JP2002232224A - Antenna system and radio equipment using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problems that radio equipment radiates strongly even in the direction of a human body to exert an influence on the human body and also to lower sensitivity when the radio equipment is carried and also that sensitivity deteriorates in the case the incoming direction of radio waves is different from a direction where the directivity of an antenna system exists even when the radio equipment is away from the human body such as at a waiting time. SOLUTION: This radio equipment is provided with at least two antennas 101 and 102 and a switch circuit 105 for performing switching so as to feed at least one antenna between the antennas 101 and 102, and the unfed antenna between the antennas 101 and 102 switches the directivity of the antenna by functioning as a parasitic element with respect to the fed antenna.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an antenna and a radio device mainly used for a radio device for mobile communication such as a portable telephone.

[0002]

2. Description of the Related Art In recent years, wireless devices for mobile communication such as portable telephones have rapidly become widespread. Since a wireless device is used close to a human body during a call, a characteristic of strongly emitting radio waves in a direction opposite to the human body is required.

FIGS. 21 and 2 show examples of the configuration of a conventional antenna.
4 will be described.

FIG. 21 is a diagram showing a specific configuration of a conventional antenna. In the figure, an antenna 2101 made of a metal wire is arranged so as to be parallel to the conductor ground plate 2103 and above the conductor ground plate 2103,
04 is connected to a wireless circuit. Note that the wireless circuit is omitted in FIG. In addition, parasitic element 2102 formed of a metal wire is arranged in parallel and close to antenna 2101. In this case, the parasitic element 2102
Is the antenna 2101, the conductor ground plane 2103 and the feeding point 2
104 is not connected. Here, the antenna 210
The direction from 1 to the parasitic element 2102 is the + X direction,
The Z axis is determined in parallel with the antenna 2101. In this case, conductive ground plane 2103 is arranged in the ZY plane. When the human body is used, the head is assumed to be in the -X direction.

The operation of the antenna configured as described above will be described below. The antenna 2101 resonates at the frequency f1, for example, 2 GHz, and the parasitic element 210
2 is resonated at the same frequency f1 as the antenna 2101 by electromagnetic field coupling with the antenna 2101.

At the time of reception, a signal of the frequency f 1 received by both the antenna 2101 and the parasitic element 2102 is input from the antenna 2101 to the wireless circuit via the feeding point 2104.

Next, at the time of transmission, a signal of frequency f1 input from the radio circuit is input to antenna 2101 via feed point 2104, and both antenna 2101 and parasitic element 2102 electromagnetically coupled to antenna 2101 are transmitted. Radiated from

In this case, the directivity is obtained by the interaction between the antenna 2101 and the parasitic element 2102.
As an example, the antenna 2101 and the parasitic element 210
2 is made of a 75 mm metal wire, and the antenna 210
FIG. 22 shows the radiation directivity at 2 GHz when the distance between 1 and the parasitic element 2102 is 1.5 mm. FIG.
Indicates that it has strong directivity in the + X direction (the side opposite to the head). Thus, by suppressing radiation toward the head during a call, the influence on the human body can be reduced.

FIG. 23 is a diagram for explaining a conventional antenna different from that of FIG. In the figure, a first antenna 2301 is a portion surrounded by a dotted line, that is, a metal plate 2.
301A, metal plate 2301A and first feeding point 2305
And a metal wire 2301C connecting the metal plate 2301A and the conductor ground plate 2303. The second antenna 2302 has a portion surrounded by a dotted line, that is, a metal plate 2302A and a metal plate 2302A.
Metal wire 2 connecting 302A and second feeding point 2306
302B, and a metal wire 2302C connecting the metal plate 2302A and the conductive ground plate 2303.

One of two balanced terminals of the balanced-unbalanced conversion circuit 2304 is connected to a first feeding point 2305,
The other is connected to the second feeding point 2306. It is assumed that the unbalanced terminal of the balanced-unbalanced conversion circuit 2304 is connected to the wireless circuit via the terminal 2307. In FIG. 23, the wireless circuit is omitted.

Here, conductor ground plane 2303 is arranged on the ZY plane, and the direction from conductor ground plane 2303 to metal plate 2301A is defined as the + X direction. When using the human body, the head is -X
Direction.

The operation of the antenna configured as described above will be described below. First antenna 2301
And the second antenna 2302 is commonly referred to as a plate-shaped inverted-F antenna, and has a frequency f1, for example,
It is assumed that resonance occurs at 2 GHz.

At the time of reception, the frequency f received by both the first antenna 2301 and the second antenna 2302
1 is input to each of two balanced terminals of the balanced-unbalanced conversion circuit 2304 via the first feeding point 2305 and the second feeding point 2306, and
A balance-unbalance conversion circuit 230 synthesized in the opposite phase by 304
4 and output to the wireless circuit via the terminal 2307.

Next, at the time of transmission, the signal of the frequency f1 input from the radio circuit is input to the unbalanced terminal of the balanced-unbalanced conversion circuit 2304 via the terminal 2307, and is inverted by the balanced-unbalanced conversion circuit 2304 at equal amplitude. A phase signal is output to each of the two balanced terminals. Balance-unbalance conversion circuit 2
One of the signals output from the two balanced terminals 304 is
A first antenna 2301 via a first feeding point 2305;
, And the other is radiated from the second antenna 2302 via the second feeding point 2306.

In this case, since the conductor ground plate 2303 functions as a reflector, it has directivity. As an example, the size of the metal plate 2301A and the metal plate 2302B is 14 mm in length and 14 mm in width, and the metal wire 2301B and the metal wire 23
01C, the distance between the metal wire 2302B and the metal wire 2303C is 4 mm, and the metal plate 2301A and the metal plate 2302
The distance between A and the conductive ground plane 2303 is 12 mm,
FIG. 24 shows the radiation directivity at 2 GHz when the size of 303 is 125 mm long and 70 mm wide.

As shown in FIG. 24, it can be seen that the light is strongly radiated in the + X direction (the side opposite to the head). In this case as well, the influence on the human body can be reduced by suppressing radiation toward the head during a call.

[0017]

However, when carrying the wireless device, for example, when putting the wireless device in a breast pocket, it is quite possible to put the wireless device in the breast pocket so that the + X direction faces the human body. .

In this case, there is a problem that the radiation is strongly emitted in the direction of the human body, thereby affecting the human body and lowering the sensitivity. Also, even when the wireless device is placed away from the human body, such as during standby, if the direction of arrival of radio waves is different from the direction of the directivity of the antenna of the wireless device,
There is a problem that the sensitivity is deteriorated.

