JP2001085920A - Portable wireless terminal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a mobile wireless terminal whose gain and bandwidth of an internal antenna of which are improved. SOLUTION: A 1st internal antenna 103 connected electrically to a signal wire on a printed circuit board 102 is mounted on the printed circuit board 102 inside a terminal case 101 and a 2nd internal antenna 104 is placed on a face of terminal case 101. Through the configuration above, since the 2nd antenna 104 is spatially coupled with the 1st internal antenna 103, the gain of the internal antenna is increased and the bandwidth of the internal antenna is made broader without increasing the mount volume.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a portable radio terminal and, more particularly, to a portable radio terminal having an internal antenna disposed inside a terminal housing.

[0002]

2. Description of the Related Art Conventionally, in a portable radio terminal, it has been general to transmit and receive a radio signal using an external antenna disposed outside a terminal housing.

[0003] However, a portable radio terminal having an internal antenna inside the terminal housing may be required. From the background of miniaturization of portable wireless terminals, there are examples in which external antennas are eliminated and only internal antennas are arranged, thereby realizing miniaturization and improving the flexibility of terminal design.

[0004] Also, in view of the performance improvement of portable terminals, an internal antenna is arranged in addition to an external antenna, and diversity reception is performed using these two antennas.
There is an example in which the receiving sensitivity is improved.

However, the internal antenna disposed inside the terminal housing has a low gain and a narrow band. As an internal antenna of the portable wireless terminal, an inverted F antenna, a linear antenna, a helical antenna, or the like is generally used. Since these internal antennas are generally arranged on a circuit board, they are miniaturized. Therefore, the gain is lower and the band is narrower than that of the external antenna.

[0006]

As described above, conventionally,
Since the internal antenna arranged inside the terminal housing of the portable wireless terminal is small, it has a low gain and a narrow band as compared with the external antenna.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems, and has as its object to provide a portable radio terminal in which the gain and band of an internal antenna are improved.

[0008]

A portable radio terminal according to the present invention comprises a terminal housing, a circuit board accommodated in the terminal housing and on which circuit components are mounted, and a signal line on the circuit board. A first internal antenna electrically connected and arranged inside the terminal housing, and a second internal antenna arranged on the terminal housing surface are provided.

With such a configuration, the second antenna is spatially coupled to the first internal antenna, so that the gain and band of the internal antenna can be improved without increasing the mounting volume. It becomes possible.

Here, the second internal antenna may be configured not to be electrically connected to the signal line on the circuit board.

With such a configuration, the second antenna is spatially coupled to the first internal antenna, and the first internal antenna is provided with a parasitic element. Gain and band can be improved.

Further, a part of the second internal antenna may be electrically connected to a ground on the circuit board.

[0013] With this configuration, the length of the second antenna can be shortened, so that the size can be reduced.

[0014] The shield may be provided on the terminal housing surface, and the second internal antenna may be formed by providing a notch in the shield provided on the terminal housing surface.

Further, the terminal housing may be a conductive terminal housing, and the second internal antenna may be formed by providing a cutout in the conductive terminal housing.

[0016]

Embodiments of the present invention will be described below in detail with reference to the drawings.

(First Embodiment) FIGS. 1A and 1B are views showing the configuration of a first embodiment of a portable radio terminal according to the present invention, wherein FIG. 1A is a perspective view, and FIG. FIG.
As shown in FIG. 1, a circuit board 10 for mounting components of a radio circuit and components of a control circuit is provided inside a terminal housing 101.
2 are arranged, and the circuit board 102
First internal antenna 1 electrically connected to the upper signal line
03 is implemented.

Here, a second internal antenna 104 is arranged on the surface of the terminal housing 101. When diversity reception or the like is performed, the circuit board 10 is provided outside the terminal housing 101.
External antenna 105 electrically connected to the signal line on 2
Is arranged.

With the above configuration, the first
The internal antenna 103 and the second internal antenna 104 spatially generate electromagnetic field coupling, and the second internal antenna 104 operates as a parasitic element of the first internal antenna 103, so that the gain and the band are improved.

More specifically, the shape of the second internal antenna is determined so that the resonance frequency f1 of the first internal antenna 103 and the resonance frequency f2 of the second internal antenna are the same, and It is necessary to arrange the first internal antenna 103 or the second internal antenna 104 so that the polarization of 103 and the polarization of the second internal antenna 104 are the same.

FIG. 2 shows how the gain and band are improved at this time.
Shown in As shown in FIG. 7A, the gain of the case where the second internal antenna 104 is provided (shown by a solid line) is greater than that of the case where the second internal antenna 104 is not provided (shown by a dotted line). Directivity in the front direction is improved. Also, as shown in FIG. 3B, the band in the case where the second internal antenna 104 is provided (shown by a solid line) is compared to the case where the second internal antenna 104 is not provided (shown by a dotted line). However, it has a wide band.

