JP3467752B2 - Mobile communication terminal and its antenna device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mobile communication terminal such as a mobile phone, a simple mobile phone (a so-called PHS mobile phone, the same applies hereinafter), a pager, and a portable information processing terminal, and more particularly to an antenna device thereof. It is about.

[0002]

2. Description of the Related Art In a conventional mobile phone, the frequency band of its radio waves is often about 800 MHz, the cell radius thereof is as wide as several km, and the antenna base station is installed outdoors at a high place. Therefore, it was a method in which the vertically polarized component of the used radio wave was relatively easily transmitted and received. The frequency used in recent mobile communication terminals is as high as 1.9 GHz. The antenna device used for the mobile communication terminal is mainly configured to transmit and receive by a rod antenna (whipped antenna) which is telescopically incorporated in a case constituting the mobile communication terminal. Also known is a helical antenna that always projects shortly outside the case. Further, there is known a rod antenna in which a helical antenna is incorporated at its tip or intermediate portion.

[0003]

In the mobile communication terminal, since the frequency used is high, the cell radius is as narrow as several hundred meters.
Therefore, it is necessary to install many antenna base stations, and in some cases they are installed in the valleys of buildings. However, radio waves tend to have many polarization components that are nearly horizontal due to reflections from buildings and the like.

The rod antenna mainly used in such a portable communication terminal needs to be pulled out from the case for a long time by the knob at the tip of the rod antenna each time it is used, which is troublesome to operate and a little. There is a problem that there is a risk of being easily damaged by an external force or getting eye-catching during use.

Further, since the helical antenna is constructed by protecting the antenna element consisting of an air-core coil with a cover material such as silicone rubber, it tends to have a large outer diameter. The problem of poor appearance was inevitable.

In view of the above problems of the prior art, the object of the present invention is not to rely solely on the rod antenna or the external antenna of the helical antenna for the antenna device of the mobile communication terminal, but to the circuit inside the mobile communication terminal. A built-in antenna is configured by forming a conductor pattern on the board in a direction perpendicular to the direction of the external antenna, and by connecting the ends of both antennas in common, vertical polarization and horizontal polarization components can be transmitted and received. The present invention provides an antenna device for a mobile communication terminal and a communication terminal equipped with such an antenna device, in which the outer dimensions can be minimized to improve the outer shape of both antennas and the handling and reliability. Especially.

[0007]

In order to solve the above problems, according to the present invention, an antenna device in a mobile communication terminal comprises a conductor pattern provided on an insulating substrate, and a power feeding portion and a connection terminal portion. And a whip antenna that is connected to the connection terminal portion of the first antenna element and that is tuned to the vertical polarization of the radio wave of the transmission / reception frequency. And a second antenna element consisting of

According to one aspect of the present invention, the conductor pattern in the first antenna element includes a linear pattern serving as an antenna portion, and the feeding portions connected to the antenna portion and extending from the linear feeding portion. It is characterized by comprising the connection terminal portion.

Further, it is preferable that the power feeding section is made of a linear conductor film, and ground patterns are formed on both sides of the linear conductor film at intervals so as to form a coaxial line.

[0010]

According to the present invention, the first antenna element as the external antenna corresponds to the vertically polarized component, and the second antenna element as the built-in antenna arranged at a right angle to this is connected to connect the horizontally polarized component. It is compatible with, and has a performance that is more omnidirectional than a conventional external antenna alone, and has a small size.
It is inexpensive and can be highly reliable.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

1 (a) and 1 (b) are a front view and a top view showing an embodiment of an antenna device for a mobile communication terminal according to the present invention.

Referring to FIGS. 1 (a) and 1 (b),
The illustrated antenna device corresponds to a first antenna element 1 corresponding to a horizontal polarization component composed of a conductor pattern provided on an insulating substrate 6 and a vertical polarization component composed of a rod antenna via a feeding point 4 thereof. It comprises a second antenna element 2.

The first antenna element 1 includes an antenna portion having a folded linear pattern and its feeding point 4
The connecting terminal portion 41 is composed of a linear conductor pattern and extends from the power supply line 9. The ground pattern 7 is provided on both sides of the power supply line 9 to form a coaxial line. By doing so, it is possible to suppress the influence of the feeder line 9 on the radiation characteristic of the antenna.

