KR100735355B1 - Liquid antenna having leakage prevention structure - Google Patents

Abstract

A liquid antenna having a leakage prevention structure is provided to improve a resonant characteristic by providing a ground path to a liquid radiator. A liquid antenna having a leakage prevention structure includes an antenna main body(110), a feeding cable(122), a connection member(130), and a leakage prevention member(170). The antenna main body(110) receives a solid radiator and a liquid radiator. An end of a feeding unit connected to the solid radiator is exposed. An end of the feeding cable(122) is contacted to an end of the antenna main body(110), and has a core line which is electrically connected to the feeding unit of the solid radiator, and an external conductor which is electrically connected to the liquid radiator. The connection member(130) maintains the feeding cable(122) and the antenna main body(110) to be opposite to each other. The connection member(130) provides electric connection between the liquid radiator of the antenna main body(110) and the external conductor of a cable. The leakage prevention member(170) is installed between the end of the antenna main body(110) and an edge of the feeding cable(122) to prevent a leakage of the liquid radiator.

Description

LIQUID ANTENNA HAVING LEAKAGE PREVENTION STRUCTURE}

1 is a schematic perspective view showing a liquid antenna to which the present invention is applied.

2 is a schematic perspective view showing another example of a liquid antenna to which the present invention is applied.

3 is a schematic perspective view showing a helical antenna having a spiral radiator as a liquid antenna to which the present invention is applied.

4 is a schematic perspective view showing a chip antenna to which a resonant frequency adjusting means is applied as a liquid antenna to which the present invention is applied.

5 is a partially cut away front view of a liquid antenna according to the present invention.

FIG. 6 is an enlarged cross-sectional view of part A of FIG. 5.

7 is an exploded view of FIG. 6.

8 is a plan view of the connecting member of FIG. 7.

9 is a partial exploded view of FIG. 6.

10 is a view showing a modification of the liquid antenna of the present invention, showing a configuration corresponding to the container-connecting member coupling configuration of FIG.

11 is a view showing a modification of the connecting member of FIG.

12 is a graph showing the resonance frequency adjustment effect of the liquid antenna according to the present invention.

<Explanation of symbols of main parts in drawings>

100: liquid antenna 110: antenna body

120: solid radiator 122: feed section

124: liquid radiator 130: connecting member

140: grounding projection 142: female thread

150: RF cable 152: core wire

154: contact portion 156: outer conductor

160: fastening member 162: male thread

170: leakage preventing packing 180: soldering portion

The present invention relates to a liquid antenna, and more particularly to a liquid antenna having a leak-proof structure capable of providing ground while preventing leakage of the liquid radiator of the liquid antenna.

In general, the antenna uses a conductor that resonates in a constant frequency band. For example, the chip antenna has a structure in which a conductor of a predetermined pattern is formed on a body made of a dielectric or a magnetic body.

These antennas have a unique resonant frequency determined by the structure (length) of the conductor and / or the dielectric constant of the dielectric. Therefore, when the material of a specific conductor and / or dielectric is determined, the resonance frequency can be changed only by the method of geometrically changing the conductor structure.

In particular, chip antennas, which are mainly used in mobile communication terminals, are required to be miniaturized and to reduce the resonant frequency. In recent years, the development of a special magnetic material has been attempted to manufacture a small antenna of a low frequency band, the conventional chip antenna is still difficult to secure a sufficient resonance length due to space constraints.

On the other hand, although a typical antenna generally covers only a narrow narrow band, it is known that a wide band is more advantageous even if the gain is slightly reduced. Ideally, an antenna that can cover the entire band while maintaining a high gain is the most beneficial. However, this can be said to be almost impossible with an antenna method using a conventional conductor radiator.

As described above, since a common antenna such as a chip antenna employs a conductor radiator having a specific structure, the resonance frequency is difficult to adjust, and there is a limitation in widening and low banding.

