JP3044966U - Loop antenna for mobile phone - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To improve the reception capability without impairing the portability of a mobile telephone and without being affected by a human body or a building. SOLUTION: In a relay loop antenna mounted on a case body surface of a mobile phone for relaying a radio wave, a first loop antenna having a first feeding portion and resonating in a first use frequency band is provided. At least a single loop and a second single loop having a second power supply unit and resonating in a second frequency band lower than the first frequency band,
A loop antenna, wherein the second single loop is disposed on the same plane in the first single loop.

Description

[Detailed description of the invention]

[0001]

[Technical field to which the invention belongs]

 The present invention relates to a loop antenna for relaying radio waves. More specifically, the present invention relates to a mobile phone typified by a mobile phone, a personal handy phone (PHS), and the like (hereinafter referred to as a “mobile phone, etc.” as appropriate). The present invention relates to a loop antenna (hereinafter simply abbreviated as “loop antenna”) attached to the surface of a case body.

[0002]

[Prior art]

 Recently, mobile phones and the like have been dramatically spread. At the same time, mobile phones have been improved to be smaller and lighter. As a result, portability has been simplified, and communication and communication at destinations have become very convenient. On the other hand, mobile phones and the like still have problems to be solved. The phone does not work. The call has been interrupted. The other party's voice cannot be heard well due to noise. Most of these problems are caused by the lack of reception capabilities of mobile phones and the like. In order to solve such a problem, a repeater antenna (repeater antenna) has been proposed which is placed near a mobile phone or the like to amplify a received signal or remove unnecessary noise.

As a conventional relay antenna, a loop antenna described in Japanese Patent Application Laid-Open No. 8-78941 (hereinafter, this loop antenna is abbreviated as “conventional loop antenna”) is known. The conventional loop antenna is a dipole antenna as described in paragraph 0006 of the publication. It is generally said that a dipole antenna is an electric field antenna in which an electromotive force is generated by the action of an electric field component out of an electric field component and a magnetic field component of an electric wave.

[0004]

[Problems to be solved by the invention]

 However, the conventional loop antenna has been desired to be improved in the following points. That is, since the conventional loop antenna operates as an ungrounded dipole, it requires two loops, so that the occupied area is inevitably increased. In the first place, mobile phones are characterized by being highly portable and easy to carry. However, even if it is to improve the receiving ability, if an antenna with a large occupied area is installed, its characteristic portability will be lost. A first problem to be solved by the present invention is to provide a repeater loop antenna capable of enhancing the receiving capability without impairing the portability.

[0005] On the other hand, the conventional loop antenna is an electric field antenna as described above, and thus is liable to be adversely affected by the human body, the ground, nearby buildings, and the like. For this reason, even if an electric field antenna is used for a mobile phone, etc., it is thought that it will be adversely affected by the user's body, and when used indoors or in a vehicle, it will be further adversely affected by buildings. The receiving ability cannot be improved as much. To provide a loop antenna for relay that is not adversely affected by the human body and buildings. This is the second problem that the present invention seeks to solve.

[0006]

[Means for Solving the Problems]

 As a result of intensive research to simultaneously solve the above two problems, the inventor found that a single loop antenna is less likely to be adversely affected by the human body or buildings because it is a magnetic field type antenna. (Solving the second problem). In particular, since the surface of the human body has a property of enhancing the magnetic field, if such a magnetic field type loop antenna is attached to the surface of the case body of a mobile phone or the like, the loop from the human body to the loop antenna and to the mobile phone or the like can be obtained. We thought that a radio wave (magnetic field) would flow to the built-in antenna, and a better antenna effect could be obtained. Further, since this loop antenna is of a single type, the occupied area can be reduced as compared with a non-grounded dipole (solution of the first problem). The present invention has been made from such a viewpoint. The specific configuration will be explained again.

That is, the relay loop antenna according to the first aspect of the present invention is mounted on the surface of a case body of a mobile telephone and used for relaying radio waves. As long as portability is not impaired, it can be installed and used near mobile phones. The feature of this relay loop antenna is that it is constituted by a single loop that has a feed section and resonates in a used frequency band.

[0008] By configuring the relay loop antenna with a single (single) loop, that is, one loop, the occupied area can be reduced as compared with a dipole antenna requiring two loops. . Further, since the antenna functions as a magnetic field type antenna, the receiving ability of the mobile telephone can be improved since the antenna is not adversely affected by the human body. The term “loop having a power supply unit” in this specification refers to any material and form that constitutes the power supply unit or loop as long as it resonates in the frequency band of the radio waves used by the mobile phone. Good.

The relay loop antenna according to the invention described in claim 2 has basically the same configuration as that described in claim 1, and has the same function and effect. A major feature of this relay loop antenna is that it is constituted by a single loop that has a feed section and resonates at a quarter wavelength of the used frequency band.

[0010] That is, the larger the loop antenna for relaying is, the higher the efficiency can be expected. Therefore, in the present invention, a relay loop antenna is configured by a single loop having a power supply unit and resonating at a quarter wavelength of the operating frequency band.