The antenna portion of the first antenna element 1 is tuned to a quarter wavelength or a half wavelength of the horizontal polarization component of the radio wave in the used frequency band.

As shown in FIG. 1, one end of the second antenna element 2 is connected to the connection terminal portion 41 of the first antenna element 1 through the joint portion 5, and the arrangement configuration thereof is the first. It is perpendicular to the antenna element. That is, the second antenna element 2 is parallel to the insulating substrate 6. The second antenna element is configured to be tuned to a quarter wavelength or a half wavelength of the vertically polarized component of the radio wave in the used frequency band.

The insulating substrate 6 is shown here as a circuit substrate on which a communication circuit of a communication terminal, for example, an RF circuit 8 is mounted. That is, the conductor pattern of the first antenna element is formed on this circuit board.

However, the insulating substrate of the first antenna element may be mounted on a circuit board on which a communication circuit such as the RF circuit 8 is mounted, as a board different from the circuit board.

FIG. 2 is a partial cross-sectional view showing the structure of the main part of a communication terminal equipped with the antenna device of FIGS. 1 (a) and 1 (b).

The rod antenna part of the second antenna element 2 is installed in a case 11 of the communication terminal so as to be able to expand and contract,
Moreover, the joint portion 5 that holds the rod antenna portion is connected to the connection terminal portion 41 of the first antenna element of the insulating substrate 6. At the tip of the second antenna element 2,
Knob 3 is attached and serves as a knob for expanding and contracting the rod antenna.

When the rod antenna portion of the second antenna element 2 is pulled out from the case 11 of the communication terminal and extends, the joint portion 5 makes electrical contact with the connection terminal portion 41. In the actual structure, the metal stopper portion 10 at the end portion of the rod antenna also serves as a contact in the joint portion 5.

The signals of the first and second antenna elements 1 and 2 are transmitted to and received from the RF circuit 8 via the feeder line 9.

According to the above-described antenna device shown in FIGS. 1 and 2, the first antenna element 1 mainly transmitting / receiving the horizontally polarized component and the second antenna element 2 mainly transmitting / receiving the vertically polarized component. Since the mobile communication terminals are in the operating state at the same time, it is possible for the mobile communication terminal to transmit and receive radio waves that are nearly omnidirectional.

Further, even if the rod antenna part of the second antenna element 2 is stored in the case 11 of the communication terminal, by keeping the first antenna element 1 in the operating state, it is possible to receive incoming radio waves. Becomes

The shape of the conductor pattern of the antenna portion of the first antenna element 1 is not limited to the linearly folded shape as shown in FIG. 1 (a), but is L as shown in FIG. 3 (a).
A letter shape or a zigzag shape (also called a miranda shape) as shown in FIG. 3B is also possible. Further, it may have a land shape.

Further, the antenna portion of the first antenna element 1 is a dielectric chip antenna 14 in which a conductor pattern is formed on a dielectric substrate, and as shown in FIG. 4, a feeding point 4, a feeding line 9 and a connecting terminal. It may be mounted on an insulating substrate provided with the portion 41.

The measurement result of the radiation pattern of the antenna device for the mobile communication terminal according to the above embodiment is shown in FIG.
Shown in (b) and (c). Good measurement results were obtained for all directions of vertical polarization and horizontal polarization at an angle of 360 degrees.

[0028]

As described above, as described in the embodiments, the first antenna element corresponding to the horizontally polarized wave formed on the insulating substrate by the conductor pattern so as to be in the direction orthogonal to the rod antenna and the vertically polarized wave. Since the antenna device of the mobile communication terminal is configured with the rod antenna as the second antenna that expands and contracts from the case corresponding to the wave, the transmission / reception characteristics of the radio wave in the used frequency band are good, and the size, cost and reliability are good. It was possible to realize a communication terminal equipped with an antenna device having a high appearance and a good appearance.

[Brief description of drawings]

FIG. 1A is a front view showing an outline of an antenna device of the present invention. (B) A top view showing the outline of the antenna device of the present invention.

FIG. 2 is a sectional view of a main part of a communication terminal equipped with the antenna device of the present invention.