In order to overcome such a problem, a new concept of liquid antenna employing polar liquid as a radiator has recently been developed. Such a liquid antenna can design a wide range of characteristics of the antenna by using a liquid of various components, controlling the concentration and type of the electrolyte, and controlling the content and type of the conductor powder injected into the liquid. This has the advantage that it is possible to lower the bandwidth and further wider bandwidth, and to easily adjust the resonance frequency.

However, since the liquid antenna uses liquid as a radiator, an airtight structure that can prevent leakage of liquid is essential. In addition, it is preferable to ground the liquid since it functions as a radiator.

Accordingly, the present invention has been made to solve the above-mentioned problems of the prior art, and an object of the present invention is to provide a liquid antenna having a leakage preventing structure capable of preventing polar liquid leakage constituting the liquid radiator.

It is another object of the present invention to provide a liquid antenna having improved resonance characteristics by providing a ground path to the liquid radiator.

In order to achieve the above object of the present invention, the present invention provides an antenna comprising: an antenna body in which a solid radiator and a liquid radiator are housed, and a feed part connected to the solid radiator is exposed to one end; A feed cable having one end opposed to one end of the antenna main body, the feed cable having a core wire electrically connected to a feed section of the solid radiator and an external conductor electrically connected to the liquid radiator, respectively; A connection member configured to provide an electrical connection between the liquid radiator of the antenna body and the outer conductor of the cable while maintaining the abutment between the feed cable and the antenna body; And a leakage preventing member provided between one end of the feed cable and one end of the antenna body to prevent leakage of the liquid radiator.

In the liquid antenna of the present invention, the connecting member is formed integrally with the connecting member main body and the connecting member main body, and the connecting member main body, the lower part of which is coupled around the outer conductor of the cable, And a ground protrusion penetrating into the antenna body.

In the liquid antenna of the present invention, a female screw is formed in the lower inner side of the connecting member main body, and a male screw having a form matching the female screw is formed around the outer conductor of the cable.

In the liquid antenna of the present invention, the ground protrusion of the connecting member, the connecting member body and the outer conductor of the cable form a ground path.

In the liquid antenna of the present invention, a female thread is formed inside the lower portion of the connecting member main body, and the liquid antenna is mounted around the outer conductor of the cable to form a male thread having a shape that coincides with the female thread. Characterized in that it further comprises a fastening member. Here, the ground protrusion of the connecting member, the connecting member body, the fastening member and the outer conductor of the cable form a ground path.

In the liquid antenna of the present invention, the connecting member is configured to receive one end of the antenna body, the antenna body further comprises a pin coupled to one end of the antenna body through the connecting member. .

In the liquid antenna of the present invention, the connecting member is configured in the form of a tube to receive one end of the antenna body, the liquid antenna is an inner wall of the connecting member for receiving one end of the antenna body and one edge of the antenna body It further comprises a second leakage preventing member disposed between.

In the liquid antenna of the present invention, the feeding portion of the antenna body is formed in a wider width than the solid radiator, the feed cable is wider than the core wire so as to electrically connect the core wire with the feeding portion of the antenna body It is characterized in that it further comprises a contact portion formed at one end of the feed cable to face the feed portion of the antenna body.

In addition, the liquid antenna of the present invention is characterized in that it further comprises a soldering portion formed on the connecting portion of the lower end of the coupling member and the outer conductor of the feed cable.

Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings.

1 is a schematic perspective view showing a liquid antenna to which the present invention is applied.

Referring to FIG. 1, the antenna 10 is connected to a liquid 15 through a polar liquid 15, a liquid container 11 containing the polar liquid 15, and one end of the container 11. It consists of a power feeding part 17.

The polar liquid 15 employed in the present invention is introduced as a new radiator. The polar liquid 15 has a high dielectric constant with constant conductivity based on ionic or molecular bonds, thereby allowing various current source distributions. Therefore, the polar liquid 15 may act as a radiator having a specific resonance wave by the electric current supplied through the feed section 17. For example, water is known to have a dielectric constant of about 80 and a conductivity of about 3 S / m. As described above, since the polar liquid 15 has electromagnetic characteristics different from those of ordinary dielectrics and metal conductors, it has been confirmed that the polarizing liquid 15 obtains widening or low banding, which is not expected from conventional antennas in terms of resonance frequency characteristics.

