JPH0536917U - Spiral antenna - Google Patents

Abstract

(57) [Summary] (Modified) [Purpose] To provide a spiral antenna that facilitates miniaturization and improves transmission and reception efficiency. An insulating columnar body 2a, a spiral groove 4a provided on a side surface of the insulating columnar body 2a, and a plating layer 5a provided on a concave surface of the spiral groove 4a are provided. To do. [Effect] Since the plating layer for the antenna conductor does not move by an external force, the space between the adjacent plating layers can be narrowed and the antenna can be downsized. The plating layer 5a can be made thin because it does not protrude from the side surface of the insulating columnar body 2a. Moreover, since the surface area of the plating layer 5a can be increased without increasing the size, the efficiency of transmission and reception is improved.

Description

[Detailed description of the device]

[0001]

[Industrial application]

 The present invention relates to a spiral antenna using an antenna conductor composed of a spiral plating layer.

[0002]

[Prior Art]

 Antennas used in small-volume devices such as mobile phones often use small spiral antennas with spirally formed antenna conductors.

FIG. 3 is a side view of a conventional spiral antenna 1c. FIG. 3 shows a spiral antenna 1c in which an antenna conductor 3c made of a metal wire, a metal strip, a metal foil or the like is spirally wound around an insulating columnar body 2c made of ceramics or resin. There is also a spiral antenna in which only the antenna conductor 3c is spirally wound and the insulating columnar body 2c is air. The spiral antenna 1c is made smaller than a conventional linear rod antenna (not shown) or the like because the antenna conductor is spirally wound.

FIG. 4 is a side view of another conventional spiral antenna 1d. FIG. 4 shows a spiral antenna in which three antenna conductors, that is, an antenna conductor 3d1, an antenna conductor 3d2, and an antenna conductor 3d3 are spirally wound around an insulating columnar body 2d made of ceramics or resin. 1d is shown. Since the spiral antenna 1d uses a plurality of antenna conductors, it has an advantage that the resonance frequency band is wider than that of the spiral antenna 1c.

[0005]

[Problems to be solved by the device]

 Since the spiral antennas 1c and 1d are still large for the purpose of incorporating an antenna in the small volume device, it is necessary to further miniaturize the antenna. However, the smaller the spiral antennas 1c and 1d are, the more difficult it is to wind the antenna conductors 3c, 3d1 to 3d3 around the insulating columnar bodies 2c and 2d in a spiral shape. Has working limits. In addition, since most of the spiral winding work has conventionally been done manually, there has been an economic problem that the manufacturing cost increases as the size is reduced.

Further, for example, when an external force that bends the spiral antennas 1c and 1d is received, the antenna conductors 3c and 3d1 to 3d3 on the inside of the bend move along the insulating columnar bodies 2c and 2d, and the adjacent antenna conductors In order to prevent contact between them and shortening from the initially set electrical antenna length, it is necessary to make the distance between antenna conductors Pc greater than this moving distance, and there is a physical limit to miniaturization. there were.

Further, when the antenna is built in the device as described above, the efficiency of transmission / reception decreases, so an antenna with higher efficiency of transmission / reception is preferable. Generally, the transmission / reception efficiency can be improved by enlarging the surface area of the antenna conductor, but in this case, the spiral antennas 1c and 1d become large in size, which is contrary to the above-mentioned demand for miniaturization, which is difficult to carry out. Becomes

Here, the reason for this will be described in more detail for the spiral antenna 1c. The surface area of the antenna conductor 3c of the spiral antenna 1c is expanded only by increasing the diameter of the antenna conductor 3c, because the length of the antenna conductor 3c is made constant by the electric antenna length suitable for the frequency used. . Further, as described above, the distance Pc between the antenna conductors needs to be sufficient for each circumference. Therefore, the outer diameter of the spiral antenna 1c becomes twice as large as the diameter of the antenna conductor 3c. Further, the length of the insulating columnar body 2c is increased by a length obtained by multiplying the number of spirals by the amount of the diameter of the antenna conductor 3c being increased. As described above, it is impossible to improve the transmission / reception efficiency and achieve the size reduction at the same time. In view of the above problems, the present invention aims to provide a spiral antenna which can be easily miniaturized and has improved transmission / reception efficiency.

[0009]

[Means for Solving the Problems]

 The present invention has been made to achieve the above object, and is provided in an insulating columnar body, a spiral groove provided on a side surface of the insulating columnar body, and a concave surface formed by the spiral groove. A spiral antenna comprising a plated layer.

[0010]

[Action]

 Since the antenna conductor in the spiral antenna of the present invention is the spiral plating layer provided on the side surface of the insulating columnar body, there is no movement along the insulating columnar body due to an external force. Therefore, even if the distance between the adjacent plating layers that circulate is narrowed, since they do not contact each other at all, it is easy to reduce the size.

Further, since this plating layer is provided on the concave surface of the spiral groove provided on the side surface of the insulating columnar body, it does not project from the side surface of the insulating columnar body, which is smaller than that of the conventional antenna. Can be made thinner by the diameter of the antenna conductor. Further, the surface area of the plating layer serving as the antenna conductor can be increased depending on the depth, width, and cross-sectional shape of the spiral groove, so that transmission / reception efficiency can be improved.

The insulating columnar body is made of ceramics or resin and has an arbitrary shape such as a cylinder, an elliptic cylinder, or a prism. Further, when a material having a high dielectric constant is used for the insulating columnar body, the length of the electric antenna is shortened, and thus the spiral antenna is further downsized.

