KR20080032434A - Telescopic antenna - Google Patents

Abstract

A telescopic antenna is provided to increase electrical length of the antenna with equally maintaining the entire size of the antenna and have high durability even when using a wire-shaped antenna conductor. A first hollow antenna conductor(10) has a first outer diameter. A second hollow antenna conductor(20) has a first inner diameter larger than the first outer diameter and a bending unit(22) bent at one end to have a second inner diameter smaller than the first inner diameter but larger than the first outer diameter. A stopper(30) is inserted into the first antenna conductor, and a convex unit(32), which has an outer diameter larger than the first outer diameter and the second inner diameter but smaller than the first inner diameter, is formed in the remaining part other than the part inserted into the first antenna conductor. A fixing unit(14) is arranged on an outer periphery of the first antenna conductor and has an outer diameter smaller than the first inner diameter but larger than the second inner diameter. An elastic body(40) is fixed by the fixing unit and the convex unit and has elasticity in one direction. The first antenna conductor, the stopper, and the fixing unit are movably inserted into the second antenna conductor. The fixing unit and the bending unit restrict movement of the second antenna conductor with respect to the first antenna conductor.

Description

Multistage antenna {TELESCOPIC ANTENNA}

1 is a side cross-sectional view of a conventional multi-stage antenna.

2 is a side cross-sectional view of another conventional multi-stage antenna.

3 is a side cross-sectional view of a multi-stage antenna according to an embodiment of the present invention.

4 is a side cross-sectional view of a multi-stage antenna according to another embodiment of the present invention.

5 is a diagram illustrating an example of a third antenna conductor.

<Description of main parts of drawing>

10, 110: first antenna conductor 20, 120: second antenna conductor

30, 130: stopper 40, 140: elastic body

50, 150: third antenna conductor 60, 160: stopper

The present invention relates to a multi-stage antenna, and more particularly, to a multi-stage antenna extending the electrical length by improving the coupling structure of each stage of the antenna.

An antenna is an essential component of wireless communication for transmitting / receiving electromagnetic waves. Among the various configurations, a monopole antenna composed of a conductor having a quarter electrical length (λ / 4) of an operating wavelength (λ) is widely used. The monopole antenna operates the same as having an electrical length of λ / 2 substantially by the mirror effect of the ground plane, and emits or receives electromagnetic waves by causing resonance at a predetermined wavelength. As such, the electrical length of the antenna is proportional to the operating wavelength.

Recently, wireless broadcasting services such as T-DMB using the VHF band or the UHF band have been widely introduced. The antenna of the radio broadcast receiver must be manufactured to operate in the VHF band or the UFH band, which leads to an increase in the antenna length. For example, a signal at 200 MHz, which is a frequency in the VHF band, has a wavelength of about 150 cm in air, and an antenna of about 37.5 cm is required to transmit / receive this signal. This is too large to be applied to terminals that are becoming smaller.

In order to miniaturize the antenna, a multi-stage antenna capable of shrinking and extending is widely used. For example, registered practical 397908 discloses a multi-stage antenna including an elastic member. Conventional multistage antennas, such as those disclosed in the registration application, include two or more cylindrical antenna conductors that can be reduced and extended.

1 is a side cross-sectional view of a conventional multi-stage antenna. The conventional multi-stage antenna has a second antenna conductor 120 formed to surround the outer periphery of the first antenna conductor 110 with an inner diameter larger than the outer diameter of the cylindrical first antenna conductor 110 and the first antenna conductor 110. It includes. Thus, when the antenna is reduced, the first antenna conductor 110 may be inserted into the second antenna conductor 120.

At one end of the first antenna conductor 110, a stopper 130 is inserted into the first antenna conductor 110. A recess 112 is formed in the first antenna conductor 110 of the portion where the stopper 130 is coupled by rolling to fix the stopper 130 to the first antenna conductor 110. On the other hand, in the stopper 130 outside the first antenna conductor 110, a convex portion 132 having an outer diameter larger than the outer diameter of the first antenna conductor 110 is formed to protrude out of the first antenna conductor 110, The insertion range of the stopper 130 is limited.

