JP2008160247A - MIMO antenna apparatus and radio communication apparatus - Google Patents

Abstract

Provided is a MIMO antenna device that is mounted on a wireless communication device and realizes high-quality wireless communication compared to the prior art regardless of the environment in which the wireless communication device is used.
An antenna element 10a has feed points Q1-1 and Q1-2 at different positions, and receives a first radio signal. The antenna element 10b has feeding points Q2-1 and Q2-2 at different positions, and receives the second radio signal. The controller 60 controls the switch 21 so as to select the feeding point of the first antenna element so that the level of the first radio signal is maximized, and the level of the second radio signal is maximized. Thus, the switch 22 is controlled so as to select the feeding point of the second antenna element. The MIMO decoding circuit 70 MIMO-demodulates and outputs the demodulated signal of the first radio signal and the demodulated signal of the second radio signal from the switches 21 and 22.
[Selection] Figure 2

Description

  The present invention relates to a MIMO antenna device used in a radio communication system of a microwave band, a quasi-millimeter wave band, or a millimeter wave band, and a radio communication apparatus having the MIMO antenna apparatus.

  Conventionally, in a wireless communication system in a microwave band, a quasi-millimeter wave band, or a millimeter wave band, in order to achieve higher signal quality and faster communication, among each wireless signal received by a plurality of antenna elements, A selection diversity process for selecting a radio signal having a larger received power is performed. Thereby, the influence of fading can be relieved. For example, in a foldable portable terminal device according to the related art in which a lower housing containing a wireless communication circuit or the like and an upper housing provided with a liquid crystal display or the like are connected to each other by a hinge portion, the upper housing By providing two antenna elements, the mobile terminal device is miniaturized, and selective diversity processing is performed using the two antenna elements.

Japanese Patent Application Laid-Open No. 2004-274445. JP 2004-56426 A.

  In portable wireless terminal devices that transmit and receive broadband wireless signals, such as fourth-generation mobile phones and portable wireless terminal devices that receive digital television broadcast signals, higher signal quality is required. In this case, the transmission capacity is increased by spatially multiplexing a plurality of signal sequences transmitted simultaneously in the same frequency band using a plurality of antenna elements respectively, and the sum of the plurality of signal sequences after MIMO decoding is increased. Use of a MIMO communication system, which is a technique for increasing the transmission rate, is effective. In this case, it is necessary to increase the radiation efficiency of the plurality of antenna elements of the receiver.

  However, since the portable wireless terminal device is used by being held by a human, the directivity and radiation efficiency of the antenna device depends on the contact between the portable wireless terminal device and the human head, the distance from the trunk, the position of the hand, and the like. It changes a lot. In the foldable portable terminal device according to the prior art, the feeding points of the two antenna elements provided in the upper housing are provided in the vicinity of the hinge part, and a human uses the portable terminal device by hand. When the feed point is covered with a hand as in the case, the radiation efficiency of the two antenna elements is greatly reduced, and there is a problem that MIMO communication cannot be performed. In addition, with the miniaturization of portable wireless terminal devices, the distance between a plurality of antenna elements becomes closer, the correlation between radio signals received between the plurality of antenna elements increases, and there is a problem that data cannot be received. there were.

  An object of the present invention is to solve the above-described problems, and a MIMO antenna device that is mounted on a wireless communication device and realizes high-quality wireless communication compared to the prior art regardless of the environment in which the wireless communication device is used, and An object of the present invention is to provide a radio communication apparatus having the MIMO antenna apparatus.

