JPS603209A - Antenna in common use for multi-frequency band - Google Patents

Abstract

PURPOSE:To attain ease of arrangement of a primary radiator by forming two foci being in the relation of mirror image respectively by one focus of a reflection mirror face and two frequency selecting plates so as to realize three mechanically separated foci in total. CONSTITUTION:The 1st primary radiator 3 at a frequency band f1 is arranged at a focus F0 of an offset reflection mirror face 1' and the 2nd primary radiator 4 for a frequency band f2 is arranged at a focus F1 being in the relation of mirror image to the focus F0 by the 1st frequency selecting plate 6. Moreover, the primary radiator 5 having the same frequency bands f3, f3' and obtaining different radiation beams P3, P3' is arranged at a focus F2 in the relation of mirror image to the focus F0 by the 2nd frequency selecting plate 7. The selecting plates 6, 7 are so constituted that the former passes through the frequency band f1 and reflects the frequency band f2 and the latter passes through the frequency bands f1, f2 and reflects the frequency bands f3, f3'.

Description

[Detailed description of the invention] [Technical field to which the invention pertains] The present invention relates to a microwave band antenna.

In particular, the present invention relates to an offset mirror antenna for multiple frequency bands that uses a reflective mirror surface for multiple frequency bands.

[Description of prior art]

Conventionally, as an example of a reflective quad antenna in which a Qi-offset reflecting mirror surface is shared in multiple frequency bands, a method of constructing it with a primary radiator that can be used in multiple frequency bands as shown in FIG. 1 has been well known. However, in this method, not only does the configuration of the primary radiator 2 become more complicated as the number of frequency bands that are shared increases, but also the equivalent phase center of the radiation of the primary radiator 2 is set to the reflecting mirror surface for each frequency band. It has to be arranged at the focal point F, which is difficult to arrange due to mechanical dimensional restrictions and has the drawback of deterioration of radiation characteristics.

Furthermore, in order to obtain a shaped beam and a supplementary beam for tracking, the configuration of the primary radiator becomes more complex and larger.
Mechanical interference becomes large, making it difficult to arrange the primary radiator at the focal point, and also making it difficult to design the primary radiator, which has the disadvantage that the radiation characteristics are more likely to deteriorate.

[Purpose of the Invention] Based on the above considerations, the present invention makes the configuration of the primary radiator as simple as possible to facilitate its design, and also facilitates the arrangement of the primary radiator to improve its radiation characteristics. It is an object of the present invention to provide a multi-frequency band shared antenna that can reduce deterioration of the antenna, share multiple frequency bands, and obtain different radiation beams.

[Summary of the invention]

This invention creates one focal point of one reflective mirror surface and two focal points that are mirror images using two frequency selection plates, realizing a total of three mechanically separated focal points, and arranging the primary radiator. It was designed to be easy to set up.

That is, the present invention provides a multi-frequency band shared antenna including an offset reflecting mirror and two or more primary radiators that irradiate the reflecting mirror surface to the focal point of the reflecting mirror surface. A first primary radiator that transmits or receives radio waves is disposed between the focal point and the reflecting mirror surface, and passes the radio waves in the first frequency band and transmits or receives radio waves in the first frequency band. a first frequency selection plate that reflects radio waves in a second frequency band; and a first frequency selection plate that passes radio waves in the first and second frequency bands and reflects radio waves in frequency bands other than the first and second frequency bands; a second frequency selection plate, and a second primary radiator that transmits or receives radio waves in the second frequency band at a position that is a mirror image of the focal point by the first frequency selection plate. and a second frequency selection plate other than the first and second frequency bands is arranged at a position that is a mirror image of the focal point by the second frequency selection plate.
A third primary radiator for transmitting or receiving radio waves in two frequency bands is disposed, and the radiation beam of the second primary radiator and the radiation beam of the third primary radiator are partially connected to each other. It is characterized by being configured so that they overlap.

[Explanation based on examples]

Next, embodiments of the present invention will be described in detail based on the drawings.

FIG. 2 is a central vertical sectional view of the antenna according to the first embodiment of the present invention. The antenna shown in Figure 2 shares three frequency bands,
and an antenna with two different radiation beams. In FIG. 2, fl is the lowest frequency band, f2 is the next lowest frequency band, f3 is the highest frequency band, and 61
has a radiation beam p, / in the same frequency band as f3 and different from radiation beam P5 in the frequency band f5.

Focal point F of offset reflecting mirror surface 1'. A first primary radiator 3 for the frequency band f1 is arranged at and a focal point F by a first frequency selection plate 6. A second primary radiator 4 for the frequency band f2 is arranged at the focal point F1 which is in mirror image relationship with the second primary radiator 4 for the frequency band f2. Furthermore, the focal point F is determined by the second frequency selection plate 7. The same frequency bands f5 and f3 are placed at the focal point F2, which has a mirror image relationship with
' and from which different radiation beams P3, P5' are provided. The first frequency selection plate 6 passes frequency bands 1 and reflects frequency bands 2, and the second frequency selection plate 7 passes frequency bands f1 and f2 and reflects frequency bands f3 and f3'. Constructed to be reflective.