It is estimated that the polar liquid contributes to the adjustment of the resonance frequency of the antenna due to the following causes.

First, when a polar liquid is exposed to radio waves of a certain frequency, the polarity changes and resonates. This is similar to the application of microwaves to food in a microwave oven, where the liquid (mainly water) in the food resonates and the food is heated by the resonance. Such resonance of the polar liquid may cause interference with radio waves passing through the polar liquid.

Second, when the polar liquid itself is exposed to radio waves, it can interfere with radio waves by forming a closed path of current.

Third, liquids such as water generally cause loss of propagation by increasing the wavelength of the radio waves. It is also possible that the above effects occur due to the wavelength change of the radio wave.

The polar liquid 15 may be in various forms such as SAR liquid, electrolyte solution or synthetic liquid in addition to water. In particular, the polar liquid 15 can realize low band or wide band at a level unprecedented in a conventional antenna by dissolving other electrolytes and changing conductivity through dissociated ions. Alternatively, similar effects can be obtained by mixing a conductive powder, such as iron, for example, a metal powder, such as iron, in a liquid even if it is not an electrolyte.

Such a liquid antenna can design a wide range of characteristics of the antenna using various liquid components, concentrations and types of electrolytes, and contents and types of conductor powders. This is described in Korean Patent Application No. 10-2005-0062352 (antenna using a liquid radiator) filed under the name of the applicant of the present application, and the present specification includes the contents of the above application as a reference.

2 is a schematic perspective view showing another type of liquid antenna 20 to which the present invention is applied.

Referring to Fig. 2, a monopole antenna 20 having an L-shaped radiator 25 as a liquid antenna is shown. One end of the radiator 25 is provided as a feed section 25a connected to an external circuit. The radiator 25 of the monopole antenna 20 is disposed inside the container for liquid 27. The interior of the container 27 for liquid is filled with a polar liquid 29.

In addition, the polar liquid 29 employable in the present invention may be water, alcohol or SAR, but is not limited thereto. The polar liquid 29 has a high dielectric constant with a constant conductivity by ionic or molecular bonding. Accordingly, the polar liquid 29 may have various current distributions affecting the characteristics of the antenna 20, thereby changing the intrinsic resonance frequency of the radiator 25. In general, since polar liquids have higher permittivity and lower conductivity than conventional dielectric materials or conductive materials such as metals, polar liquids have a tendency to widen, unlike dielectrics and metals.

In the conventional monopole antenna, the length of the radiating portion 25, which is a conductor, or the geometric change is attempted to change the resonant frequency. However, when the polar liquid 29 is used, a wider bandwidth can be realized and a desired resonant frequency can be obtained. Can be.

This configuration is such that most of the radiator 25 is included in the liquid container 27 so as to give an electromagnetic influence of the polar liquid 29 to the entire radiation area. However, it is satisfied that the polar liquid 29 contained in the liquid container 27 is a structural design in which electromagnetic influences can be applied to at least a part of the radiator 25, so that only a part of the radiator is placed in the liquid container, or It may also be implemented in such a way that the container is provided in an adjacent position of the radiator.

In this case, by adding a component such as an electrolyte or a conductor powder to the polar liquid 29 employed as the resonant frequency changing means, it is possible to expect further changes in electromagnetic properties. In general, in the case of adding the conductor powder or the electrolyte, the conductivity tends to be high, so that the adjustment range of the resonance frequency can be increased. Accordingly, various resonance frequency change characteristics can be expected by varying the concentration (content) and the components of the electrolyte and / or the conductor powder contained in the polar liquid 29. As such an electrolyte, various electrolytes such as NaCl may be used. As the conductor powder, metals affected by magnetic force, such as iron (Fe) and nickel (Ni), may be used.

In the case where the resonant frequency of the antenna is adjusted using the polar liquid as described above, low band or high band can be selectively realized depending on the structure of the antenna along with the wide band. For example, in the L-shaped monopole wire antenna shown in FIG. 2, a low band tendency can be expected, while in the helical antenna shown in FIG. 3, there is a tendency to be high band.