A MIMO antenna apparatus according to a first invention is
A first antenna element having a plurality of feed points at different positions and receiving a first radio signal;
A second antenna element having a plurality of feeding points at different positions and receiving a second radio signal;
First switch means for selecting one feeding point from the plurality of feeding points of the first antenna element and outputting a first radio signal from the selected feeding point;
Second switching means for selecting one feeding point from a plurality of feeding points of the second antenna element and outputting a second radio signal from the selected feeding point;
The first switch means is controlled so as to select the feeding point of the first antenna element so that the evaluation value related to the first radio signal is maximized, and the evaluation value related to the second radio signal Control means for controlling the second switch means so as to select the feeding point of the second antenna element such that
The demodulated signal of the first radio signal from the first switch means and the demodulated signal of the second radio signal from the second switch means are decoded by MIMO (Multi-Input Multi-Output) decoding to obtain a decoded signal. And a MIMO decoding means for generating and outputting.

In the MIMO antenna apparatus,
The first antenna element has a rectangular shape, and has one feeding point at each of an upper edge portion and a lower edge portion in the longitudinal direction of the rectangular shape,
The second antenna element has a rectangular shape, and has one feeding point at each of an upper edge portion and a lower edge portion in the longitudinal direction of the rectangular shape.

In the MIMO antenna apparatus,
The first antenna element has a rectangular shape, and has a plurality of feeding points different from each other at one edge in the longitudinal direction of the rectangular shape,
The second antenna element has a rectangular shape, and has a plurality of feeding points different from each other at one edge portion in the longitudinal direction of the rectangular shape.

Furthermore, in the MIMO antenna device,
The MIMO antenna device is housed in first and second housings that are connected to each other so as to be openable and closable,
Both the first and second antenna elements are housed in the first housing.

Still further, in the MIMO antenna apparatus,
The evaluation value is a level of the radio signal or a signal quality of a demodulated signal of the radio signal.

In the MIMO antenna apparatus,
The control means includes a feeding point of the first antenna element and the second radio frequency so that a correlation coefficient between the level of the first radio signal and the level of the second radio signal is minimized. The first and second switch means are controlled so as to select the feeding points of the antenna elements, respectively.

  A wireless communication apparatus according to a second aspect of the present invention is a wireless communication apparatus provided with wireless communication means for transmitting and receiving wireless signals, characterized in that it includes the above-described MIMO antenna apparatus.

  According to the MIMO antenna apparatus or the radio communication apparatus according to the present invention, the first antenna element that has a plurality of feeding points at different positions and receives the first radio signal, and the plurality of feeding points at different positions. And a second antenna element that receives the second radio signal, and selects one feed point from among the plurality of feed points of the first antenna element, and the first antenna point from the selected feed point First switch means for outputting a radio signal, and a second switch for selecting one feed point from a plurality of feed points of the second antenna element and outputting a second radio signal from the selected feed point. And the first switch means to select the feeding point of the first antenna element so that the evaluation value related to the first radio signal is maximized, and the second The evaluation value for wireless signals is maximized. Control means for controlling the second switch means so as to select a feeding point of the second antenna element, a demodulated signal of the first radio signal from the first switch means, and the second Since the demodulated signal of the second radio signal from the switch means is MIMO-decoded to generate and output a decoded signal, the radio communication apparatus is used as compared with the prior art. Regardless of the environment, high-quality wireless communication can be realized compared to the prior art.

  Hereinafter, embodiments according to the present invention will be described with reference to the drawings. In the following embodiments, the same reference numerals are assigned to the same components.

Embodiment.
FIG. 1 is a partially broken schematic perspective view seen from the back side in the open state of a foldable mobile phone 1 according to an embodiment of the present invention. FIG. 2 is a block diagram showing a configuration of the MIMO antenna apparatus of the foldable mobile phone 1 of FIG.

