JP2009206604A - Radome structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To set an optional frequency bandwidth even though a radome structure is a simple structure and to appropriately adjust transmission frequency bandwidth even after the radome structure is manufactured. <P>SOLUTION: An antenna is supported on a plane plate, a radome plate is provided in the irradiation direction of the antenna, and a half-wavelength resonator is formed from the radome plate and the plane plate. Then, the radome plate includes a polarizing plate in at least a portion thereof. Consequently, transmission frequency bandwidth in the radome plate is configured so as to be adjustable by an angle provided between a polarizing direction irradiated from the antenna and a polarizing direction of the polarizing plate. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a radome structure used for protecting an antenna supported by a flat plate.

In general, a radome is used in a wireless communication device or a radar device in order to prevent the influence of wind and rain.
However, when a radome is installed, there is a problem that the radiation output or the reception sensitivity is reduced due to reflection on the radome plate. In order to solve this problem, a half-wave resonator structure in which the transmittance of the radiated electromagnetic wave is set to 1 by setting the distance from the antenna to the radome plate to a half wavelength, or the radome plate itself having a half-wave thickness of the radome plate Has a half-wave resonator.

  A radome having a half-wave resonator has a transmission frequency band centered on the design frequency. This radome structure can be used as a band-pass filter using this characteristic. The use of a radome as a bandpass filter has an advantage that simplifies and reduces the size of the transmission or receiver circuit because the ratio of the filter circuit in the transceiver is large.

  However, in a general radome structure in which a half-wave resonator is formed by an antenna support substrate and a radome plate, the transmission frequency band is determined by the radome material. This is because the half width of the transmission frequency of the half-wave resonator is determined by the Q value of the resonator, and the Q value is determined by the reflectance of the reflector of the resonator.

For this reason, an arbitrary frequency bandwidth could not be set with a radome having a half-wavelength resonator structure. Therefore, a radome structure having a function as a band-pass filter has been proposed by laminating a radome plate having a sandwich structure (see, for example, Patent Document 1).
The structure of Patent Document 1 realizes a desired transmission frequency band by laminating a plurality of sandwich structure radome plates each having a different resonance frequency.
Japanese Patent Laying-Open No. 2003-229712 (page 8, FIG. 5)

  However, the first problem of the laminated radome structure as shown in Patent Document 1 described above is that the structure is complicated and the design is difficult. In order to realize a wider transmission frequency band than a single-layer radome structure, in principle, a large number of radome plates must be laminated. For this reason, it is necessary to set the transmission center frequency for each radome plate in the design, and to consider the interaction between layers due to the influence of reflected waves from other radome plates. There are many difficult points.

  The second problem of the laminated radome structure is that it is difficult to adjust the transmission frequency bandwidth after fabrication. When a manufacturing error occurs in the film thickness of the radome plate, it is difficult to adjust the transmission frequency band after manufacturing. In particular, in the ultra-short wavelength region such as the millimeter wave band, for example, a manufacturing error of about 1 mm at 60 GHz corresponds to a quarter wavelength in the air, and the equivalent wavelength is further shortened in the dielectric substrate. The change in the frequency band due to increases. Depending on the communication method, the frequency bandwidth used may be changed depending on the communication environment. In order to effectively use the frequency band, it is necessary to be able to change the transmission frequency bandwidth appropriately according to the frequency bandwidth to be used. For this reason, adjustment of the frequency band after manufacture is needed.

  The present invention has been made in view of such circumstances, and it is possible to set an arbitrary frequency bandwidth while making the radome structure simple, and to adjust the transmission frequency bandwidth appropriately even after fabrication. An object of the present invention is to provide a radome structure that can be used.

  In order to achieve such an object, the radome structure according to the present invention has an antenna supported by a plane plate, a radome plate is provided in the radiation direction of the antenna, and a half-wave resonator is formed by the radome plate and the plane plate. A radome structure formed, wherein the radome plate includes at least a part of a polarizing plate, and is transmitted through the radome plate according to an angle formed by a polarization direction radiated from the antenna and a polarization direction of the polarizing plate. The frequency bandwidth can be adjusted.