An object of the present invention is to provide an antenna and a wireless device that have little effect on the human body and do not reduce sensitivity when the wireless device is carried in consideration of the above problems.

Another object of the present invention is to provide an antenna and a radio device that do not deteriorate in sensitivity even when the radio device is placed away from a human body, for example, in a standby mode. Things.

[0021]

In order to solve the above-mentioned problems, a first invention (corresponding to claim 1) comprises at least two antennas and control means for controlling power supply to these antennas. And the control means is an antenna system that controls directivity depending on whether power is supplied to the antennas.

The second invention (corresponding to claim 2)
Is the antenna system according to the first aspect of the present invention, wherein the control means performs the control according to an instruction from a manual switch.

The third invention (corresponding to claim 3)
Is an antenna system according to the first aspect of the present invention, wherein the control unit controls to feed power to all the antennas to realize substantially omnidirectionality.

The fourth invention (corresponding to claim 4)
The antenna system according to the first aspect of the present invention, wherein the control means short-circuits an antenna other than an antenna that controls to feed power among the antennas to a conductive ground plane in order to substantially realize omnidirectionality. .

The fifth invention (corresponding to claim 5)
Comprises at least one antenna, at least one parasitic element functioning with respect to the antenna, and control means for controlling whether to short-circuit the parasitic element to a conductive ground plane, wherein the control means comprises: An antenna system for controlling directivity depending on whether or not a parasitic element is short-circuited to the conductor ground plane.

The sixth invention (corresponding to claim 6)
Is the antenna system according to the third aspect of the present invention, wherein the control means controls so as to feed all the antennas at the time of reception.

Further, a seventh aspect of the present invention (corresponding to claim 7)
The antenna system according to the sixth aspect of the present invention, wherein the control means controls so that the antenna having the stronger signal received during reception among the antennas is not fed during transmission.

The eighth invention (corresponding to claim 8)
The control means controls the antennas, which are controlled to be non-powered, out of those antennas so as to supply power at predetermined time intervals, and when all of the antennas are powered, the signal received at the time of reception is An antenna system according to a seventh aspect of the present invention, in which the stronger antenna is controlled so as not to be fed during transmission.

The ninth invention (corresponding to claim 9)
Are the first to eighth antennas having different antenna directivities.
An antenna system according to any of the present inventions.

A tenth invention (corresponding to claim 10) is the antenna system according to any one of the first to ninth inventions, wherein at least the antenna resonates at a plurality of frequencies.

The eleventh invention (corresponding to claim 11) is the antenna system according to any one of the first to tenth inventions, wherein at least one of the antennas is a balanced antenna.

A twelfth aspect of the present invention (corresponding to claim 12) relates to any one of the first to eleventh aspects of the present invention in which any one of the antennas and any one of the parasitic elements are built in a radio apparatus. An antenna system as described.

A thirteenth aspect of the present invention (corresponding to claim 13) is the antenna system according to the twelfth aspect of the present invention, wherein at least one of the antennas is disposed on both surfaces of the conductive ground plane.

A fourteenth aspect of the present invention (corresponding to claim 14) is the twelfth or thirteenth aspect of the present invention in which one or more of the antennas are disposed on the upper and lower portions of the conductor ground plane, respectively. An antenna system as described.

According to a fifteenth aspect of the present invention (corresponding to claim 15), at least one of the antenna and the parasitic element is disposed on an inner wall of a case of a wireless device.
3 is an antenna system according to the present invention.

A sixteenth aspect of the present invention (corresponding to claim 16) is the antenna system according to the twelfth aspect of the present invention, wherein the parasitic element is a whip antenna housed inside the wireless device.

In a seventeenth aspect of the present invention (corresponding to claim 17), any one of the twelfth to fifteenth aspects of the present invention, wherein at least one of the antenna and the parasitic element is formed on a dielectric material. Antenna system.

According to an eighteenth aspect of the present invention (corresponding to claim 18), any one of the twelfth to fourteenth aspects of the present invention wherein at least one or a part of the antenna and the parasitic element is formed on a printed circuit board. An antenna system according to the present invention.

A nineteenth aspect of the present invention (corresponding to claim 19) is any of the twelfth to fourteenth aspects of the invention, wherein at least one or a part of the antenna and the parasitic element is formed on a flexible substrate. An antenna system according to the present invention.

A twentieth aspect of the present invention (corresponding to claim 20) is a radio apparatus comprising the antenna system according to any one of the first to nineteenth aspects, and a transmission circuit for supplying a transmission signal to the antenna system. .

According to a twenty-first aspect (corresponding to claim 21), there is provided a radio apparatus comprising the antenna system according to the first to nineteenth aspects and a receiving circuit for demodulating a received signal received by the antenna system. It is.

A twenty-second aspect of the present invention (corresponding to claim 22) is the wireless device according to the twentieth aspect of the present invention, comprising a receiving circuit for demodulating a received signal received by the antenna system.

In order to solve the above problem, the present invention is expected to reduce the influence on the human body and reduce the sensitivity deterioration by switching antennas having different directivities, regardless of the direction in which the wireless device is placed. it can.

[0044]

(Embodiment 1) Hereinafter, Embodiment 1 of the present invention will be described with reference to the drawings.

FIG. 1 is a diagram showing an outline of a configuration of an antenna system and a radio apparatus according to a first embodiment of the present invention.

In FIG. 1, a first antenna 101 arranged on a conductor ground plane 103 is connected to a terminal 105 b of a switch circuit 105. A second antenna 102 arranged close to the first antenna 101 is connected to a terminal 105c of the switch circuit 105. The terminal 105 a of the switch circuit 105 is connected to the feeding point 104. Although not shown in FIG. 1, the feeding point 104 is connected to a wireless circuit on the conductive ground plane 103. In this case, the switch circuit 105 includes the terminal 105a and the terminal 105b.
Alternatively, the switching control is performed such that one of the terminal 105a and the terminal 105c conducts.

The operation of the antenna and the radio apparatus configured as described above will be described below. The first antenna 101 and the second antenna 102 have a frequency f1,
For example, it is assumed that resonance occurs at 2 GHz.

First, the terminal 105a of the switch circuit 105
When the terminal 105b is controlled to be conductive, the second antenna 102 functions as a parasitic element.
Resonance occurs due to electromagnetic field coupling with the first antenna 101, and the directivity of the first antenna 101 changes.

