JPH0540465Y2 - - Google Patents

Description

[Detailed Description of the Invention] "Industrial Application Field" This invention relates to an antenna device for measuring horizontal polarization direction, which is used to measure the arrival direction of horizontally polarized radio waves.

"Prior Art" When measuring the direction of arrival of radio waves, the radio waves that are targeted are generally vertically polarized waves. To measure the arrival direction of vertically polarized radio waves, rotate the directional characteristic of an antenna with a figure-8 directional characteristic, find the direction in which the received radio wave has the minimum value, and then convert the output of the omnidirectional antenna into a figure-8 directional characteristic. The antenna output is used to determine from which direction the radio waves are coming.

It is conceivable to measure the direction of arrival of horizontally polarized radio waves in the same manner as in the case of conventional vertically polarized radio waves. A horizontal doublet antenna with a length of one wavelength or less is known as an antenna that exhibits a figure-eight directivity characteristic for horizontally polarized radio waves. However, there is no known antenna that exhibits omnidirectionality for horizontally polarized radio waves, and therefore it is not possible to determine the direction of arrival of horizontally polarized radio waves by combining the figure-eight directional characteristic and the omnidirectional characteristic.

The purpose of this invention is to provide an antenna device that can measure the direction of arrival of horizontally polarized radio waves.

``Means for solving the problem'' According to this invention, first and second horizontal doublet antennas each having a length of one wavelength or less are arranged almost perpendicularly, and the first and second horizontal doublet antennas are The output is synthesized by a figure-of-eight directional synthesizer,
An output with a figure-eight directional pattern is obtained in the horizontal plane. Further, the respective outputs of the first and second horizontal doublet antennas are combined in an omnidirectional combiner with their phases shifted appropriately, for example, by about 90 degrees, so that an almost omnidirectional output is produced in the horizontal plane. can get. At the time of sense determination, the output of the figure-8 directional combiner and the output of the omnidirectional combiner can be combined by the sense combiner. Furthermore, the figure-8 directional pattern can be rotated.

"First Embodiment" FIG. 1 shows an example of an antenna device for measuring horizontal polarization direction according to this invention. According to this invention, a horizontal doublet antenna 11,1 having a length of one wavelength or less
2 are arranged approximately perpendicular to each other. These horizontal doublet antennas 11 and 12 are respectively connected to the respective primary sides of rotary transformers 13 and 14, and the respective secondary sides of these rotary transformers 13 and 14 are respectively connected to the distributor 1.
5 and 16. The distribution outputs of each of the dividers 15 and 16 are combined by a figure-8 directivity combiner 17, and the phase of the other distribution output of one divider 16 is shifted by a phase shifter 18, and the output of the other divider 16 is shifted in phase with the output of the other divider 16. The other distribution output of the distributor 15 and the omnidirectional combiner 1
9 is synthesized. The output of the figure-8 directivity synthesizer 17 is sent to the reception indicator 22 through the sense synthesizer 21.
supplied to The output of the omnidirectional combiner 19 can be supplied to the sense combiner 21 through the sense determination switch 23, and the outputs of the combiners 17 and 19 are combined by the combiner 21 and sent to the reception indicator. 22. The primary sides of the horizontal doublet antennas 11, 12 and the rotary transformers 13, 14 are rotated in a horizontal plane by a motor 24.

Horizontal doublet antenna 2 as shown in Figure 2.
The directional characteristics of No. 5 in the horizontal plane show a figure-8 directional characteristic in the horizontal plane when the length l of the antenna 25 is one wavelength λ or less, the maximum sensitivity direction is perpendicular to the antenna 25, and the minimum sensitivity direction is This is the length direction of the antenna 25. As shown by + and - in FIG. 2, the phase differs by 180 degrees between one side and the other side of the antenna 25.

Therefore, the directivity characteristics 26, 27 of the orthogonally arranged horizontal doublet antennas 11, 12 in FIG.
(Fig. 3), the antenna 11,
The figure 8 characteristic 28 is oriented at 45 degrees with respect to 12. When the directional characteristics 26 and 27 are differentially combined, a figure-8 characteristic 29 is obtained which is shifted by 90 degrees from the figure-8 characteristic 28. The figure 8 directivity combiner 17 in FIG.
The outputs of 1 and 12 are summarily or differentially combined to obtain a combined output with a figure-8 directivity pattern 28 or 29, as shown in FIG.

When the output of the directional characteristic 27 of one horizontal doublet antenna 12 is shifted in phase by 90 degrees and combined with the output of the other horizontal doublet antenna 11, the directional characteristic of the combined output becomes omnidirectional as shown in Figure 4. The gender becomes 31. When this omnidirectional pattern 31 and the figure-8 directional pattern 28 of FIG. 3 are combined, as shown in FIG.
becomes.

Therefore, in the configuration shown in FIG. 1, by rotating the horizontal doublet antennas 11 and 12 in the horizontal plane with the sense determination switch 23 turned off and rotating the figure-eight directivity pattern 28, the horizontally polarized radio waves can be adjusted. The direction of minimum sensitivity shifted by 90 degrees with respect to the direction of arrival can be measured by the reception indicator 22 in the same manner as a conventional vertical polarization direction finder. Next, the amount of phase shift of the phase shifter 18 is set to 90 degrees, the sense determining switch 23 is turned on, and it is possible to measure from which side the radio waves are arriving in the direction of minimum sensitivity. In this example, the phase shifter 18 gave a phase shift of 90 degrees, but for example, when a phase shift of 45 degrees is given, the directional characteristic obtained by combining the outputs of the antennas 11 and 12 is approximately square as shown in FIG. The characteristic is 33. Since it is sufficient to know which direction the sensing direction is, the phase shift amount of the phase shifter 18 only needs to be about 45 degrees or more.

