JPH0568124B2 - - Google Patents
Info
- Publication number
- JPH0568124B2 JPH0568124B2 JP58067108A JP6710883A JPH0568124B2 JP H0568124 B2 JPH0568124 B2 JP H0568124B2 JP 58067108 A JP58067108 A JP 58067108A JP 6710883 A JP6710883 A JP 6710883A JP H0568124 B2 JPH0568124 B2 JP H0568124B2
- Authority
- JP
- Japan
- Prior art keywords
- reflector
- sub
- horn
- reflecting mirror
- antenna device
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
- 230000005684 electric field Effects 0.000 claims description 7
- 239000006096 absorbing agent Substances 0.000 claims description 2
- 239000000463 material Substances 0.000 claims description 2
- 230000009977 dual effect Effects 0.000 claims 1
- 230000005574 cross-species transmission Effects 0.000 description 3
- 238000000034 method Methods 0.000 description 3
- 230000005540 biological transmission Effects 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 230000004907 flux Effects 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 230000005855 radiation Effects 0.000 description 1
- 229910000859 α-Fe Inorganic materials 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01Q—ANTENNAS, i.e. RADIO AERIALS
- H01Q19/00—Combinations of primary active antenna elements and units with secondary devices, e.g. with quasi-optical devices, for giving the antenna a desired directional characteristic
- H01Q19/10—Combinations of primary active antenna elements and units with secondary devices, e.g. with quasi-optical devices, for giving the antenna a desired directional characteristic using reflecting surfaces
- H01Q19/18—Combinations of primary active antenna elements and units with secondary devices, e.g. with quasi-optical devices, for giving the antenna a desired directional characteristic using reflecting surfaces having two or more spaced reflecting surfaces
- H01Q19/19—Combinations of primary active antenna elements and units with secondary devices, e.g. with quasi-optical devices, for giving the antenna a desired directional characteristic using reflecting surfaces having two or more spaced reflecting surfaces comprising one main concave reflecting surface associated with an auxiliary reflecting surface
Description
【発明の詳細な説明】
本発明は主にマイクロ波帯以上の周波数帯で用
いられるアンテナの改良に関するものであり、更
に詳しくは開口径が数十波長以下の小開口径のア
ンテナ装置の改良に関するものである。DETAILED DESCRIPTION OF THE INVENTION The present invention mainly relates to the improvement of antennas used in frequency bands above the microwave band, and more specifically relates to the improvement of antenna devices with small aperture diameters of several tens of wavelengths or less. It is something.
従来この種のアンテナとしては、第１図に断面
図を示すようなアンテナがあつた。同図におい
て、１は主反射鏡、２は副反射鏡、３はホーン、
４はホーンの位相中心、５は主反射鏡１および副
反射鏡２の焦点、６は電波の進行方向を示す矢
印、７はホーンの中心軸を表わしている。中心軸
７は主反射鏡を構成する放物線の軸に一致してい
る。以下、本アンテナの動作を送信の場合を例に
とつて説明する。 Conventionally, as this type of antenna, there has been an antenna whose sectional view is shown in FIG. In the figure, 1 is a main reflector, 2 is a sub-reflector, 3 is a horn,
Reference numeral 4 represents the phase center of the horn, 5 the focus of the main reflecting mirror 1 and the sub-reflecting mirror 2, 6 an arrow indicating the direction of propagation of radio waves, and 7 the central axis of the horn. The central axis 7 coincides with the axis of the parabola constituting the main reflecting mirror. The operation of this antenna will be explained below using the case of transmission as an example.