On the surface of the first antenna conductor 110, a fixing part 114 having an outer diameter larger than the outer diameter of the first antenna conductor 110 and smaller than the inner diameter of the second antenna conductor 120 is disposed. The fixing part 114 may be made of a separate component such as a ring and coupled to the first antenna conductor 110. Further, at one end of the second antenna conductor 120, a bent portion 122 bent inwardly is formed so that its inner diameter is smaller than the outer diameter of the fixing portion 114. As shown in FIG. As a result, when the antenna is extended, the bent portion 122 is caught by the fixing portion 114 to restrict the movement of the second antenna conductor 120 and the first antenna conductor 110 and the second antenna conductor 120. Is not separated. At this time, it is also possible to limit the movement of the second antenna conductor 120 by the convex portion 132 without arranging the fixing portion 114.

An elastic installation portion 136 is defined at an upper portion (right side in the drawing) of the stopper 130 by a locking portion 134 and a convex portion 132 formed to protrude a predetermined height. The elastic installation portion 136 is provided with a C-shaped elastic body 140 to contact the inner surface of the second antenna conductor 120. This provides proper frictional force to the relative movement of the first antenna conductor 110 and the second antenna conductor 120 so that they do not move loosely and can be fixed at any position even if the user does not otherwise apply a fixing force.

As described above, in the conventional multi-stage antenna, the elastic body mounting portion 136 for mounting the elastic body 140 is formed to extend outside the first antenna conductor 110. Accordingly, the component inserted into the second antenna conductor 120 upon reduction is the stopper 130 including the first antenna conductor 110 and the elastic installation portion 136, and the total insertion length is the first antenna conductor 110. ) And the length of the elastic body mounting portion 136 are combined. However, among them, only the first antenna conductor 110 operates as an actual antenna, and the length of the elastic installation portion 136 in the internal space of the second antenna conductor 120 is wasted without contributing to the antenna operation.

This waste of space causes the entire antenna to be large in size to achieve the desired electrical length. This problem is more serious in a service where the antenna length is increased due to the use of low frequency signals, especially when the antenna is composed of three or more stages. There is a problem that greatly increases the size of the.

2 is a side cross-sectional view of another conventional multi-stage antenna. The illustrated structure is generally used for the last stage of a multistage antenna, and includes a third antenna conductor 150 that is tapered for insertion into the innermost portion of the antenna conductor. In FIG. 2, the third antenna conductor 150 is shown to be inserted into the first antenna conductor 110.

Since the third antenna conductor 150 of the conventional multistage antenna is thinly formed, it cannot include a hollow for inserting a stopper. Therefore, the stopper 160 is formed by insert molding or the like on the outside of the third antenna conductor 150. Movement of the first antenna conductor 110 is limited by the convex portion 162 formed in the stopper 160.

Also, the stopper 160 is formed with an elastic body arranging portion 166 defined by the double-block portions 162 and 164, and the elastic body 140 is disposed to impart frictional force with the first antenna conductor 110. Thus, the problem of waste of space by the elastomeric arrangement 136 still exists. In addition, when the third antenna conductor 150 is drawn out with excessive force, the third antenna conductor 150 and the stopper 160 may be separated.

The present invention has been made in view of the above problems, and an object thereof is to provide a miniaturized antenna by improving a coupling structure of antenna conductors.

In addition, an object of the present invention is to provide a miniaturized antenna with high durability even when an antenna conductor having no hollow is formed.

In order to achieve the above object, according to an aspect of the present invention, a hollow first antenna conductor having a first outer diameter; A hollow second antenna conductor having a first inner diameter larger than the first outer diameter and having a bent portion at one end bent to have a second inner diameter smaller than the first inner diameter and larger than the first outer diameter; A convex portion having a portion having an outer diameter greater than the first outer diameter and the second inner diameter and smaller than the first inner diameter, the other portion of which is partially fixed to the inner side of the first antenna conductor and not inserted into the inner side of the first antenna conductor. Formed stopper; A fixing part disposed on an outer circumference of the first antenna conductor and having an outer diameter smaller than the first inner diameter and larger than the second inner diameter; And an elastic body disposed to be fixed by the fixing part and the convex part and having an elasticity in one direction, wherein the first antenna conductor, the stopper, and the fixing part are movably inserted into the second antenna conductor. In addition, a multi-stage antenna is provided in which movement of the second antenna conductor relative to the first antenna conductor is limited by the fixing portion and the bent portion.