  As described above, according to the present invention, an arbitrary frequency bandwidth can be set while the radome structure is a simple structure. In addition, the transmission frequency bandwidth can be adjusted as appropriate even after fabrication.

Next, an embodiment to which the radome structure according to the present invention is applied will be described in detail with reference to the drawings.
Each embodiment of the present invention exemplifies a suitable one that realizes a radome structure capable of adjusting a transmission frequency bandwidth while having a simple structure.

[First Embodiment]
First, an outline of the first embodiment of the present invention will be described.
In the present embodiment, as shown in FIG. 1, a half-wave resonator is configured by the flat substrate 101 and the polarizing plate 103, and the distance between the flat substrate 101 and the polarizing plate 103 is a half wavelength of the center frequency of the transmission frequency band. Corresponds to minutes. The polarization direction of the polarizing plate 103 is set to an angle formed with respect to the polarization direction of the radiated electromagnetic wave 105 from the antenna.

Here, the reflectivity of the radiated electromagnetic wave 105 in the polarizing plate 103 is determined by the angle formed by the polarization direction of the polarizing plate 103 and the polarization direction of the radiated electromagnetic wave 105, and the Q value in the half-wave resonator is determined. For this reason, by adjusting the angle between the polarization direction radiated from the antenna and the polarization direction of the polarizing plate 103, the reflectance of the radiated electromagnetic wave 105 in the polarizing plate 103 can be adjusted, and as a result, the light passes through the radome 10. The frequency bandwidth can be adjusted.
As described above, the frequency bandwidth can be determined only by setting the polarization direction of the polarizing plate 103 while the design is very easy with the single layer structure.

Next, the configuration of each embodiment of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a cross-sectional view schematically showing a first embodiment of the present invention. The illustrated radome structure 10 includes a planar substrate 101, an antenna 102, a polarizing plate 103, and a side wall 104. The upper part of the antenna 102 supported by the flat substrate 101 in the radial direction is covered with a radome plate constituted by the polarizing plate 103. The lateral direction of the antenna 102 is closed by a side wall 104.

  The flat substrate 101 and the polarizing plate 103 constitute a half-wave resonator, and the distance between the flat substrate 101 and the polarizing plate 103 corresponds to the half wavelength of the center frequency of the transmission frequency band. The distance between the flat substrate 101 and the polarizing plate 103 is preferably a half wavelength, but may be a natural number multiple of the half wavelength.

  As described above, in this embodiment, the radome structure is configured such that the distance between the flat substrate 101 and the radome plate (polarizing plate 103) is a natural number multiple of the half wavelength. A half-wave resonator is formed by the radome plate.

  The polarization direction of the polarizing plate 103 is set to an angle formed with respect to the polarization direction of the radiated electromagnetic wave 105 from the antenna. The reflectivity of the radiated electromagnetic wave 105 in the polarizing plate 103 is determined by the angle formed by the polarization direction of the polarizing plate 103 and the polarization direction of the radiated electromagnetic wave 105, and the Q value in the half-wave resonator is determined. Bandwidth is determined.

  In order to increase the effect of controlling the transmission frequency bandwidth by the polarizing plate 103, it is desirable to totally reflect on the planar substrate 101, and a structure in which metal is attached to the entire surface of the substrate or the back surface is desirable. As the polarizing plate 103, for example, a wire grid polarizer in which metal wires are arranged at equal intervals in the air can be used.

  With the above configuration, a radome structure having a function of adjusting the transmission bandwidth can be realized while the radome plate is a single layer. Since it has a single layer structure and the frequency bandwidth can be determined only by setting the polarization direction of the polarizing plate 103, the design is very easy. The frequency bandwidth can also be modified after the radome structure is fabricated.