１次放射器の位相中心４より出た電波は副反射
鏡２で反射された後、主反射鏡で集束されて正面
方向に出る。一般に、主反射鏡が小さくなるに従
いホーンの開口径および副反射鏡は小さくせざる
をえない。ところが、ホーン３の開口径を小さく
すると其の放射パターンが広くなるため、大口径
アンテナと類似の状態を得るには位相中心４から
見込む副反射鏡２の見込み角を大きくする必要が
あり、ホーンと副反射鏡２とを近づけざるをえな
くなつてくる。その結果、次のような問題が生じ
てくる。 Radio waves emitted from the phase center 4 of the primary radiator are reflected by the sub-reflector 2, then focused by the main reflector and exit in the front direction. Generally, as the main reflecting mirror becomes smaller, the aperture diameter of the horn and the sub-reflecting mirror must be made smaller. However, if the aperture diameter of the horn 3 is made smaller, its radiation pattern becomes wider. Therefore, in order to obtain a state similar to that of a large-diameter antenna, it is necessary to increase the viewing angle of the sub-reflector 2 from the phase center 4. It becomes necessary to bring the auxiliary reflector 2 closer to the auxiliary reflector 2. As a result, the following problems arise.
即ち、ホーン３と副反射鏡２２とを近づける
と、副反射鏡２で反射された電波はその多くがホ
ーン３に当たつてしまうため、主反射鏡に到達す
ることができない。そのため、アンテナ能率が低
くなつてしまう。このような欠点は主反射鏡の開
口径が概ね50波長以下になると現れてくる。 That is, if the horn 3 and the sub-reflector 22 are brought close together, most of the radio waves reflected by the sub-reflector 2 will hit the horn 3 and cannot reach the main reflector. As a result, the antenna efficiency becomes low. Such drawbacks appear when the aperture diameter of the main reflecting mirror becomes approximately 50 wavelengths or less.
本発明はこのような原因によるアンテナ能率の
低下を防ぐため、ホーンと副反射鏡とを近づけて
も電波がホーンで邪魔されないような構造のアン
テナ装置を提供するものである。以下、同図に基
づいて詳細に説明する。 In order to prevent antenna efficiency from decreasing due to such causes, the present invention provides an antenna device having a structure in which radio waves are not obstructed by the horn even if the horn and the sub-reflector are brought close to each other. Hereinafter, a detailed explanation will be given based on the same figure.
第２図は本発明の一実施例を示す断面図であつ
て、８は主反射鏡の上半分に用いている放物線の
軸を示している。本実施例の構造を上半分につい
て説明する。 FIG. 2 is a sectional view showing an embodiment of the present invention, and 8 indicates the axis of a parabola used in the upper half of the main reflecting mirror. The upper half of the structure of this embodiment will be explained.
焦点位置は５であるから、焦点位置５は、ホー
ン中心軸７から概ね副反射鏡の半径に等しい距離
だけ離れている。また、軸８はホーン中心軸７と
平行である。副反射鏡はホーンの位相中心４およ
び主反射鏡の焦点５を焦点とする楕円の一部であ
り、概ね放物線の軸８とホーンの中心軸７に挾ま
れた部分を用いている。主反射鏡の中心部の内、
ホーン中心軸からの距離が副反射鏡の半径に等し
い範囲には電波が到達しないため、その形状はど
のようなものでも良く、例えば、平面としても何
らさしつかえない。 Since the focal position is 5, the focal position 5 is separated from the horn central axis 7 by a distance approximately equal to the radius of the sub-reflector. Further, the axis 8 is parallel to the horn central axis 7. The sub-reflector is a part of an ellipse whose focal points are the phase center 4 of the horn and the focal point 5 of the main reflector, and is approximately sandwiched between the axis 8 of the parabola and the center axis 7 of the horn. In the center of the main reflector,
Since the radio waves do not reach an area where the distance from the central axis of the horn is equal to the radius of the sub-reflector, it may have any shape, for example, it may be a flat surface.
下半分は上半分をホーンの中心軸７の回りに
180度回転してできた曲線であるから、全ての構
造がホーンの中心軸７に対して対称である。 The lower half is the upper half around the central axis 7 of the horn.
Since the curve is created by rotating 180 degrees, all structures are symmetrical about the central axis 7 of the horn.