At the time of reception, the signal of the frequency f1 received by both the first antenna 101 and the second antenna 102 functioning as a parasitic element is switched by the switch circuit 1
05, is input to terminal 105b, passes through terminal 105a,
The signal is input to the wireless circuit via the feeding point 104.

At the time of transmission, the signal of the frequency f1 input from the radio circuit is supplied to the switch circuit 10 via the feeding point 104.
5, and is radiated from both the first antenna 101 and the second antenna 102 functioning as a parasitic element via the terminal 105b.

Next, the terminal 105a of the switch circuit 105
When the first antenna 101 functions as a parasitic element when the terminal and the terminal 105c are controlled to conduct,
Resonance occurs due to electromagnetic field coupling with the second antenna 102, and the directivity of the second antenna 102 changes.

Here, the input / output operation of the signal to be transmitted / received is as follows.
The same operation as when the terminal 105a and the terminal 105b of the switch circuit 105 are conducted is performed.

At this time, it is important that the antenna that is not fed functions as a parasitic element and that the directivity of the fed antenna changes. As a result, the directivity of the antenna is changed by switching the conduction of the switch circuit 105. Can switch.

FIG. 2 shows a specific configuration of the present embodiment. In FIG. 2, the first antenna 201 and the second antenna 202 are made of a metal wire having a length of 75 mm, and the distance between the first antenna 201 and the second antenna 202 is 1.5 mm above the conductor ground plate 103. Place them apart. Here, the direction from the first antenna 201 to the second antenna 202 is defined as the + X direction, and the Z axis is determined in parallel with the first antenna 201. In this case, the conductor ground plane 103 is arranged in the ZY plane. In the call state, the head is -X.
Direction.

At this time, the radiation directivity when the first antenna 201 is fed is shown in FIG. 3, and the directivity when the second antenna 202 is fed is shown in FIG. Both frequencies are 2G
Hz.

FIG. 3 shows that when the first antenna 201 is fed, it has strong directivity in the + X direction. FIG. 4 shows that when the second antenna 202 is fed, it has strong directivity in the −X direction. This makes it possible to radiate strongly in the + X direction and-
It is possible to switch between two types of directivities when radiating strongly in the X direction.

When the wireless device is placed in a breast pocket or the like,
For example, when the antenna is placed in a breast pocket so that the −X direction faces the human body direction, the first antenna 201 is fed by the switch circuit 105 to increase the radiation in the + X direction, and −
Radiation in the X direction, that is, in the direction of the human body can be suppressed.

Next, when the antenna is placed in the breast pocket so that the + X direction side faces the human body, the radiation in the -X direction is enhanced by feeding the second antenna 202 by the switch circuit 105, that is, in the + X direction, that is, Radiation toward the human body can be suppressed. Therefore, it is possible to switch to directivity that suppresses radiation toward the human body depending on the direction in which the wireless device is inserted into the breast pocket.

As described above, the directivity of the antenna can be switched by switching the combination of the antenna and the parasitic element having different directivities.
In addition to reducing the effect on the human body according to the direction in which the wireless device is placed, it is possible to reduce sensitivity degradation.

In the present embodiment, the first antenna 101 and the second antenna 101 may have the same shape, but similar effects can be obtained with different shapes as long as the frequency characteristics are the same. Also, the first antenna 101 and the second antenna 101
By resonating the antenna 102 at a plurality of frequencies, it is possible to increase the frequency and the bandwidth.

In this embodiment, the first antenna 101 and the second antenna 102 are arranged close to each other. However, if the two antennas have different directivities, the two antennas need not be close to each other. Directivity switching is possible. Further, the first antenna 101 or the second antenna 1
When the antenna 02 is composed of a planar antenna such as a plate-shaped inverted-F antenna or a microstrip antenna, it is possible to provide directivity by itself and to reduce the size of the antenna. In this case, further miniaturization can be realized by forming the antenna on the dielectric.

It is needless to say that the same effect can be expected even if a balanced antenna is used. FIG. 5 shows an example in which the first antenna 101 is constituted by a balanced antenna. FIG.
, The first antenna 101 includes a first antenna element 501, a second antenna element 502, and a balanced-unbalanced conversion circuit 503, and the balanced terminals 503B and 503C of the balanced-unbalanced conversion circuit 503 are connected to the first terminal, respectively.
Are connected to the antenna element 501 and the second antenna element 502, and the unbalanced terminal 503A is connected to the switch circuit 10
5 terminal 105b. Also in this case, the same effect can be expected if the directivity of the first antenna 101 and the second antenna 102 are different.

Further, it is conceivable to dispose antennas on both sides of the conductor ground plane. In this case, the same effect can be expected because the conductive ground plate functions as a reflector for each antenna. As an example, as shown in FIG. 6, a first antenna 601 and a second antenna 602
Are arranged on both surfaces of the conductor ground plate 103, two types of directivities can be provided, which are diametrically opposite directions, that is, the surface direction or the back surface direction of the conductor ground plate 103. In this case, the first antenna 601 and the second antenna 602 may have different configurations, but by having the same configuration, it is possible to realize diametrically opposite directivities. Furthermore, by arranging the first antenna 601 and the second antenna 602 by a planar antenna such as a plate-shaped inverted F antenna or a balanced antenna that feeds two antenna elements in opposite phases, radiation in two opposite directions is achieved. Can be switched so that the image becomes sharper. In this case, it goes without saying that miniaturization is possible by forming the antenna on the dielectric.

As shown in FIG. 7, it is conceivable that the first antenna 701 and the second antenna 702 are arranged above and below the conductor ground plate 103, respectively. When holding the lower part 706B of the case of the wireless device by hand,
Since the second antenna 702 is covered with a hand, switching is performed by the switch circuit 705 so that the first antenna 701 is supplied with power. In contrast, the upper 70
When holding 6A by hand, the switch circuit 705 switches so as to feed the second antenna 702. In this manner, by switching by the switch circuit 705 so that the antenna that is not held by the hand is supplied with power, deterioration of characteristics due to the hand can be reduced.

FIG. 8 shows an example of a configuration in which FIGS. 6 and 7 are combined. As shown in FIG. 8, the first antenna 8
Similar effects can be obtained by disposing the second antenna 802 above the front surface 103A of the conductor ground plate and the second antenna 802 below the back surface 103B of the conductor ground plate.

In this embodiment, two types of antennas, the first antenna 101 and the second antenna 102, are used. However, by using three or more antennas, directivity control can be performed in multiple directions. Of course can be performed. Further, as shown in FIG. 9, by arranging the antennas on the conductor ground plane 103 and arranging the antennas apart from each other, the effect of directivity control in multiple directions is improved, and the wireless device is held by hand. It is possible to reduce the characteristic deterioration caused by the position.