In order to achieve the above object, according to another aspect of the invention, the first antenna conductor of the columnar shape having a first outer diameter and a convex portion having a second outer diameter larger than the first outer diameter at one end; A hollow second antenna conductor having a first inner diameter larger than the second outer diameter and having a bent portion at one end bent to have a second inner diameter smaller than the first inner diameter and larger than the first outer diameter; Two fixing parts disposed on an outer circumference of the first antenna conductor and having an outer diameter smaller than the first inner diameter and larger than the second inner diameter; And an elastic body arranged to be fixed between the fixing parts and having an elasticity in one direction, wherein the first antenna conductor and the fixing part are movably inserted into the second antenna conductor, and the first antenna conductor The movement of the second antenna conductor with respect to is limited by at least one of the fixing portions and the bent portion, wherein at least one of the fixing portions has an inner diameter smaller than the second outer diameter by the convex portion of the first antenna. A multi-stage antenna is provided in which deviation from the conductor is limited.

Further, according to still another aspect of the present invention, there is provided a wireless signal transmission / reception apparatus including the above-described multi-stage antenna.

Hereinafter, specific embodiments of the present invention will be described with reference to the accompanying drawings. Although only two antenna conductors are described herein for convenience of description, embodiments that further include additional antenna conductors are possible, and those skilled in the art will readily appreciate that the following description may equally apply in such cases. There will be.

3 is a side cross-sectional view of a multi-stage antenna according to an embodiment of the present invention. The multistage antenna of this embodiment includes a hollow first antenna conductor 10 and a hollow second antenna conductor 20 having an inner diameter larger than the outer diameter of the first antenna conductor 10. Include. When the antenna is retracted, the first antenna conductor 10 is inserted into the second antenna conductor 20 of the antenna. The first antenna conductor 10 and the second antenna conductor are preferably made of a metal material having sufficient strength, such as titanium or titanium alloy, to maintain conductivity while operating as a radiator and not to be broken or broken by external forces. In addition, the first antenna conductor 10 and the second antenna conductor 20, and other antenna conductors that may additionally exist, allow the total length in extension to be 1/4 of the antenna operating wavelength to operate as a monopole antenna. Each may have a length.

The first antenna conductor 10 and the second antenna conductor can have the same cross section to facilitate reduction and extension. Typically, the first antenna conductor 10 and the second antenna conductor 20 have a circular cross section, but are not limited thereto.

A stopper 30 is inserted into an end portion of the first antenna conductor 10 that is inserted into the second antenna conductor 20. The recessed part 12 is formed in the insertion part of the stopper 30 of the 1st antenna conductor 10 by a rolling process etc., and the stopper 30 is fixedly coupled. At the end of the stopper 30 exposed to the outside of the first antenna conductor 10, a convex portion 32 having an outer diameter larger than the outer diameter of the first antenna conductor 10 is formed. The convex part 32 may have a cross section of the same shape as the cross section of the first antenna conductor 10. Alternatively, it is also possible for the convex portion 32 to consist of two or more protrusions separated from each other.

The convex portion 32 has an outer diameter smaller than the inner diameter of the second antenna conductor 20, so that the convex portion 32 can be inserted into the second antenna conductor 20. In particular, most of the stopper 10 is inserted inside the first antenna conductor 10 and only the convex portion 32 is exposed to the outside.

The fixing part 14 is arrange | positioned at the outer periphery of the 1st antenna conductor 10. As shown in FIG. The fixing part 14 can be implemented by coupling a ring shaped component to the first antenna conductor 10. The fixing portion 14 may also be inserted into the second antenna conductor 20 with an outer diameter smaller than that of the second antenna conductor 20.

