JP2001308628A - Multiwinding loop antenna - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a multiwinding loop antenna that can be used not only for transmission but also for reception, despite its being a compact unit. SOLUTION: The multiwinding loop antenna is constituted of a wire, of which effective diameter is set in the range of 3.2 to 15 millimeters, the circumferential length per loop being formed as to be equal to 0.03 to 1.2 millimeter wavelength, so that it becomes the same as that of the operating frequency, and the number of loop is set in the range of 2 to 8. Such a constitution enables the antenna to be used for both transmitting and receiving purposes.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-turn loop antenna (frame antenna) mainly used for amateur radio.
About.

[0002]

2. Description of the Related Art As a conventional multi-turn loop antenna, a wire rod having a diameter of about 1 mm is used.
Some loops are wound several meters, and a transceiver is connected to both ends of the loop antenna via a matching device.

[0003]

However, according to an experiment conducted by the inventor using the above-mentioned loop antenna, the matching between the transmitter and the receiver was achieved by the operation of the matching device, but the matching was achieved with the amateur. In a frequency band that can be used for radio, if it is dedicated to reception, it can hardly be used for both transmission and reception. The problem to be solved by the present invention is to provide a loop antenna that can be used not only for reception but also for transmission despite its small size.

[0004]

Means for Solving the Problems The inventors of the present invention who have conducted experiments in order to solve the above-mentioned problems have set the wire diameter of the wire, the length of the loop-winding (perimeter), the distance between the wires, and the like within a certain range. It was found that by limiting to within, the loop antenna could be used for transmission and reception. The detailed configuration will be described in the next section.

[0005] The configuration of the invention described in claim 1, that is, the multi-turn loop antenna according to the invention described in claim 1 (hereinafter referred to as "the loop antenna of claim 1"), comprises a plurality of wire rods in a rectangular shape (square). It is an antenna that is wound. The wire material has a substantial wire diameter of 3.2 to 15.
0 mm, the circumference of the wire-winding is formed equal to the used frequency of 0.03 to 1.2 wavelength, the distance between each loop is set to 5 to 50 mm, the winding The number is 2 to 8 times. The loop surface is generally vertical, but may be horizontal or inclined. It is preferable to provide an automatic matching device (auto antenna tuner) between the feeding point of the loop antenna and the transceiver that can automatically perform impedance matching for each used frequency.

According to the first aspect of the present invention, the use of the loop antenna according to the first aspect enables transmission and reception in a used frequency band. If the automatic matching device is provided, the impedance can be automatically matched in a wide frequency band and in a plurality of frequency bands, so that the loop antenna can be used efficiently and conveniently.

The configuration of the invention described in claim 2 The multi-turn loop antenna according to the invention described in claim 2 (hereinafter referred to as "loop antenna of claim 2") is limited to the configuration of the loop antenna of claim 1. Is added, and the loop is formed in a substantially square shape.

According to the second aspect of the present invention, when the loop antenna of the second aspect is used, basically the same operational effects as those of the loop antenna of the first aspect can be obtained. In addition to this, the mechanical strength can be increased by forming a substantially square shape, for example, as compared with a case of forming a circular shape.

According to a third aspect of the present invention, there is provided a multi-turn loop antenna according to the third aspect of the present invention (hereinafter referred to as a "loop antenna of the third aspect"). Is limited,
The loop surface is configured to be vertically installed.

[0010] Loop antennas operational effects claim 3 of the invention described in claim 3 has been confirmed to have a directivity. Thereby, in addition to the effects of the loop antenna according to claim 1 or 2, transmission and reception according to the directional characteristics can be performed.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment of the present invention (hereinafter, referred to as "the present embodiment") will be described with reference to the drawings. FIG. 1 is a perspective view of a loop antenna.
FIG. 2 is a partially enlarged view of FIG.

Schematic Configuration of Loop Antenna The schematic configuration of the loop antenna 1 will be described with reference to FIGS. The loop antenna 1 includes an element 3
A support part 5 for vertically supporting the element part 3 and
It is roughly constituted from. Reference numeral 11 denotes an element portion 3
3 shows an automatic matching device provided between the power feeding point of FIG. The number of turns of the element portion 3 can be appropriately selected in a range of 2 to 8 times, preferably in a range of 4 to 6 times.

[0013] Configuration element portion 3 of the element portion 5 turns the wire square (rectangle) (i.e., the loop 3e are five form) is constituted by, feeding unit by the beginning and end of the wire 4 are configured. The wire diameter of the wire rod is 3.2 to 15.
It is good to select in the range of 0 mm, preferably in the range of 3.5 to 5.5 mm. In this embodiment,
The wire diameter is an aluminum wire having a diameter of 4 mm. The reason why the aluminum wire was selected is that it is not easily rusted, is lightweight, is inexpensive, and is relatively easy to obtain. However, the material is not limited to the aluminum wire, and for example, a copper wire or a stainless steel wire can be used. Further, the above-described wire diameter may be substantially formed by twisting or bundling thin wires made of these materials. Similarly, the above-described substantial wire diameter may be formed by using a pipe material. The wire may be composed of a bare wire, but may be coated to alleviate aging deterioration or the like.