  In FIG. 1, a foldable mobile phone 1 that is a wireless communication device includes a housing 2 and a housing 3 that are connected to each other so as to be opened and closed. Here, the hinge cylindrical portions 4a and 4b integrally formed at one end of the casing 2 are hinge cylinder portions 4c (hereinafter referred to as hinge cylindrical portions 4a, 4b and 4c) integrally formed at one end of the casing 3, respectively. Are also supported by the hinge part 4) and are pivotally supported so as to be rotatable. With this configuration, the foldable mobile phone 1 has an open state (see FIG. 1) and a closed state. Here, in the embodiment, the open state is a state in which the housing 2 and the housing 3 are deployed in a straight line, but the present invention is not limited to this, and the housing 2 and the housing 3 are, for example, 150 degrees or the like. It may be in a state of being developed at a predetermined angle. In the embodiment, the open state is a state in which the housing 2 and the housing 3 are in contact with each other and closed.

  In FIG. 1, a housing 2 includes a liquid crystal display (not shown) provided on the front side, an antenna element 10a having feeding points Q1-1 and Q1-2, and an antenna element 10b having feeding points Q2-1 and Q2-2. And feeding cables 11-1, 11-2, 12-1, 12-2. The housing 3 includes a wireless communication circuit 6 formed on a dielectric substrate, and a ground conductor 5 having a width approximately equal to the width of the housing 3 and a flat plate shape. Further, in FIG. 2, the radio communication circuit 6 includes an impedance matching circuit 61a-1, 61a-2, 61b-1 and 61b-2, switches 21 and 22, radio reception circuits 62a and 62b, and a MIMO decoding circuit. 70, level detection circuits 63a and 63b, a controller 60, and an output terminal 80. Here, the antenna elements 10a and 10b, the feeding cables 11-1, 11-2, 12-1, 12-2, and the wireless communication circuit 6 constitute a MIMO antenna apparatus according to the first embodiment.

  Here, in FIG. 1 and FIG. 2, the MIMO antenna apparatus according to the present embodiment includes an antenna element 10a having feeding points Q1-1 and Q1-2 at different positions and receiving the first radio signal, and An antenna element 10b having feeding points Q2-1 and Q2-2 at different positions and receiving the second radio signal, and one feeding point selected from the feeding points Q1-1 and Q1-2 of the antenna element 10a Then, one switch point is selected from the switch 21 that outputs the first radio signal from the selected feed point and the feed points Q2-1 and Q2-2 of the antenna element 10b. A switch 22 that outputs a second radio signal; controls the switch 21 to select a feed point of the first antenna element so that the level of the first radio signal is substantially maximized; and Second radio signal record A controller 60 that controls the switch 22 to select the feed point of the second antenna element so that the signal is substantially maximized, the demodulated signal of the first radio signal from the switch 21 and the first signal from the switch 22 And a MIMO decoding circuit 70 which generates a decoded signal by MIMO decoding the demodulated signal of the radio signal 2 and outputs the decoded signal.

  As shown in FIG. 1, in the housing 2, the antenna elements 10 a and 10 b are each a long side approximately the same as the length in the longitudinal direction of the housing 2 and a half of the length in the direction perpendicular to the longitudinal direction of the housing 2. It has a rectangular flat plate shape having a short side, and is provided on the back side of the housing 2 on the left side and the right side of FIG. A feeding point Q <b> 1-1 is provided at an upper right side edge portion in the longitudinal direction of the antenna element 10 a, and the feeding point Q <b> 1-1 feeds the feeding cable 11-1 accommodated in the housing 2, the hinge portion 4, and the housing 3. To the impedance matching circuit 61a-1. In addition, a feeding point Q1-2 is provided at the lower left edge in the longitudinal direction of the antenna element 10a, and the feeding point Q1-2 is a feeding cable 11- accommodated in the housing 2, the hinge portion 4, and the housing 3. 2 is connected to the impedance matching circuit 61a-2. On the other hand, a feeding point Q2-1 is provided at the left upper edge of the antenna element 10b in the longitudinal direction. The feeding point Q2-1 is a feeding cable 12- accommodated in the housing 2, the hinge portion 4, and the housing 3. 1 is connected to the impedance matching circuit 61b-1. In addition, a feeding point Q2-2 is provided at the lower right edge of the antenna element 10b in the longitudinal direction. The feeding point Q2-2 is a feeding cable 12 accommodated in the housing 2, the hinge portion 4, and the housing 3. -2 to the impedance matching circuit 61b-2. Here, the impedance matching circuit 61a-1 is used to match the impedance of the antenna element 10a and the feeding cable 11-1 with the impedance of the wireless reception circuit 62a (50Ω), and the impedance matching circuit 61a-2. Is used to match the impedance of the antenna element 10a and the feeding cable 11-2 with the impedance of the wireless reception circuit 62a. The impedance matching circuit 61b-1 is used to match the impedance of the antenna element 10b and the feeding cable 12-1 with the impedance of the wireless reception circuit 62b (50Ω). The impedance matching circuit 61b-2 This is used to match the impedance of the antenna element 10b and the feeding cable 12-2 with the impedance of the wireless reception circuit 62b.

