JPH07131241A - Diversity antenna - Google Patents

Abstract

PURPOSE:To reduce the size of the diversity antenna by fitting a dielectric piece on the top surface of a ground box which crosses the front of a telephone set body almost at right angles, and then reducing the influence of a human body on an internal antenna and sharing the ground of the internal and external antennas. CONSTITUTION:This antenna is equipped with a monopole antenna 1 which projects from the telephone set body 4 and an inverted F type antenna 2 which is different in operation mode from the monopole antenna. A matching circuit 6 for the monopole antenna 1 is put in the telephone set body 4 and the ground box 3 connecting with the ground of the matching circuit 6 is provided. The dielectric piece 2 is fitted on the top surface of the ground box 3 which crosses the front surface of the telephone set body almost at right angles. The top surface of the ground box 3 crosses the front of the telephone set body 4 almost at right angles, so when the telephone set is used, the metallic foil 8 of the dielectric piece 2 is never covered with a hand and the influence of the human body on the internal antenna is made small. Further, both the ground parts of the dielectric piece 2 and the matching circuit 6 for the external antenna are both connected to the same ground box 3, so the telephone set body 4 is reduced effectively in size.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a diversity antenna which is a communication antenna for mobile phones.

[0002]

2. Description of the Related Art Conventionally, two antennas having the same operation mode are used to switch and combine received signals,
A diversity antenna that performs stable communication is known. Usually, in order to maximize the effect of the diversity antenna, it is said that the interval between the two antennas is preferably 0.3 times the transmission / reception wavelength (Journal of the Institute of Electronics, Information and Communication Engineers, B-II, June 1992, 370). ~ Page 378). In a mobile phone, an external antenna and an internal antenna are provided as diversity antennas. However, due to the demand for downsizing, the distance between both antennas is set to 0.
Some are set to 3 times or less. In order to avoid radio wave interference, such a mobile phone has external antennas and internal antennas having different operation modes, for example, one is an electric field sensitive antenna and the other is a magnetic field sensitive antenna.
The diversity characteristics do not affect the use.

An example is shown in FIGS. 7 and 8. As shown in FIG. 7, a metal plate (90) is provided facing the front of the telephone body (4). Between the metal plate (90) and the front of the telephone body (4),
A dielectric piece (2) is provided. Dielectric piece (2) is a metal plate
A metal foil (8) is attached to the opposite side of the surface in contact with (90). The metal foil (8) is electrically connected to the metal plate (90) by the conductive member (91), and the power feeding (93) is performed between the metal foil (8) and the metal plate (90). ing. In this way, an inverted F-type antenna which is an internal antenna is constructed. As shown in FIG. 8, a monopole antenna (1) that is an external antenna
Is provided apart from the dielectric piece (2) and is connected to the ground (92) at a location different from the metal plate (90).

[0004]

In the conventional portable telephone, the dielectric piece (2) is arranged so as to face the front surface of the telephone body (4), so that the hand is in contact with the dielectric piece (2) during a call. Metal foil
Covering (8), the directivity of the internal antenna may be affected by the human body and deteriorate. Further, since the two antennas are provided with separate grounds, a space for two grounds is required, which hinders downsizing of the telephone body (4). The present invention reduces the effect of the human body on the internal antenna,
In addition, the ground of both antennas is shared to provide a configuration that contributes to miniaturization.

[0005]

[Means for Solving the Problems] The portable telephone is a telephone body
An external antenna protruding from (4) and an internal antenna whose operation mode is different from that of the external antenna are provided. Phone body (4)
A matching box (6) for the external antenna is housed therein, and an earth box (3) connected to the ground of the matching circuit (6) is provided. The dielectric piece (2) is attached to the upper surface of the earth box (3) which is substantially orthogonal to the front surface of the telephone body (4). The dielectric piece (2) is
A metal foil (8) is formed on at least one surface, and a power supply terminal (21) and a ground terminal (20) are exposed from the surface opposite to that surface.
The dielectric piece (2) is attached by directing both terminals (20) and (21) to the upper surface of the earth box (3) and electrically connecting the earth terminal (20) to the upper surface.

