JPH0347764B2 - - Google Patents
Info
- Publication number
- JPH0347764B2 JPH0347764B2 JP3820984A JP3820984A JPH0347764B2 JP H0347764 B2 JPH0347764 B2 JP H0347764B2 JP 3820984 A JP3820984 A JP 3820984A JP 3820984 A JP3820984 A JP 3820984A JP H0347764 B2 JPH0347764 B2 JP H0347764B2
- Authority
- JP
- Japan
- Prior art keywords
- reflector
- sub
- main
- reflecting mirror
- focal point
- 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
Links
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
- H01Q19/192—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 with dual offset reflectors
Landscapes
- Aerials With Secondary Devices (AREA)
Description
【発明の詳細な説明】
〔発明の技術分野〕
この発明はマイクロ波中継回線等に用いられる
アンテナ装置の改良に関するものである。DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to improvements in antenna devices used in microwave relay lines and the like.
従来、アンテナ装置には、第１図に示すように
位相中心F0を有する一次放射器１、一次放射器
の位相中心F0を共有し、さらに、焦点F1を有す
る副反射鏡２および焦点F1を共有する回転放物
面鏡からなる主反射鏡３より構成されているもの
がある。
Conventionally, an antenna device includes a primary radiator 1 having a phase center F 0 as shown in FIG. Some reflectors are composed of a main reflecting mirror 3 consisting of a parabolic mirror of revolution that shares F1 .
図中、M1，Ｍは一次放射器１の中心軸に沿つ
て放射される光線４が各鏡面に当る点である。 In the figure, M 1 and M are points where the light ray 4 emitted along the central axis of the primary radiator 1 hits each mirror surface.
このアンテナは第１図の構成図から明らかなよ
うに、幾何光学的に設計されているために、幾何
光学が成立する周波数領域やＤ／λ（Ｄ：主反射
鏡の開口径、λ：自由空間波長）が非常に大きい
アンテナでは、広帯域にわたつて開口能率が一定
でしかも低サイドローブとなる。しかしながら、
開口径が50λ以下の小口径の主反射鏡を有するア
ンテナや主反射鏡３の周辺レベルを高くして高能
率化を狙いとするアンテナでは、電波５が図中点
線で示すように、波動的な広がりを有するため、
主反射鏡３からのスピルオーバ成分が多くなり、
アンテナの広角指向特性を劣化させていた。又、
図中、電波５の行路から明らかなように、副反射
鏡２と主反射鏡３の共通の焦点であるF1は、見
かけ上
1＞2 (1)
が成立するF2となり、このF2から電波５が放射
されるように見える。このため、主反射鏡の焦点
距離fnは
fn＝１／２2（１＋cosθ0） (2)
となり、見かけ上短かくなる。すなわち
一般に、電波は波動性をもつているため、第１
図の点線に示すように電波５は幾何光学的な分布
（第１図実線）と違つて広がりを持つて伝搬する。
これが、スピルオーバ成分となり、アンテナの広
角指向特性を劣化させる。 As is clear from the configuration diagram in Figure 1, this antenna is designed using geometrical optics, so it is difficult to determine the frequency range where geometrical optics is valid. An antenna with a very large spatial wavelength (spatial wavelength) has a constant aperture efficiency over a wide band and low side lobes. however,
In antennas that have a small-diameter main reflector with an aperture diameter of 50λ or less, or antennas that aim at high efficiency by increasing the peripheral level of the main reflector 3, the radio waves 5 have wave dynamics as shown by the dotted line in the figure. Because it has a wide range of
The spillover component from the main reflecting mirror 3 increases,
This caused the antenna's wide-angle directional characteristics to deteriorate. or,
In the figure, as is clear from the path of the radio wave 5, F 1 , which is the common focus of the sub-reflector 2 and the main reflector 3, becomes F 2 where 1 > 2 (1) apparently holds, and this F 2 Radio waves 5 appear to be emitted from the Therefore, the focal length f n of the main reflecting mirror becomes f n =1/2 2 (1+cosθ 0 ) (2), which makes it appear shorter. In other words, since radio waves generally have wave properties, the first
As shown by the dotted line in the figure, the radio wave 5 propagates with a spread, unlike the geometrical optical distribution (solid line in Figure 1).
This becomes a spillover component and deteriorates the wide-angle directivity characteristics of the antenna.
この場合、主反射鏡の開口径は、スピルオーバ
成分だけ見かけ上小さくなつたことになる（利得
が低下するため）。 In this case, the aperture diameter of the main reflecting mirror is apparently reduced by the spillover component (because the gain is reduced).
