JP2669246B2 - Primary radiation feeder - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an antenna device for satellite communication and microwave communication using a plurality of frequencies.
Particularly, it relates to improvement of the primary radiation feeder.

[0002]

2. Description of the Related Art Conventionally, a small antenna having a structure shown in FIGS. 7 and 8 has been known as a small antenna for receiving signals in two different frequency bands having a large frequency difference. Among them, the one shown in FIG. 7 includes two independent primary radiation feeders 1 and 2 corresponding to respective frequencies and a parabolic main reflecting mirror 3.
It is installed near the focal point of. Also, the one shown in FIG.
The double reflecting mirror 4 arranged on the front side of the main reflecting mirror 3 has a frequency selection plate structure, and one frequency is from the horn of the radiation feeding section 5 on the front side of the double reflecting mirror 4 and the other frequency is the double reflecting mirror 4. The radiation is supplied from the horn of the radiation feeder 6 installed on the back.

[0003]

In recent years, there has been an increasing demand for small-sized reception-only satellite earth stations due to multi-frequency satellite communication using hybrid satellites and an increase in the effective radiation power of the satellites.
Also for the primary radiation power supply unit used for this purpose, there is a demand for downsizing of the power supply unit capable of sharing multiple frequencies.

However, in the conventional structure, for example, in the case of the structure shown in FIG. 7, since the two primary radiation feeding parts 1 and 2 are located in front of the opening of the main reflecting mirror 3, the projected area of the opening increases and blocking occurs. Problems such as phase efficiency deterioration and beam shift have occurred due to the deterioration of the efficiency or the fact that the primary radiation feeders 1 and 2 are not at the focal point of the main reflecting mirror 3. On the other hand, in the case of the one shown in FIG. 8, there is a problem that the cost of the double reflection mirror 4 having the frequency selection plate structure is high and the structure is complicated.

Therefore, an object of the present invention is to use two different frequencies.
An object of the present invention is to provide a small and inexpensive primary radiation feeder that can efficiently separate two signals.

[0006]

According to the first aspect of the present invention,
A horn for inputting and outputting at least two or more signals having different frequency bands, a coaxial tube connected to the horn throat and having a low-pass filter, and a coaxial tube disposed at the center of the coaxial tube and having a hollow inside. A center conductor having a waveguide structure capable of propagating a high-frequency signal, a dielectric rod antenna provided on an end face of the center conductor on the horn side, and radiating a high-frequency band signal; A circular TE1 is provided for signals in the low frequency band provided on the outer conductor portion of the central conductor.
A probe for converting from one mode to a coaxial TEM mode is provided in the primary radiation feeder.

According to a second aspect of the present invention, the center conductor is rotatable about an axis.

[0008]

As described above, according to the present invention, by combining a horn, a dielectric rod antenna, a coaxial tube with a low-pass filter, a center conductor having a waveguide structure, and a conversion probe, one primary radiation feed is provided. It is possible to efficiently demultiplex two or more signals having different frequencies, and it is possible to provide a small and inexpensive structure.

[0009]

Next, the present invention will be described with reference to the drawings. FIG. 1 is a sectional view showing an embodiment of a primary radiation feeder according to the present invention, and FIGS. 2 and 3 are lines AA and BB in FIG.
4 and 5 are sectional views taken along lines CC and DD in FIG. 1, and FIG. 6 is a sectional view taken along line EE in FIG. A horn 10 to which signals in two or more different frequency bands can be input is connected to a coaxial tube 12 having a low-pass filter 11 at the throat. Further, the inside of the central conductor 13 of the coaxial waveguide 12 is hollow and has a circular waveguide structure capable of propagating a signal in a high frequency band. The central conductor 13 is arranged at the center of the coaxial waveguide 12 via the dielectric support 19. Further, a dielectric rod antenna 14 for efficiently radiating a signal in a high frequency band is movably provided inside the horn-side end face of the center conductor 13.
A probe 15 for converting a signal in a low frequency band from the TE11 mode to the coaxial TEM mode is attached to the outer conductor portion of the center conductor 13.

Signals in the low frequency band are transmitted from the horn 10 to the TE.
The signal is input as the 11 mode, converted into the coaxial TEM mode by the probe 15 attached to the center conductor 13 of the coaxial tube 12, and propagated in the coaxial tube 12. Further, the signal is converted from the coaxial TEM mode to the rectangular waveguide TE10 mode by the doorknob type coaxial waveguide converter 16 and output from the waveguide terminal 17.

On the other hand, the signal in the high frequency band FH is
The light propagates from the dielectric rod antenna 14 provided inside the center conductor 13 to the inside of the circular waveguide central conductor 13 and is output from the waveguide terminal 18. Since the low-pass filter 11 is provided in the coaxial tube 12, a signal in a high frequency band is transmitted to the coaxial tube 12
To prevent leaks. Further, by adjusting the position of the dielectric rod antenna 14 back and forth, the phase center of the high frequency band can be made closer to the phase center of the low frequency band. This also makes it possible to prevent the deterioration of the frequency characteristics due to the difference in the phase centers.

By providing the rotary joint 20 at one end of the coaxial waveguide 12 and making the central conductor 13 rotatable about its axis, the polarization can be easily adjusted.

[0013]

As described above, according to the primary radiation feeder according to the present invention, a horn for inputting / outputting at least two or more signals having different frequency bands, and a low range connected to the horn base. A coaxial tube having a filtering section, a central conductor having a waveguide structure, a dielectric rod antenna provided on an end surface of the central conductor on the horn side, and a probe provided on an outer surface conductor section of the central conductor. With the configuration provided, it is possible to effectively demultiplex two or more signals having different frequencies with one primary radiation feeding unit, and it is possible to provide a small and inexpensive structure.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing an embodiment of a primary radiation feeder according to the present invention.

FIG. 2 is a view taken along the line AA of FIG. 1;

FIG. 3 is a view taken in the direction of arrows BB in FIG. 1;

FIG. 4 is a sectional view taken along line CC of FIG. 1;

FIG. 5 is a sectional view taken along line DD of FIG. 1;

FIG. 6 is a view taken along the line EE of FIG.

FIG. 7 is a schematic configuration diagram showing an example of a conventional small antenna.

FIG. 8 is a schematic configuration diagram showing another example of a conventional small antenna.

[Explanation of symbols]

 10 Horn 11 Low-pass Filter 12 Coaxial Tube 13 Center Conductor 14 Dielectric Rod Antenna 15 Probe

Claims (2)

(57) [Claims] 1. A horn for inputting / outputting at least two or more signals having different frequency bands, a coaxial tube connected to the throat of the horn and having a low-pass filter, and arranged at the center of the coaxial tube. A central conductor having a hollow inside and a waveguide structure capable of propagating a high-frequency signal, and a dielectric material provided on the horn-side end surface of the central conductor and radiating a high-frequency band signal. A primary radiation feeder comprising: a rod antenna; and a probe provided on the outer conductor of the center conductor and converting a signal in a low frequency band from a circular TE11 mode to a coaxial TEM mode. 2. The primary radiation feeder according to claim 1, wherein the center conductor is rotatable about an axis.