[0006]

The function and effect of the invention: the dielectric piece (2) is the earth box (3).
Since it is attached to the upper surface of the, the ground area is increased compared to the configuration attached to the conventional metal plate (90),
The earth effect can be increased. Further, since the upper surface is substantially orthogonal to the front surface of the telephone body (4), the hand does not cover the metal foil (8) of the dielectric piece (2) when the telephone is used, and the human body does not receive the internal antenna. Can be reduced. Further, since both the ground of the dielectric piece (2) and the matching circuit (6) of the external antenna are connected to the same ground box (3), the space occupied by the ground in the telephone body (4) is occupied. It can be made smaller, which is effective for downsizing the telephone body (4).

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings. In the following description, the monopole antenna (1) is used as the external antenna and the inverted F-type antenna (2) is used as the internal antenna. FIG. 1 shows the entire mobile phone. A lid (42) is pivotally supported at one end of the telephone body (4). A plurality of operation buttons (41) are arranged in a portion of the telephone body (4) covered by the lid (42), and a display (9) for displaying a call state is provided at an end opposite to the pivot portion.
And a receiver (40) for transmitting and receiving radio waves.
In the vicinity of the receiver (40), from the end face of the telephone body (4),
The expandable monopole antenna (1) is protruding.

FIG. 2 shows a state in which the inside of the telephone body (4) is viewed from the back side. On the back side of the display (9), a wiring board
(5) is provided, and the earth box (3) is soldered to the surface of the wiring board (5). Various electric parts are attached to the portion of the wiring board (5) covered with the ground box (3), but the description thereof is omitted. The earth box (3) has a notch (35) at the bottom,
A connector (not shown) or the like is provided in the notch (35). A dielectric piece (2) is attached to the upper surface of the earth box (3), and one corner of the earth box (3) has openings (30) and (31) on the upper and lower surfaces.
Are formed respectively.

FIG. 3 shows a perspective view of the earth box (3). A shield piece (7) is attached to one corner of the earth box (3) having upper and lower openings (30) and (31). Shield piece
(7) is a straight plate body having an L-shaped cross section, which is attached to a corner of the earth box (3) and surrounds a rectangular space. In the space, the matching circuit of the monopole antenna (1)
(6) is provided. FIG. 6 is a cross-sectional view of FIG. 2 viewed from the cross section AA. As shown in FIGS. 6 and 3, a matching circuit
The earth (62) of (6) is grounded to the earth box (3) and the matching circuit
A power supply cable (60) is connected to the lower end of (6).
The upper end of the matching circuit (6) passes through the opening (30) and is connected to the ground box.
It protrudes from the upper surface of (3).

A conductive joining piece (61) is attached to the upper end of the matching circuit (6). The joining piece (61) is the telephone body (4)
It is pressed against the holder nut (10) fixed by the spring elasticity. The holder nut (10) is made of brass in consideration of conductivity. The lower end of the monopole antenna (1) is fitted to the holder nut (10). A through hole (34) is formed in the side surface of the earth box (3), and rectangular mounting holes (32) (33) are formed in the upper surface thereof. One edge of the mounting hole (33) is the ground box.
I'm approaching the front of (3). The dielectric piece (2) is placed so that both ends thereof respectively cover a part of the mounting holes (32) (33).

As shown in FIG. 4, the dielectric piece (2) is a rectangular parallelepiped, and solderable metal foils (8) are attached to the upper and lower surfaces thereof. At one end, the power supply terminal (21) and the ground terminal (20)
Is provided downward, and the lower ends of the terminals (20) and (21) are exposed to the lower surface of the dielectric piece (2). The ground terminal
Ground the (20) and feed power to the power supply terminal (21) to obtain the dielectric piece (2).
And the earth box (3) form an inverted F type antenna.

The dielectric piece (2) is attached to the earth box (3) as follows. As shown in FIG. 3, the dielectric piece
Place (2) on the top of the earth box (3). At this time, the power supply terminal (21) and the ground terminal (20) cover the mounting hole (33) and are not in contact with the upper surface of the ground box (3). In this state, the dielectric piece (2) is soldered from the back side of the upper surface of the earth box (3).
Figure 5 shows the ground box (3) turned upside down.
The lower surface of (2) and the edge of the mounting hole (32) are soldered to the edge of the mounting hole (33) and the ground terminal (20) as indicated by the dotted line. The power supply line (22) is attached to the power supply terminal (21) through the through hole (34). In this state, as shown in FIG. 2, ground box
Place (3) so that the dielectric piece (2) is facing upwards
Attach to (4). The joining piece (61) is a monopole antenna (1)
Press on the holder nut (10) of. That is, the dielectric piece (2) and the ground of the monopole antenna (1) are shared by the ground box (3). The power supply line (22) and the power supply cable (60) are
Of the received signals detected by the detector, which are respectively connected to the detection circuit,
Generally, the one with the higher reception sensitivity is selected and sent to the demodulation circuit for communication, but detailed description thereof will be omitted.