次に本アンテナの動作を送信の場合を例にとつ
て説明する。ホーンの位相中心４より上半分に向
かつて出た電波は副反射鏡で反射された後、焦点
５で集束されて主反射鏡１に至る。このとき、第
２図から明らかなように電波が焦点５で集束され
るため、ホーン３と副反射鏡２とを近づけても副
反射鏡２で反射された電波がホーン３に邪魔され
ることなくすべて有効に主反射鏡１に至ることが
できる。 Next, the operation of this antenna will be explained using the case of transmission as an example. Radio waves emitted toward the upper half of the horn from the phase center 4 are reflected by the sub-reflector, then focused at a focal point 5 and reach the main reflector 1. At this time, as is clear from FIG. 2, the radio waves are focused at the focal point 5, so even if the horn 3 and the sub-reflector 2 are brought close together, the radio waves reflected by the sub-reflector 2 will not be obstructed by the horn 3. All of them can effectively reach the main reflecting mirror 1 without any problems.
従来の双反射鏡と同様、本発明においても反射
鏡の枚数が２枚あるため、所望の開口面電界分布
を得るための鏡面修正を行なうことができる。そ
の方法は従来のアンテナにおける場合と同じよう
に、各種の方法を用いることができる。 Similar to the conventional double-reflector, since the present invention has two reflectors, it is possible to modify the mirror surface to obtain a desired aperture electric field distribution. As in the case of conventional antennas, various methods can be used for this purpose.
例えば、電力束の条件、反射の法則、光路長一
定の条件を用いた幾何光学的手法等がある。この
ような従来の双反射鏡アンテナのの鏡面修正方法
については公知の刊行物にも記載されており、当
業者にとつて周知のことである。本発明の場合、
レイの対応が異なることに基づく若干の計算式の
違いはあるが、基本的な考え方は同様であるため
説明を省略する。 For example, there are geometrical optics methods using power flux conditions, reflection laws, and constant optical path length conditions. A method for modifying the mirror surface of such a conventional double-reflector antenna is also described in known publications and is well known to those skilled in the art. In the case of the present invention,
Although there is a slight difference in the calculation formula based on the difference in ray correspondence, the basic idea is the same, so the explanation will be omitted.
第３図は、本発明においてホーンとして円錐ホ
ーンを用い、アンテナパラメータを適切に選んだ
場合の開口面電界分布の一例を示す図である。こ
こで、Ｅ面とは主偏波の電界に平行な開口面半径
方向軸上の分布であり、Ｈ面とはこれに垂直な軸
上の分布である。第３図から明らかな様に、パラ
メータを適切に選ぶことによりほぼ一様な開口面
電界分布を実現し得ることを示している。 FIG. 3 is a diagram showing an example of the aperture surface electric field distribution when a conical horn is used as the horn in the present invention and antenna parameters are appropriately selected. Here, the E-plane is a distribution on the radial axis of the aperture plane parallel to the electric field of the main polarized wave, and the H-plane is a distribution on the axis perpendicular to this. As is clear from FIG. 3, it is shown that a substantially uniform electric field distribution on the aperture surface can be achieved by appropriately selecting the parameters.
このような分布は開口角180゜のアンテナにおい
ては、副反射鏡のエツジレベルを略マイナス
10dB程度の条件に選んだ時に得られる。 For an antenna with an aperture angle of 180°, this kind of distribution is approximately minus the edge level of the sub-reflector.
Obtained when selecting conditions of about 10 dB.
一方エツジレベルをマイナス10dBという高い
レベルに設定すると、副反射鏡２のエツジ部分に
おけるスピルオーバ現象が大となるので、これを
防止する必要が生ずる。 On the other hand, if the edge level is set to a high level of minus 10 dB, the spillover phenomenon at the edge portion of the sub-reflector 2 becomes large, so it becomes necessary to prevent this.
