JP2003332931A - Portable radio terminal - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem that mounting a number of passive element sections 4 to a compact portable radio terminal is difficult and makes large external dimensions although the radiation pattern of an antenna can be changed by changing the state of the passive element section 4, when the passive element sections 4 are arranged in a number of lines each while a number of lines are wired among a plurality of cases. <P>SOLUTION: An high-impedance element 17 that increases the impedance of a linear conductor 14 is provided, and a linear conductor 18 for mutually connecting a ground conductor 11 to a ground conductor 12 is arranged in parallel with the linear conductor 14, thus connecting a load 19 in series with the linear conductor 18. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mobile wireless terminal such as a mobile phone whose housing can be folded.

[0002]

2. Description of the Related Art FIG. 8 is a block diagram showing a conventional portable wireless terminal disclosed in, for example, Japanese Unexamined Patent Publication No. 6-314920, in which 1 is a main metal housing of the portable wireless terminal and 2 is a portable wireless terminal. The sub-metal housing 3 of the terminal is a monopole antenna installed on the top of the main metal housing 1, and the reference numeral 4 is a passive element portion that connects the main metal housing 1 and the sub-metal housing 2 to each other.

Next, the operation will be described. When the monopole antenna 3 is excited, the main metal housing 1 and the sub metal housing 2
Although a current is induced above, if the potentials of the main metal casing 1 and the sub metal casing 2 are controlled by changing the state of the passive element portion 4, the electric current is induced on the main metal casing 1 and the sub metal casing 2. Since the flowing current distribution changes, the radiation pattern of the antenna can be changed to a desired shape.

The lower sub-metal casing 2 has a battery and an RF.
Circuits, digital circuits, etc. may be arranged, and a display etc. may be arranged in the upper main metal casing 1.
There are dozens of lines (about 4
0 to 80) is required. Therefore, in order to change the radiation pattern of the antenna by changing the state of the passive element section 4, it is necessary to arrange the passive element section 4 on several tens of lines.

[0005]

Since the conventional portable radio terminal is constructed as described above, when a large number of lines are wired between a plurality of casings, the passive element section 4 is arranged on each of the plurality of lines. If arranged, the radiation pattern of the antenna can be changed by changing the state of the passive element section 4. However, it is difficult to mount a large number of passive element units 4 on a small portable wireless terminal, and there is a problem in that the external dimensions are increased.

The present invention has been made in order to solve the above problems, and even when a large number of lines are wired between a plurality of housings, the radiation of the antenna can be radiated without increasing the outer dimensions. An object is to obtain a mobile wireless terminal capable of changing a pattern.

[0007]

A portable radio terminal according to the present invention is provided with a high-impedance increasing means for increasing the impedance of a first linear conductor and a second linear conductor for connecting a plurality of ground conductors to each other. The conductor is arranged in parallel with the first linear conductor, and the load is connected in series with the second linear conductor.

In the portable wireless terminal according to the present invention, a second linear conductor is arranged in parallel with a plurality of first linear conductors that connect a plurality of ground conductors to each other in a state of being bent in a loop shape. ,
The load is connected in series with the second linear conductor.

A portable radio terminal according to the present invention is provided with a second linear conductor in parallel with a plurality of first linear conductors that connect a plurality of ground conductors to each other in a bent state on one of the ground conductors. Is arranged so that the load is connected in series with the second linear conductor.

In the portable wireless terminal according to the present invention, the bent portion of the first linear conductor has an electrical length of 1/10 wavelength or more.

The portable radio terminal according to the present invention has a function that the load accepts a change in impedance.

The portable radio terminal according to the present invention has a function of allowing the load to accept a change in the capacity value.

In the portable radio terminal according to the present invention, the impedance of the load is changed so that the bandwidth becomes wider than that in the case where the second linear conductor is not installed.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below. Embodiment 1. 1 is a block diagram showing a portable wireless terminal according to Embodiment 1 of the present invention. In the figure, 11 is a ground conductor on which a speaker, display, etc. are arranged, and 12 is an RF circuit, a battery, a digital circuit, a microphone, for example. And a ground conductor on which a keyboard and the like are arranged. The ground conductor 11 and the ground conductor 12 are connected by a mechanism that can be opened and closed, and can be folded in two when not in use, for example.