The first antenna 101 or the second antenna 101
The same effect can be expected even if the antenna 102 is arranged on the inner wall of the case 1006 of the wireless device as shown in FIG. 10 or the antenna is formed on a printed board or a flexible board, and the number of parts is reduced. It becomes possible. Further, the same effect can be obtained even when both or one of the first antenna 101 and the second antenna 102 is built in the wireless device or arranged outside the wireless device. Also,
As shown in FIG. 11, when the first antenna 1101 is a whip antenna that is used by extending to the outside of the case 1106 of the wireless device and can be stored inside the case 1106 of the wireless device, the first antenna It is needless to say that when the antenna 1101 is stored in the case 1106 of the wireless device, the directivity can be controlled by the first antenna 1101 and the second antenna 1102 built in the case 1106 of the wireless device.

In the present embodiment, when either the first antenna 101 or the second antenna 102 is not supplied with power, the conductor ground plate 103 is opened. However, the present invention is not limited to this. Not something. As an example, as shown in FIG. 12, by operating a first switch circuit 1205 and a second switch circuit 1206 in conjunction with each other, the first antenna 1201 and the second antenna
02 is switched to supply power, and the antenna that is not supplied is switched to be connected to the load element 1207. By optimizing the impedance value of the load element 1207, the interaction between the fed antenna and the unpowered antenna can be increased,
The directivity of the antenna can be further changed. Here, the impedance value of the load element 1207 is mainly a reactance component, that is, an arbitrary value of -j∞ to + j∞Ω. Here, when the impedance of the load element 1207 is set to j∞Ω, the load element 1207 is opened to the conductive ground plane 103, so that it is natural that the same operation as the antenna shown in FIG. 1 can be performed. Although one load element 1207 is used in FIG. 12, the same effect can be obtained by connecting independent load elements to the first antenna 1201 and the second antenna 1202.

Since the effect on the human body becomes stronger during transmission, it is natural that directivity control can be performed only during transmission. In this case, for example, diversity reception may be performed during reception. FIG. 13 shows an example of a specific configuration when diversity reception is used. In FIG. 13, a first antenna 1301 arranged on a conductive ground plane 1303 is connected to a terminal 1305a of a first switch circuit 1305 via a first feeding point 1304A, and a second antenna 1302 is connected to a second feeding point. Point 13
04B via the terminal 13 of the second switch circuit 1306
06a. First switch circuit 1305
And the terminal 1306b of the second switch circuit 1306 are connected to the transmission-side wireless circuit 1308. Terminal 1305c of first switch circuit 1305
And a terminal 1306c of the second switch circuit 1306
Are connected to a reception side radio circuit 1309 via a diversity reception circuit 1307. Although not shown in FIG. 13, the transmission-side radio circuit 1308 and the reception-side radio circuit 1
Reference numeral 309 is connected to the baseband unit. Here, the first switch circuit 1305 and the second switch circuit 130
6 is controlled in conjunction with the control. At the time of reception, first antenna 1301 and second antenna 1302
Are received by the diversity receiving circuit 1
The first switch circuit 1305 and the second switch circuit 1306 are controlled in conjunction with each other so as to be input to the respective switches 307. In this case, of the two signals input to diversity circuit 1307, the one with the higher reception level is selected and input to reception-side wireless circuit 1309. Next, at the time of transmission, the first switch circuit 1305 and the second switch circuit 1306 supply power to the antenna having the higher reception level at the time of reception, and open the unpowered antenna to the transmission-side wireless circuit 1308. It is interlocked and controlled. At this time, the antenna that is not fed functions as a parasitic element, so that the directivity of the fed antenna can be changed. In this case, a signal input from the transmission-side wireless circuit 1308 is input to an antenna whose reception level is increased by the first switch circuit 1305 and the second switch circuit 1306, and is radiated from the antenna to which the signal is input. Therefore, by performing diversity reception, it is possible to perform directivity control by selecting one of the two antennas having a higher reception level during reception and switching to feed the antenna having the higher reception level during transmission.

In the diversity reception, the antenna is controlled so as to feed the antenna having the higher reception level. However, it is conceivable to control the directivity so that the antenna having the lower reception level radiates more strongly to the antenna having the higher reception level. In this case, it is considered that a human body exists on the antenna side having a low reception level. As an example, in FIG.
-Consider a case where a human body exists in the X direction. In this case, the reception level of the second antenna 202 is higher because the second antenna 202 is farther from the human body than the first antenna 201 is. At this time, it is necessary to switch the directivity so as to radiate strongly in the direction in which the second antenna 202 is arranged with respect to the first antenna 201, that is, in the + X direction. By switching so that the first antenna 201 is fed by the radiation directivity of FIG. 3, it is possible to radiate strongly in the + X direction and suppress radiation in the −X direction, that is, in the direction of the human body. Therefore, by controlling the directivity so as to radiate strongly from the antenna with the low reception level to the antenna with the high reception level, it is possible to reduce the deterioration of the characteristics due to the influence of the human body.

In this case, when the radio device is reinserted into the breast pocket or the human body changes the radio device to change the positional relationship between the radio device human body and the radio device, the influence of the human body is affected. There is a possibility that the deterioration of the characteristics due to the occurrence of a new phenomenon may occur. Therefore, even after the directivity control is performed so as to supply power to either the first antenna 201 or the second antenna 202 of the wireless device, the first antenna 201 and the second antenna 202 can be changed at predetermined time intervals. Power both. Then, as described above, diversity control is performed, and directivity control is performed so that the antenna is strongly radiated again from the antenna with the lower reception level toward the antenna with the higher reception level. As described above, by repeating the directivity control at predetermined time intervals, even if the positional relationship between the human body and the wireless device is changed, it is possible to automatically reduce the deterioration of the characteristics due to the influence of the human body.

When the directional gains of the two antennas are different, it is conceivable to estimate the direction of the human body by integrating the directional gain and the reception level. In this case, since it is considered that a human body exists on the antenna side where the difference between the directivity gain and the reception level becomes large, it is natural that the directivity control is performed so as to radiate strongly to the opposite side to the human body. . Note that directivity control can be performed so as to suppress radiation in the direction of the human body.

In this embodiment, an example in which the directivity control is performed so as to reduce the influence of the human body has been described. However, the present invention is not limited to this. Naturally, directivity can be controlled.

It is natural that the directivity of the antenna can be switched so as to suppress radiation toward the human body when a manual switch, for example, a voice call button is pressed.