The circumference length L (shown as 1 / 4L in FIG. 1) of the wire material constituting the element portion 3 is used frequency, that is, the lowest frequency (lowest used frequency) of the frequencies to be used. Preferably, the wavelength is equal to or less than 0.05 to 0.
It is set so as to have the same length as five wavelengths. For example,
Assuming that 3.5 megahertz (MHz) is the lowest frequency used, the wavelength of this frequency is about 85.7 meters. Therefore, if the perimeter is set to 0.04 wavelength here, the perimeter of about 3.4 meters is obtained. . If the highest frequency used is, for example, 50 MHz, the wavelength is 6 meters. Here, a comparison between the circumference of 3.4 meters and the wavelength of 6 meters results in a relationship of 0.56 wavelengths. 0.56
Since the wavelength is 1.2 wavelengths or less, it falls within the above-mentioned set range.

Each wire 3e constituting the element portion 3 is
Support arms 25, 25,. . Stopper 26,
26,. . . Therefore, they are arranged and fixed at equal intervals via the line interval G. It has been found that good results can be obtained by setting the line interval G to 5 to 50 mm, preferably 15 to 30 mm. Although the element portion 3 in the present embodiment is formed in a substantially square shape, the element portion 3 may be formed in a shape other than this, for example, a circle or a polygon other than a square.

The structure of the support 5 will be described in detail with reference to FIGS. The support portion 5 includes a substantially cross-shaped connection pipe (connection member) 19 located at the center of the element portion 3.
And the horizontal arm 2 inserted and fixed in the connecting pipe 19.
1, 21 and the vertical arms 23, 23 and the support arms 25, 25,. . And In the present embodiment, the connection pipe 19
Only the arm is made of metal, and each arm is made of synthetic resin in consideration of insulation. The lower vertical arm 23 is connected to the support 9, and the support 9 is configured such that the upper portion thereof is rotated by the rotator 7 in the horizontal direction together with the loop antenna 1. As shown in FIG. 1, in the present embodiment, the support portion 5 is arranged such that the loop surface of the element portion 3 is oriented vertically.
Is configured, but the loop surface may be configured to be horizontal.

Using the loop antenna The aluminum wire having a wire diameter of 4 mm was set to have a circumference L of 3.8 m (1 / 4L = 0.95 m) and the line interval G of 22 mm. When a loop antenna constituted by winding 5 times into a substantially square shape was used by being vertically installed 8 meters above the ground, the following results were obtained. In addition, almost the same result was obtained when the film was wound six times. In these experiments, an automatic antenna tuner (A
H-4) was used.

First, regarding the directivity of the loop antenna,
Since better results were obtained in the direction parallel to the loop surface than in the vertical direction, it was confirmed that this loop antenna had a figure-eight characteristic in a direction substantially parallel to the loop surface (the length direction of the horizontal arm). Was. Next, the results of use by frequency band are as follows. Each frequency band (3.5, 7, 10, 14, 18, 21, 21) for amateur radio up to 3.5 to 28 MHz.
28), it was possible to communicate (receive and transmit) with domestic and foreign amateur radio stations, and it was found that the antenna had at least sufficient performance as an amateur radio communication antenna. In addition, since the antenna is a loop antenna, there is an advantage that an occupied area for installation is smaller than that of a dipole antenna or the like. When this loop antenna was horizontally installed, it was confirmed that the antenna had omnidirectional characteristics.

[0019]

According to the multi-turn loop antenna according to the present invention, not only reception,
It can also be used for transmission.

[Brief description of the drawings]

FIG. 1 is a perspective view of a loop antenna.

FIG. 2 is a partially enlarged view of FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Loop antenna 3 Element part 4 Feeding part 5 Support part 7 Rotator 9 Post 11 Automatic matching device 15 Transceiver 19 Connecting member (connecting pipe) 21 Horizontal arm 23 Vertical arm 25 Support arm 26 Stopper

Claims (3)

[Claims] 1. A multi-turn loop antenna formed by winding a wire a plurality of times, wherein the wire has a substantial wire diameter of 3.2 to 15 millimeters, and the circumference of each wire-turn is equal to 0. 03-1.
A multi-turn loop antenna, which is formed equal to two wavelengths, the distance between each loop is set to 5 to 50 mm, and the number of turns is 2 to 8 times. 2. The multi-turn loop antenna according to claim 1, wherein the loop is formed in a substantially square shape. 3. The multi-turn loop antenna according to claim 1, wherein the loop surface is configured to be vertically installed.