第４図は本発明の一実施例の断面図であつて、
９は副反射鏡周囲に設けた電波を透過しない材料
からなる筒である。電波の進行方向を示す矢印６
で挾まれた部分以外は副反射鏡から主反射鏡に向
かう電波の通路でないため、この部分にに筒９を
設けても電波の通路を邪魔しない。筒９を設ける
ことにより、ホーンから出て副反射鏡２に当たら
ずにアンテナ斜め前方に洩れるスピルオーバ波を
遮蔽することができ、サイドロープ特性を良好な
ものとすることができるという効果がある。筒９
の内壁面に凹凸を設ければ内壁面での反射波が散
乱され特定方向に強い不要波が生ずることがな
い。 FIG. 4 is a sectional view of an embodiment of the present invention,
Reference numeral 9 denotes a cylinder made of a material that does not transmit radio waves and is provided around the sub-reflector. Arrow 6 indicating the direction of radio waves
Since the area other than the part sandwiched between is not the path of the radio wave from the sub-reflector to the main reflector, even if the tube 9 is provided in this area, the path of the radio wave will not be obstructed. By providing the tube 9, it is possible to block spillover waves that come out from the horn and leak diagonally forward of the antenna without hitting the sub-reflector 2, and there is an effect that the side rope characteristics can be improved. Tube 9
By providing unevenness on the inner wall surface, reflected waves from the inner wall surface are scattered, and strong unnecessary waves are not generated in a specific direction.
更に、内壁面にフエライト或いはカーボンなど
からできた電波吸収体を用いれば内壁面での反射
による不要波をほぼ完全に吸収することができ、
スピルオーバ波を防ぐ効果は更に大となる。 Furthermore, if a radio wave absorber made of ferrite or carbon is used on the inner wall surface, unnecessary waves reflected from the inner wall surface can be almost completely absorbed.
The effect of preventing spillover waves is even greater.
以上説明したように、本発明により従来問題と
なつていた副反射鏡で反射された電波の通路をホ
ーンが邪魔することがなくなるため、アンテナ能
率を改善することができるという利点がある。従
つて同一開口径の従来のアンテナに比べ利得を高
くすることができ、無線システムを余裕のあるも
のにすることができる。 As explained above, the present invention has the advantage that the antenna efficiency can be improved because the horn no longer obstructs the path of radio waves reflected by the sub-reflector, which has been a problem in the past. Therefore, the gain can be increased compared to conventional antennas with the same aperture diameter, and the radio system can be made more flexible.
第１図は従来のアンテナの断面図、第２図は本
発明の一実施例の断面図、第３図は本発明におけ
る開口面電界分布の一例、第４図は本発明の一実
施例の断面図である。
１…主反射鏡、２…副反射鏡、３…ホーン、４
…ホーンの位相中心、５…焦点、６…電波の進行
方向を示す矢印、７…ホーンの中心軸、８…放物
線の対称軸、９…筒。
Fig. 1 is a cross-sectional view of a conventional antenna, Fig. 2 is a cross-sectional view of an embodiment of the present invention, Fig. 3 is an example of the aperture electric field distribution in the present invention, and Fig. 4 is a cross-sectional view of an embodiment of the present invention. FIG. 1...Main reflector, 2...Sub reflector, 3...Horn, 4
...Phase center of the horn, 5...Focal point, 6...Arrow indicating the direction of propagation of radio waves, 7...Central axis of the horn, 8...Axis of symmetry of the parabola, 9...Cylinder.
Claims (1)
対向する副反射鏡とを有し、主反射鏡および副反
射鏡の構造の中心がホーンの中心軸上にある如く
構成された双反射鏡アンテナであつて、前記主反
射鏡の母線の一部が放物線であり、その焦点がホ
ーン中心軸から、副反射鏡の該ホーン中心軸から
の垂直半径に概ね等しい距離だけ離れた位置にあ
り、前記放物線の軸は前記ホーン中心軸と平行で
あり、前記副反射鏡の母線は、前記ホーンの位相
中心点と前記放物線の焦点位置とをその焦点とす
る楕円の一部であることを特徴とするアンテナ装
置。 ２ 主反射鏡および副反射鏡の形状を所望の開口
面電界分布が得られるように鏡面修正した特許請
求の範囲第１項記載のアンテナ装置。 ３ 開口面電界分布が概ね一様となるように、ホ
ーン形状、主反射鏡形状および副反射鏡形状並び
にそれらの位置関係を選んだ特許請求の範囲第１
項記載のアンテナ装置。 ４ 副反射鏡で反射された電波の通路を遮らない
範囲の該副反射鏡周囲に、電波を透過しない材料
から成る筒を設けた特許請求の範囲第３項記載の
アンテナ装置。 ５ 前記筒の内壁面に電波吸収体を用いた特許請
求の範囲第４項記載のアンテナ装置。[Claims] 1. A main reflecting mirror, a horn, and a sub-reflecting mirror that faces the horn in close proximity, and the center of the structure of the main reflecting mirror and the sub-reflecting mirror is on the central axis of the horn. A dual reflector antenna configured as shown in FIG. the axis of the parabola is parallel to the central axis of the horn, and the generatrix of the sub-reflector is a part of an ellipse whose focal point is the phase center point of the horn and the focal point position of the parabola. An antenna device characterized in that: 2. The antenna device according to claim 1, wherein the shapes of the main reflecting mirror and the sub-reflecting mirror are mirror-modified so as to obtain a desired aperture surface electric field distribution. 3. Claim 1 in which the shape of the horn, the shape of the main reflector, the shape of the sub-reflector, and the positional relationship thereof are selected so that the electric field distribution on the aperture surface is approximately uniform.