13 is installed on the ground conductor 12, and the ground conductor 1
The radiating element fed from the RF circuit installed on 2 via the feeding line, 14 is a linear conductor (first linear conductor) that connects the ground conductor 11 and the ground conductor 12 to each other, and The conductor 14 is wiring for operating a speaker or a display installed on the ground conductor 11, and is usually
About 40 to 80 wires are wired (only three wires are wired in FIG. 1 for simplification of the drawing). 15 is a connector,
Reference numeral 16 is a capacitive element that prevents a high-frequency current on the line of the linear conductor 14 generated by coupling with the radiating element 13 from flowing into a circuit (not shown) on the ground conductors 11 and 12.
That is, since the capacitive element 16 is grounded, the linear conductor 14 has a high frequency, and the ground conductor 1 is formed at the connector 15.
Short-circuited with 1 and 12.

Reference numeral 17 denotes a high-impedance element (high-impedance increasing means) for increasing the impedance of the linear conductor 14. The high-impedance element 17 is, for example, a strong material such as ferrite capable of covering the linear conductor 14. A magnetic material is considered. Reference numeral 18 denotes a linear conductor (second linear conductor) that is arranged in parallel with the linear conductor 14 and connects the ground conductor 11 and the ground conductor 12 to each other. It is a load having a function of accepting a change in the capacity value. As the load 19, for example, a load that is composed of a plurality of inductances and capacitors, and the inductances and capacitors that are actually used are selected according to a control signal from the outside.

Next, the operation will be described. First, the correlation between the impedance of the load 19 and the radiation pattern of the antenna will be described. 3 shows a change in impedance of the load 19, and FIG. 4 shows a correlation coefficient of a radiation pattern when the impedance of the load 19 is changed as shown in FIG. 3 when the mobile radio terminal has the configuration of FIG. ing.
The frequency is in the 900 MHz band.

The value of the load 19 corresponds to the deflection angle Arg on the Smith chart with the standardized impedance of 50 [Ω] shown in FIG. 3. For example, when Arg = 0 [deg], Z '= ∞.
[Ω], Arg = 180 [deg] is Z ′ = 0 [Ω],
Arg = 90 [deg] is Z '= + j50 [Ω], Ar
g = 270 [deg] corresponds to Z '=-j50 [Ω]. The correlation coefficient of the radiation pattern is Arg = 0 [d
eg] is defined as the value when the radiation pattern in the case of [eg] is used as a reference.

A state where the correlation coefficient of the radiation pattern is low is A
This corresponds to a large deformation of the radiation pattern as compared with the case of rg = 0 [deg]. In the example of FIG. 4, Ar
The correlation coefficient decreases to about 0.3 in the vicinity of g = 270 [deg]. That is, there is a large difference between the radiation pattern of Arg = 0 [deg] and the radiation pattern of Arg = 270 [deg], which indicates that the radiating element 13 operates in common but operates as a different antenna.

Therefore, it is possible to operate as a diversity antenna by switching between the two radiation patterns. Note that the conventional diversity antenna is realized by providing two antenna elements on the mobile wireless terminal and switching them, but if two radiation patterns are switched in this way, one radiating element 13 can be provided. Since it is sufficient to install the mobile wireless terminal, it is possible to reduce the size of the mobile wireless terminal.

Next, consider the configuration of an actual portable wireless terminal. As shown in FIG. 1, the actual mobile wireless terminal is a ground conductor 1
1 and the ground conductor 12 are short-circuited by the linear conductor 14.
That is, the impedance between the ground conductor 11 and the ground conductor 12 is almost 0 [Ω]. In this state, even if the load 19 is arranged in parallel, the impedance between the ground conductor 11 and the ground conductor 12 remains short-circuited, and it is difficult to change the impedance between the ground conductor 11 and the ground conductor 12. Is.

Therefore, in this state, the loads 19 may be arranged in series with respect to the plurality of linear conductors 14, but it is not realistic to arrange several tens of the loads 19, and therefore the linear conductors are not arranged. A high impedance element 17 for increasing the impedance of 14 is installed. That is, the linear conductor 14
In order to make it possible to change the impedance between the ground conductor 11 and the ground conductor 12 by the load 19 arranged in parallel with the line conductor 14, the impedance of the line conductor 14 may be increased. A high impedance element 17 is installed to enhance the The impedance of the linear conductor 14 is ideally ∞ [Ω]. In this way, the high impedance element 17 for increasing the impedance of the linear conductor 14 is installed, and the load 19
The radiation pattern of the antenna can be changed by changing the impedance or capacitance of the antenna.

As is clear from the above, the first embodiment
According to this, the high-impedance increasing element 17 for increasing the impedance of the linear conductor 14 is provided, and the ground conductor 11
The linear conductor 18 that connects the ground conductor 12 with the ground conductor 12 is arranged in parallel with the linear conductor 14, and the load 19 is connected in series with the linear conductor 18.
The ground conductor 11 and the ground conductor 1 are connected to each other.
Even when a large number of lines are wired between the two, there is an effect that the radiation pattern of the antenna can be changed without increasing the outer dimensions.