  In the MIMO antenna apparatus of FIG. 2, when the first wireless signal received by the antenna element 10a uses the feeding point Q1-1, the feeding cable 11-1 and the impedance matching circuit 61a-1 from the feeding point Q1-1. When the power supply point Q1-2 is used, the power supply cable 11-2, the impedance matching circuit 61a-2, and the switch are input to the wireless reception circuit 62a via the contact a side of the switch 21. 21 is input to the wireless reception circuit 62a via the contact b side. When the second wireless signal received by the antenna element 10b uses the feeding point Q2-1, the feeding point 12-1, the feeding cable 12-1, the impedance matching circuit 61b-1, and the contact point a of the switch 22 are used. On the other hand, when using the power supply point Q2-2, the power supply cable 12-2, the impedance matching circuit 61b-2, and the contact b side of the switch 22 are connected from the power supply point 2-2. Via the wireless reception circuit 62b.

  Each of the radio receiving circuits 62a and 62b includes a high frequency filter for separating the frequency of the radio signal, a high frequency amplifier for amplifying the radio signal, and a mixer for converting the radio signal to an intermediate frequency signal having a predetermined intermediate frequency. A high frequency circuit such as an intermediate frequency filter and an intermediate frequency amplifier, and a demodulation circuit that demodulates the intermediate frequency signal into a baseband signal. The radio reception circuit 62a performs predetermined high frequency filter processing and high frequency amplification processing on the input first radio signal, and converts the processed radio signal into a first intermediate frequency signal having a predetermined intermediate frequency as a low frequency. After the conversion, the intermediate frequency filter process is performed on the first intermediate frequency signal, and the filtered first intermediate frequency signal is output to the level detection circuit 63a. Further, the radio reception circuit 62a demodulates the first intermediate frequency signal to generate a first demodulated signal, and outputs the first demodulated signal to the MIMO decoding circuit 71. On the other hand, the radio reception circuit 62b performs predetermined high frequency filter processing and high frequency amplification processing on the input second radio signal, and reduces the processed radio signal to a second intermediate frequency signal having a predetermined intermediate frequency. After the band frequency conversion, the intermediate frequency filter process is performed on the second intermediate frequency signal, and the filtered second intermediate frequency signal is output to the level detection circuit 63b. Further, the radio reception circuit 62 b demodulates the second intermediate frequency signal to generate a second demodulated signal, and outputs the second demodulated signal to the MIMO decoding circuit 71.

  The level detection circuit 63a detects the power level of the input first intermediate frequency signal, generates a detection signal indicating the detected power level, outputs the detection signal to the controller 60, and the level detection circuit 63b receives the input. The power level of the second intermediate frequency signal is detected, and a detection signal indicating the detected power level is generated and output to the controller 60.