Embodiment 2 Hereinafter, Embodiment 2 of the present invention will be described with reference to the drawings.

FIG. 14 is a diagram showing an outline of the configuration of an antenna system according to the second embodiment of the present invention. In the figure, an antenna 1401 arranged on a conductor ground plane 1403 is connected via a feed point 1404 on the conductor ground plane 1403. A parasitic element 1402 disposed close to the antenna 1401 is connected to a terminal 1405b of the switch circuit 1405. Switch circuit 1405
Terminal 1405a is short-circuited to the conductor ground plane 1403. Although not shown in FIG.
Are connected to a radio circuit on the conductor ground plane 1403. In this case, the parasitic element 140 is switched by the switch circuit 1405.
The switching control is performed so that 2 is short-circuited or opened with respect to the conductive ground plane 1403.

The operation of the antenna and the radio apparatus configured as described above will be described below. Antenna 1
It is assumed that 401 resonates at a frequency f1, for example, 2 GHz.

First, when the parasitic element 1402 is controlled by the switch circuit 1405 to open to the conductor ground plane 1403, the parasitic element 1402 is connected to the antenna 1
Due to electromagnetic field coupling with 401, resonance occurs at the same frequency f1 as antenna 1401, and the directivity of the antenna changes.

At the time of reception, a signal of frequency f1 received by both antenna 1401 and parasitic element 1402 is input to the radio circuit via feed point 1404. At the time of transmission, a signal of frequency f1 input from the wireless circuit is input to the antenna 1402 via the feeding point 1404,
It is radiated from both the antenna 1401 and the parasitic element 1402. At this time, the input / output operation of the signal to be transmitted / received is the same as the case where the first antenna is fed in Embodiment 1.

Next, when the parasitic element 1402 is controlled by the switch circuit 1405 so as to be short-circuited to the conductive ground plane 1403, the parasitic element 1402 is connected to the conductive ground plane 1
403 is short-circuited to 403 and has the same frequency f1 as antenna 1401.
Therefore, the parasitic element 1402 does not affect the directivity of the antenna 1401. Here, the input / output operation of a signal to be transmitted / received is such that the parasitic element 1402 does not perform electromagnetic field coupling with the antenna 1401, and the antenna 1
Except that only 401 operates, the same operation as in the case of feeding the first antenna in Embodiment 1 is performed.

At this time, the parasitic element 1402 functions as a parasitic element by the switch circuit 1405 and the antenna 1
The case where the directivity of 401 is changed and the case where the parasitic element 140
It is important that the directivity can be switched between a case where the antenna 2 does not function as a parasitic element and does not affect the directivity of the antenna 1401 when the conductor 2 is short-circuited to the conductive ground plane 1403.

FIG. 15 shows a specific configuration of the present embodiment. In FIG. 15, the antenna 1501 and the parasitic element 1502 are made of a metal wire having a length of 75 mm, and the antenna 1501 and the parasitic element 1502 are arranged above the conductor ground plane 1403.
2 and 1.5 mm apart. Here, the direction from the antenna 1501 to the parasitic element 1502 is + X
The direction is defined, and the Z axis is determined in parallel with the antenna 1501. In this case, the conductive ground plane 1403 is arranged in the ZY plane. In a call state, it is assumed that the head exists in the −X direction. At this time, the radiation directivity when the parasitic element 1502 is short-circuited to the conductor ground plane 1403 by the switch circuit 1405 is shown in FIG. Here, the parasitic element 1
The radiation directivity when 502 is open to the conductor ground plane 1403 is shown in FIG. Both frequencies are 2GHz
It is.

FIG. 3 shows that when the parasitic element 1502 is open to the conductor ground plane 1403, it has strong directivity in the + X direction.

FIG. 16 shows that when the parasitic element 1502 is short-circuited to the conductive ground plane 1403, it becomes omnidirectional and the parasitic element 1502 does not affect the directivity of the antenna 1501. .

As a result, it is possible to switch between two types of directivity, that is, non-directionality and directivity that radiates strongly in the + X direction. During a call, the switch circuit 1405 switches the parasitic element 1502 so as to be open to the conductor ground plane 1403, thereby increasing the radiation in the + X direction.
-It is possible to suppress radiation in the X direction, that is, in the direction of the human body. Next, when the wireless device is placed away from the human body, such as in a standby mode, the switch circuit 1405 switches the parasitic element 1502 so as to be short-circuited to the conductive ground plane 1403, so that omnidirectionality, that is, It is possible to reduce the deterioration of the sensitivity due to the arrival direction of the radio wave. Therefore, when talking, reduce radiation toward the human body, and when the wireless device is placed away from the human body, such as during standby,
It is possible to reduce the deterioration of the sensitivity due to the arrival direction of the radio wave.

As described above, the directivity of the antenna can be switched by switching the parasitic element so as to be short-circuited or opened with respect to the conductive ground plane. Therefore, the human body can be switched according to the state of the wireless device. And the deterioration of sensitivity due to the direction of arrival of radio waves can be reduced.

In this embodiment, the antenna 140
1 and the parasitic element 1401 may have the same shape, but similar effects can be obtained with different shapes as long as the frequency characteristics are the same. The antenna 1401 and the parasitic element 14
Since 02 resonates at a plurality of frequencies, it is possible to increase the frequency and the bandwidth.

As a specific configuration of the present embodiment, the antenna 1501 is constituted by a linear antenna in FIG. 15, but is not limited to this.
By using a planar antenna such as a plate-like inverted-F antenna or a microstrip antenna, it is possible to provide directivity by itself and to reduce the size of the antenna. In this case, further miniaturization can be realized by forming the antenna on the dielectric. Needless to say, a similar effect can be expected even if a balanced antenna is used.

In this embodiment, the antenna 140
Although one and the parasitic element 1402 are used, it goes without saying that directivity control can be performed in multiple directions by configuring two or more antennas or parasitic elements. Note that it is conceivable that at least two antennas and a parasitic element are arranged on both surfaces of the conductive ground plane 1403 as in the configuration shown in FIG. In this case, the conductor ground plane 1
Since 403 functions as a reflector for each antenna, it is possible to have two types of directivity, which are opposite to each other, that is, the surface direction or the back surface direction of the conductor ground plate 1403, and the same effect can be expected. further,
By configuring an antenna with a planar antenna such as a plate-shaped inverted F antenna or a balanced antenna that feeds two antenna elements in opposite phases, it is possible to switch the directivity so that radiation in two opposite directions is sharp. Becomes
Further, at least two antennas and a parasitic element may be arranged above and below the conductor ground plate 1403 as in the configuration shown in FIG. 7, or may be scattered on the conductor ground plate 1403 as in the configuration shown in FIG. It is conceivable to arrange them apart from each other. This enables directivity control in multiple directions, and can reduce characteristic degradation caused by the position where the wireless device is held by hand.

