JP3183457B2 - Helical antenna - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a helical antenna, and more particularly to a helical antenna which is easy to manufacture and has few errors.

2. Description of the Related Art Conventionally, helical antennas mounted on artificial satellites and the like require weight reduction. In general, the design data of a helical element is determined analytically based on its structure and manufacturing method, and is determined by trial production and performance evaluation. Since the performance of helical antennas is greatly affected by the element length, element diameter, and element pitch of the helical elements of the component parts, it is important to adopt a structure and manufacturing method that stably achieve the accuracy as specified in the design specifications. It is.

FIG. 8 is a diagram showing a configuration example of a conventional helical antenna. The helical antenna in FIG.
It is manufactured by spirally winding a wire 6 around a wire.

FIG. 9 is a diagram showing another configuration example of a conventional helical antenna and a method of manufacturing the same. The helical antenna shown in the figure is manufactured by combining a dielectric pipe 7 as a component and a flexible printed board (element film) 8. The flexible printed board 8 has a parallelogram shape in which the angle between the bottom side and the side is not a right angle, and a plurality of metal conductor patterns are formed in parallel with the side.

This helical antenna is manufactured by a method in which the flexible printed board 8 is wound around the cylindrical surface of the dielectric pipe 7 with an adhesive such that the bottom side thereof is along the circumference of the lower side of the dielectric pipe 7 and is fixed. The individual metal conductor patterns are appropriately combined and used as an antenna (JP-A-57-99006, JP-A-9-3266).
No. 27).

FIG. 10 is a diagram showing another configuration example of a conventional helical antenna and a method of manufacturing the same. In the figure, a flexible printed board 9 has a configuration in which a conductor pattern is formed on one side of a flexible sheet, and is wound around a dielectric pipe or the like to form a helical antenna. In this helical antenna, each conductor pattern of the flexible printed board has a constant pitch angle and a certain interval so that one end of the conductor pattern is connected to the other end of the other conductor pattern, and each conductor pattern is wound around a dielectric pipe. Are arranged so that the ends thereof abut against each other, and the space between them is connected by a connection line or the like (Japanese Patent Laid-Open No. 3-74906).

As described above, the conventional lightweight helical antenna for sanitary mounting is often manufactured by basically winding a helical element or the like formed in a printed board shape around a dielectric core material or the like.

[0007]

The conventional helical antenna is, as shown in FIG. 9, particularly a helical antenna manufactured by winding a helical element formed in a printed board shape around a dielectric core material. Deviation from the design value of the actual winding diameter caused by the error of the outer diameter of the material or the unevenness of the thickness of the adhesive applied between the core material and the printed board, and when winding the printed board spirally There was a drawback that it was difficult to obtain a required pitch over the entire length of the element due to displacement or the like. In particular, in such a helical antenna, as the number of turns of the helical element increases, an error from the design value is accumulated, and the accuracy with respect to the design value of the helical antenna decreases, thereby deteriorating the performance of the antenna.

Further, as shown in FIG. 10, a printed board having a specific pitch angle and interval is used, and this printed board is wound around a dielectric core material, and one end of one conductive pattern and the other end of another conductive pattern are connected to each other. The helical antenna configured to connect the conductor patterns to each other has a problem in that it is difficult to perform accurate butting and connection work between the ends of the conductor patterns.

(Object of the Invention) It is an object of the present invention to provide a helical antenna capable of easily forming a helical antenna having a required pitch with a small error.

Another object of the present invention is to use a flexible printed board configured to connect one end of a conductor pattern to the other end of another conductor pattern, thereby facilitating connection between terminals of the conductor pattern. And a helical antenna.

[0011]

A helical antenna according to the present invention is a helical antenna comprising a dielectric core material and a flexible printed board formed with parallel line-shaped conductor patterns wound therearound. In the flexible printed board, the conductor pattern has a constant inclination angle and an interval with respect to a winding direction around the dielectric core material on an outer surface side, and one end of the conductor pattern is the other end of another conductor pattern. It is characterized by being wound around the dielectric core material so as to overlap with the side by a line length of about 1/4 wavelength.

Further, in the flexible printed board of the present invention, a conductor pattern is also formed on the back side corresponding to the conductor pattern, and the corresponding conductor patterns on the front and back are electrically connected through through holes on the conductor. It is characterized by having.

According to the present invention, the flexible printed board has a rectangular shape, and the through-hole is provided at an end of the flexible printed board in the winding direction, and a portion where the conductor pattern overlaps through the through-hole. And that the dielectric core material and the flexible printed board are fixed via an adhesive.

(Function) A substantially rectangular flexible printed board on which a helical element pattern of a required shape is formed by etching is attached to the outer surface of a pipe-shaped dielectric, and the ends of the flexible printed boards are overlapped with each other to perform high-frequency coupling. , Forming a spiral line. A helical antenna having a constant spiral winding pitch without being affected by a slight change in the pipe diameter.

