JPS6018003A - Frequency sharing antenna - Google Patents

Abstract

PURPOSE:To ensure the highly effective actuation of an antenna even with two frequencies having a big difference by irradiating the radio wave radiated from a horn antenna to a main reflector after reflecting it by a metallic substrate of a print antenna. CONSTITUTION:The phase center of a horn 9 for high frequencies is set at a symmetrical position to the focal point 8 of a main reflector 1 against a print antenna 13. The distribution of irradiation of the reflector 1 is approximately equal to that obtained when the phase center of the horn 9 is set at the focal point 8 of the reflector 1. The original phase shift of the horn 9 is corrected by setting the phase center of the horn 9 at the front of an image point 12 of the focal point 8.

Description

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

In an anti-Q4 mirror type frequency sharing antenna, the characteristics of the primary radiator that illuminates the reflecting mirror are important. Conventionally, in this type of antenna, there are those that use a frequency-sharing horn antenna as the i-th order radiator, and those that use a horn antenna and a frequency selection plate dedicated to each frequency.

FIG. 1 is a side view showing an example of a conventional frequency sharing antenna using a Koji wave number sharing horn antenna. That is, the main reflector 1 is irradiated with two types of radio waves emitted by the frequency-sharing horn antenna 2, and the radio waves of these two frequencies are reflected by the main reflector l, and are transmitted in the air along the radio wave path 7.7'. radiate to. Coupling terminals 3 and 3' are provided on the horn wall of the frequency-sharing horn antenna 2, and radio waves of lower frequency are inputted from the input/output terminal 5 and sent via the combining circuit 4 to the coupling terminals 3 and 3'. The higher frequency radio waves are input from the input/output terminal 6. Reference numeral 8 is the focal point of the main reflector l. In this antenna,
The diameter of the open area 11 of the frequency-sharing horn antenna 2 is at least 1
For example, if the frequency ratio of the two shared frequencies is 5 (for example, 2 GHz and 10 GHz), the horn pattern becomes too sharp at high frequencies and the center of the main refracting mirror l becomes This results in a decrease in gain. In addition, high frequency radio waves are connected to coupling terminal 3.
．． 3', the amplitude distribution and phase distribution of the aperture surface change, resulting in a decrease in gain.

FIG. 2 is a side view showing an example of a conventional frequency sharing antenna using a frequency selection plate. In this case, a horn 9 for high frequencies and a signal 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, The frequency of radio waves is
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 main reflector l, and the horn 10 for low frequencies is placed at the focal point '8 of the main reflector l with respect to the frequency selection plate 11.
The image point 12 of j:15 point 8 is placed symmetrically with the focal point 8 of . Since this antenna emits two frequencies using dedicated horns, it is possible to obtain a highly efficient illuminance distribution at each frequency. However, there is a drawback that loss occurs when radio waves of each frequency pass through the frequency selection plate 11 and are reflected. Furthermore, the frequency selection plate 11 is very difficult to manufacture and expensive. Furthermore, the horn 10 for low frequencies is quite large.

An object of the present invention is to solve the conventional drawbacks mentioned in (1) and to provide a frequency sharing antenna that is small, inexpensive, and highly efficient.

The antenna of the present invention includes a primary radiator and one or more reflecting mirrors that reflect radio waves radiated by the primary radiator, wherein the primary radiator is arranged on the upper surface of a metal substrate. The printed antenna is composed of a printed antenna in which a dielectric layer is formed on the substrate and a plurality of radiating elements are arranged on the dielectric layer, and a horn antenna. The horn antenna is arranged at a position symmetrical to the focal point with respect to the printed 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 diagram showing details of the primary radiator portion of this embodiment. That is, the primary radiator is composed of a horn 9 for high frequencies and a printed antenna 13 for low frequencies, and the printed antenna 13 is arranged on the main reflecting mirror l side near the focal point 8 of the main reflecting mirror l. The horn 9 for high frequencies has its phase center located at a position symmetrical to the focal point 8 of the main reflector 1 with respect to the printed antenna 13, that is, the image point 12 of the focal point 8.
It is set up so that it will come. The printed antenna 13 is a substantially planar antenna in which a dielectric layer 15 is formed on the upper surface of a metal substrate 14, and a plurality of radiating elements 16 are arranged on two sides of the dielectric layer 15. Excite frequency radio waves. High frequency radio waves are excited by a high frequency horn 9. Most of the radio waves radiated from the high frequency horn 9 are reflected by the metal substrate 14 of the printed antenna 13 and directed toward the main reflecting mirror l. Therefore, the irradiation distribution on the main reflecting mirror 1 is almost the same as when the phase center of the high frequency horn 9 is located at the focal point 8 of the main reflecting mirror 1. A portion of the radio waves emitted from the high frequency horn 9 is reflected by the radiation element 16 and has a phase advance compared to the radio waves reflected by the metal substrate 14. In a normal horn, the phase of the part emitted at an angle away from the central axis of the horn is slightly shifted from the phase of the middle and sixth parts, and the phase shift is.