The same effect can be expected even if the antenna 1401 or the parasitic element 1402 is arranged on the inner wall of the case of the wireless device, or the antenna or the parasitic element is formed on a printed board or a flexible board. Thus, the number of parts can be reduced. Further, the same effect can be obtained even when both or one of the antenna 1401 and the parasitic element 1402 is built in the wireless device or arranged outside the wireless device. In addition, a whip antenna that is used by extending to the outside of the case of the wireless device, and when housed in the case of the wireless device, causes the whip antenna to function as a parasitic element of the present embodiment. It is needless to say that the directivity control can be performed by the interaction with the antenna built in the case of the wireless device.

In the present embodiment, the parasitic element 14
02 is short-circuited or opened with respect to the conductive ground plane 1403, but the present invention is not limited to this. As an example, as shown in FIG. 17, the switching circuit 1705 switches between a case where the parasitic element 1702 is opened to the conductor ground plane 1403 and a case where it is connected to the load element 1706. By optimizing the impedance value of the load element 1706, the directivity of the antenna 1701 can be further changed.
701 can be further reduced. Here, the impedance value of the load element 1706 is mainly a reactance component, that is, −j∞ to + j∞.
Any value of Ω can be given. Here, the load element 1706
Is set to j0Ω, the conductor ground plane 140
3 is short-circuited, so that the same operation as the antenna shown in FIG. 14 can be performed.

In this embodiment, an example in which the directivity control is performed so as to reduce the influence of the human body has been described. However, the present invention is not limited to this, and the influence of other obstacles may be reduced. Naturally, directivity can be controlled.

(Embodiment 3) Hereinafter, Embodiment 3 of the present invention will be described with reference to the drawings.

FIG. 18 is a diagram showing an outline of the configuration of an antenna system according to the third embodiment of the present invention. In the figure, a first antenna 1801 arranged on a conductor ground plane 1803 is connected to a terminal 1805b of a first switch circuit 1805. First antenna 1801
Is connected to the terminal 1806a of the second switch circuit 1806. Terminal 1806c of second switch circuit 1806 is short-circuited to conductive ground plane 1803, and terminal 1806b is connected to first ground.
Is connected to the terminal 1805c of the switch circuit 1805. A terminal 1805a of the first switch circuit 1805 is connected to a feeding point 1804. Although not shown in FIG. 18, the feeding point 1804 is connected to a wireless circuit on the conductor ground plane 1803.

In this case, the first switch circuit 1805 and the second switch circuit 1806 are controlled in conjunction with each other. First, the terminal 1806 of the second switch circuit 1806
When the terminal a is connected to the terminal 1806b, the first switch circuit 1805 is switched so that one of the terminal 1805a and the terminal 1805b or the terminal 1805a and the terminal 1805c is connected. Next, when the terminal 1806a and the terminal 1806c of the second switch circuit 1806 conduct, the terminal 1806 of the first switch circuit 1805 is turned on.
Control is performed so that the terminal 5a and the terminal 1805b conduct.

The operation of the antenna and the radio device configured as described above will be described below. The first antenna 1801 and the second antenna 1802 have a frequency f
For example, it is assumed that resonance occurs at 2 GHz. First, consider the case where the terminal 1806a and the terminal 1806b of the second switch circuit 1806 conduct. The first switch circuit 1805 switches so as to feed either the first antenna 1801 or the second antenna 1802, and the antenna that is not fed functions as a parasitic element, so that the same operation as in Embodiment 1 can be performed. Do. Next, the second
Terminal 1806a and terminal 180 of the switch circuit 1806 of FIG.
6c is conducted. First switch circuit 1
Since the first antenna 1801 is fed by 805 and the second antenna 1802 is short-circuited to the conductive ground plane 1803 by the second switch circuit 1806, the parasitic element is connected to the conductive ground plane in the second embodiment. The same operation as in the case of a short circuit is performed.

At this time, by switching the feeding of the two antennas, the antenna that is not fed functions as a parasitic element, and the directivity of the fed antenna is changed. It is important to be able to switch the directivity when short-circuiting the conductive ground plane does not affect the directivity of the antenna that is feeding power.

FIG. 19 shows a specific configuration of the present embodiment. In FIG. 19, a first antenna 1901 and a second antenna 1902 are formed of a metal wire having a length of 75 mm, and the first antenna 1901 is located above a conductive ground plane 1803.
And the second antenna 1902 are arranged at a distance of 1.5 mm. Here, the direction from the first antenna 1901 to the second antenna 1902 is defined as the + X direction, and the Z axis is determined in parallel with the first antenna 1901. In this case, the conductor ground plane 1803 is arranged in the ZY plane. In a call state, it is assumed that the head exists in the −X direction.

At this time, the first switch circuit 1805 and the second switch circuit 1806 control the first antenna 19
FIG. 3 shows the radiation directivity when power is supplied to the first antenna 1902 and the second antenna 1902 functions as a parasitic element. The power is supplied to the second antenna 1902 and the first antenna 1901 functions as a parasitic element. FIG. 4 shows the radiation directivity in this case. FIG. 16 shows the radiation directivity when the first antenna 1901 is fed and the second antenna 1902 is short-circuited to the conductor ground plane 1803. Both frequencies are 2G
Hz.

According to FIG. 3, FIG. 4 and FIG. 16, there are three types of directivity that strongly radiates in the + X direction, directivity that strongly radiates in the −X direction, and omnidirectional which is the directivity of the first antenna 1901 itself. Has directivity. When the wireless device is placed in a breast pocket or during a call, directivity control is performed so as to suppress radiation toward the human body. Further, when the wireless device is placed away from a human body, directivity control is performed such that the wireless device is omni-directional or radiates strongly in the direction of arrival of radio waves. Therefore, directivity control is performed in accordance with the situation where the wireless device is placed with respect to the human body and the direction of arrival of radio waves, so that the influence on the human body can be reduced and sensitivity degradation can be reduced.

As described above, in addition to switching the combination of an antenna having a different directivity and a parasitic element, the antenna functioning as a parasitic element does not affect the directivity, so that the directivity of the antenna is reduced. Can be switched in multiple directions, so that it is possible to reduce the effect on the human body and reduce the sensitivity degradation according to the direction in which the wireless device is placed and the direction in which radio waves arrive.