FIG. 2 shows the control effect of the transmission frequency bandwidth of the present invention. A half-wave resonator was formed with an antenna support substrate and a polarizing plate at a center frequency of 57 GHz. The distance between the antenna support substrate and the polarizing plate was 2.6 mm. FIG. 2 shows the frequency change of the radiated electromagnetic wave gain from the plane substrate to the vertical upper side when the angle formed by the polarization direction of the polarizing plate and the polarization direction of the radiated electromagnetic wave is changed from 5 ° to 30 ° under the above conditions. Is shown.
At an angle of 0 °, the electromagnetic wave is completely blocked by the polarizing plate and is totally transmitted at 90 °. The frequency band is controlled from 0.4 GHz to 2.1 GHz at an angle of 5 ° to 30 ° of the polarizing plate, and a sufficient effect is recognized.

  In order to determine the reflectance of the radome plate 103, the angle between the polarization direction of the radiated electromagnetic wave 105 and the polarization direction of the polarizing plate 103 changes not by adjusting the angle of the polarizing plate 103 but also by rotating the antenna 101. Therefore, the same effect can be obtained.

[Second Embodiment]
Next, a second embodiment of the present invention will be described.
FIG. 3 is a cross-sectional view schematically showing a second embodiment of the present invention. 1 is configured by replacing the polarizing plate 103 with a radome plate 203 made of metal or a radio wave absorber. In the radome plate 203, the main beam passage region 206 of the radiated electromagnetic wave 105 from the antenna 102 is opened and replaced with a polarizing plate 207. Both sides of the antenna 102 are closed by side walls 104. The material constituting the side wall 104 may be a radio wave absorber similar to the radome plate 203.
The polarization direction of the polarizing plate 207 is set to an angle formed with respect to the polarization direction of the radiated electromagnetic wave 105 from the antenna, as in the first embodiment.

  With the above structure, the effect of the first embodiment can be obtained, and the radiation from the antenna 102 in the unnecessary direction can be suppressed. Similar to the first embodiment, the same effect can be obtained by rotating the antenna 102.

[Third Embodiment]
Next, a third embodiment of the present invention will be described.
FIG. 4 is a cross-sectional view schematically showing a third embodiment of the present invention. It is configured by adding a shielding plate 307 made of metal or a radio wave absorber to the configuration of FIG. The shielding plate 307 is installed so as to cover the lower side of the polarizing plate 103, and the main beam passage region 306 of the electromagnetic wave 105 radiated from the antenna 102 is opened. The aperture portion is provided with a diaphragm mechanism 308 capable of adjusting the aperture area. There is no particular restriction on the structure of the diaphragm mechanism 308.

  FIG. 5 is a structural view of the shielding plate 307 as viewed from above, but the diaphragm structure 308 can be realized by using, for example, an iris diaphragm as shown in the figure. By providing the aperture mechanism 308, the effect of the second embodiment can be obtained, and the beam width to be passed can be selected. Naturally, it is possible to block radio waves. The shielding plate 307 may cover the upper side of the polarizing plate 103.

[Fourth Embodiment]
Next, a fourth embodiment of the present invention will be described.
FIG. 6 is a cross-sectional view schematically showing a fourth embodiment of the present invention. In the configuration of FIG. 1, a rotating mechanism 406 as shown in FIG. 6 is configured at a connection portion between the side wall 104 and the flat substrate 101. The rotation mechanism 406 does not necessarily have a structure as shown in FIG. 6, and it is sufficient that the polarizing plate 103 or the planar substrate 101 can rotate while maintaining the connection between the side wall 104 and the planar substrate 101.
Thereby, since the polarization direction of the polarizing plate 103 or the radiated electromagnetic wave 105 can be continuously adjusted, the frequency bandwidth can be appropriately adjusted while obtaining the effect of the first usage pattern.

[Fifth Embodiment]
Next, a fifth embodiment of the present invention will be described.
FIG. 7 is a cross-sectional view schematically showing a fifth embodiment of the present invention. In the configuration of FIG. 6, a rotation mechanism 406 is formed at a connection portion between the polarizing plate 103 and the side wall 104. Thereby, an effect equivalent to that of the fourth embodiment can be obtained.