In the first embodiment, the frequency is 9
Although the one in the 00 MHz band is shown, the same operation is possible in other frequency bands. In that case,
The impedance of the load 19 whose correlation coefficient decreases in each frequency band is different. When the radiating element 13 is used by switching in a plurality of bands, the impedance of the load 19 is changed in accordance with each used band and selected so as to reduce the correlation coefficient, so that the diversity corresponding to a plurality of frequencies is obtained. An antenna can be realized.

Embodiment 2. FIG. 5 is a block diagram showing a portable wireless terminal according to Embodiment 2 of the present invention. In the figure, the same reference numerals as those in FIG. Reference numeral 21 is a thin dielectric that is bent in a loop shape, and 22 is disposed on the thin dielectric 21.
Is a linear conductor (first linear conductor) that connects the ground conductor 12 to each other.

In the first embodiment, the impedance of the linear conductor 14 is increased by installing the high impedance element 17, but the linear conductor 2 has been described above.
The high impedance element 17 may be omitted by bending 2 in a loop shape. That is, when the linear conductor 22 is bent in a loop shape, the linear conductor 22 operates as an inductive element, so that the impedance between the ground conductor 11 and the ground conductor 12 can be increased. Thereby, the same effect as that of the first embodiment can be obtained, and the high impedance element 17 can be omitted.

Embodiment 3. 6 is a block diagram showing a portable wireless terminal according to Embodiment 3 of the present invention. In the figure, the same reference numerals as those in FIG. Reference numeral 23 is a thin dielectric that is bent on the ground conductor 11, and 24 is a linear conductor (first linear conductor) that is arranged on the thin dielectric 23 and connects the ground conductor 11 and the ground conductor 12 to each other. Yes, the bent portion of the linear conductor 24 is λ / 10
It has an electrical length of (1/10 wavelength) or more.

In the above-described first embodiment, the impedance of the linear conductor 14 is increased by installing the high impedance element 17, but the ground conductor 11 is described.
The high impedance element 17 may be omitted by bending the linear conductor 24 above.

That is, the linear conductor 24 is short-circuited to the ground conductor 11 by the capacitive element 16 at the connector 15 at high frequencies. Therefore, λ / 4 from the connector 15
At the points separated from each other, the linear conductor 24 and the ground conductor 11 are in an open state. That is, the length of the bent portion of the linear conductor 24 is λ / 4.
By having the electrical length of, the impedance between the ground conductor 11 and the ground conductor 12 can be set to an ideal ∞ [Ω]. The length of the bent portion of the linear conductor 24 is ideally an electrical length of λ / 4, but it is practical if it is λ / 10 or more. In addition, in the third embodiment, the linear conductor 24 is bent on the ground conductor 11, but the ground conductor 1
The same effect can be obtained by bending the linear conductor 24 on the wire 2.

Fourth Embodiment FIG. 7 shows the bandwidth B.V. when the impedance of the load 19 is changed in the configuration of the mobile wireless terminal of FIG. W. Is shown. The frequency is 900 MHz band, and the bandwidth B. W. Is defined by VSWR <3. As shown in FIG. 7, when Arg = 315 [deg], the bandwidth B. W. It can be confirmed that is about 150 [MHz]. This is compared with the case of Arg = 0 [deg], which corresponds to the case where there is no linear conductor 18 and load 19, and the bandwidth B. W. Is more than double. That is, by mounting the linear conductor 18 and the load 19 on the mobile wireless terminal and appropriately selecting the impedance of the load 19, the bandwidth can be made wider than in the case where the linear conductor 18 and the load 19 are not provided. . By using a means for switching the impedance of the load 19, it is possible to freely select a state with a low correlation coefficient or a wide bandwidth.

[0031]

As described above, according to the present invention, the first
And a second linear conductor that connects a plurality of ground conductors to each other is arranged in parallel with the first linear conductor.
Since the load is configured to be connected in series with the second linear conductor, even when a large number of lines are wired between the plurality of ground conductors, the radiation pattern of the antenna can be obtained without increasing the outer dimensions. There is an effect that can be changed.

According to the present invention, the second linear conductor is arranged in parallel with the plurality of first linear conductors that connect the plurality of ground conductors to each other in the state of being bent in a loop shape, and the second linear conductor is arranged. Since the load is configured to be connected in series with the linear conductor of, the radiation pattern of the antenna can be changed without increasing the outer dimensions even when a large number of lines are wired between multiple ground conductors. There is an effect that can be.

