JPS6018004A - Frequency sharing antenna - Google Patents

Abstract

PURPOSE:To obtain the equivalent efficiency among antennas with use of each exclusive primary antenna by piercing a horn antenna through the area at the center of a print antenna where no radiating element is formed. CONSTITUTION:For higher frequencies, a primary reflector 1 is irradiated by a horn 9 for high frequencies which is piercing through a hole drilled at the center part of a print antenna 13 where no irradiating element 16 is formed. Then the reflector 1 reflects two radio waves of high and low frequencies radiated from the antenna 13 to the spaces along radio wave routes 7 and 7' respectively.

Description

[Detailed description of the invention] The present invention relates to a reflector type frequency sharing antenna.

In a reflector type frequency sharing antenna, the characteristics of the primary radiator that irradiates the reflector are important. Conventionally, in this type of antenna, there are those that use a horn antenna that can be used for one frequency as a primary radiator, and those that use a horn antenna and a frequency selection plate dedicated to each frequency. 1st
FIG. 1 is a side view showing an example of a conventional frequency sharing antenna using a same wave number sharing horn antenna. That is,
Main reflector l is radiated by frequency sharing horn antenna 2 2
The radio waves of these two frequencies are reflected by the main reflector 1 and radiated into the air along the radio wave path 7.7'. A coupling terminal 3.3' is provided on the horn wall of the frequency-sharing horn antenna 2, and the lower frequency radio waves are inputted from the input/output terminal 5 and sent to the combining circuit 4.3'.
The higher frequency radio waves are applied to the coupling terminal 3, 3' via the input/output terminal 6. Reference number 8 is
This is the focal point of the main reflecting mirror 1. In this antenna, the frequency sharing horn antenna 2 has at least one
For example, if the frequency ratio of the two shared frequencies is 5 (for example, 2GH2 and 10GHz), the horn pattern will become too sharp at high frequencies and the center of 1 reflector 1 will become too sharp. As a result, the gain (1i) decreases because the high-frequency radio waves are disturbed by the coupling terminal 3゜3', and the amplitude distribution and phase distribution of the aperture surface change, causing a decrease in gain, etc. There are drawbacks.

FIG. 2 is a side view showing an example of a conventional frequency sharing antenna using one frequency selection plate. In this case, a horn 79 for high frequencies and a horn 10 for low frequencies are provided separately, and the low frequency radio waves are reflected by the frequency selection plate 11 and then irradiated onto the main reflector 1, and the high frequency radio waves are The radio waves are
The light passes through a high-pass frequency selection plate 11 and illuminates the main reflecting mirror l. That is, the horn 9 for high frequencies is placed at the focal point 8 of the t-reflector l, and the horn 10 for low frequencies is placed at the image point 12 of the focal point 8, which is symmetrical to the focal point 8 of the main reflecting mirror 1 with respect to the frequency selection plate 11. Place it in δ. This antenna has two frequencies, each with its own dedicated antenna.
Since the light is emitted by 5, a highly efficient illuminance distribution can be obtained at each frequency. However, frequency selection board 1
One drawback is that loss occurs when radio waves of each frequency pass through or are reflected. In addition, the frequency selection board 11
is very difficult and expensive to manufacture. Furthermore, the horn 10 for low frequencies is quite large.

An object of the present invention is to solve the conventional drawbacks mentioned above and to provide a frequency sharing antenna that is small, inexpensive, and highly efficient.

The frequency sharing antenna of the present invention includes a primary radiator and one or more reflectors that reflect radio waves radiated by the primary radiator, wherein the primary radiator is arranged on the upper surface of a metal substrate. a printed antenna having a dielectric layer formed thereon and a plurality of radiators arranged on the dielectric layer L, and a horn disposed through a hole drilled in the center of the printed antenna; It is characterized by being comprised of an antenna.

Next, the present invention will be explained in detail with reference to the drawings.

FIG. 3 is a side view showing one embodiment of the present invention, and FIG.
The figure is a perspective view showing details of the primary radiator portion of this embodiment. That is, for lower frequencies, a dielectric layer 15 is formed on a metal substrate 141, and a printed antenna 13 in which a plurality of radiating elements 16 are arranged on the dielectric layer 15 is used to irradiate the main reflecting mirror 1. do. The higher frequency is irradiated onto the main reflecting mirror 1 by a horn 9 for higher frequencies, which is disposed through a hole drilled in the central part of the printed antenna 13 where the radiating element 16 is not formed6. ,
The main reflecting mirror 1 reflects radio waves of two high and low frequencies radiated from the high frequency horn 9 and the printed antenna 13, and radiates them into space along radio wave paths 7 and 7', respectively. Horn for high frequencies 9. The phase center of the printed antenna 13 is located at the focal point 8 of the main reflector 1, respectively.
Of course, it will be placed in

FIG. 4 shows a case where the printed antenna 13 has four radiating elements 16, and the center distance between the radiating elements 16 is 0.5.
The diameter of the radiating element 16 is selected to be approximately 0.9 wavelength.
It is determined by the dielectric constant ε' and the thickness t of the dielectric layer 15. For example, when εr=2..55°t=1.6 mm, it is approximately 0.3
There are 5 wavelengths.