[Sixth Embodiment]
Next, a sixth embodiment of the present invention will be described.
FIG. 8 is a cross-sectional view schematically showing a sixth embodiment of the present invention. In the sixth embodiment, the polarizing plate 103 in the configuration of FIG. 1 is replaced with a radome plate 506 made of a dielectric material.

  The upper surface of the radome plate 506 forms a striped structure of the exposed portion of the radome plate 506 and the metal portion 507 by metal patterning. A wire grid polarizing plate is formed by this striped structure, and the same effect as that of the polarizing plate 103 in the first embodiment can be obtained.

  The radome plate 506 may be made of the same dielectric material as the side wall 104. The metal patterning surface may be the lower surface instead of the upper surface of the radome plate 506. With the above configuration, it is possible to easily produce the same effect as the first usage pattern.

[Seventh Embodiment]
Next, a seventh embodiment of the present invention will be described.
FIG. 9 is a cross-sectional view schematically showing a seventh embodiment of the present invention. In the configuration of FIG. 8, the main beam passage region 608 of the electromagnetic wave 105 radiated from the antenna 102 forms a polarizing plate 609 with a metal pattern on the radome plate 506, and the other portions are coated with metal over the entire surface. Yes. As a result, the same effects as those of the second embodiment can be obtained, and the production is simplified.

[Eighth Embodiment]
Next, an eighth embodiment of the present invention will be described.
FIG. 10 is a cross-sectional view schematically showing an eighth embodiment of the present invention. In the configuration of FIG. 1, the polarizing plate 103 is replaced with a liquid crystal polarizing plate 706. A control circuit 707 is connected to the outside of the liquid crystal polarizing plate, and the direction of the applied electric field from the outside to the liquid crystal polarizing plate can be controlled. Thereby, the polarization direction of the liquid crystal can be controlled from the outside. This structure is applicable not only to the first embodiment but also to each of the embodiments described above. In particular, the above-described third to third embodiments can be realized by simply replacing the polarizing plate.

[Ninth Embodiment]
Next, a ninth embodiment of the present invention will be described.
FIG. 11 is a cross-sectional view schematically showing a ninth embodiment of the present invention. Four radome structures 11 to 14 which are the structure of FIG. 1 are arranged side by side. Actually, the number is not limited to four, and any number may be arranged. Thereby, a high gain can be realized. Moreover, since the output of 12-14 is maintained also when the radome 11 is damaged and transmission output falls, the influence given to communication can be made small.

  The structure as the ninth embodiment can be arranged not only in a horizontal row but also in a vertical direction to form a two-dimensional array. Further, the present embodiment can be applied by replacing the polarizing plate with a liquid crystal polarizing plate in the structure up to the eighth structure as well as the first structure.

[About each embodiment]
As described above, as a first configuration example to which the present invention is applied, in the antenna supported by the flat substrate, a radome plate made of a polarizing plate is provided in the radiation direction of the antenna, and the radome plate and the flat substrate are half-finished. The angle formed between the polarization direction radiated from the antenna and the polarization direction of the polarizing plate, which forms a wavelength resonator, is such that the rotation angle of the polarizing plate is such that the radiated electromagnetic wave has a desired reflectance in the polarizing plate. There is a radome structure characterized by being set.

  In the radome structure according to the first configuration example, the distance between the flat substrate supporting the antenna and the radome plate in the radial direction of the antenna is a natural number multiple of half the wavelength of the center frequency of the transmission frequency band, and the radome plate is a polarizing plate. The angle between the polarization direction of the polarizing plate and the polarization direction of the electromagnetic wave is adjusted by the rotation angle of the polarizing plate so that the electromagnetic wave radiated from the antenna has a desired reflectance in the polarizing plate. Features.

  As an operation according to this first configuration example, a half-wave resonator is formed by setting the distance between the flat substrate supporting the antenna and the radome plate to a natural number multiple of the half wavelength of the center frequency of the transmission frequency band. The antenna is supported by adjusting the angle between the polarization direction of the polarizing plate and the polarization direction of the electromagnetic wave by the rotation angle of the polarizing plate so that the electromagnetic wave radiated from the antenna has a desired reflectance at the polarizing plate. Since the Q value of the half-wave resonator formed by the planar substrate and the radome plate is adjusted, a radome structure having a desired transmission frequency bandwidth can be realized by one radome plate.