When the phase center of the horn is before the image point 12 of the focal point 8, it is delayed, and when it is located after, it is advanced. Therefore, if the phase center of the horn 9 for high frequencies is placed in front of the image point 12 of the focal point 8, the phase shift that the horn 9 for high frequencies originally has will be corrected, and the effect of can be achieved.

On the other hand, radio waves radiated from the printed antenna 13 are directly reflected by the main reflecting mirror 1 and radiated into space. The center direction of the radio waves radiated from the printed antenna 13 is not perpendicular to the printed antenna 13, but needs to be tilted slightly upward in the figure.
This can be easily realized by appropriately imparting the phase of the high frequency wave supplied to 6 between the radiating elements.

By arranging a plurality of high-frequency horns 9 or appropriately setting the excitation amplitude 9 phase of each radiating element of the printed antenna 13, it is possible to obtain not only a pencil beam but also a shaped beam. be. Further, the printed antenna is not limited to a planar shape, but can also be a hyperboloid, an ellipsoid, or the like.

The above is an explanation for the case where there is one reflecting mirror, but when applying to a Cassegrain antenna or Gregorian antenna with two reflecting mirrors, the sub-reflecting mirror and the above-mentioned sub-reflecting mirror where the primary radiator is usually installed. A printed antenna can be placed between the focal point and the focal point.

As described above, in the present invention, a printed antenna and a horn antenna are provided as primary radiators, and the radio waves radiated from the horn antenna are reflected by the metal substrate of the printed antenna and then reflected by the main reflection. Since it is configured to irradiate a mirror, it can operate efficiently even at two frequencies with a large difference in frequency. In addition, if a printed antenna is used as a primary radiator for low frequencies, 2"
, one horn antenna is not required, and a compact configuration is possible.

INDUSTRIAL APPLICABILITY The present invention can reduce the number of installed antennas when emitting or receiving radio waves of several frequencies in the rotational direction, such as in fixed communication or satellite communication, and has a large economic effect.

[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 a selection board, and Fig. 31-A is an embodiment of the present invention. A side view showing 1. FIG. 3 is a side view showing details of the primary radiator portion of the embodiment. In the figure, l: main reflector, 2: frequency common horn antenna, 3.3': coupling terminal, 48 synthesis. Circuit, 5, 6: Input/output terminal, 7.7': 'Radio wave path, 8
: Focus of main reflector l, 9: Horn for high frequency, lO
: Horn for low frequencies, 11/Frequency selection board, 12:
Image point at focal point 8, 13 niblint antenna, 14:
Metal substrate, 15: dielectric layer, 16: radiation element. Applicant 1 Koki Telegraph and Telephone Public Corporation Agent Patent Attorney Toshimune Sumita 4 2'l, 2 Figure 3

Claims (1)

[Claims] In an antenna comprising a primary radiator and one or more reflecting mirrors that reflect radio waves emitted by the primary radiator, the primary radiator includes a dielectric layer formed on the upper surface of a metal substrate and It is composed of a printed antenna in which a plurality of radiating elements are arranged on a dielectric layer, and a horn antenna, the printed antenna being disposed between the reflecting mirror and the focal point of the reflecting mirror, and the horn antenna comprising: A frequency sharing antenna, characterized in that the antenna is arranged at a position symmetrical to the focal point with respect to the printed antenna.