In this embodiment, the diversity antenna is composed of the monopole antenna (1) and the dielectric piece (2) in order to improve the transmission / reception sensitivity by disposing the antennas having different operation modes. Is. That is, as is well known, the electric field and the magnetic field are transmitted while crossing each other vertically, but the monopole antenna (1) is sensitive to the electric field of the electric wave, and the dielectric piece (2).
Is sensitive to the magnetic field of radio waves, so a monopole antenna (1)
The mutual interference is small even if the dielectric piece (2) is brought close to In reality, the directivity characteristics change when the monopole antenna (1) and the dielectric piece (2) are brought close to each other, but if the matching state of both antennas is adjusted, the best antenna characteristics will be obtained without disturbing transmission and reception. Can be obtained. The feeding section of the matching circuit (6) of the monopole antenna (1) shown in FIG. 2 and the dielectric piece (2)
The distance L from the power supply terminal (21) is about 0.2 times the transmission / reception wavelength.

Since the dielectric piece (2) is mounted on the upper surface of the grounding box (3), the grounding area is increased and the grounding effect is increased as compared with the structure mounted on the conventional metal plate (90). Can be increased. Further, since the upper surface is substantially orthogonal to the front surface of the telephone body (4), the hand does not cover the metal foil (8) of the dielectric piece (2) when the telephone is used,
The influence of the human body on the internal antenna can be reduced. Also, a matching circuit for the dielectric piece (2) and the external antenna.
Since both earths of (6) are connected to the same earth box (3), the space occupied by the earth in the telephone body (4) can be reduced, and the telephone body (4) can be downsized. Is effective for. Furthermore, the ground terminal (20) of the dielectric piece (2) is
Since it is soldered to the upper surface of the earth box (3), a conductive member is not required as in the conventional case, which leads to a reduction in the number of parts.

The above description of the embodiments is for explaining the present invention, and should not be construed as limiting the invention described in the claims or reducing the scope. The configuration of each part of the present invention is not limited to the above-mentioned embodiment, and it goes without saying that various modifications can be made within the technical scope described in the claims. For example, the earth box (3) is formed by bending a thin plate, but in order to provide a large earth area and enhance the earth effect, the earth box (3) has a front surface of substantially the same shape as the front surface of the earth box (3). A ground plate (not shown) can be attached. In addition, in this embodiment, an inverted F is used as the internal antenna.
Although the type antenna is used, an antenna having a different operation mode from the external antenna, for example, an inverted L type antenna may be used.

[Brief description of drawings]

FIG. 1 is an overall view of a telephone.

FIG. 2 is a cross-sectional view of the phone body as viewed from the back.

FIG. 3 is a perspective view of an earth box and each component attached to the earth box.

FIG. 4 is a perspective view of an inverted F type antenna.

FIG. 5 is a perspective view in which an earth box is turned upside down.

FIG. 6 is a cross-sectional view of the telephone body viewed from the cross section AA shown in FIG.

FIG. 7 is a side cross-sectional view showing the arrangement of antennas in a conventional telephone.

FIG. 8 is a front sectional view of the above.

[Explanation of symbols]

 (1) Monopole antenna (2) Dielectric piece (3) Ground box (4) Telephone body

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location H04B 7/04 4229-5K 7/26

Claims (1)

[Claims] 1. A diversity antenna used in a mobile phone, comprising an external antenna projecting from a telephone body (4) and an internal antenna having an operation mode different from that of the external antenna. ) Is stored, matching circuit (6)
A grounding box (3) connected to the ground of (1) is provided in the telephone body (4), a metal foil (8) is formed on at least one surface, and a power supply terminal (21) and a ground terminal ( 20) The dielectric piece (2) is provided, and both terminals (20) (21) of the dielectric piece (2) are provided on the upper surface of the earth box (3) which is substantially orthogonal to the front surface of the telephone body (4). ), The ground terminal (20) is electrically connected to the upper surface of the ground box (3) to form an inverted F-type antenna which is an internal antenna.