Corresponding to the fixed portion 14, a bent portion 22 bent to have an inner diameter smaller than the other portion of the second antenna conductor 20 is formed at one end of the second antenna conductor 20. As shown in FIG. Further, the inner diameter of the bent portion 22 is smaller than the outer diameter of the fixing portion 14 so that the second antenna conductor 20 when the second antenna conductor 20 moves in one direction (right direction in the drawing) for the antenna extension. Is restricted, and the first antenna conductor 10 and the second antenna conductor 20 are not separated.

The leaf spring 40 is disposed in the stopper attachment portion of the first antenna conductor 10. The leaf spring 40 is fixed at one end by the convex portion 32 and fixed at the other end by the fixing portion 14. The leaf spring 40 has a predetermined elasticity and can elastically contract and relax in one direction (up and down direction in the drawing). Thus, when the first antenna conductor 10 is inserted into the second antenna conductor 20, the leaf spring 40 contacts the inner surface of the second antenna conductor 20 to provide a predetermined frictional force. Thereby, the relative movement of the first antenna conductor 10 and the second antenna conductor 20 can be initiated only by a force equal to or greater than the predetermined static frictional force, and can be maintained only by a force equal to or greater than the predetermined kinetic frictional force. That is, the antenna conductors 10 and 20 can be fixed without moving unless an external force is applied.

As the leaf spring 40, any elastic structure can be used, and a C-ring is usually used, but is not limited thereto.

In the multi-stage antenna of this embodiment, most of the stoppers 30 are inserted into the first antenna conductor 10, and only the smallest convex portions 32 are exposed to the outside of the first antenna conductor 10. FIG. And is inserted into the second antenna conductor 20. Accordingly, the length of the antenna inserted into the second antenna conductor 20 when the antenna is reduced is occupied by the first antenna conductor 10 which can operate as a radiator except for the convex portion 32 which is extremely small.

That is, the antenna of this embodiment has a longer electrical length than the conventional antenna in the same size. Specifically, the antenna of the present embodiment forms the leaf spring 40 on the surface of the first antenna conductor 10 without forming the elastic body mounting portion 136 (FIG. 1) in the conventional antenna of FIG. The space for forming the antenna conductor is secured by the corresponding length. For example, in one embodiment of the present invention manufactured for application to a T-DMB service, by not forming an elastic installation portion, the size of the stopper 30 and the first antenna conductor 10 combination may be kept the same. The length of the first antenna conductor 10 was extended about 4.7 mm.

The effect of such length extension increases as the number of antenna conductors coupled, that is, as the number of antenna stages increases. For example, in the case of a three-stage antenna, if there are two coupling parts between antenna conductors and a length extension effect of 4.7 mm is obtained at each part, the length extension effect of 4.7 x 2 mm is obtained overall. Thus, antennas of the same size can be used for transmitting / receiving lower frequency (ie, longer wavelength) signals.

On the other side, it is also possible to manufacture the antenna compact since the antenna length can be extended. That is, a smaller antenna can be used to transmit / receive signals of the same frequency.

4 is a side cross-sectional view of a multi-stage antenna according to another embodiment of the present invention. The multi-stage antenna of this embodiment includes a third antenna conductor 50 formed in the form of a wire having no hollow. The third antenna conductor 50 is inserted into another hollow antenna conductor, for example the first antenna conductor 10, and is generally inserted at the innermost of several antenna conductors. In the present embodiment, the third antenna conductor 50 is described as being inserted into the first antenna conductor 10, but this is for convenience of description and the present invention is not limited thereto.

The third antenna conductor 50 is a columnar wire without a hollow, and is preferably formed of a metallic material having elasticity. Specifically, it is formed of a shape memory material such as titanium alloy and is not deformed by bending or the like during use.

Two or more fixing parts 54 and 56 are formed on the outer circumference of the third antenna conductor 50. The fixing portions 54, 56 may be formed in the form of rings to be combined with the third antenna conductor 50. An elastic body 40 fixed by them is disposed between the fixing portions 54, 56 to provide a frictional force to the inner surface of the first antenna conductor 10. In addition, the fixing portion 56, together with the bent portion 12 having an inner diameter smaller than the outer diameter, limits the relative movement of the first antenna conductor 10 and the third antenna conductor 50.