  The controller 60 is based on the detection signal from the level detection circuit 63a when the switch 21 is switched to the contact a side and the detection signal from the level detection circuit 63a when the switch 21 is switched to the contact b side. The switch 21 is switched so that the feeding point Q1-1 or Q1-2 is selected so that the power level of the first baseband signal from 62a is increased. Further, the controller 60 is wireless based on a detection signal from the level detection circuit 63b when the switch 22 is switched to the contact a side and a detection signal from the level detection circuit 63b when the switch 22 is switched to the contact b side. The switch 22 is switched so that the feeding point Q2-1 or Q2-2 is selected so that the power level of the second baseband signal from the receiving circuit 62b is increased.

  The MIMO decoding circuit 70 generates a decoded signal by performing MIMO decoding on the input first and second demodulated signals, outputs the decoded signal via the output terminal 80, and outputs the decoded signal to the controller 60.

  In general, a portable wireless terminal device such as the folding cellular phone 1 of FIG. 1 is used while being held by a human hand. Therefore, when the foldable mobile phone 1 is held by the hinge part 4 by a human hand, a part of the antenna elements 10a and 10b is covered, compared to a case where the hinge part 4 is not covered by the hand. The antenna radiation efficiency (value inversely proportional to VSWR) of the antenna elements 10a and 10b is greatly reduced, the communication quality is lowered, and wireless communication is impossible in the worst case. In general, since the electric field distribution is concentrated at the feeding point in the antenna element, the radiation efficiency of the antenna element is lowered particularly when the feeding point is covered. 2, the two feeding points Q1-1 and Q1-2 are provided at different positions of the antenna element 10a, and the feeding points Q2-1 and Q2-2 are provided at different positions of the antenna element 10b. And the switches 21 and 22 are controlled so as to select the feeding point where the power level of the intermediate frequency signal is increased, by converting the radio signal received by each antenna element into an intermediate frequency signal. The radiation efficiency of the two antenna elements 10a and 10b can be kept high, and the communication quality can be kept high. In addition, since it is not necessary to provide a plurality of different antenna elements, the wireless terminal device can be downsized as compared with the prior art.

  In addition, when the controller 60 determines that a power level equal to or higher than a predetermined threshold is detected in the level detection circuits 63a and 63b, regardless of which of the feeding points Q1-1 to Q2-2 is selected, the feeding point The switches 21 and 22 may be switched so as to select Q1-1 and Q2-2 or feeding points Q1-2 and Q2-1. By switching in this way, the distance between the antenna element 10a and the antenna element 10b becomes wider than when the feed points Q1-1 and Q2-1 or the feed points Q1-2 and Q2-2 are selected. Since the correlation between the radio signals received by the elements 10a and 10b is reduced, the error rate of the data extracted from the output signal from the MIMO decoding circuit 70 can be reduced. Therefore, compared with the prior art, the foldable mobile phone 1 can be downsized and the signal quality can be improved. Note that which one of the combination of the feeding points Q1-1 and Q2-2 or the combination of the feeding points Q1-2 and Q2-1 is selected depends on the radio wave environment of the radio signal and the folding mobile phone 1 and the hand. What is necessary is just to determine based on positional relationship.

  Further, the controller 60 calculates BER (Bit Error Rate, hereinafter referred to as BER), PER (Packet Error Rate, hereinafter referred to as PER) or throughput based on the decoded signal from the MIMO decoding circuit 70. The switches 21 and 22 may be switched when it is determined that the calculated BER or PER is equal to or higher than a predetermined threshold value or the throughput is equal to or lower than the predetermined threshold value.

  Furthermore, in the above embodiment, the MIMO decoding circuit 70 includes the impedance matching circuits 61a-1, 61a-2, 61b-1, and 61b-2. However, the present invention is not limited to this, and the antenna element 10a includes When the impedance matches the impedance of the radio reception circuit 62a and the impedance of the antenna element 10b matches the impedance of the radio reception circuit 62b, these impedance matching circuits may not be provided. In this case, the switches 21 and 22 may be provided in the housing 2.