The radiation pattern of the printed antenna 13 at this time becomes a curve 19 shown by a dotted line in FIG. Since the beam width can be adjusted by the element spacing of the radiating elements 16, the element spacing is set according to the aperture angle of the main reflecting mirror 1, required antenna efficiency, edge level, etc. FIG. 5 shows the case where the element spacing is set to 0.25 wavelengths, the horizontal axis shows the angle from the center, and the vertical axis shows the relative level of electric field strength.

Reference numbers 21.21' indicate the angle of the main reflector 1 with respect to the edge.

In the central part of the printed antenna 13, there is a space without the radiating element 16, and this part has a diameter of 0.35 to 0.9! Even if a circular object with the same wavelength is placed, the antenna 13
The radiation characteristics of are hardly affected.

For example, the operating frequency of the printed antenna 13 is set to 2.5G.
Hz, the operating frequency of '9 for high frequencies is 11
In the case of GHz, the aperture diameter of the horn 9 for high frequencies can be set to 1.54 to 4 wavelengths. When the opening r:I 11 of the horn 9 for high frequencies is set to 1.8 wavelength, the radiation pattern becomes a curve 20 shown by a solid line in FIG. Therefore, both the printed antenna 13 for low frequencies and the horn 9 for high frequencies can efficiently illuminate the main reflecting mirror 1. In order to make the phase distribution uniform on the aperture plane, it is necessary to place the phase centers of the printed antenna 13 and the horn 9 for high frequencies at the focal point 8 of the main reflector 1; This can be easily accomplished by inserting and removing the opening of the horn 9 into and out of a hole drilled in the center of the printed antenna 13.

FIG. 6 is a side view showing an embodiment of the present invention (m).
In this case, the printed antenna used is a normal printed antenna in which a waveguide element 22 is disposed in front of each radiating element. A plurality of waveguide elements 22 are arranged on the dielectric layer 15, and a high frequency horn 9 is provided at the center of the dielectric layer 15, similar to the above-mentioned printed antenna.
There is space to place.

In FIG. 3, a front foot offset type antenna has been described as the antenna type, but the antenna type may also be an axially symmetric type.

Alternatively, it may be of a double-reflector type. Further, the horn antenna may be a normal round or square It horn, a corrugated horn, or a dual mode horn.

Note that the excitation amplitude of each radiating element of the printed antenna 13,
By setting the phase appropriately, printed antenna 1
At an operating frequency of 3, not only the pencil beam but also
It is also possible to obtain shaped beams.

As described above, in the present invention, 1 of the low force frequency
1. Using a printed antenna as the next antenna. A horn antenna is used as the primary antenna for the higher frequency, and the horn antenna is arranged so as to penetrate through the central part of the printed antenna where the radio element r- is not formed. It is possible to obtain the same amplifier efficiency at two different frequencies using dedicated primary antennas. That is, there is an effect that a highly efficient frequency sharing antenna is realized. Furthermore, since the primary antenna for the low power frequency is a printed antenna, there is an advantage that the overall configuration is more compact than when a large-sized horn antenna is used as in the past.

The present invention can achieve great economic effects when used in communication system antennas that radiate and receive radio waves of several frequencies in the same direction, such as fixed communication and satellite communication.

[Brief explanation of drawings]

Fig. 1 is a side view showing an example of a conventional frequency sharing antenna, Fig. 2 is a side view showing an example of a conventional frequency sharing antenna using a frequency selection board, and Fig. 3 is a side view showing an example of the conventional frequency sharing antenna. A side view, No. 45!1 is a perspective view showing details of the primary radiator of the embodiment described above, and FIG. The WJS diagram is a side view showing another embodiment of the present invention. In the figure, ■ = main reflector, 2: frequency-sharing horn antenna, 3.3': coupling terminal, 4: combining circuit, 5.6 two-person output terminal, 7.7': radio wave path, 8: main reflector 1 focal point, 9: Horn for high frequency, IO: Horn for low frequency, 11: Frequency selection board, 12: Image point of focal point 8, 13: □ ``' Broom print antenna, 14'': Metal substrate, 15 : dielectric layer,
16: Radiating element, 22: Waveguide element f-0 Applicant Nippon Telegraph and Telephone Public Corporation agent Patent attorney Sumi 1-11 Toshimuneman ψ1 Insai 2 figure 'it'; 3 figure 31, 4 prisoner

Claims (1)

[Claims] In an antenna comprising a primary radiator and one or more reflectors that reflect radio waves radiated by the primary radiator, the primary radiator includes a dielectric layer formed on the upper surface of a metal substrate and It is characterized by being composed of a printed antenna in which a plurality of radiating elements are arranged on a dielectric layer, and a horn antenna disposed through a hole drilled in the center of the printed antenna. Frequency sharing antenna.