FIG. 3A is a front view of an example in which the first antenna element has an L-shaped conductor pattern. (B) A front view of an example in which the first antenna element has a zigzag conductor pattern.

FIG. 4 is a front view in which a dielectric chip antenna is used for the first antenna element.

FIG. 5A, FIG. 5B, and FIG. 5C are radiation pattern measurement diagrams of an example of the present invention.

[Explanation of symbols]

1 First antenna element 2 Second antenna element 3 knobs 4 feeding points 41 Connection terminal 5 joints 6 insulating substrate 7 Grand pattern 8 RF circuit 9 power lines 10 Stopper part 11 Communication terminal case 12 L-shaped conductor pattern 13 Zigzag conductor pattern 14 Dielectric chip antenna

Front page continued (58) Fields surveyed (Int.Cl. ⁷ , DB name) H01Q 1/24 H01Q 1/10 H01Q 1/38 H01Q 21/24

Claims (13)

(57) [Claims] 1. A antenna device used in mobile communication terminals, made of a conductor pattern provided on the insulator substrate to have a connection terminal portion and the power supply unit, a radio wave of water transmitting and receiving frequency
A first antenna element tuned to a plane polarized wave;
It is connected to the connection terminal portion of the antenna element, feed
An antenna device for a mobile communication terminal, comprising: a second antenna element composed of a whip antenna which is tuned to a vertically polarized wave of a radio wave of a reception frequency . 2. The antenna device for a mobile communication terminal according to claim 1, wherein the conductor pattern in the first antenna element is a linear pattern serving as an antenna portion and is extended from the linear pattern connected to the antenna portion. An antenna device for a mobile communication terminal, comprising the existing power supply unit and the connection terminal unit. 3. The antenna device for a mobile communication terminal according to claim 2, wherein the feeding portion is composed of a linear conductor film, and ground patterns are formed on both sides of the linear conductor film with a space therebetween to form a coaxial line. An antenna device for a mobile communication terminal, which is configured. 4. The antenna device for a mobile communication terminal according to claim 1, wherein the conductor pattern of the first antenna element has an antenna portion formed of a zigzag linear pattern. An antenna device for a mobile communication terminal. 5. The antenna device for a mobile communication terminal according to claim 1, wherein the conductor pattern of the first antenna element has an antenna portion having a linear linear pattern. An antenna device for a mobile communication terminal. 6. The antenna device for a mobile communication terminal according to claim 1, wherein the conductor pattern of the first antenna element has an antenna portion formed of a folded linear pattern. An antenna device for a mobile communication terminal. 7. The antenna device for a mobile communication terminal according to claim 1, wherein the conductor pattern of the first antenna element has an antenna portion formed of an L-shaped linear pattern. An antenna device for a mobile communication terminal, characterized in that 8. The antenna device for a mobile communication terminal according to claim 1, wherein the conductor pattern of the first antenna element has an antenna portion formed of a land pattern. An antenna device for a mobile communication terminal. 9. The antenna device for a mobile communication terminal according to claim 2, wherein the first antenna unit is a dielectric chip antenna and is mounted on the insulating substrate. Antenna device for mobile communication terminal. 10. A mobile communication terminal having a communication circuit and an antenna device, the antenna device comprising a conductor pattern formed on a surface of an insulating substrate and connected to a power feeding section connected to the communication circuit. have a terminal portion, sending and receiving
A first antenna element that is tuned to a horizontally polarized wave of a radio wave of a frequency, and is connected to the connection terminal portion of the first antenna element, and is tuned to a vertically polarized wave of a radio wave of a transmission / reception frequency.
And a second antenna element which is a whip antenna. 11. The mobile communication terminal according to claim 10, wherein the first antenna element is provided in a case of the mobile communication terminal, and the second antenna element is expandable and contractible when contracted. A mobile communication terminal, which is provided so as to be stored inside. 12. The mobile communication terminal according to claim 11, wherein at least a part of the communication circuit is provided on the insulator substrate. 13. The mobile communication terminal according to claim 11, wherein a circuit board having at least a part of the communication circuit is provided in the case, and the first antenna element is mounted on the circuit board. A mobile communication terminal characterized in that