Referring to FIG. 3, a helical antenna 30 having a helical radiator 35 is shown. One end of the radiator 35 is provided as a feed section 35a connected to an external circuit.

The radiator 35 of the helical antenna 30 is disposed inside the container 37 for liquid similar to FIG. The interior of the container for liquid 37 is filled with a polar liquid 39. The polar liquid 39 may include, but is not limited to, water, alcohol or SAR. The polar liquid 39 can be provided as a new current distribution source to change the natural resonant frequency of the radiator 35.

As described above, the helical antenna 30 may have a resonance frequency adjusted according to a track (loop) spacing of the helical radiator. Due to this structural characteristic, the polar liquid 39 exhibits an electromagnetic effect between its orbits, thereby exhibiting a tendency to high band the resonance frequency with widening.

The antenna device employing such a resonant frequency adjusting means can be applied to a chip antenna. 4 is a view showing an example of a chip antenna to which the resonant frequency adjusting means is applied, and a chip antenna 40 having a FIFA structure is formed on the ground plate 44.

Referring to FIG. 4, the chip antenna 40 has a radiation electrode 45 connected to the feeder 42 and provided with a short circuit 43 on one side, and the short circuit 43 is connected to the ground plate 44. It may be a connected FIFA structure. In this form, the container 47 for liquid is filled with a polar liquid 49 and can be employed as a structure to replace a conventional dielectric block. That is, the conductor pattern including the radiation electrode 45 has a form formed on the surface of the liquid container 47.

The polar liquid 49 has a high dielectric constant with a constant conductivity based on ionic or molecular bonding as described above, thereby changing the current distribution of the radiation electrode 45, thereby causing the intrinsic resonance frequency by the radiation electrode 45. Can be adjusted.

As such, the dielectric block itself in the chip antenna may be replaced by the liquid container 47 containing the polar liquid 49. Alternatively, the desired resonance frequency adjustment effect may be expected by arranging the liquid container 47 in the region adjacent to the radiation electrode 45 in the form of the dielectric block.

The resonance frequency adjustment effect can be obtained according to the above-described configuration of FIGS. 2 to 4, and specific description thereof is described in Korean Patent Application No. 10-2005-0070730 (a broadband antenna device using a liquid medium) filed under the name of the applicant of the present application. The disclosure is incorporated by reference herein.

Hereinafter, a liquid antenna according to an exemplary embodiment of the present invention will be described with reference to FIGS. 5 to 9. In these figures, FIG. 5 is a partially cut away front view of the liquid antenna according to the present invention, FIG. 6 is an enlarged cross-sectional view of the portion A of FIG. 5, FIG. 7 is an exploded view of FIG. 6, and FIG. 8 is a connecting member of FIG. 7. 9 is a partially exploded view of FIG. 6.

As shown in FIGS. 5 to 9, the liquid antenna 100 of the present invention includes an antenna body 110, a connection member 130, and an RF cable 150.

The antenna body 110 is an insulator container in which a polar liquid 124 is contained, and is formed of a cylindrical side wall 112 and an upper end and a lower end 116. At this time, a helical radiator 120 having a spiral shape is disposed inside the container 112 through an opening (not shown) of the lower end 116. The lower end of the radiator 120 penetrates through the lower end 116 of the antenna main body and is connected to the feeder 122 attached to the bottom of the lower end 116. If the lower end of the radiator 120 is in close contact with the opening of the lower end of the antenna body 116 so that the polar liquid 124 inside the antenna body 112 does not leak through the gap between the radiator 120 and the lower end of the antenna body 116. good. On the other hand, a portion of the sidewall 112 adjacent to the lower end 116 is formed with a fin groove 114 to accommodate the pin 146 to be described later.

As described above, since the polar liquid 124 also functions as a radiator, the polar liquid 124 may be classified as a liquid radiator, and the radiator 120 may be classified as a solid radiator.