以上は、Ｄ＝4fntanθ／２（Ｄ：主反射鏡開口径
fn：主反射鏡の焦点距離、θ：主反射鏡開口角）
から分る通り、θを一定とすると焦点距離fnの距
離が短かくなつたことに相当する。 The above is D=4f n tan θ/2 (D: main reflector aperture diameter f n : focal length of main reflector, θ: main reflector aperture angle)
As can be seen, if θ is constant, this corresponds to the focal length f n becoming shorter.
従つて、第１図の主反射鏡の焦点は見かけ上
F1からF2となり、(2)式が成立する。 Therefore, the focal point of the main reflector in Figure 1 is apparently
F 1 becomes F 2 , and formula (2) is established.
なおここで、θ0は中心軸光線４の入射波、反射
波の成す角度である。 Note that here, θ 0 is the angle formed by the incident wave and the reflected wave of the central axis ray 4.
従つて、上述したような小口径のアンテナでは
幾何光学的に考えたときの主反射鏡の有効開口径
が焦点距離fnに比例するため、等価的に小さくな
り、広角指向特性の劣化ばかりでなく、開口能率
の低下ももたらしていた。 Therefore, in the case of a small-diameter antenna such as the one described above, the effective aperture diameter of the main reflecting mirror is proportional to the focal length f n when considered from a geometric optics perspective, so it becomes equivalently smaller, and the wide-angle directivity characteristics only deteriorate. This also resulted in a decrease in aperture efficiency.
この発明は、これらの欠点を除去するため、副
反射鏡２および主反射鏡３の焦点が共焦点となら
ないように鏡面系を構成したものであり、以下図
面に従つて詳細に説明する。
In order to eliminate these drawbacks, the present invention configures a mirror system so that the focal points of the sub-reflecting mirror 2 and the main reflecting mirror 3 are not confocal, and will be described in detail below with reference to the drawings.
第２図は、この発明の一実施例を示すもので、
１は一次放射器となる円錐ホーン、２は回転二次
曲面鏡からなる副反射鏡、３は回転放物面鏡から
なる主反射鏡である。F0，F1は副反射鏡２の焦
点であり、F0は円錐ホーンの位相中心でもある。
さらに、F2は主反射鏡３の焦点である。第２図
において、幾何光学的に考えた場合、円錐ホーン
１の中心軸に沿つて放射される光線４が、それぞ
れの反射鏡に当たる点を順にM1，Ｍとするとき、
F0，F1，F2，M1，Ｍが同一平面内にあり、しか
もF1M―→とF2M―→が同一線上にあるものとする。
FIG. 2 shows an embodiment of this invention.
1 is a conical horn serving as a primary radiator, 2 is a sub-reflector made of a rotating quadratic curved mirror, and 3 is a main reflector made of a rotating parabolic mirror. F 0 and F 1 are the focal points of the sub-reflector 2, and F 0 is also the phase center of the conical horn.
Furthermore, F 2 is the focal point of the main reflecting mirror 3. In FIG. 2, when considered from the perspective of geometrical optics, when the points where the light ray 4 emitted along the central axis of the conical horn 1 hits each reflecting mirror are M 1 and M in that order,
It is assumed that F 0 , F 1 , F 2 , M 1 , and M are on the same plane, and that F 1 M-→ and F 2 M-→ are on the same line.
このアンテナの鏡面系は、幾何光学的には、円
錐ホーン１の位相中心F0から出た光線４が、副
反射鏡２を経由して上記副反射鏡２の焦点F1で
交差して、主反射鏡３に到達するが、主反射鏡３
の形状は、第(3)式を満足するように決定されてい
る。 In terms of geometric optics, the mirror system of this antenna is such that the light ray 4 emitted from the phase center F 0 of the conical horn 1 passes through the sub-reflector 2 and intersects at the focal point F 1 of the sub-reflector 2. It reaches the main reflecting mirror 3, but the main reflecting mirror 3
The shape of is determined to satisfy equation (3).
2＞1 (3)
又、主反射鏡３の開口径は、副反射鏡２の周辺と
上記焦点F2を結んだ円錐の延長曲線が上記主反
射鏡３と交差するまで拡大されている。 2 > 1 (3) Furthermore, the aperture diameter of the main reflecting mirror 3 is enlarged until the extension curve of the cone connecting the periphery of the sub-reflecting mirror 2 and the focal point F 2 intersects with the main reflecting mirror 3.
以上のように構成されたアンテナ装置におい
て、円錐ホーン１の位相中心F0から放射され、
副反射鏡２を経由してきた電波５は、電波の波動
性のために、等価的に主反射鏡３の焦点F2から
放射されるように見える。このため、主反射鏡３
からのスピルオーバ成分はほとんどなくなり、し
かも主反射鏡３の全面を有効に照射しているた
め、アンテナの低サイドローブ化や高能率化を図
ることができる。 In the antenna device configured as above, radiation is radiated from the phase center F 0 of the conical horn 1,
The radio waves 5 that have passed through the sub-reflector 2 appear to be equivalently radiated from the focal point F 2 of the main reflector 3 due to the wave nature of the radio waves. For this reason, the main reflecting mirror 3
Since the spillover component from the main reflecting mirror 3 is almost eliminated and the entire surface of the main reflecting mirror 3 is effectively irradiated, it is possible to achieve low side lobes and high efficiency of the antenna.