  Further, in the above embodiment, the controller 60 switches the switches 21 and 22 so as to select the feeding point at each antenna element so that the power level of the intermediate frequency signal of the radio signal received by each antenna element is increased. Although the present invention is controlled, the present invention is not limited to this, and an RSSI (Received Signal Strength Indicator; hereinafter referred to as RSSI) value based on the level of the intermediate frequency signal of the radio signal received by each antenna element. The switches 21 and 22 may be controlled so as to calculate and select a feeding point for each antenna element so that the RSSI value becomes large.

First modification.
FIG. 3 is a block diagram showing the configuration of the MIMO antenna apparatus according to the first modification of the present invention. The MIMO antenna apparatus of FIG. 3 includes a wireless communication circuit 6A instead of the wireless communication circuit 6 as compared with the MIMO antenna apparatus of FIG. Compared with the wireless communication circuit 6, the wireless communication circuit 6A includes signal quality measuring devices 64a and 64b and a controller 60A instead of the level detection circuits 63a and 63b and the controller 60. Here, the MIMO antenna apparatus of FIG. 3 switches the feed point Q1-1 or Q1-2 so that the signal quality of the demodulated signal of the first radio signal received by the antenna element 10a is high. And the switch 22 is switched so as to select the feeding point Q2-1 or Q2-2 so that the signal quality of the demodulated signal of the second radio signal received by the antenna element 10b is high. And

  In FIG. 3, the radio receiving circuit 62a outputs a first demodulated signal, which is a demodulated signal of the first radio signal received by the antenna 10a, to the signal quality measuring device 64a and the MIMO decoding circuit 71, and the radio receiving circuit 62b outputs a second demodulated signal, which is a demodulated signal of the second radio signal received by the antenna 10b, to the signal quality measuring device 64b and the MIMO decoding circuit 71. Each of the signal quality measuring devices 64a and 64b detects the BER that is the signal quality of the input demodulated signal, generates a detection signal indicating the detected BER, and outputs it to the controller 60A. Here, the first radio signal and the second radio signal are generated based on signals obtained by inserting pattern signals having a predetermined reference pattern into a plurality of encoded signals generated by encoding transmission data, respectively. .

Based on the detection signal from the signal quality measuring device 64a when the switch 21 is switched to the contact a side and the detection signal from the signal quality measuring device 64a when the switch 21 is switched to the contact b side, the controller 60A The switch 21 is switched so that the feeding point Q1-1 or Q1-2 is selected so that the BER of the first baseband signal from the receiving circuit 62a is increased. Further, the controller 60A is based on the detection signal from the signal quality measuring device 64b when the switch 22 is switched to the contact a side and the detection signal from the signal quality measuring device 64b when the switch 22 is switched to the contact b side. The switch 22 is switched so that the feeding point Q2-1 or Q2-2 is selected so that the BER of the first baseband signal from the wireless reception circuit 62b becomes large.

  The MIMO antenna apparatus according to the first modification has the same effects as the MIMO antenna apparatus according to the embodiment.

  Each of the signal quality measuring devices 64a and 64b may detect the PER of the input demodulated signal, generate a detection signal indicating the detected PER, and output it to the controller 60A.

Second modification.
FIG. 4 is a partially broken schematic perspective view as seen from the back surface in the open state of the folding mobile phone 1A according to the second modification of the present invention. Compared with the foldable mobile phone 1 of FIG. 1, the foldable mobile phone 1A has a feed point Q1-3 at the lower right edge of the antenna element 10a instead of the feed point Q1-1 of the antenna element 10a. And a feeding point Q2-3 is provided at the lower left edge of the antenna element 10b instead of the feeding point Q2-1 of the antenna element 10b.