The connection member 130 is made of a conductor, and is configured to receive the upper end of the RF cable 150 while accommodating the lower portion of the antenna body 110 and to connect them to each other.

Specifically, the connection member 130 is formed of a cylindrical body 132 having an inner space 144 that is drilled up and down, the groove (between the outer wall 134 and the ground protrusion 140 of the upper end of the body 132) 138 is formed to accommodate the lower portion of the side wall 112 of the antenna body 110, the lower end 116 of the antenna body 110 is fitted inside the ground protrusion 140. The grounding protrusion 140 extends in the form of a pair of opposed arc columns as shown in FIG. 8. Accordingly, when the lower portion of the antenna body 110 is coupled with the connecting member 130, the ground protrusion 140 protrudes into the container 112 through the opening 118 of the container bottom 116. In addition, the pin 146 is inserted into and coupled to the pin hole 136 of the connecting member 130 and the pin groove 114 of the container 112 to strengthen the coupling of the connecting member 130 and the container 112. On the other hand, the female screw 142 is formed in the lower portion of the inner space 144, it is configured to be screwed with the male screw 162 of the fastening member 160 mounted on the upper end of the RF cable 150 to be described later.

The RF cable 150 is configured such that the insulator 156 surrounds the inner conductor, that is, the core wire 152, and the outer conductor 150 surrounds the insulator again. An upper portion of the RF cable 150 is provided with a conductor feeding part 154 made of a conductor and connected to the lower core line 152. In addition, a fastening member 160 made of a conductor is mounted around the upper end of the outer conductor 150, and a male screw 162 is formed on the outer circumference of the fastening member 160. The male screw 162 of the fastening member 160 is screwed with the female screw 142 of the connecting member 130 to couple the RF cable 150 and the connecting member 130 to the contact portion 154 of the RF cable 150. Are in contact with the feeder 122 of the antenna 120 to be electrically connected to each other, so that the antenna 120 can be fed by the RF cable 150. In addition, the fastening member 160 may be electrically connected to the main body 132 of the coupled connection member 130 by being a conductor.

In this configuration, in the configuration shown in FIGS. 5 and 6, the ground protrusion 140, the connection member body 132, the fastening member 160, and the outer conductor 158 may be electrically connected in sequence, and the inside of the antenna 110 may be electrically connected. If an overvoltage occurs at, it forms a ground path that pulls it out.

On the other hand, the packing 170 is installed around the contact portion 154. The packing 170 is preferably made of an opaque material having elasticity such as rubber. When the RF cable 150 is coupled to the connecting member 130, the polar liquid 124 is formed from the inside of the antenna body 110. 120 and the leakage in the power supply 122 is blocked.

As such, when the antenna main body 110, the connection member 130, and the RF cable 150 are coupled to each other, a soldering unit 180 is formed at the lower end of the connection member 130 and the connection portion of the RF cable 150. The coupling force between the connecting member 130 and the RF cable 150 is increased. The soldering unit 180 also performs a function of blocking the leakage when passing through the polar liquid 124 packing 170.

As described above, the liquid antenna 100 according to the present invention may improve stability by providing a grounding path through which an overvoltage or the like may be taken out while solving a leakage problem by using the polar liquid 124 as a frequency adjusting means. .

10 is a view showing a modification of the liquid antenna of the present invention, showing a configuration corresponding to the container-connecting member coupling configuration of FIG.

The configuration of FIG. 10 is the same as that of the liquid antenna 100 of FIGS. 5 to 9 except for installing a second packing 172 engaged around the lower end of the antenna body 112. Therefore, the same reference numerals are used for the same parts, and repeated description thereof will be omitted.

As such, when the second packing 172 made of an elastic material having a groove formed inside the outer wall 134 of the connecting member 130 is installed, the second packing 172 is inserted into the opening 118 of the lower end 116 of the antenna body. The polar liquid 124 may be prevented from leaking toward the upper end of the outer wall 134 through a gap between the ground protrusion 140 and the lower end 116 of the antenna body.

11 is a view showing a modification of the connecting member of FIG.