[0015]

FIG. 1 is a diagram showing one embodiment of a helical antenna and a method for manufacturing a helical antenna according to the present invention. The helical antenna in the present embodiment is
It is composed of a dielectric pipe, which is the main structure of the helical element, and a flexible printed board wound around the dielectric pipe.

FIGS. 2 and 3 are views showing a flexible printed board which is a component of the helical antenna used in the present embodiment. FIG. 2 is a diagram illustrating a surface of the flexible printed board, and FIG. 3 is a diagram illustrating a cross section of the flexible printed board.

The helical element according to the present embodiment includes:
A flexible printed board in which a copper foil is adhered to one surface of a rectangular film-shaped dielectric (film base) is used. As the flexible printed board, for example, it is preferable to use a printed board based on a polyimide film,
A helical element pattern 2 is formed by plating a copper foil on one side of such a flexible printed board and etching it.

The helical element pattern 2 is formed on one surface of the film 1 as a conductor pattern of a strip-shaped line having a required inclination angle and a required interval with respect to the lower end of the film. The inclination angle of the helical element pattern 2 and the interval between the conductor patterns determine the number of helical antennas.

FIG. 3 is a cross-sectional view (enlarged view) of the flexible printed board in a direction crossing the helical element pattern 2. The conductor pattern 2 is formed on the film substrate 1 by copper foil.

FIG. 4 is a view showing a dielectric pipe 4 which is a main structure of the helical element. A helical antenna is manufactured by winding a flexible printed board around the dielectric pipe 4 shown in FIG. The upper and lower sides of the flexible printed board shown in FIG. 3 are wound in parallel around the upper and lower ends of the dielectric pipe 4 via an adhesive, and the winding ends of the flexible printed board partially overlap the left and right parts. Wrap and glue and secure. The length between the lines of the conductor pattern caused by the overlap is approximately λ / 4 (λ:
(Used wavelength).

With such a structure, the overlapping portions of the conductor patterns are insulated in terms of direct current, but are connected via the film substrate 1 in terms of high frequency, so that the overlapping portions of the conductor patterns overlap. High-frequency conduction is ensured.

In the case of setting the angle and the interval of the conductor pattern on the flexible printed board shown in FIG. 2, two helical antennas are formed around the dielectric pipe 4. FIG. 1 is an external perspective view showing the structure of a helical antenna manufactured by such a manufacturing method. Dielectric pipe 4
By using a cylindrical dielectric having strength to
The characteristics and performance of the helical antenna can be improved, and the mechanical strength of the helical antenna can be increased to prevent deformation.

(Other Embodiments) Next, another embodiment of the present invention will be described with reference to FIGS.

FIG. 5 is a diagram showing a flexible printed board used in the present embodiment. In the present embodiment, a flexible printed board in which copper foil is adhered to both sides of a substantially rectangular film substrate is used. The helical element pattern 2 is formed on both sides of the flexible printed board by etching the copper foil on both sides. The helical element pattern 2 forms a conductor pattern that forms a strip-shaped line having a required inclination angle and a required interval based on the upper and lower ends of the film base material at positions facing each other on the front and back surfaces. That is, each conductor pattern is formed at the same position on the back surface, and the arrangement relationship is such that the inclination and the conductor width match. FIG. 5A shows a helical element pattern 2 on the front surface, and FIG. 5B shows a helical element pattern on the rear surface.

Further, in this embodiment, in order to electrically conduct the corresponding conductive patterns on the front and back sides of the flexible printed board, through-holes penetrating the base material at the left, right, and lower end portions of the flexible printed board. Hole 3 is provided, and the entire through hole is plated.

FIG. 6 is a cross-sectional view (enlarged view) of the end of the flexible printed board in a direction crossing the helical element pattern 2. The structure of the helical element is such that a double-sided conductor pattern 2 is formed on a film substrate 1 by copper foil,
It has a structure in which through-hole plating 3 is applied to the through-hole and the conductor patterns on the front and back are electrically connected.

FIG. 7 is an external perspective view showing a helical antenna in which the flexible printed board shown in FIGS. 5 and 6 is bonded and fixed to the dielectric pipe 4 with an adhesive.

The upper and lower sides of the flexible printed circuit board are wound in parallel with each other in the circumferential direction of the upper and lower ends of the dielectric pipe 4 via an adhesive. / 4 (λ: used wavelength) are overlapped and adhered and fixed.

Although the overlapping portions of the conductor patterns on the front and back sides are insulated in terms of direct current by using an adhesive, they are satisfactorily coupled via a thin film of the adhesive in terms of high frequency, and are also in contact with the conductor patterns on the surface. Since the connection is made through the through holes, high-frequency conduction is ensured.