A relay loop antenna according to a third aspect of the present invention basically has a configuration similar to that of the first aspect and has a similar operation and effect. A major feature of this relay loop antenna is that it has a first single loop that has a first feeder and resonates in a first use frequency band, and a second feeder that has a second feeder. And a second single loop that resonates in a second frequency band lower than the first frequency band, so that it can be used in at least two frequency bands. It may be composed of three or more single loops so that it can be used in three or more frequency bands. Another characteristic is that the second single loop is arranged on the same plane in the first single loop, so that the occupied area is reduced as much as possible.

That is, taking a mobile phone as an example, the three frequencies currently used are an 800 megahertz (MHz) band, a 1.5 gigahertz (GHz) band, and a 1.9 gigahertz (GHz) band. Here, for example, when the first frequency band is a 1.5 GHz band and the second frequency band is an 800 MHz band, a first single loop and a second single loop resonating in each frequency band are provided. The loop is provided by the relay loop antenna according to the present invention. However, arranging the first single loop and the second single loop requires a large occupied area as in the case of the dipole antenna described above. Therefore, the first single loop is arranged on the same plane in the second single loop, that is, the former is included in the latter, and the occupied area of the entire relay loop antenna is Was prevented from spreading beyond the second occupied area. Note that the combination of the first frequency band and the second frequency band can be freely selected from the frequency bands used by the mobile phone, but in any case, the lower frequency band (having a longer wavelength) is the second frequency band. It goes without saying that the higher frequency band (short wavelength) is the first frequency band.

[0013] The relay loop antenna according to the invention described in claim 4 has basically the same configuration as that described in claim 3 and has the same operation and effect. A major feature of this relay loop is that by providing this relay loop antenna on one surface of a mounting film having a luminous function, the mounting film (mobile telephone) can be found even in a dark place due to its light emitting function. It is to have done. Note that, in this specification, the term “luminous action” refers to an action of emitting light for a certain period of time after irradiation with ultraviolet light such as fluorescent light or sunlight, even if the irradiation is cut off. Also called phosphorescence. Further, the "mounting film" is a thin plate-shaped member, and may or may not have flexibility.

[0014] The relay loop antenna according to the invention described in claim 5 has basically the same configuration as that described in claim 4, and has the same operation and effect. The major feature of this relay loop antenna is that the mounting film provided with the antenna on one side has an adhesive surface on the other side so that it can be easily mounted on the surface of the case body. The adhesive surface may be, for example, a material that does not easily peel off when pasted, or a material that can be easily removed and pasted many times.

[0015] The relay loop antenna according to the invention described in claim 6 has basically the same configuration as that described in claim 5 and has the same operation and effect. A major feature of this relay antenna is that the first single loop and the second single loop are each formed in a triangular shape, and the first triangular single loop is formed within each of the second triangular single loops. The common power supply unit including the first power supply unit and the second power supply unit is provided at any one of the apex angles. Each loop was formed as a triangle because this shape is the most appropriate for multiple loops to coexist in the smallest possible area.

[0016]

[Embodiment of the invention]

 Next, an embodiment of the present invention (hereinafter, abbreviated as “the present embodiment”) will be described with reference to FIGS. FIG. 1 is a perspective view showing a state in which the relay loop antenna is attached to a mobile phone, and FIG. 2 is an enlarged front view of the relay loop antenna. FIG. 3 is a view of a virtual section including the line AA in FIG. 2 viewed in the direction of the arrow, and FIGS. 4 and 5 are graphs showing the relationship between the operating frequency and the gain of the loop antenna for relay.

In FIG. 1, reference numeral 1 denotes a mobile phone. The 1.5 GHz band of the mobile phone 1 is used as a use frequency band, and transmission and reception are performed using the built-in antenna 3. Reference numeral 4 indicates a loop antenna for relay. In FIG. 2, a loop antenna 4 is formed by depositing a metal foil (silver foil in the present embodiment) on a flexible synthetic resin film (mounting film) 5 and forming a single loop 7 (9) and a feeder 6 ( 8) is formed. It is preferable to mix a phosphorescent material having a phosphorescent (phosphorescent) action on one surface 10 of the film 5 so that the film 5 can be seen even in a dark place. On the other hand, when the adhesive member 12 is applied to the other surface 11 of the film 5 so that the film 5 can be attached to the surface of the case body 2 of the mobile phone 1, the attachment can be easily performed. The film 5 is provided for simplifying the mounting of the loop antenna 4, and may be omitted when unnecessary.

Next, a single loop will be described. The loop antenna 4 in the present embodiment can be used in two frequency bands, that is, 1.5 GHz band which is the first frequency band and 800 MHz band which is the second frequency band. It consists of two loops that resonate with the band. If it is used for a single frequency band, it may be used for a single frequency band by leaving unnecessary loops and omitting unnecessary loops. However, if the configuration is such that it can be used for two frequency bands as in the present embodiment, it is not necessary to manufacture a loop antenna for each frequency band, so that the manufacturing cost can be reduced.