  Generally, a foldable mobile phone has an elongated shape. Therefore, as shown in FIG. 1, it is shown in FIG. 4 that the feeding points Q1-1, Q1-2, Q2-1, and Q2-2 are provided at positions as far as possible in the longitudinal direction of the antenna elements 10a and 10b. Thus, compared with the case where feed points Q1-2, Q1-3, Q2-2, and Q2-3 are provided at different positions at one end of each of antenna elements 10a and 10b, each feed point is covered with a hand. There is little possibility that communication quality will deteriorate. However, according to the foldable mobile phone 1A of FIG. 4, the lengths of the power supply cables 11-1 and 12-1 can be shortened compared to the foldable mobile phone 1 of FIG. The propagation loss in 12-1 can be reduced and the configuration in the housing 2 can be simplified.

Third modification.
FIG. 5 is a block diagram showing a configuration of a MIMO antenna apparatus according to a third modification of the present invention. The MIMO antenna apparatus of FIG. 5 includes a wireless communication circuit 6B instead of the wireless communication circuit 6 as compared to the MIMO antenna apparatus of FIG. Compared with the wireless communication circuit 6, the wireless communication circuit 6B includes a controller 60B instead of the controller 60, and does not include the level detection circuits 63a and 63b. Here, the MIMO antenna apparatus of FIG. 5 has the power level P1 of the first intermediate frequency signal of the first radio signal received by the antenna element 10a and the second radio signal of the second radio signal received by the antenna element 10b. The feeding point Q1-1 or Q1-2 and the feeding point Q2-1 or Q2-2 are selected so that the correlation coefficient between the two intermediate frequency signals and the power level P2 is substantially minimized. The switches 21 and 22 are respectively switched.

  In FIG. 5, the controller 60B switches the switch 21 to the contact a and switches the switch 22 to the contact b when the switches 21 and 22 are switched to the contact a, when the switches 21 and 22 are switched to the contact b, respectively. And when the switch 21 is switched to the contact point b and the switch 22 is switched to the contact point a, the power level P1 in the predetermined time period of the first intermediate frequency signal of the first radio signal received by the antenna element 10a. And the correlation coefficient ρp between the second intermediate frequency signal of the second radio signal received by the antenna element 10b and the power level P2 in a predetermined time period are calculated using the following equations.

  Here, the brackets represent an average value in a predetermined time period.

  Further, the controller 60B controls the operations of the switches 21 and 22 so as to select the combination of the feeding points when the correlation coefficient is the smallest among the calculated four correlation coefficients ρp.

  The MIMO antenna apparatus according to the third modification has the same effects as the MIMO antenna apparatus according to the embodiment.

  In the above embodiment and each modification, the number of antenna elements is two. However, the present invention is not limited to this and may be three or more. Moreover, in the said embodiment and each modification, although the number of the feed points provided in each antenna element was two, this invention is not limited to this, You may provide three or more feed points.

  In the above embodiment and each modification, the antenna elements 10a and 10b are planar antennas provided in the housing 2. However, the present invention is not limited to this, and the plate-like conductor and the housing 3 provided in the housing 2 are not limited thereto. It may be a dipole antenna configured to include an inner ground conductor.

  As described above in detail, according to the MIMO antenna apparatus or the radio communication apparatus according to the present invention, the first antenna element having a plurality of feeding points at different positions and receiving the first radio signal is mutually connected. A second feeding element having a plurality of feeding points at different positions and receiving a second radio signal and one feeding point selected from the plurality of feeding points of the first antenna element are selected. The first switch means for outputting the first radio signal from the feed point, and one feed point is selected from the plurality of feed points of the second antenna element, and the second switch from the selected feed point Second switch means for outputting a radio signal, and controlling the first switch means to select a feeding point of the first antenna element so that an evaluation value related to the first radio signal is maximized. And the second radio signal Control means for controlling the second switch means so as to select the feeding point of the second antenna element so that the evaluation value is maximized, and the first radio signal from the first switch means. Since the demodulated signal and the demodulated signal of the second radio signal from the second switch means are provided with MIMO decoding means for generating and outputting a decoded signal, compared with the prior art, Regardless of the environment in which the wireless communication device is used, it is possible to realize high-quality wireless communication compared to the prior art.