As described above, the effect of the first configuration example described above is that the half-wave resonator is formed by the radome plate including the flat substrate supporting the antenna and the polarizing plate, and the angle of the polarizing plate with respect to the polarization direction of the radiated electromagnetic wave is adjusted. Thus, the transmission frequency band from the radome can be easily set with a single-layer radome plate.
The reason is that the reflectivity of the electromagnetic wave in the polarizing plate changes depending on the angle formed by the polarization direction of the incident electromagnetic wave and the polarizing direction of the polarizing plate, and the Q value in the resonator changes. This is because the transmission band of the wavelength resonator can be adjusted.

  Further, as a second configuration example to which the present invention is applied, in the antenna supported by the planar substrate, a radome plate made of a polarizing plate is provided in the radiation direction of the antenna, and the half-wave resonator is formed by the radome plate and the planar substrate. The angle between the polarization direction radiated from the antenna and the polarization direction of the polarizing plate is set so that the radiated electromagnetic wave has a desired reflectance in the polarizing plate. There is a radome structure characterized by this.

  In the radome structure according to the second configuration example, the distance between the flat substrate supporting the antenna and the radome plate in the radial direction of the antenna is a natural number multiple of half the wavelength of the center frequency of the transmission frequency band, and the radome plate is a polarizing plate. The angle between the polarization direction of the polarizing plate and the polarization direction of the electromagnetic wave is adjusted by the rotation angle of the antenna so that the electromagnetic wave radiated from the antenna has a desired reflectance in the polarizing plate. Features.

  As an effect of this second configuration example, a half-wave resonator is formed by setting the distance between the flat substrate supporting the antenna and the radome plate to be a natural number multiple of the half wavelength of the center frequency of the transmission frequency band. The antenna is supported by adjusting the angle between the polarization direction of the polarizing plate and the polarization direction of the electromagnetic wave according to the rotation angle of the antenna so that the electromagnetic wave radiated from the antenna has a desired reflectance at the polarizing plate. Since the Q value of the half-wave resonator formed by the planar substrate and the radome plate is adjusted, a radome structure having a desired transmission frequency bandwidth can be realized by one radome plate.

As described above, the effect of the second configuration example described above is that a half-wave resonator is formed by a radome plate composed of a flat substrate that supports an antenna and a polarizing plate, and the polarization direction of electromagnetic waves radiated from the antenna and the polarizing plate The transmission frequency band from the radome can be easily set with a single-layer radome plate by adjusting the angle of rotation of the antenna so that the radiated electromagnetic wave has a desired reflectance at the radome plate. There is a point that can be.
The reason is that the reflectivity of the electromagnetic wave in the polarizing plate changes depending on the angle formed by the polarization direction of the electromagnetic wave radiated from the antenna and the polarizing direction of the polarizing plate, and the Q value in the resonator changes. This is because it is possible to adjust the transmission band of the half-wave resonator.

  Further, as a third configuration example to which the present invention is applied, in the radome plate of the first or second configuration example described above, an area through which the main beam of the electromagnetic wave radiated from the antenna passes is opened, and the area other than the above area There is a radome structure characterized in that is made of a metal or a radio wave absorber.

  The radome structure according to the third configuration example is the same as the radome structure according to the first or second configuration example described above, but uses a radome plate made of a polarizing plate in the main beam passage region of the electromagnetic wave radiated from the antenna, A radome plate made of metal or an electromagnetic wave absorber is used.

  As an effect of the third configuration example, in the structure of the first or second configuration example described above, a polarizing plate is used for the radome plate in the main beam passage region of the electromagnetic wave radiated from the antenna, and other portions are used. By using a metal or a radio wave absorber, in addition to the effects of the first or second configuration example described above, radiation of a beam in an unnecessary direction is suppressed by reflection by the metal or absorption of electromagnetic waves by the radio wave absorber. effective.