On the other hand, by shifting the resonance frequencies of the first internal antenna 103 and the second internal antenna 104, it is possible to further widen the band. FIG. 3 shows how the band is improved at this time. As shown in the figure, compared to the case of only the first internal antenna 103 (shown by a dotted line),
There is a second antenna 104 and the first internal antenna 10
When the resonance frequencies of the third internal antenna 104 and the second internal antenna 104 are shifted from f1 and f2, respectively (shown by solid lines), the bandwidth is further wider.

At this time, as the first internal antenna 103 mounted on the circuit board 102, an inverted F antenna 401 on a plate as shown in FIG. 4A and a linear antenna as shown in FIG. Elements such as an inverted F antenna 402 and a helical antenna 403 as shown in FIG. In recent years, for the purpose of miniaturization, a chip antenna 404 serving as an antenna by forming a conductor 404b on a dielectric 404a having a high dielectric constant as shown in FIG.

(Second Embodiment) FIG. 5 is a perspective view showing the configuration of a second embodiment of the portable radio terminal according to the present invention. The figure shows a linear inverted F antenna 501 and a second internal antenna arranged inside a terminal housing 500.
2 shows a specific configuration in the case of using the λ / 2 plate antenna 502 as the internal antenna.

The linear inverted F antenna 501 is connected to the signal line 5 of the circuit board 503 also mounted inside the terminal housing 500.
04 and ground 505, the length of the element at this time is about one quarter of the wavelength λ of the desired frequency.
Is the length of On the other hand, the λ / 2 plate antenna 502 is not electrically connected to the signal line on the circuit board 503, and the length of the pair of sides is about half the wavelength λ of the desired frequency. .

At this time, a linear inverted F antenna 501 as a first internal antenna and a λ /
When the two plate antennas 502 are arranged so that the polarization directions 506 are the same, the gain is most improved in the front direction.

(Third Embodiment) FIG. 6 is a perspective view showing the configuration of a third embodiment of the portable radio terminal according to the present invention. The figure shows a linear inverted-F antenna 601 and a second internal antenna arranged inside a terminal housing 600.
2 shows a specific configuration in the case of using the λ / 4 plate antenna 602 as the internal antenna.

The linear inverted F antenna 601 is connected to the signal line 6 of the circuit board 603 also mounted inside the terminal housing 600.
04 and ground 605, and the length of the element at this time is about one quarter of the wavelength λ of the desired frequency.
Is the length of On the other hand, the λ / 4 plate antenna 602 is electrically connected to the ground 605 on the circuit board 603 via the short-circuiting plate 607, and the length of the pair of sides is about 4 times the wavelength λ of the desired frequency. It's a fraction.

With such a configuration, the area of the λ / 4 plate antenna 602 as the second internal antenna can be reduced. At this time, the polarization direction 606 of the linear inverted F antenna 601 serving as the first internal antenna and the λ / 4 plate antenna 602 serving as the second internal antenna.
Are arranged to be the same, the gain is most improved in the front direction.

(Fourth Embodiment) Next, FIG. 7 is a perspective view showing the configuration of a fourth embodiment of the portable radio terminal according to the present invention.

In the figure, a terminal housing 700 provided with a shield 704 electrically connected to the ground of a circuit board 703 is internally connected to a signal line on the circuit board 703. One internal antenna 701 is provided. Further, a cutout portion 702 having a length of about half the wavelength λ of the desired frequency is provided on the terminal housing 700 to constitute a second internal antenna.

With such a configuration, the first internal antenna 701 and the notch 702 constituting the second internal antenna spatially generate electromagnetic field coupling, and the notch 702 is connected to the internal antenna 701. , The gain and band can be improved.

More specifically, the shape of the notch 702 is determined so that the resonance frequency f1 of the first internal antenna 701 and the resonance frequency f2 of the notch 702 constituting the second internal antenna become the same. And the first internal antenna 7
01 or the notch 70 so that the polarization of the first internal antenna 701 and the polarization of the notch 702 are the same.
2 needs to be arranged.

On the other hand, a first internal antenna 701,
By shifting the resonance frequency of the notch 702, it is possible to further widen the band.

(Fifth Embodiment) Next, a fifth embodiment of the portable radio terminal according to the present invention will be described.

In this embodiment, a terminal housing 700 provided with a shield 704 in the fourth embodiment shown in FIG.
Is replaced with a conductive terminal housing (for example, made of a magnesium alloy) 800, and the configuration is shown in FIG.

That is, also in this embodiment, the first internal antenna 801 electrically connected to the signal line on the circuit board 803 is provided inside the conductive terminal housing 800. Further, a cutout portion 802 having a length of about half the wavelength λ of the desired frequency is provided on the conductive terminal housing 800 to constitute a second internal antenna.

With such a configuration, the first internal antenna 801 and the notch 802 constituting the second internal antenna spatially generate electromagnetic field coupling, and the notch 802 is Since the antenna operates as a parasitic element of the internal antenna 801, the gain and the band can be improved.