It is a partially broken schematic perspective view seen from the back surface in the open state of the foldable mobile phone 1 according to one embodiment of the present invention. FIG. 2 is a block diagram illustrating a configuration of a MIMO antenna device of the foldable mobile phone 1 of FIG. 1. It is a block diagram which shows the structure of the MIMO antenna apparatus which concerns on the 1st modification of this invention. It is the partially broken schematic perspective view seen from the back surface in the open state of 1 A of foldable mobile telephones which concern on the 2nd modification of this invention. It is a block diagram which shows the structure of the MIMO antenna apparatus which concerns on the 3rd modification of this invention.

Explanation of symbols

1, 1A ... Folding type mobile phone,
2, 3 ... housing,
4a, 4b, 4c ... hinge cylindrical part,
4 ... Hinge part,
5 ... Ground conductor,
6, 6A, 6B ... wireless communication circuit,
10a, 10b ... antenna elements,
11-1, 11-2, 12-1, 12-2 ... feeding cable,
21, 22 ... switches,
60, 60A, 60B ... controller,
61a-1, 61a-2, 61b-1, 61b-2 ... impedance matching circuit,
62a, 62b ... wireless receiving circuit,
63a, 63b ... level detection circuit,
64a, 64b ... signal quality measuring device,
70: MIMO decoding circuit,
73 ... Signal synthesizer,
Q1-1, Q1-2, Q1-3, Q2-1, Q2-2, Q2-3... Feeding point.

Claims (7)

A first antenna element having a plurality of feed points at different positions and receiving a first radio signal;
A second antenna element having a plurality of feeding points at different positions and receiving a second radio signal;
First switch means for selecting one feeding point from the plurality of feeding points of the first antenna element and outputting a first radio signal from the selected feeding point;
Second switching means for selecting one feeding point from a plurality of feeding points of the second antenna element and outputting a second radio signal from the selected feeding point;
The first switch means is controlled so as to select the feeding point of the first antenna element so that the evaluation value related to the first radio signal is maximized, and the evaluation value related to the second radio signal Control means for controlling the second switch means so as to select the feeding point of the second antenna element such that
The demodulated signal of the first radio signal from the first switch means and the demodulated signal of the second radio signal from the second switch means are decoded by MIMO (Multi-Input Multi-Output) decoding to obtain a decoded signal. A MIMO antenna apparatus comprising MIMO decoding means for generating and outputting. The first antenna element has a rectangular shape, and has one feeding point at each of an upper edge portion and a lower edge portion in the longitudinal direction of the rectangular shape,
2. The MIMO according to claim 1, wherein the second antenna element has a rectangular shape, and has one feeding point at each of an upper edge portion and a lower edge portion in the longitudinal direction of the rectangular shape. Antenna device. The first antenna element has a rectangular shape, and has a plurality of feeding points different from each other at one edge in the longitudinal direction of the rectangular shape,
The MIMO antenna apparatus according to claim 1, wherein the second antenna element has a rectangular shape, and has a plurality of feeding points different from each other at one edge in the longitudinal direction of the rectangular shape. The MIMO antenna device is housed in first and second housings that are connected to each other so as to be openable and closable,
4. The MIMO antenna apparatus according to claim 1, wherein both the first and second antenna elements are accommodated in the first housing. 5.   The MIMO antenna apparatus according to claim 1, wherein the evaluation value is a level of the radio signal or a signal quality of a demodulated signal of the radio signal.   The control means includes a feeding point of the first antenna element and the second radio frequency so that a correlation coefficient between the level of the first radio signal and the level of the second radio signal is minimized. 5. The MIMO antenna apparatus according to claim 1, wherein the first and second switch means are controlled so as to select a feeding point of the antenna element, respectively. In a wireless communication apparatus provided with wireless communication means for transmitting and receiving wireless signals,
A wireless communication apparatus comprising the MIMO antenna apparatus according to any one of claims 1 to 6.

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