  As described above, the effect of the above-described third configuration example is that in the radome structure in which the effect of the above-described first or second configuration example is obtained, the unnecessary beam passing portion of the radiated electromagnetic wave from the antenna of the radome plate can be obtained. By using a metal or radio wave absorber, only the main beam radiated from the antenna can be radiated to the outside of the radome while obtaining the effects of the first or second configuration example described above.

  Further, as a fourth configuration example to which the present invention is applied, in the radome plate of the first or second configuration example described above, an upper side or a lower side of the radome plate made of the polarizing plate by a shielding plate made of metal or a radio wave absorber. There is a radome structure in which a side is covered, a region through which a main beam of electromagnetic waves radiated from the antenna passes is opened in the shielding plate, and the opening portion has a function of adjusting an opening area. .

  The radome structure according to the fourth configuration example is the same as the structure of the first or second configuration example described above, and covers the upper side or the lower side of the radome plate in which the metal or the radio wave absorber is a polarizing plate, and radiates electromagnetic waves from the antenna. The main beam passage region is opened, and the opening has a function of adjusting the opening area.

  As an effect of the fourth configuration example, in the structure of the first or second configuration example described above, the shielding plate made of a metal or a radio wave absorber covers the upper side or the lower side of the radome plate made of a polarizing plate, and shields it. The plate has an opening area for the main beam of electromagnetic waves radiated from the antenna, and the opening portion has a function that allows the opening area to be adjusted, so that the beam in an unnecessary direction is reflected by a metal or is a radio wave absorber. In addition to suppressing the radiation of the beam in the unnecessary direction due to the absorption of the electromagnetic wave by, there is an effect that the beam region of the electromagnetic wave radiated from the antenna can be appropriately selected and emitted.

  As described above, the effect of the fourth configuration example described above is that the radome made of a polarizing plate by the shielding plate made of a metal or a radio wave absorber in the radome structure in which the effect of the first or second configuration example described above is obtained. Covering the upper or lower side of the plate, the area where the main beam of the electromagnetic wave radiated from the antenna passes is opened, and the opening has a function that allows the opening area to be adjusted. Alternatively, the electromagnetic wave is suppressed by absorption of the electromagnetic wave by the radio wave absorber, and the desired beam region of the electromagnetic wave radiated from the antenna can be appropriately selected and radiated.

  Further, as a fifth configuration example to which the present invention is applied, in the radome plate of the first to fourth configuration examples described above, the connecting portion of the polarizing plate is provided with a polarizing plate rotating mechanism. There is a structure.

  The radome structure according to the fifth configuration example is characterized in that, in the above-described first to fourth configuration examples, a rotating mechanism of the polarizing plate is provided at the connecting portion of the radome plate made of the polarizing plate.

  As an effect of the fifth configuration example, in the first to fourth configuration examples described above, by providing a rotating mechanism of the polarizing plate at the connection portion of the radome plate made of the polarizing plate, The reflectance can be changed as appropriate, and the frequency bandwidth can be adjusted as appropriate.

As described above, the effect of the fifth configuration example described above is that in the radome structure in which the effects of the first to fourth configuration examples described above are obtained, the rotating mechanism of the polarizing plate is connected to the connecting portion of the radome plate made of the polarizing plate. The transmission frequency band can be appropriately adjusted according to the frequency bandwidth used after the radome structure is manufactured and during communication.
The reason is that the angle formed between the polarizing plate and the polarization direction of the electromagnetic wave radiated from the antenna can be continuously changed by the rotation mechanism provided in the radome plate made of the polarizing plate, and the frequency bandwidth is adjusted. Because it will be able to.

  As a sixth configuration example to which the present invention is applied, there is a radome structure in which the antenna includes a rotation mechanism in the radome plates of the first to fifth configuration examples described above.

  The radome structure according to the sixth configuration example is characterized in that, in the structures of the first to fifth configuration examples described above, the antenna is provided with a rotation mechanism.