In this embodiment, the first antenna 1801 and the second antenna 1801 may have the same shape, but similar effects can be obtained with different shapes as long as the frequency characteristics are the same. In addition, since the first antenna 1801 and the second antenna 1802 resonate at a plurality of frequencies, a multi-frequency or wide band can be achieved.

In this embodiment, the first antenna 1801 and the second antenna 1802 are arranged close to each other. However, if the two antennas have different directivities, the two antennas need not be close to each other. Directivity switching is possible.
Further, the first antenna 1801 or the second antenna 1802 is constituted by a planar antenna such as a plate-shaped inverted-F antenna or a microstrip antenna, or a balanced antenna which feeds two antenna elements in opposite phases, so that the antenna is a single antenna. Thus, it is possible to provide directivity, and the size of the antenna can be reduced. In this case, further miniaturization can be realized by forming the antenna on the dielectric.

It is conceivable to use a balanced antenna in which both or one of the first antenna 1801 and the second antenna 1802 supplies power to the two antenna elements in opposite phases as in the configuration shown in FIG. Can be In this case, it is needless to say that directivity can be provided by the antenna alone.

Further, similarly to the configuration shown in FIG. 6, it is conceivable to dispose antennas on both sides of the conductor ground plane. In this case, the same effect can be expected because the conductive ground plate functions as a reflector for each antenna. Furthermore, by arranging the first antenna 1801 and the second antenna 1802 by a planar antenna such as a plate-shaped inverted F antenna or a balanced antenna that feeds two antenna elements in opposite phases, radiation in two opposite directions is achieved. Can be switched so that the image becomes sharper. In this case, it goes without saying that miniaturization is possible by forming the antenna on the dielectric.

As in the configuration shown in FIG. 7, it is conceivable to dispose the first antenna and the second antenna above and below the conductive ground plane, respectively. In this case, the wireless device is switched by a switch circuit so that the antenna that is not held by hand is fed,
It is possible to reduce deterioration of characteristics due to hand.

In this embodiment, two types of antennas, the first antenna 1801 and the second antenna 1802, are used. However, by using three or more antennas, directivity control can be performed in multiple directions. Of course can be performed. Further, as in the configuration shown in FIG. 9, the antennas are scattered on the conductor ground plane and the antennas are arranged apart from each other, thereby increasing the effect of directivity control in multiple directions and holding the wireless device by hand. It is possible to reduce the deterioration of the characteristics caused by the position where it is performed.

Note that the first antenna 1801 or the second antenna 1802 can be arranged on the inner wall of the case of the wireless device in the same manner as the configuration shown in FIG. 10, or the antenna can be formed on a printed board or a flexible board. However, the same effect can be expected, and the number of parts can be reduced. Further, the same effect can be obtained if both or one of the first antenna 1801 and the second antenna 1802 is built in the wireless device or arranged outside the wireless device.
In addition, if the first antenna 1801 is a whip antenna that is used to extend outside the case of the wireless device and can be stored inside the case of the wireless device, the first antenna 1801
Needless to say, when the antenna 1801 is stored in the case of the wireless device, directivity control can be performed by the first antenna 1801 and the second antenna 1802 built in the case of the wireless device.

In the present embodiment, when power is not supplied to second antenna 1802, second switch circuit 1
806 causes the second antenna 1802 to
3, the circuit was switched to be open or short-circuited, but is not limited to this. FIG. 20 as an example
As shown in the figure, the terminal 20 of the second switch circuit 2006
The load element 2007 is connected instead of short-circuiting 06c to the conductor ground plane 1803. In this case, switching is performed between a case where the second antenna 2002 is opened to the conductor ground plane 1803 and a case where the second antenna 2002 is connected to the load element 2007.
By optimizing the impedance value of the load element 2007, the interaction between the first antenna 2001 and the second antenna 2002 functioning as a parasitic element can be enhanced to further change the directivity of the antenna. ,
Second antenna 2002 functioning as a parasitic element
Of the first antenna 2001 can be further reduced. Although one load element 2007 is used in FIG. 20, the first antenna 2001
The same effect can be obtained by connecting an independent load element to the second antenna 2002 and the second antenna 2002.

Since the influence on the human body becomes stronger at the time of transmission, it is natural that directivity control can be performed only at the time of transmission. In this case, for example, diversity reception may be performed during reception. By performing diversity reception, one of the two antennas having the higher reception level is selected during reception, and the directivity control is performed by switching so as to feed the antenna having the higher reception level during transmission. This makes it possible to suppress radiation to the human body during transmission and reduce sensitivity degradation.

In the diversity reception, the antenna is controlled so that the antenna having the higher reception level is fed. However, it is conceivable to control the directivity so that the antenna having the lower reception level is more strongly radiated toward the antenna having the higher reception level. In this case, since it is considered that a human body exists on the antenna side with the low reception level, it is natural that the directivity control is performed so that the antenna with the low reception level radiates strongly toward the antenna with the high reception level. .

When the directional gains of the two antennas are different, it is conceivable to estimate the direction of the human body by integrating the directional gain and the reception level. In this case, since it is considered that a human body exists on the antenna side where the difference between the directivity gain and the reception level becomes large, it is natural that the directivity control is performed so as to radiate strongly to the opposite side to the human body. . Note that directivity control can be performed so as to suppress radiation in the direction of the human body.

In the present embodiment, an example in which the directivity control is performed so as to reduce the influence of the human body has been described. However, the present invention is not limited to this, and the influence of other obstacles may be reduced. Naturally, directivity can be controlled.

Note that the radio circuit of this embodiment is an example of the transmission circuit of the present invention, the radio circuit of this embodiment is also an example of the reception circuit of the present invention, and the switch circuit of this embodiment is It is an example of the control means of the present invention.

As described above, according to the present invention, the directivity of the antenna can be switched by switching the combination of the antenna and the parasitic element having different directivities.
According to the present invention, it is possible to obtain an antenna in which the influence on the human body is reduced in accordance with the direction in which the wireless device is placed and sensitivity deterioration is reduced, and a wireless device using the antenna.

[0116]

As apparent from the above description,
The present invention can provide an antenna and a wireless device that have little effect on the human body and do not reduce sensitivity when the wireless device is carried.

Further, the present invention can provide an antenna and a radio device whose sensitivity does not deteriorate even when the radio device is placed away from a human body such as in a standby mode.

[Brief description of the drawings]

FIG. 1 is a diagram showing an outline of an antenna system and a wireless device according to a first embodiment of the present invention.