In FIG. 2, reference numeral 7 denotes a first single loop that resonates at a quarter wavelength in the 1.5 GHz band, and the first single loop has a first power supply unit 6. I have. On the other hand, reference numeral 9 denotes a second single loop that resonates at a quarter wavelength in the 800 MHz band, and the second single loop has the second power supply unit 8. Reference numeral 13 denotes a curved portion that is curved in order to increase the length of the loop element. Thus, each of the first and second triangular single loops is an isosceles triangle having a short base as shown in FIG. 2, but the three sides are substantially formed by providing the curved portion 13. Form an equal regular triangle. Accordingly, one side L1 of the _first triangular single loop 7 has a length substantially equal to approximately 1/12 wavelength (1/4 quarter) of the 1.5 GHz band, and similarly to this, one side of the triangle single loop 9 _{L 2} is substantially 1/12 wave length equal to the length of the 800 MHz band. In this embodiment, the vertices of the first triangular single loop 7 and the vertices of the second triangular single loop 9 are matched so that the first power supply unit 6 and the second power supply unit 8 have a common configuration. The former is included in the latter in the state of becoming a power supply unit. Further, since the phase in the 1.5 GHz band is reversed, short bars 14 are provided to shift the phase.

Next, data measured by actually attaching the loop antenna 4 to the mobile phone 1 will be described with reference to FIGS. FIG. 4 shows the measurement results in the 800 MHz band, and FIG. 5 shows the measurement results in the 1.5 GHz band. As is clear from the graph, the efficiency was improved by 1.4 to 1.5 decibels (dB), that is, about 40% in the range of 860 to 887 MHz as compared with the case where the built-in antenna 3 was used alone. On the other hand, in the range of 1.477-1.501 GHz, similarly, 1.7-2. An efficiency improvement of 4 dB, 45-70% was achieved.

[0021]

[Effect of the invention]

 By using the loop antenna for relaying according to the present invention, it is possible to enhance the receiving capability without impairing the portability of the mobile phone and without being affected by a human body or a building.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a state in which a relay loop antenna is attached to a mobile phone.

FIG. 2 is an enlarged front view of a relay loop antenna.

FIG. 3 is a view of a virtual cross section including the line AA in FIG.

FIG. 4 is a graph showing a relationship between a used frequency and a gain of a loop antenna for relay.

FIG. 5 is a graph showing a relationship between a used frequency and a gain of a loop antenna for relay.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Mobile telephone 2 Case body 3 Built-in antenna 4 Loop antenna for relay 5 Mounting film 6 1st feeding part 7 1st single loop 8 2nd feeding part 9 2nd single loop 10 One surface 11 The other Surface 12 Adhesive member 13 Curved section 14 Short bar

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[Procedure amendment]

[Submission date] June 9, 1997

[Procedure amendment 1]

[Document name to be amended] Drawing

[Correction target item name] All figures

[Correction method] Change

[Correction contents]

FIG.

FIG. 2

FIG. 3

FIG. 4

FIG. 5

Claims (6)

[Utility model registration claims] 1. A relay loop antenna mounted on the surface of a case body of a mobile phone for relaying radio waves, wherein the loop antenna is constituted by a single loop having a feeding unit and resonating in a used frequency band. Features loop antenna for relay. 2. A relay loop antenna mounted on the surface of a case body of a mobile phone for relaying a radio wave, wherein the loop antenna has a power supply unit and has a frequency band of 1
A relay loop antenna comprising a single loop resonating at / 4 wavelength. 3. A relay loop antenna mounted on a surface of a case body of a mobile phone for relaying radio waves, wherein the loop antenna has a first feeder and resonates in a first use frequency band. And a second single loop having a second power supply unit and resonating in a second frequency band lower than the first frequency band, wherein the second single loop is , A relay loop antenna arranged on the same plane in the first single loop. 4. A relay loop antenna mounted on the surface of a case body of a mobile phone for relaying radio waves, wherein the loop antenna has a first feeder and resonates in a first use frequency band. And a second single loop having a second feeding section and resonating at a second frequency lower than the first frequency band, wherein the first single loop is A relay loop antenna, which is disposed in a second single loop and is provided on one surface of a mounting film having a luminous action. 5. A loop antenna mounted on a surface of a case body of a mobile phone for relaying radio waves, comprising: a first antenna having a first power supply unit and resonating in a first use frequency band. At least a single single loop and a second single single loop having a second feed unit and resonating at a second frequency, wherein the second single loop is the first single loop A loop antenna for relaying, wherein these are provided on one surface of a mounting film having a luminous action, and the other surface of the mounting film is an adhesive surface. 6. A loop antenna mounted on the surface of a case body of a mobile phone for relaying a radio wave, wherein the loop antenna has a first power supply section and resonates in a first use frequency band. The second triangular single loop, comprising at least a single loop and a second triangular single loop having a second power supply unit and resonating in a second frequency band lower than the first frequency band; Are arranged in the first triangular single loop such that their apex angles coincide with each other, and
A common power supply unit comprising a power supply unit and a second power supply unit is provided at any one of the apex angles, and these are provided on one surface of a mounting film having a luminous action, and the other of the mounting film A loop antenna for relaying, characterized in that the surface of the loop is an adhesive surface.