  As an effect of the sixth configuration example, in the first to fifth configuration examples described above, the antenna includes a rotation mechanism, so that the polarization direction of the electromagnetic wave radiated from the antenna and the polarization direction of the polarizing plate Is changed, the reflectance of the radiated electromagnetic wave on the radome plate can be changed as appropriate, and the frequency bandwidth can be adjusted as appropriate.

As described above, the effect of the sixth configuration example described above is that, in the radome structure in which the effects of the first to fifth configuration examples described above are obtained, the antenna is provided with a rotation mechanism, whereby the radome structure is manufactured. The transmission frequency band can be appropriately adjusted according to the frequency bandwidth used later and during communication.
The reason is that the angle formed between the polarizing plate and the polarization direction of the electromagnetic wave radiated from the antenna can be continuously changed by the rotation mechanism provided in the radome plate made of the polarizing plate, and the frequency bandwidth is adjusted. It is because it becomes possible to do.

  Further, as a seventh configuration example to which the present invention is applied, in the radome plate of the first to sixth configuration examples described above, a polarizer is formed by metal patterning on an upper surface or a lower surface of the radome plate. There is a radome structure.

  The radome structure according to the seventh configuration example is characterized in that, in the first to sixth configuration examples described above, a polarizing plate is formed by metal patterning on the upper surface or the lower surface of the dielectric substrate.

  As an effect of the seventh configuration example, in the first to sixth configuration examples described above, it is necessary to prepare a polarizing plate separately by forming the polarizing plate by metal patterning on the upper surface or the lower surface of the dielectric substrate. Since the polarizing plate can be easily formed without any effect, the radome structure of the first to fourth configuration examples described above can be easily realized.

As described above, the effect of the seventh configuration example described above is that the polarizing plate is formed by metal patterning on the upper surface or the lower surface of the dielectric substrate constituting the radome plate in the first to sixth configuration examples described above. Thus, the radome structure can be realized more easily.
The reason is that it is not necessary to separately prepare a polarizing plate in addition to the radome material for forming the radome plate, so that the radome structure can be realized more easily.

  As an eighth configuration example to which the present invention is applied, the polarizing plates of the first to fifth configuration examples described above are liquid crystal polarizers, and the polarization direction of the liquid crystal polarizer is electrically controlled by an external electric circuit. There is a radome structure characterized by this.

  The radome structure according to the eighth configuration example is characterized in that, in the first to fifth configuration examples described above, the polarizing plate is a liquid crystal polarizing plate.

  The operation of the eighth configuration example is as follows. In the first to fifth configuration examples described above, the polarizing plate is a liquid crystal polarizing plate, and the polarization direction is electrically controlled by an external electric circuit. There is an effect that the polarization direction can be adjusted.

As described above, the effect of the above-described eighth configuration example is that the radome structure in which the effects of the above-described first to fifth configuration examples are obtained can be controlled by external control by using a liquid crystal polarizing plate as the polarizing plate. The transmission bandwidth from the radome can be adjusted.
The reason is that since the polarization direction of the liquid crystal polarizing plate can be adjusted by an external electric field, the polarization direction can be adjusted by control by an external circuit.

  As a ninth configuration example to which the present invention is applied, there is a radome structure characterized in that a plurality of the radome structures in the first to eighth configuration examples described above are arranged.

  The radome structure according to the ninth configuration example is characterized in that a plurality of the radome structures are arranged in the first to eighth configuration examples described above.

  As an effect of the ninth configuration example, a large gain can be realized by arranging a plurality of the radome structures of the first to eighth configuration examples described above, and a part of the radomes among the plurality of structures is damaged. In this case, normal communication can be maintained without damaging other transmitters.

As described above, the effects of the ninth configuration example described above are obtained by arranging a plurality of radome structures that can achieve the effects of the first to eighth configuration examples described above, thereby obtaining high gain and operating against a failure. It is in the point that reliability improvement is obtained.
The reason is that, by arranging a plurality of transmitters or receivers, the gain is improved, and since a plurality of radome structures are used, even when a failure occurs in a part of the radome structure constituting the array, This is because other transmitters or receivers are not affected by the radome breakage.