According to the present invention, the second linear conductor is arranged in parallel with the plurality of first linear conductors that connect the plurality of ground conductors in a bent state on one of the ground conductors. Second
Since the load is configured to be connected in series with the linear conductor of, the radiation pattern of the antenna can be changed without increasing the outer dimensions even when a large number of lines are wired between multiple ground conductors. There is an effect that can be.

According to the present invention, since the bent portion of the first linear conductor is configured to have an electrical length of one-tenth wavelength or more, the impedance between the ground conductors is ideally ∞ [Ω]. ] Is effective.

According to the present invention, the load has a function of accepting a change in impedance.
There is an effect that the radiation pattern of the antenna can be changed.

According to the present invention, since the load has the function of accepting the change of the capacitance value, there is an effect that the radiation pattern of the antenna can be changed.

According to the present invention, the impedance of the load is changed so that the bandwidth is widened as compared with the case where the second linear conductor is not installed, so that the band of the antenna can be broadened. is there.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a portable wireless terminal according to Embodiment 1 of the present invention.

FIG. 2 is a configuration diagram showing a portable wireless terminal used for explaining a correlation coefficient of a radiation pattern.

FIG. 3 is an explanatory diagram showing a change in impedance of a load.

FIG. 4 is an explanatory diagram showing a correlation coefficient of a radiation pattern when a load impedance is changed.

FIG. 5 is a configuration diagram showing a portable wireless terminal according to Embodiment 2 of the present invention.

FIG. 6 is a configuration diagram showing a portable wireless terminal according to Embodiment 3 of the present invention.

FIG. 7 is an explanatory diagram showing a bandwidth when the impedance of the load is changed.

FIG. 8 is a block diagram showing a conventional portable wireless terminal.

[Explanation of symbols]

11 ground conductors, 12 ground conductors, 13 radiating elements, 14
Linear conductor (first linear conductor), 15 connector, 16
Capacitance element, 17 high impedance element (high impedance means), 18 linear conductor (second linear conductor),
19 load, 21 thin dielectric, 22 linear conductor (first
Linear conductors, 23 thin dielectrics, 24 linear conductors (first
Linear conductor).

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Shigeru Makino             2-3 2-3 Marunouchi, Chiyoda-ku, Tokyo             Inside Ryo Electric Co., Ltd. (72) Inventor Yasuto Imanishi             2-3 2-3 Marunouchi, Chiyoda-ku, Tokyo             Inside Ryo Electric Co., Ltd. (72) Inventor Yasuhiro Nishioka             2-3 2-3 Marunouchi, Chiyoda-ku, Tokyo             Inside Ryo Electric Co., Ltd. (72) Inventor Tetsuya Tanaka             2-3 2-3 Marunouchi, Chiyoda-ku, Tokyo             Inside Ryo Electric Co., Ltd. F-term (reference) 5J046 AA04 TA03                 5J047 AA04 FD01                 5K011 AA06 AA16 DA02 EA06 JA01                 5K027 AA11 BB03 MM00

Claims (7)

[Claims] 1. A radiating element installed on any one of a plurality of ground conductors, a plurality of first linear conductors interconnecting the plurality of ground conductors, and the first wire. Impedance increasing means for increasing the impedance of the linear conductor, a second linear conductor arranged in parallel with the first linear conductor and connecting the plurality of ground conductors to each other, and the second linear conductor And a load connected in series with the mobile wireless terminal. 2. A radiating element installed on any ground conductor of the plurality of ground conductors, and a plurality of first linear conductors interconnecting the plurality of ground conductors in a bent state in a loop shape. A conductor, a second linear conductor arranged in parallel with the first linear conductor and connecting the plurality of ground conductors to each other, and a load connected in series with the second linear conductor. A portable wireless terminal equipped. 3. A radiating element installed on any ground conductor of the plurality of ground conductors, and a plurality of radiating elements for mutually connecting the plurality of ground conductors in a bent state on any of the ground conductors. A first linear conductor, a second linear conductor which is arranged in parallel with the first linear conductor and which connects the plurality of ground conductors to each other, and a second linear conductor which are connected in series with each other. Wireless terminal with a load. 4. The bent portion of the first linear conductor is 10
The mobile wireless terminal according to claim 3, wherein the mobile wireless terminal has an electrical length of one-half wavelength or more. 5. The mobile wireless terminal according to claim 1, wherein the load has a function of accepting a change in impedance. 6. The mobile wireless terminal according to claim 5, wherein the load has a function of accepting a change in the capacity value. 7. The portable wireless terminal according to claim 5, wherein the impedance of the load is changed so that the bandwidth is wider than when the second linear conductor is not installed.