Further, for example, (1) changing the insulating columnar body to an insulating tubular body, (2) the cross-sectional shape of the spiral groove is a semi-circular groove, a semi-elliptical groove, a semi-gulberry groove, a wrinkle shape. The technology of the present invention, such as forming grooves of any shape such as uneven grooves, trapezoidal grooves, and triangular grooves, (3) changing the distance between adjacent plating layers, and (4) changing the number of plating layers Of course, various changes are possible within the idea.

[0014]

【Example】

 FIG. 1 is a side view of a spiral antenna according to an embodiment of the present invention. To explain based on FIG. 1, a spiral groove 4a is provided on the side surface of an insulating columnar body 2a made of ceramics or resin and having an arbitrary shape such as a cylinder, an elliptic cylinder, or a prism, and the spiral groove 4a is used. A spiral antenna 1a having a plated surface 5a made of gold, silver, copper, tin, solder or the like on the concave surface is shown.

The spiral antenna 1a has a spiral groove 4a on the side surface of the insulating columnar body 2a and a plating layer 5a on the concave surface of the spiral groove 4a. A spiral groove 4a is provided on the side surface, and then a plating layer is applied to the entire surface or the entire side surface of the insulating columnar body 2a, and finally an extra plating layer of the outermost layer on the side surface of the insulating columnar body 2a is formed, It is obtained by a manufacturing method or the like, which is removed by polishing or the like, and the plated layer 5a on the concave surface due to the spiral groove 2a is left.

In this spiral antenna 1a, since the plating layer 5a serving as an antenna conductor does not move along the insulating columnar body 2a due to an external force, the antenna conductor distance Pc of the spiral antenna 1c shown in FIG. In comparison, since it is easy to reduce the plating layer distance Pa, it is easy to reduce the size. Further, since the plating layer 5a is provided on the concave surface formed by the spiral groove 4a, it does not protrude from the side surface of the insulating columnar body 2a and can be made thinner than the conventional antenna.

Further, the surface area of the plating layer 5a is widened by increasing the width of the spiral groove 4a, forming a deep groove, providing a groove having wrinkle-shaped irregularities, etc., and thereby improving the transmission / reception efficiency. can do. As a matter of course, unless the circulating plating layers 5a are connected to each other, it is possible to reduce the plating layer distance Pa to reduce the size of the antenna and to increase the surface area of the plating layer 5a to improve the efficiency of transmission and reception. It can be carried out.

FIG. 2 is a side view of a spiral antenna according to another embodiment of the present invention. Referring to FIG. 2, the spiral groove 4b1, the spiral groove 4b2, and the spiral groove 4b3 are separated from each other on the side surface of the insulating columnar body 2b such as a cylinder, an elliptic cylinder, or a prism made of ceramics or resin. A spiral antenna 1b is shown in which the plating layers 5b1, 5b2, and 5b2 made of gold, silver, copper, tin, solder, or the like are provided on the concave surfaces of the spiral grooves 4b1 to 4b3, respectively. Since the broken lines showing the plating layers 5b1 to 5b3 on the back surface are complicated when all are shown, only the upper end of the plating layer 5b1 and the lower end of the plating layer 5b3 are shown, and the others are omitted.

This spiral antenna 1b is basically the same as the spiral antenna 1a, but since it has a plurality of plated layers 5b1 to 5b3 to be antenna conductors, the resonance frequency band can be widened. . Further, the size can be reduced as compared with the spiral antenna 1d shown in FIG. It should be noted that the present invention is not limited to the above-mentioned embodiment, and various modifications can be made within the technical idea of the present invention, such as obtaining by other manufacturing methods.

[0020]

[Effect of the device]

 As described above, according to the present invention, the insulating columnar body, the spiral groove provided on the side surface of the insulating columnar body, and the plating layer provided on the concave surface by the spiral groove are provided. Since the spiral antenna is characterized by being provided, the plating layer that serves as the antenna conductor does not move, and as a result, even if the distance between the adjacent plating layers spirally spiraling is narrowed, they do not come into contact with each other, resulting in miniaturization. It has the unique effect of facilitating.

Further, since the plated layer which becomes the antenna conductor does not protrude from the side surface of the insulating columnar body, it can be made thinner than the conventional antenna diameter. In addition, since the surface area of the plated layer serving as the antenna conductor can be increased, the efficiency of transmission and reception can be improved. Further, since the plating layer is provided on the concave surface of the spiral groove, an easy manufacturing method can be adopted when forming the spiral plating layer.

[Brief description of drawings]

FIG. 1 is a side view of a spiral antenna according to an embodiment of the present invention.

FIG. 2 is a side view of a spiral antenna according to another embodiment of the present invention.

FIG. 3 is a side view of a conventional spiral antenna.

FIG. 4 is a side view of another conventional spiral antenna.

[Explanation of symbols]

 1a, 1b, 1c, 1d Spiral antenna 2a, 2b, 2c, 2d Insulating columnar body 3c, 3d1, 3d2, 3d3 Antenna conductor 4a, 4b1, 4b2, 4b3 Spiral groove 5a, 5b1, 5b2, 5b3 Plating layer

Claims (1)

[Scope of utility model registration request] 1. A spiral antenna comprising: an insulating columnar body; a spiral groove provided on a side surface of the insulating columnar body; and a plating layer provided on a concave surface of the spiral groove. ..