At one end of the third antenna conductor 50, a convex portion 52 is formed by various known processing methods. The convex portion 52 is formed to have an outer diameter larger than the inner diameter of the fixing portion 54 so that the fixing portion 54 is not separated from the third antenna conductor 50.

The convex portion 52 may be formed by combining separate components, but is preferably formed integrally with the third antenna conductor 50. Specifically, the convex portion 52 may be a convex portion 52 ', as shown in FIG. 5, formed by hedging the third antenna conductor 50, which is a titanium wire, in which case the convex portion 52' The third antenna conductor 50 extends even after the formed portion.

Thus, the multistage antenna of this embodiment does not contain a separate stopper, and the elastic body 40 is arrange | positioned on the outer periphery of a 3rd antenna conductor. Therefore, since only the third antenna conductor 50 is inserted into the internal space of the first antenna conductor 10, the electrical length of the antenna can be extended and the antenna can be made smaller in the same principle as in the previous embodiment.

In addition, since the coupling structure of the third antenna conductor 50 and the stopper is not included, there is no fear of separation of the stopper and the third antenna conductor 50 even when the third antenna conductor 50 is pulled out, and the durability of the antenna is high. Can be improved.

As mentioned above, although this invention was demonstrated with reference to specific embodiment, this is only an illustration and this invention is not limited to this. The shape, material, and size of each component described herein can be easily changed by those skilled in the art according to the application, and such changes are also within the scope of the present invention. In addition, the components shown and described herein are a part of the entire antenna selected for the convenience of description, and configuring the antenna including additional components in addition to those described is not departing from the scope of the present invention. Therefore, the scope of the present invention should be defined only by the matter described in the claims and equivalents thereof, not by the description of the specification.

According to the present invention, a multi-stage antenna can be obtained in which the electrical length of the antenna is increased while maintaining the same overall size of the antenna. In addition, according to the present invention, it is possible to obtain a multi-stage antenna that can be manufactured compactly even at low frequencies.

Further, according to the present invention, even in the case of using a wire-shaped antenna conductor, it is possible to obtain a multistage antenna having excellent durability.

Claims (3)

A hollow first antenna conductor having a first outer diameter; A hollow second antenna conductor having a first inner diameter larger than the first outer diameter and having a bent portion at one end bent to have a second inner diameter smaller than the first inner diameter and larger than the first outer diameter; A convex portion having a portion having an outer diameter greater than the first outer diameter and the second inner diameter and smaller than the first inner diameter, the other portion of which is partially fixed to the inner side of the first antenna conductor and not inserted into the inner side of the first antenna conductor. Formed stopper; A fixing part disposed on an outer circumference of the first antenna conductor and having an outer diameter smaller than the first inner diameter and larger than the second inner diameter; And An elastic body disposed to be fixed by the fixing part and the convex part and having an elasticity in one direction, The first antenna conductor, the stopper and the fixing portion are movably inserted inside the second antenna conductor, and the movement of the second antenna conductor with respect to the first antenna conductor is caused by the fixing portion and the bent portion. Multistage antenna limited. A pillar-shaped first antenna conductor having a first outer diameter and a convex portion having a second outer diameter larger than the first outer diameter at one end thereof; A hollow second antenna conductor having a first inner diameter larger than the second outer diameter and having a bent portion at one end bent to have a second inner diameter smaller than the first inner diameter and larger than the first outer diameter; Two or more fixing parts disposed on an outer circumference of the first antenna conductor and having an outer diameter smaller than the first inner diameter and larger than the second inner diameter; And An elastic body disposed to be fixed between the fixing parts and having elasticity in one direction, The first antenna conductor and the fixing portion are movably inserted inside the second antenna conductor, and the movement of the second antenna conductor with respect to the first antenna conductor is caused by at least one of the fixing portions and the bent portion. And at least one of the fixing portions has an inner diameter smaller than the second outer diameter such that deviation from the first antenna conductor is restricted by the convex portion. Wireless signal transmission and reception device comprising the multi-stage antenna of claim 1.

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