Next, as still another embodiment of the present invention, in order to secure the connection of the overlap portion, the adhesive is not applied to the through-hole portion, and the flexible print is performed through the through-hole portion. Solder can be poured into the lower conductor pattern from the surface side of the plate via the through hole to perform DC connection.

In the embodiment described above, an example is described in which a flexible printed circuit board having a conductor pattern formed thereon adopts a rectangular shape as a component for manufacturing a helical antenna. It goes without saying that a quadrilateral can be used. That is, in the configuration of the helical antenna of the present invention, a conductor pattern having a predetermined angle with respect to the direction in which the flexible printed board is wound is formed. The connection may form a helical antenna line, and the shape of the terminal portion in the winding direction of the flexible printed board may be appropriately implemented. In addition, the connection between the conductor patterns is replaced with an overlap of λ / 4 or λ / 4.
As described above, in addition to the above overlap, it is also possible to solder the through-hole plated portion 3 provided at the end portion in order to further enhance the conduction between the elements of the wrap portion. Furthermore, the number of elements of the helical antenna is not limited to two (two), but can be configured as a multi-element helical antenna of three or more elements by designing the angle and interval of the conductor pattern.

Further, the conductor pattern of a predetermined angle formed on the flexible printed board is a pattern cut in the middle, and each of the conductor patterns is independently fed so that different helical antennas can be easily formed in the axial direction of the pipe. Obviously, it can be formed.

[0033]

According to the helical antenna and the method of manufacturing the same of the present invention, the flexible printed board (element film) wound around the dielectric pipe is made rectangular, and the helical element pattern having a required inclination angle is etched in advance with respect to the element film. Helical with a constant helical winding pitch without being affected by any variation in the diameter of the dielectric pipe because the end of the dielectric pipe and the end of the film are stuck together. Antennas can be easily manufactured.

According to the present invention, the flexible printed board may be wound only once around the dielectric pipe, and the flexible printed board is spirally wound around the dielectric pipe at a required pitch angle. It is possible to easily perform the manufacturing operation as compared with the case.

In particular, the connection between the ends of the conductor pattern
Since it can be realized simply by overlapping the flexible printed boards by about λ / 4, it is possible to manufacture a helical antenna that is simple, has high accuracy, and has little variation in quality.

[Brief description of the drawings]

FIG. 1 is an external perspective view showing an embodiment of a helical antenna according to the present invention.

FIG. 2 is a diagram showing a surface of a flexible printed board used for the helical antenna according to one embodiment of the present invention.

FIG. 3 is an enlarged cross-sectional view of a flexible printed board used in the helical antenna according to the present embodiment.

FIG. 4 is a view showing a dielectric pipe as a main structure of the helical element.

FIG. 5 is a diagram showing helical element patterns on the front and back surfaces of a flexible printed board according to another embodiment.

FIG. 6 is an enlarged cross-sectional view of a flexible printed board used for a helical antenna according to another embodiment.

FIG. 7 is an external perspective view showing a helical antenna according to another embodiment of the present invention.

FIG. 8 is a diagram showing a structure of a conventional helical antenna.

FIG. 9 is a diagram showing another structure of a conventional helical antenna and a method of manufacturing the same.

FIG. 10 is a diagram showing another structure of a conventional helical antenna and a method of manufacturing the same.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Film base material 2, 10 Helical element pattern 3 Through hole 4, 7 Dielectric pipe 5 Dielectric 8, 9 Flexible printed board 11 Connection line

Continuation of front page (56) References JP-A-7-176929 (JP, A) JP-A-3-74906 (JP, A) JP-A-9-326627 (JP, A) JP-A-57-99006 (JP) , A) JP-A-10-276029 (JP, A) JP-A-8-78945 (JP, A) US Patent 3503075 (US, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01Q 11/08 H01Q 1/28 H01Q 1/38

Claims (5)

(57) [Claims] 1. A helical antenna comprising a dielectric core material and a flexible printed board formed with a parallel line-shaped conductor pattern wound therearound, wherein the flexible printed board has a conductor pattern. The outer surface has a certain inclination angle and a spacing with respect to the winding direction around the dielectric core material, and one end of the conductor pattern is substantially equal to the other end of the other conductor pattern by a line length of about 1/4 wavelength. A helical antenna, wherein the helical antenna is wound around the dielectric core so as to overlap. 2. The flexible printed board has a conductor pattern also formed on the back side corresponding to the conductor pattern, and the corresponding conductor patterns on the front and back are electrically connected via through holes on the conductor. The helical antenna according to claim 1, wherein: 3. The helical antenna according to claim 1, wherein the flexible printed board has a rectangular shape. 4. The through hole is provided at an end of the flexible printed board in the winding direction, and a direct current connection is made at an overlapping portion of the conductor pattern via the through hole. The helical antenna according to claim 1, 2 or 3. 5. The helical antenna according to claim 1, wherein the dielectric core material and the flexible printed board are fixed via an adhesive.