More specifically, the shape of the notch 802 is determined so that the resonance frequency f1 of the first internal antenna 801 and the resonance frequency f2 of the notch 802 constituting the second internal antenna are the same. And the first internal antenna 8
01 or the notch 80 so that the polarization of the first internal antenna 801 and the polarization of the notch 802 are the same.
2 needs to be arranged.

On the other hand, by shifting the resonance frequency of the first internal antenna 801 and the resonance frequency of the notch 802, it is possible to further increase the bandwidth.

(Modification) The shape of the conductor or the cutout constituting the second internal antenna described in each of the above embodiments is arbitrary. In the above embodiments, for example, the second internal antenna 104, the λ / 2 plate antenna 5
02, λ / 4 plate antenna 602, notch 702,
The cutout portion 802 and the like have a rectangular shape with a length of λ / 2 or λ / 4 as shown in FIG.
FIG. 9B shows a zigzag shape as shown in FIG.
As shown in (c), by forming a spiral shape, miniaturization is possible. In the case of a zigzag shape or a spiral shape, the entire length of the zigzag shape or the length of the spiral may be λ / 2 or λ / 4.

The size can also be reduced by inserting a dielectric between the antenna and the first internal antenna.

The position of the power supply means, the position of the short-circuit plate, the length of the short-circuit plate, and the like can be arbitrarily adjusted, whereby the resonance frequency, the input impedance and the like can be easily adjusted.

[0044]

As described above, according to the portable radio terminal of the present invention, in addition to the first internal antenna disposed inside the terminal housing, the second antenna is disposed on the terminal housing surface. By doing so, the second antenna is spatially coupled to the first internal antenna, so that it is possible to increase the gain and broaden the bandwidth of the internal antenna without increasing the mounting volume.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a first embodiment of the present invention.

FIG. 2 is a diagram for explaining how a gain and a band are improved by a second antenna in the first embodiment.

FIG. 3 is a diagram for explaining how a band is improved by shifting a resonance frequency between a first internal antenna and a second internal antenna in the first embodiment.

FIG. 4 is a diagram showing an example of a first internal antenna according to the first embodiment.

FIG. 5 is a perspective view showing the configuration of a second embodiment of the present invention.

FIG. 6 is a perspective view showing the configuration of a third embodiment of the present invention.

FIG. 7 is a perspective view showing the configuration of a fourth embodiment of the present invention.

FIG. 8 is a perspective view showing the configuration of a fifth embodiment of the present invention.

FIG. 9 is a view showing an example of a shape of a conductor or a cutout constituting a second internal antenna in each embodiment of the present invention.

[Explanation of symbols]

101, 500, 600, 700, 800 terminal housing 102, 503, 603, 703, 803 circuit board 103, 701, 801 first internal antenna 104 second internal antenna 105 external antenna 401 plate Upper inverted F antenna 402 ... Linear inverted F antenna 403 ... Helical antenna 404 ... Chip antenna 404a ... Dielectric 404b ... Conductor 501,601 ... Linear inverted F antenna (first internal antenna) 502 ... λ / 2 plate antenna (Second internal antenna) 504, 604: Signal line 505, 605: Ground 506, 606: Polarization direction 602: λ / 4 antenna on plate (second internal antenna) 607: Short-circuit plate 702, 802 ... Off Notch (second internal antenna) 704: shield

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01Q 19/22 H01Q 19/22 21/30 21/30 (72) Inventor Norimichi Chiba Asahigaoka, Hino City, Tokyo 3-1-1 F-term in Toshiba Hino Plant Co., Ltd. (Reference) 5J020 AA00 BC08 BC13 DA01 DA02 5J021 AA02 AA06 AA13 AB02 AB05 AB06 BA00 CA03 GA03 HA05 HA10 JA02 5J045 AA02 AA05 DA03 DA08 FA01 HA02 LA01 NA03 5J046 AA12 AB08 AB08 AB13 PA07 SA00 TA03 5J047 AA03 AA12 AB08 AB10 AB12 AB13 FD01 FD06

Claims (5)

[Claims] 1. A terminal housing, a circuit board accommodated in the terminal housing for mounting circuit components, and electrically connected to signal lines on the circuit board and arranged inside the terminal housing. A portable internal radio terminal, comprising: a first internal antenna that is provided; and a second internal antenna that is disposed on the terminal housing surface. 2. The portable wireless terminal according to claim 1, wherein said second internal antenna is not electrically connected to a signal line on said circuit board. 3. The portable wireless terminal according to claim 1, wherein a part of the second internal antenna is electrically connected to a ground on the circuit board. 4. A shield is provided on the surface of the terminal housing, and the second internal antenna is formed by providing a cutout in a shield provided on the surface of the terminal housing. The mobile wireless terminal according to claim 1. 5. The terminal housing according to claim 1, wherein the terminal housing is a conductive terminal housing, and the second internal antenna is formed by providing a cutout in the conductive terminal housing. A portable wireless terminal according to claim 1.