FIG. 2 is a diagram illustrating an example of a detailed configuration of an antenna system and a wireless device according to Embodiment 1 of the present invention.

FIG. 3 is a diagram showing radiation directivity when a first antenna is fed in the antenna system and the wireless device in FIG. 2 according to Embodiment 1 of the present invention;

FIG. 4 is a diagram showing radiation directivity when a second antenna is fed in the antenna system and the wireless device of FIG. 2 according to Embodiment 1 of the present invention;

FIG. 5 is a diagram showing an example of a detailed configuration of an antenna system and a wireless device according to Embodiment 1 of the present invention.

FIG. 6 is a diagram illustrating an example of a detailed configuration of an antenna system and a wireless device according to Embodiment 1 of the present invention.

FIG. 7 is a diagram illustrating an example of a detailed configuration of an antenna system and a wireless device according to Embodiment 1 of the present invention.

FIG. 8 is a diagram illustrating an example of a detailed configuration of an antenna system and a wireless device according to Embodiment 1 of the present invention.

FIG. 9 is a diagram illustrating an example of a detailed configuration of an antenna system and a wireless device according to Embodiment 1 of the present invention.

FIG. 10 is a diagram illustrating an example of a detailed configuration of an antenna system and a wireless device according to Embodiment 1 of the present invention.

FIG. 11 is a diagram illustrating an example of a detailed configuration of an antenna system and a wireless device according to Embodiment 1 of the present invention.

FIG. 12 is a diagram illustrating an example of a detailed configuration of an antenna system and a wireless device according to Embodiment 1 of the present invention.

FIG. 13 is a diagram illustrating an example of a detailed configuration of an antenna system and a wireless device according to Embodiment 1 of the present invention.

FIG. 14 is a diagram showing an outline of an antenna system and a wireless device according to a second embodiment of the present invention.

FIG. 15 is a diagram illustrating an example of a detailed configuration of an antenna system and a wireless device according to a second embodiment of the present invention.

FIG. 16 is a diagram showing directivity when a parasitic element is short-circuited to a conductive ground plane in the antenna system and the wireless device of FIG. 15 according to Embodiment 2 of the present invention;

FIG. 17 is a diagram illustrating an example of a detailed configuration of an antenna system and a wireless device according to a second embodiment of the present invention.

FIG. 18 is a diagram showing an outline of an antenna system and a wireless device according to a third embodiment of the present invention.

FIG. 19 is a diagram illustrating an example of a detailed configuration of an antenna system and a wireless device according to a third embodiment of the present invention.

FIG. 20 is a diagram illustrating an example of a detailed configuration of an antenna system and a wireless device according to a third embodiment of the present invention.

FIG. 21 is a diagram showing an example of a specific configuration of a conventional antenna system and a wireless device.

FIG. 22 is a view showing the radiation directivity of the antenna system of FIG. 21;

FIG. 23 is a diagram illustrating an example of a specific configuration of a conventional antenna system and a wireless device.

FIG. 24 is a diagram showing the radiation directivity of the antenna system of FIG. 23;

[Explanation of symbols]

 101 first antenna 102 second antenna 103 conductor ground plane 104 feed point 105 switch circuit 105a terminal 105b terminal 105c terminal

Continuing on the front page (72) Inventor Koichi Ogawa 1006 Kazuma Kadoma, Kadoma City, Osaka Prefecture F-term in Matsushita Electric Industrial Co., Ltd. (reference) KK02 KK03

Claims (22)

[Claims] 1. An antenna system comprising: at least two antennas; and control means for controlling power supply to the antennas, wherein the control means controls directivity depending on whether power is supplied to the antennas. 2. The antenna system according to claim 1, wherein the control unit performs the control according to an instruction from a manual switch. 3. The antenna system according to claim 1, wherein said control means controls to feed power to all of said antennas to realize substantially omnidirectionality. 4. The antenna system according to claim 1, wherein the control unit short-circuits an antenna other than the antenna that controls power supply among the antennas to a conductive ground plane in order to substantially realize omnidirectionality. 5. At least one antenna; at least one parasitic element functioning with respect to the antenna; and control means for controlling whether or not the parasitic element is short-circuited to a conductive ground plane. Is an antenna system that controls directivity according to the presence or absence of a short circuit of the parasitic element to the conductive ground plane. 6. The antenna system according to claim 3, wherein said control means controls so as to feed power to all of said antennas during reception. 7. The antenna system according to claim 6, wherein said control means controls such that one of the antennas having a stronger signal received at the time of reception is supplied with no power at the time of transmission. 8. The control means controls such that the antenna controlled to be non-powered among the antennas is fed at predetermined time intervals, and when all of the antennas are fed, reception is performed at the time of reception. 8. The antenna system according to claim 7, wherein the antenna having the stronger signal is controlled so as not to be fed during transmission. 9. The antenna system according to claim 1, wherein said antennas have different directivities. 10. The antenna system according to claim 1, wherein at least the antenna resonates at a plurality of frequencies. 11. The antenna system according to claim 1, wherein at least one of said antennas is a balanced antenna. 12. The wireless device according to claim 1, wherein one of said antennas and one of said parasitic elements are built in a wireless device.
An antenna system according to any one of the eleventh to eleventh aspects. 13. The antenna system according to claim 12, wherein one or more antennas are arranged on both surfaces of the conductor ground plane. 14. An upper portion and a lower portion of the conductor ground plate,
13. The device according to claim 12, wherein at least one of the antennas is arranged.
Or the antenna system according to 13. 15. The antenna system according to claim 12, wherein at least one of the antenna and the parasitic element is disposed on an inner wall of a case of the wireless device. 16. The antenna system according to claim 12, wherein the parasitic element is a whip antenna housed inside the wireless device. 17. The apparatus according to claim 12, wherein at least one of the antenna and the parasitic element is formed on a dielectric.
The antenna system according to any one of claims 15 to 15. 18. The antenna system according to claim 12, wherein at least one or a part of the antenna and the parasitic element is formed on a printed circuit board. 19. The antenna system according to claim 12, wherein at least one or a part of the antenna and the parasitic element is formed on a flexible substrate. 20. A radio apparatus comprising: the antenna system according to claim 1; and a transmission circuit that supplies a transmission signal to the antenna system. 21. A radio apparatus comprising: the antenna system according to claim 1; and a reception circuit that demodulates a reception signal received by the antenna system. 22. The wireless device according to claim 20, further comprising a receiving circuit for demodulating a received signal received by said antenna system.