  As described above, according to each embodiment of the present invention described above, design difficulty is reduced by making the radome structure simple, and the transmission frequency bandwidth can be adjusted as appropriate due to manufacturing errors. It is possible to provide a radome structure that can cope with a change in bandwidth and a change in frequency bandwidth in communication.

  Each of the above-described embodiments is a preferred embodiment of the present invention, and the present invention is not limited to this, and various modifications can be made based on the technical idea of the present invention.

It is sectional drawing which shows the radome structure as the 1st Embodiment of this invention. It is a figure which shows the control effect of the transmission frequency bandwidth of this invention. It is sectional drawing which shows the radome structure as the 2nd Embodiment of this invention. It is sectional drawing which shows the radome structure as the 3rd Embodiment of this invention. It is a top view which shows the example of a form of the shielding board which has an opening area adjustment function among 3rd Embodiment. It is sectional drawing which shows the radome structure as the 4th Embodiment of this invention. It is sectional drawing which shows the radome structure as the 5th Embodiment of this invention. It is sectional drawing which shows the radome structure as the 6th Embodiment of this invention. It is sectional drawing which shows the radome structure as the 7th Embodiment of this invention. It is sectional drawing which shows the radome structure as the 8th Embodiment of this invention. It is sectional drawing which shows the radome structure as the 9th Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Radome structure 101 Planar substrate 102 Antenna 103,207 Polarizing plate 104 Side wall 105 Radiated electromagnetic wave 206,306,608 Main beam passage area 307 of radiated electromagnetic wave 307 Shield plate 308 Aperture mechanism 406 Rotating mechanism 506 Radome plate 507 Metal part 706 Liquid crystal polarizing plate 707 Control circuit

Claims (11)

A radome structure in which an antenna is supported on a plane plate, a radome plate is provided in the radiation direction of the antenna, and a half-wave resonator is formed by the radome plate and the plane plate,
The radome plate includes a polarizing plate at least in part,
A radome structure configured such that a transmission frequency bandwidth in the radome plate can be adjusted by an angle formed by a polarization direction radiated from the antenna and a polarization direction of the polarizing plate.   The radome plate is configured such that a metal or a radio wave absorber is disposed in a portion other than the region so as to exclude at least a region through which a main beam of electromagnetic waves radiated from the antenna passes. Item 1. A radome structure according to Item 1. A shielding plate is provided on the upper side or the lower side of the radome plate with respect to the antenna,
2. The radome structure according to claim 1, wherein the shielding plate includes an opening including at least a region through which a main beam of an electromagnetic wave radiated from the antenna passes in the radome plate.   The radome structure according to claim 3, wherein the shielding plate includes a diaphragm mechanism capable of adjusting an opening area of the opening.   5. The angle according to claim 1, wherein an angle formed between a polarization direction radiated from the antenna and a polarization direction of the polarizing plate is set by a rotation angle of the polarizing plate. Radome structure.   The radome according to any one of claims 1 to 4, wherein an angle formed between a polarization direction radiated from the antenna and a polarization direction of the polarizing plate is set by a rotation angle of the antenna. Construction.   The rotation mechanism is provided in the said polarizing plate, This rotation mechanism can adjust the angle | corner which the polarization direction radiated | emitted from the said antenna and the polarization direction of the said polarizing plate adjust. The radome structure according to any one of the above.   The rotation mechanism is provided in the antenna, and the rotation mechanism is capable of adjusting an angle formed by a polarization direction radiated from the antenna and a polarization direction of the polarizing plate. The radome structure according to any one of the above.   9. The radome structure according to claim 1, wherein a polarizer is formed on the polarizing plate by metal patterning on an upper surface or a lower surface of the radome plate. 10.   The radome structure according to any one of claims 1 to 8, wherein the polarizing plate is a liquid crystal polarizer, and the polarization direction can be electrically controlled by an input from an external electric circuit.   11. A radome structure comprising a plurality of radome structures according to claim 1 arranged in an array.

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