JPS6098705A - Helical antenna - Google Patents

Abstract

PURPOSE:To obtain a helical antenna whose radiation pattern is symmetrical by arranging a cylinder where a conductive wire is wound on the circle of a dielectric at a prescribed pitch and a dielectric cylinder where a conductor wire is wound in reverse winding direction at a prescribed pitch to the former winding direction at the inside of the former cylinder coaxially. CONSTITUTION:A helix 45 is wound on the dielectric cylinder 44 at a prescribed pitch and a helix 47 is wound on the dielectric cylinder 46 placed at the inside of the cylinder 44 at a prescribed pitch in the reverse winding direction to the former winding direction. The helical antenna whose radiation pattern is symmetrical and which is small in size and light in the weight is obtained by connecting a reflector 48 and connectors 49, 50 without using a metallic grating filter.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a helical antenna formed by coaxially arranging a plurality of radiating elements.

[Background of the invention]

Conventionally, when configuring multiple radiating elements, a multi-frequency common antenna as shown in Figure 2, which is constructed using a metal lattice filter as a frequency selection plate as shown in Figure 1, or a multi-frequency antenna as shown in Figure 3, is used. There is an antenna using a coupling circuit. As shown in FIG. 2, the multi-frequency common antenna consists of a metal lattice filter l, an antenna input, and an antenna B3, and the metal scrap lattice filter is made of a rectangular mesh or the like as shown in FIG. The antenna A2 and the antenna B3 are antennas that use different frequency bands.

The metal grating filter 1 has the function of splitting microwaves, and operates as a reflection plate when the grating period is smaller than the wavelength, and as a transmission plate when it is larger.

The antenna A2 transmits and receives microwaves that pass through the metal lattice filter 1, and the antenna B3 transmits and receives microwaves that reflect the metal lattice filter 1. This multi-frequency shared antenna is for sharing a plurality of frequencies with one antenna, and the antenna B3 is different from the antenna A2. are placed so that they are at the same focal point. Moreover, the antenna 10 using the coupling circuit as shown in FIG.
) radio waves to power synthesis circuit 30-1.30-2.30-3
and a combination circuit 20-1.20-2.20-3 to perform transmission and reception over one antenna. In these two configurations C2, the multi-frequency common antenna has drawbacks such as an increase in the overall size due to demultiplexing using the metal lattice filter l. In addition, an antenna using a coupling circuit (
Second, there are drawbacks such as loss due to the power combining circuit, increased weight, and deterioration of the radiation pattern because different frequency bands are transmitted and received using a single antenna.

[Purpose of the invention]

An object of the present invention is to eliminate the drawbacks of conventional antennas such as the large size of the composite element antenna, difficulty in arrangement, and deterioration of the radiation pattern, and to provide a simple helical antenna with a symmetrical radiation pattern configuration. It is in.

[Summary of the Invention] The present invention is based on a dielectric cylinder in which a conductive line is wound at a constant pitch, and a conductive line in a dielectric cylinder with a small diameter on the inner side and a conductive line wound in a direction opposite to the outside at a constant pitch. (Secondly, this method constructs a multi-frequency common antenna that is small, lightweight, and has a symmetrical radiation pattern without using a metal grid filter.)

[Embodiments of the invention]

FIGS. 4(a) and 4(b) are a side view and a front view showing the configuration of an embodiment of the helical antenna according to the present invention.

In the figure, a hexock 45 is wound at a constant pitch on an iK body cylinder 44, and a helix 47 is arranged on a dielectric cylinder 46 inside the hexock 45.
It is wound at a constant pitch in the opposite direction. As shown in FIG.
．． By connecting 50, a sihelical antenna can be constructed.

The two hem socks 45 and 47 are wound in opposite directions, but either one may be wound to the right or to the left.

In the above configuration, the winding pitch angle of helix 45.47 is 01.01, the winding diameter is , D, and the winding length is 11. L
Let x and θ1-θg=12. DI=104-1D2-27
-1 When tt = 40 (to), and win = 12 (to) (2. When the helix 45.47 is wound in the same direction (for example, left-handed winding), the radiation pattern of the inner heel sock 47 is the 5th The figure shows the inner sock when the helices 45 and 47 are wound in opposite directions (for example, the helix 45 is wound to the left and the helix 47 is wound to the right) as shown in this embodiment (Fig. 4(a)). The radiation patterns of 47 are shown in FIG. 6. In this case, the helix 45 has 9
Radio waves in the 15 MHz frequency band are also transmitted to Hesocks 47.
was supplied with radio waves in the 3000 MB2 frequency band. If you compare Figures 5 and 6, you will understand.J, $5
In the radiation pattern shown in the figure, the radiation pattern of the inner hemsock 47 is disturbed by interference with radio waves in the frequency band shared by the hesock 45.

However, in the case of FIG. 6, a symmetrical radiation pattern can be obtained by winding the inner helix 47 in the opposite direction to the helix 45, that is, by winding it to the right. The radiation pattern of the outer hemsock 45 is also not affected by the inner hemsock 47, resulting in a symmetrical radiation (turn) as shown in FIG.
Although the case of 15 MHz to 3000 MHz is illustrated, it has been confirmed that similar results can be obtained in other frequency bands.

As described above, according to this embodiment, a radiating element covering a plurality of frequency bands can be constructed without using a metal lattice filter or the like, and a helical antenna that is small, lightweight, and has a symmetrical radiation pattern can be obtained.

Similarly, the configuration of the helical antenna in which two hexocks are arranged on the same axis shown in this embodiment can be applied to communications over multiple frequency bands such as satellite communication systems.

〔Effect of the invention〕

According to the present invention, it is possible to omit the metal lattice filter and lossy power combining circuit that were conventionally required when constructing a multi-frequency common antenna, and it is possible to obtain a helical antenna that is small, lightweight, and has a symmetrical radiation pattern. .

[Brief explanation of drawings]

Figure 1 shows the structure of a metal lattice filter, and (a)
2 is a configuration diagram of a multi-frequency common antenna, FIG. 3 is a configuration diagram of an antenna using a coupling circuit, and FIG. 4 is a configuration diagram of an antenna using a coupling circuit. The structure of an embodiment of such a helical antenna is shown, FIG. 5(a) is a side view thereof, FIG. Figure 5 is a diagram showing the radiation pattern when both the outer and inner hem socks are left-handed, and Figure 6 is a diagram showing the radiation pattern when the outer hem socks are left-handed and the inner hem socks are right-handed in this embodiment. A diagram showing a radiation pattern, FIG. 7 is a diagram showing a radiation pattern of the outer hemock in this embodiment. 1...Metal lattice filter, 2...Air, vi! A,
3... Antenna B, 44... Dielectric cylinder, 45...
- Helix, 46... Dielectric cylinder, 47... Helix, 48... Reflector, 49.50... Connector. Agent Tatsuyuki Unuma (and 1 other person) M5 Figure 6

Claims (2)

[Claims] (1) A circular segment in which a conductive line is wound at a constant pitch angle on a dielectric cylinder, and a small-diameter dielectric cylinder in which a conductive line is wound in the opposite direction at a constant pitch angle inside this cylinder are arranged coaxially. A helical antenna characterized by comprising a plurality of radiating elements. (2) The conductive lines are wound at the same pitch angle within the two dielectrics.
The helical antenna described in item 1).