Antenna device as described in section. 4. The antenna device according to claim 3, wherein a tube made of a material that does not transmit radio waves is provided around the sub-reflector in a range that does not block the passage of radio waves reflected by the sub-reflector. 5. The antenna device according to claim 4, wherein a radio wave absorber is used on the inner wall surface of the cylinder.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP6710883A JPS59193606A (en) | 1983-04-18 | 1983-04-18 | Axis symmetry antenna |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP6710883A JPS59193606A (en) | 1983-04-18 | 1983-04-18 | Axis symmetry antenna |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS59193606A JPS59193606A (en) | 1984-11-02 |
| JPH0568124B2 true JPH0568124B2 (en) | 1993-09-28 |
Family
ID=13335364
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP6710883A Granted JPS59193606A (en) | 1983-04-18 | 1983-04-18 | Axis symmetry antenna |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS59193606A (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2710416B2 (en) * | 1989-07-13 | 1998-02-10 | 日本電気株式会社 | Elliptical aperture double reflector antenna |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS59131203A (en) * | 1982-09-07 | 1984-07-28 | アンドリユ−・コ−ポレ−シヨン | Microwave antenna |
-
1983
- 1983-04-18 JP JP6710883A patent/JPS59193606A/en active Granted
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS59131203A (en) * | 1982-09-07 | 1984-07-28 | アンドリユ−・コ−ポレ−シヨン | Microwave antenna |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS59193606A (en) | 1984-11-02 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US4626863A (en) | Low side lobe Gregorian antenna | |
| EP0136818A1 (en) | Dual mode feed horn or horn antenna for two or more frequency bands | |
| US5959590A (en) | Low sidelobe reflector antenna system employing a corrugated subreflector | |
| EP0227121A1 (en) | Horn antenna with a choke surface-wave structure on the outer surface thereof | |
| US3845483A (en) | Antenna system | |
| US4673945A (en) | Backfire antenna feeding | |
| JPS5821850B2 (en) | antenna | |
| US3553707A (en) | Wide-beam horn feed for parabolic antennas | |
| US4096483A (en) | Reflector with frequency selective ring of absorptive material for aperture control | |
| US3414904A (en) | Multiple reflector antenna | |
| US3216018A (en) | Wide angle horn feed closely spaced to main reflector | |
| USRE32485E (en) | Wide-beam horn feed for parabolic antennas | |
| US2881431A (en) | Ring source omnidirectional antenna | |
| JPH0568124B2 (en) | ||
| JPH06204737A (en) | Dual reflecting mirror antenna system | |
| US20080030417A1 (en) | Antenna Apparatus | |
| EP0155761A1 (en) | Planar-parabolic reflector antenna with recessed feed horn | |
| EP0136817A1 (en) | Low side lobe gregorian antenna | |
| JPH035085B2 (en) | ||
| US4516129A (en) | Waveguide with dielectric coated flange antenna feed | |
| JPS604605B2 (en) | Reflector antenna device | |
| US2547414A (en) | Antenna | |
| CA1037155A (en) | Reflector antenna | |
| JPS6158043B2 (en) | ||
| JPS5892106A (en) | Multibeam antenna |