なお、以上の説明では、一次放射器に円錐ホー
ン１を使用したが、本発明はこれに限らず、中心
軸をもついかなる一次放射器であつてもよい。 In the above description, the conical horn 1 is used as the primary radiator, but the present invention is not limited to this, and any primary radiator having a central axis may be used.
又、以上は主反射鏡３が下向きの場合を説明し
たが、上向きの場合でも本発明を適用することが
できる。 Moreover, although the case where the main reflecting mirror 3 is facing downward has been described above, the present invention can be applied even when the main reflecting mirror 3 is facing upward.
以上のようにこの発明によれば、副反射鏡から
のスピルオーバ成分が低減でき、しかも主反射鏡
を効率よく照射するため、高能率、低サイドロー
ブのアンテナが実現できるという利点を有する。
As described above, according to the present invention, spillover components from the sub-reflector can be reduced and the main reflector can be efficiently irradiated, so that an antenna with high efficiency and low side lobes can be realized.
第１図は従来のアンテナ装置の構成図、第２図
はこの発明の実施例を示すアンテナ装置の構成図
である。
図中、１は一次放射器、２は副反射鏡、３は主
反射鏡、４は光線、５は電波である。なお、図中
同一あるいは相当部分には同一符号を付して示し
てある。
FIG. 1 is a configuration diagram of a conventional antenna device, and FIG. 2 is a configuration diagram of an antenna device showing an embodiment of the present invention. In the figure, 1 is a primary radiator, 2 is a sub-reflector, 3 is a main reflector, 4 is a light beam, and 5 is a radio wave. It should be noted that the same or corresponding parts in the figures are indicated by the same reference numerals.
Claims (1)
し、この副反射鏡によつて、電波が主反射鏡の焦
点に絞られるように構成されたアンテナ装置にお
いて、一次放射器の位相中心に一致する副反射鏡
の一方の焦点をF0、他方の焦点をF1、主反射鏡
の焦点をF2として、幾何光学的に考えたとき、
一次放射器の中心軸に沿つて放射される光線が副
反射鏡および主反射鏡に当る点をM1，Ｍとする
と、F0，F1，F2，M2，Ｍが同一面内にあり、且
つF1M―→とF2M―→が同一線上にあつて 2＞1 とし、さらに副反射鏡の周辺と上記焦点F2を結
んだ円錐の延長曲線が主反射鏡と交差するまで、
上記主反射鏡の開口径を拡大したことを特徴とす
るアンテナ装置。[Claims] 1. An antenna device configured such that a sub-reflector is arranged between a primary radiator and a main reflector, and the sub-reflector focuses radio waves onto the focus of the main reflector. When considered in terms of geometric optics, assuming that one focal point of the sub-reflecting mirror that coincides with the phase center of the primary radiator is F 0 , the other focal point is F 1 , and the focal point of the main reflecting mirror is F 2 ,
If the points where the light ray emitted along the central axis of the primary radiator hits the sub-reflector and the main reflector are M 1 and M, then F 0 , F 1 , F 2 , M 2 , and M are in the same plane. Yes, and F 1 M-→ and F 2 M-→ are on the same line, 2 > 1 , and furthermore, the extension curve of the cone connecting the periphery of the sub-reflector and the focal point F 2 intersects the main reflector. to,
An antenna device characterized in that the aperture diameter of the main reflecting mirror is enlarged.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3820984A JPS60182804A (en) | 1984-02-29 | 1984-02-29 | antenna device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3820984A JPS60182804A (en) | 1984-02-29 | 1984-02-29 | antenna device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS60182804A JPS60182804A (en) | 1985-09-18 |
| JPH0347764B2 true JPH0347764B2 (en) | 1991-07-22 |
Family
ID=12518926
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP3820984A Granted JPS60182804A (en) | 1984-02-29 | 1984-02-29 | antenna device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS60182804A (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH046908A (en) * | 1990-04-24 | 1992-01-10 | Nippon Dengiyou Kosaku Kk | Offset dual reflecting mirror antenna |
| US8303885B2 (en) | 2003-10-09 | 2012-11-06 | Nike, Inc. | Article of footwear with a stretchable upper and an articulated sole structure |
-
1984
- 1984-02-29 JP JP3820984A patent/JPS60182804A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS60182804A (en) | 1985-09-18 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EXPY | Cancellation because of completion of term |