The connecting member 130a of FIG. 11 has the same shape as the connecting member 130 of FIG. 7 except that the shape of the ground protrusion 138a is modified. Therefore, the same reference numerals are used for the same parts, and repeated description thereof will be omitted.

In FIG. 7, the ground protrusion 138 extends up and down in the form of an arc, but the ground protrusion 138a of FIG. 11 extends up and down in the form of a protrusion. In this way, the clearance between the projection 138 and the antenna body lower end 116 can be further reduced, which is more advantageous for preventing the leakage of the polar liquid 124.

12 is a graph showing the resonance frequency adjustment effect of the liquid antenna according to the present invention.

In FIG. 12, when the voltage purification wave ratio (VSWR or SWR) (A) of the liquid antenna is compared with the voltage purification wave ratio (B) of the liquid antenna of the present invention, the voltage purification wave ratio (B) of the present invention has a wider bandwidth and output power. It can be seen that the increase. Therefore, it can be seen that the liquid antenna grounded according to the present invention further has broadband and high power characteristics together with a leakage preventing effect and a grounding effect.

As described above, the liquid antenna according to the present invention has a leakage preventing structure capable of preventing the polar liquid leakage constituting the liquid radiator. In addition, it is possible to improve the resonance characteristics by providing a ground path to the liquid radiator.

Although described with reference to preferred embodiments of the present invention as described above, those skilled in the art to which the present invention pertains without departing from the spirit and scope of the invention as set forth in the claims below. It will be understood that various modifications and changes can be made.

For example, although the embodiments of the present invention have been described based on the helical liquid antenna structure shown in FIG. 3, the present invention may be applied to liquid antennas having various structures shown in FIGS. 1, 2 and 4.

Claims (10)

An antenna body accommodating a solid radiator and a liquid radiator therein and having a feed part connected to the solid radiator to one end; A feed cable having one end opposed to one end of the antenna main body, the feed cable having a core wire electrically connected to a feed section of the solid radiator and an external conductor electrically connected to the liquid radiator, respectively; A connection member configured to provide an electrical connection between the liquid radiator of the antenna body and the outer conductor of the cable while maintaining the abutment between the feed cable and the antenna body; And And a leakage preventing member provided between one end of the feed cable and one end of the antenna body to prevent leakage of the liquid radiator. The method of claim 1, wherein the connecting member, A connecting member body made of a conductor, the lower portion of which is coupled around the outer conductor of the cable, and And a grounding protrusion formed integrally with the connecting member body and penetrating into the antenna body to contact the liquid radiator. The method of claim 2, wherein the internal thread is formed inside the lower portion of the connecting member body, A liquid antenna, characterized in that a male screw is formed around the outer conductor of the cable to coincide with the female screw. The liquid antenna according to claim 1, wherein the ground protrusion of the connecting member, the connecting member body and the outer conductor of the cable form a ground path. The method of claim 1, wherein the internal thread is formed inside the lower portion of the connecting member body, The liquid antenna, And a fastening member made of a conductor mounted around the outer conductor of the cable and having a male screw in a form that coincides with the female screw. 6. The liquid antenna of claim 5, wherein the ground protrusion of the connecting member, the connecting member body, the fastening member and the outer conductor of the cable form a ground path. The method of claim 1, wherein the connecting member is configured to receive one end of the antenna body, The antenna body further comprises a pin coupled to one end of the antenna body through the connecting member. The method of claim 1, wherein the connecting member is configured in the form of a tube to receive one end of the antenna body, And the liquid antenna further comprises a second leakage preventing member disposed between an inner wall of the connection member receiving one end of the antenna body and an end edge of the antenna body. According to claim 1, wherein the feeding portion of the antenna body is formed in a wider width than the solid radiator, The feed cable further comprises a junction portion formed at one end of the feed cable with a width wider than the core wire so as to electrically connect the core wire to the feed part, and abutted against the feed part. The liquid antenna of claim 1, further comprising a soldering portion formed at a connection portion of a lower end of the coupling member and an outer conductor of the feed cable.

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