In an antenna with such a configuration, the total area A of the reflecting mirror surface 1 is
- the frequency band f reflected by C.

and f2 radiation beams P1 and P2 are obtained, and two different radiation beams P3 of the same frequency band f5, f5' reflected by the reflective mirror surface 10 reflection area B-c.
and P3' are obtained.

Here, the second frequency selection plate 7 is focused F within a range that does not interfere with the first frequency selection plate 6. It is also possible to increase the effective reflection area of the frequency bands f5 and f5' by bringing the frequency band closer to , and of course the reverse is also possible.

FIG. 3 is a central vertical sectional view of an antenna according to a second embodiment of the present invention. The antenna shown in FIG. 5 is an antenna that shares four frequency bands. In FIG. 6, each symbol corresponds to each symbol in FIG. 2, respectively. In this example, the primary radiators 3.
4 and the first frequency selection plate 6 are the same as in the first embodiment described above, but the second frequency selection plate 7' has a frequency band f.

and f2, and is configured to reflect frequency band f5 and the highest frequency band f4. Also 1
The secondary radiator 5' is configured to share frequency bands f5 and f4.

In an antenna with such a configuration, the total area A of the reflecting mirror surface 1 is
Radiation beams P and P2 in frequency bands f1 and f2 reflected by -C are obtained as in the first embodiment, but radiation in frequency bands f5 and f4 reflected by reflection areas B to C of reflective mirror surface 1. Beams P5 and P4 are obtained, making it possible to realize an antenna that can share four frequency bands.

Note that in the above two examples, the antenna was explained as a transmitting antenna, but due to the reversibility of radio waves, it can also be used as a receiving antenna or a transmitting/receiving antenna.

Further, the first frequency selection plate 6 is configured to be a high frequency pass type, that is, to reflect the frequency band f1 and pass the frequency band f2, and the primary radiators 3 and 4 are arranged interchangeably. The same characteristics as above can also be obtained.

〔Effect of the invention〕

As described above, according to the present invention, by arranging the frequency selection plate between the reflecting mirror surface and the primary radiator placed at this focal position, - a plurality of equivalent focal points can be obtained even on the reflecting mirror surface. can be realized, and the arrangement of the primary radiators can be mechanically distributed and facilitated. Further, it becomes possible to reduce the frequency band sharing of the primary radiator, the configuration of the primary radiator becomes simple, the design becomes easy, and the performance of the primary radiator can be improved.

Furthermore, since multiple frequency bands can be shared by the reflecting mirror surface, it is possible to save volume, and it can be particularly effective when used in a satellite tower antenna or the like.

In particular, the second primary radiator and the third primary radiator are configured so that their respective radiation beams are partially overlapped and radiate to the reflecting mirror surface, so the area of the reflecting mirror can be used effectively. There are also advantages.

[Brief explanation of drawings]

FIG. 1 is a central vertical sectional view of a conventional antenna. FIG. 2 is a central vertical sectional view of the antenna according to the first embodiment of the present invention. FIG. 6 is a central vertical sectional view of an antenna according to a second embodiment of the present invention. 1.1'...Offset reflecting mirror surface, 2~5.5'...
・Primary radiator, 6.7.7'...Frequency selection board. Patent applicant representative Patent attorney Naotaka Ide

Claims (3)

[Claims] (1) In a multi-frequency band shared antenna equipped with an offset reflector and two or more primary radiators that irradiate the focus of the reflector to the focus of the reflector, a radio wave in a first frequency band is emitted to the focus. A primary radiator of i'; A first frequency selection plate that reflects radio waves in a second frequency band other than the above, and a radio wave in a frequency band other than the first and second frequency bands by passing radio waves in the first and second frequency bands. a second frequency selection plate that reflects, and a second primary frequency selection plate that transmits or receives radio waves in the second frequency band at a position that is a mirror image of the focal point by the first frequency selection plate; A radiator is disposed, and a third frequency selection plate transmits or receives radio waves in two frequency bands other than the first and second frequency bands at a position that is a mirror image of the focal point by the second frequency selection plate. A multi-frequency device characterized in that a primary radiator is provided, and the radiation beam of the second primary radiator and the radiation beam of the third primary radiator partially overlap. Band sharing antenna. (2) The third primary radiator is configured to emit different radiation beams when the radio waves of the two frequency bands to be transmitted or received are the same.
) The multi-frequency band shared antenna described in section 2. (3) The third primary radiator is configured to emit the same or different radiation beams when the radio waves in the two frequency bands to be transmitted or received are different. A multi-frequency band antenna.