, the polarization splitter including the input terminal 2, and the connecting waveguide 10 is independent of the transmitter and antenna system via the rotary rejoint 11 and the rotary gap 13. rotation is possible.
By rotating this part around the central axis 6, the direction of polarization within the circular waveguide 1 is rotated, and the output terminals 3A, 3
The output power to B changes. Examples of the rotary joint 11 described here include a TM using a rotationally symmetrical waveguide mode, a type rotary joint, a coaxial type rotary joint, and the like. FIG. 3 shows another embodiment of the present invention, in which 14 indicates a rectangular to circular conversion waveguide.

This rectangular circular conversion waveguide is rectangular TE. Circular TE from mode, . It has the function of converting into mode. The rest of the configuration is the same as in Figure 2, and the operating principle is the circular waveguide 1,
The polarization excitation circuit consisting of the rectangular circular conversion waveguide 14 and the connection waveguide 10 is rotated around the central axis 6 to change the power distributed to the output terminals 3A and 3B, and they are exactly the same. As explained above, according to the present invention, the input wave from the input waveguide 1 can be arbitrarily changed to the output states 3A and 3B by rotating only the polarization excitation circuit between the rotary joint 11 and the rotary gap 13. Power is distributed in the ratio of

In order to simplify the explanation above, the variable power divider has been considered as a transmitting antenna system, but it can also be considered as a receiving antenna system.

In addition, in Figures 2 and 3, the usable frequency band is determined by the band width of the waveguide being used, and although it cannot be used outside of that one band, it is also possible to use a rotary joint that can be used in other bands. It is clear that a variable power divider that can be used in multiple frequency bands can be realized by using a polarization splitter that can be used in multiple frequency bands. As is clear from the above, according to the present invention, a variable power divider with good electrical characteristics can be realized, which is suitable when the transmitting device side waveguide system and the antenna side waveguide system are fixed.

That is, since there is no dielectric plate or ferrite phase shifter in the radio wave path, loss is low and reflection characteristics are good, and the frequency characteristics are wide-band and have little change in characteristics with respect to temperature. Additionally, it has excellent power resistance characteristics. Because of the above-mentioned characteristics, it can be used not only as a feeder circuit element for phased array antennas as described above, but also as an input,
It can be widely applied to control output power and as a variable attenuator.

[Brief explanation of the drawing]

Figure 1 is a perspective view of a conventional variable power divider, Figures 2 and 3 are
The figures each show a side view of an embodiment of the invention. 1...Circular waveguide, 2...Input terminal,
3A, 38... Output terminal, 4A, 4B...
...Binding hole, 10... ... Connection waveguide, 11...
...・Rotary joint, 12. ... Input side waveguide, 13 ... Rotary gap, 14 ...
...Rectangular circular conversion waveguide. Power 1 figure Juice 2 figure Juice 5 figure

Claims (1)

[Scope of Claims] 1. A rotary joint, a polarization splitter including output terminals orthogonal to each other, and a circular waveguide at one end interposed between the rotary joint and the polarization splitter, which is connected to the polarization splitter through the rotary gear. A polarization excitation circuit is coupled to a polarization splitter, and the other end is coupled to a rotary joint to generate a radio wave having a polarization plane in a specific direction in the circular waveguide. A variable power divider characterized in that the wave generator and the circular waveguide share a central axis, and the polarization excitation circuit is rotatable about the central axis via a rotary joint and a rotary gap. 2. The variable power divider according to item 1, wherein the polarization excitation circuit is a polarization splitter including an input power terminal and a circular waveguide. 3. The variable power divider according to item 1, wherein the polarization excitation circuit is a rectangular circular waveguide.