"Second Embodiment" In the above description, the horizontal doublet antennas 11 and 12 are rotated in the horizontal plane to rotate the figure-eight directivity pattern 28, but this horizontal doublet antenna 11 and 12
It is also possible to have a plurality of sets fixedly arranged and rotate the figure-8 directivity pattern by switching operations. For example, the 6th
As shown in the figure, orthogonal horizontal doublet antenna 1
1 and 12 (hereinafter referred to as antenna set 34) are arranged on the same circle 35 at equal intervals, for example eight. The horizontal doublet antennas 11 of the eight antenna sets 34 are designated as X ₁ , X ₂ . . . X ₈ , and the horizontal doublet antennas ₁₂ are designated as Y ₁ , Y ₂ . The length direction of the eight-shaped directivity pattern 28 of each set of antennas 34 is arranged along the circumferential direction of the antenna array circle 35. The length direction of the figure-8 directional pattern 28 may be arranged in the radiation direction with respect to the antenna array circle 35. These antenna sets 34 are each connected to a switching device 36. Switching device 3
A control signal is inputted from the terminal 37 to the terminal 38, and the output of each set of antennas 34 is sequentially switched to the terminal 38.
_x , 38 _y .

As shown in FIG. 8, in the switching device 36,
The horizontal doublet antennas X ₁ , X _{2 . .} .
connection is repeated. In synchronization with this switching, the horizontal doublet antennas _{Y 1} , Y _{2 ,} . The processing for each output of the distributors 15 and 16 is performed in the same manner as in the case of FIG. In addition, the changeover switch 39 _x ,
An electronic switch is used as _{the 39y} .

The figure-8 directivity combiner 17 outputs an output at a level corresponding to the direction of the figure-8 directivity 28 of each antenna set 34 and the direction of the arriving radio wave.
They are taken out sequentially by switching between 9 _x and 39 _y . For example, if a horizontally polarized radio wave arrives from the 0° direction as shown by the arrow 41 in FIG. 6, the output of the combiner ₁₇ will be _zero as shown in FIG. Therefore, the combined output of antennas X ₂ and Y ₂ reaches a certain level, and the combined output of antennas X ₃ and Y ₃ reaches a maximum. The envelope of the output of the synthesizer 17 is similar to the output of the synthesizer 17 in FIG. Similarly, the sense determination switch 23
The output of the omnidirectional combiner 19 when turned on is as shown in FIG. 9B, and its envelope is similar to the output of the combiner 19 in FIG.

It is obvious that if the signals from the antennas are combined at high frequencies, the directional characteristics shown in Figures 2 to 5 and Figure 7 may not be obtained. If they are combined, the directivity shown in the figure can be obtained.

``Effects of the invention'' As described above, according to the antenna device of this invention, the figure-8 directional characteristic and the omnidirectional characteristic are created by combining the outputs of two horizontal doublet antennas.
This makes it possible to measure the direction of arrival of horizontally polarized radio waves. Since two horizontal doublet antennas are used, as can be seen from Figure 3, the antenna gain is approximately lower than that of one horizontal doublet antenna.
It becomes 3dB higher. As shown in FIG. 6, when multiple antennas are used, a mechanical rotation mechanism is not required, and the diameter of the large-diameter antenna array circle 35 can be set to, for example, 10 m, resulting in high measurement accuracy and low disturbance errors. You can get smaller ones.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing an example of an antenna device for horizontal polarization direction measurement according to this invention, Fig. 2 is a directional characteristic diagram of a horizontal doublet antenna, and Fig. 3 is a composite directional characteristic diagram of orthogonal horizontal doublet antennas. Figure 4 is a directional characteristic diagram that combines the two outputs of an orthogonal horizontal doublet antenna with a phase shift of 90 degrees.
Figure 5 is a directional characteristic diagram that combines the composite directional characteristics shown in Figures 3 and 4, Figure 6 is a diagram of a plurality of orthogonal horizontal doublet antennas arranged, and Figure 7 is a diagram of orthogonal horizontal doublet antennas. A directional characteristic diagram in which two outputs are synthesized with a 45-degree phase shift, Figure 8 is a diagram showing the configuration for switching the output of each antenna shown in Figure 6 and combining the outputs, Figure 9 A and B are diagrams showing examples of respective outputs of combiners 17 and 19 in FIG. 8. 11, 12, X ₁ to X ₈ , Y ₁ to _{Y 8} ... Horizontal doublet antenna, 13, 14 ... Rotating transformer, 1
5, 16...Distributor, 17...8-shaped directional synthesizer, 18...Phase shifter, 19...Omnidirectional synthesizer, 21...Sense synthesizer, 22...Reception indicator , 23...Sense determination switch, 24...Motor, 36...Switching device.

Claims (1)

[Claims for Utility Model Registration] First and second horizontal doublet antennas having lengths of one wavelength or less and arranged substantially orthogonally with their centers substantially coincident; A figure-8 directivity synthesizer that combines the outputs without shifting their relative phases to obtain a figure-8 directivity output in the horizontal plane, and a figure-8 directivity synthesizer that combines the outputs without shifting their relative phases, and a figure-8 directivity synthesizer that combines the outputs of the outputs without shifting their relative phases. An omnidirectional synthesizer that obtains an almost omnidirectional output in the horizontal plane by synthesizing with a difference of about 135 degrees, and the outputs of the figure-8-shaped directional synthesizer and the omnidirectional synthesizer when determining the sense. An antenna device for horizontal polarization azimuth measurement, comprising: a sense synthesizer for synthesizing the signals; and a rotation means for rotating the figure-eight directivity.