JP2005012779A - Antenna assembly - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To realize an antenna assembly whose directivity can be changed in a main polarization plane as an antenna used in wireless communication, mainly in a microwave band. <P>SOLUTION: The antenna assembly has a radiation element 101 having a feed port 102, a plurality of parasitic element pieces 103 which are positioned in the main polarization plane of the radiation element 101, and an impedance-variable connecting means 104 of connecting the plurality of parasitic element pieces 103 to one another, and then the advantageous effects of the size being small in size at low attitude and the directivity in the main polarization plane being able to be switched. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an antenna device used in a radio communication system mainly using a microwave band and a millimeter wave band.

  2. Description of the Related Art As an antenna device conventionally used in a wireless communication device, there is one that changes directivity characteristics in a plane orthogonal to the main polarization plane of the antenna device (see, for example, Patent Document 1).

  FIG. 13 is a perspective view showing the structure of a conventional antenna device. In FIG. 13, the antenna device includes a radiating element 1 to which a radio signal is fed, a plurality of non-exciting elements 2 provided in parallel to the radiating element 1 at a predetermined interval, and a variable connected to the non-exciting element 2. The reactance element 3 is provided.

By adopting this configuration, the reactance value of the variable reactance element 3 is changed to control the directivity in the plane perpendicular to the main polarization plane of the antenna device.
Japanese Patent Laid-Open No. 2001-24431 (pages 1 to 3, FIG. 1)

  However, the above conventional antenna device requires an electrical length of a quarter wavelength in the height direction when applied to directivity control in the horizontal plane with respect to the main polarization, and it is difficult to realize a low-profile antenna device. It has the problem of being.

  An object of the present invention is to solve the above-described conventional problems and to realize a small and low-profile antenna apparatus capable of controlling directivity in the main polarization plane.

  In order to solve the above problems, the present invention provides a radiating element having a feed port, a plurality of parasitic element pieces located in a main polarization plane of the radiating element, and an impedance for connecting the plurality of parasitic element pieces. The antenna device has variable connecting means.

  As a result, directivity control within the main polarization plane becomes possible, and a small and low-profile antenna device can be provided.

  According to the antenna device of the present invention, a radiating element having a feeding port, a plurality of parasitic element pieces located in a main polarization plane of the radiating element, and a variable impedance connection for connecting the plurality of parasitic element pieces. By using the antenna device having the means, it is possible to obtain an advantageous effect that enables switching of directivity characteristics in the main polarization plane with a small size and a low attitude.

  Furthermore, in the wireless communication apparatus provided with the antenna device of the present invention and the directivity control signal generating means for determining the directivity suitable for the communication situation, switching to the directivity suitable for the communication situation enables better communication. The advantageous effect that quality is obtained is obtained.

  Hereinafter, embodiments of the present invention will be described with reference to FIGS.

(Embodiment 1)
FIG. 1 is a diagram of the main part of the antenna device according to the first embodiment of the present invention as viewed from above, and FIG. 2 is a functional block diagram of the antenna device. 1 and 2, the antenna device 100 includes a radiating element 101. The radiating element 101 is made of a strip-shaped conductor and includes a feeding port 102. In the main polarization plane of the radiating element 101, a plurality of parasitic element pieces 103a to 103x made of strip-like conductors are arranged in an annular shape with the radiating element 101 as the center.

  The adjacent parasitic element pieces 103 are connected by the connecting means 104. What connects between the parasitic element piece 103a and the parasitic element piece 103b is referred to as connecting means 104a, and what finally connects between the parasitic element piece 103x and the parasitic element piece 103a is referred to as connecting means 104x. The plurality of connection means 104 are variable in impedance, and when turned on, the impedance between the connection points is lowered to be in a conductive state, and when turned off, the impedance is raised to be in an open state.

  A plurality of parasitic element pieces 103 connected by a plurality of connection means 104 are called parasitic elements. The connection means 104 is turned on / off by the directivity control means 105, and this switching is performed according to a control signal input from the control input port 106.

  Next, the operation of the antenna device having the above configuration will be described.

  An input signal to the antenna device 100 is input to the radiating element 101 via the feeding port 102. And it becomes a radiation wave from radiation element 101 which operates as a dipole antenna. On the other hand, the incident radio wave to the antenna device 100 is received by the radiating element 101 and becomes an output signal from the power feeding port 102. When the length of the radiating element 101 is an electrical length that is an integral multiple of a half wavelength, better characteristics can be obtained.

  By the on / off control of the connecting means 104, a reflector is formed by establishing conduction between the parasitic element pieces 103 until the total length is equal to or longer than a half wavelength in electrical length. On the other hand, a waveguide is formed when the plurality of parasitic element pieces 103 that can be electrically connected have an electrical length of less than half a wavelength. The directivity characteristic of the antenna device 100 is inclined in the opposite direction of the reflector and is inclined in the direction of the waveguide. The directivity characteristic control means 105 switches on / off of the connection means 104a to 104x, thereby changing the positions and lengths where the reflectors and the waveguides are formed, and controlling the directivity characteristics of the antenna device 100.

  Since the radiating element 101 and the parasitic element piece 103 are formed as a band-like electrode pattern on a high frequency substrate such as a printed circuit board by a substrate manufacturing technique or the like, the thickness of the antenna device is substantially equal to this substrate. If the frequency used is about 3 GHz, the length of the radiating element 101 is 5 cm, which is equivalent to a half wavelength, and thus the antenna device has a small and low profile. The power supply port 102 is formed by a structure connecting substrate metal layers such as through holes. Although the strip-shaped conductor has been described as the radiating element 101 and the parasitic element piece 103, other shapes such as a linear conductor may be used.

  Moreover, although the example which has arrange | positioned the parasitic element piece 103 in perfect circle shape was shown in FIG. 1, an elliptical shape may be sufficient. In the case where transmission / reception of radio waves in a specific direction is not required, the parasitic element piece 103 and the connection unit 104 corresponding to the direction may not be provided.

  Further, by using a larger number of shorter parasitic element pieces 103, the range of selection of positions and lengths for forming the director and reflector is increased, and finer directivity characteristics can be adjusted.

  Note that a plurality of the antenna devices 100 of the present invention can be used as an array antenna by arranging a plurality of antenna devices 100 in a linear shape, a lattice shape, and a circular shape at regular intervals, or randomly arranging them. The array directivity is controlled by controlling the amplitude / phase of input / output signals to / from each antenna device, and at the same time, the directivity of each antenna device 100 is switched to the directivity suitable for the array directivity so that it is required for the array. Since the directivity of each antenna device 100 in the direction is improved, better array directivity can be obtained.

  As described above, it has a radiating element having a feeding port, a plurality of parasitic element pieces located in the main polarization plane of the radiating element, and a variable impedance connecting means for connecting the plurality of parasitic element pieces. By using the antenna device, it is possible to realize a small and low-profile antenna capable of switching the directivity in the main polarization plane.

(Embodiment 2)
FIG. 3 is a top view of the main part of the antenna device according to the second embodiment of the present invention. In FIG. 3, the antenna device includes eight parasitic element pieces 201 positioned in a rhombus around the radiating element 101 in the main polarization plane and inclined by 45 degrees with respect to the radiating element 101, and connection means 202 that connects between them. It has. All of the eight parasitic element pieces 201a to 201h are linear conductors having an electrical length of a quarter wavelength. Other configurations are the same as those of the first embodiment.

  FIG. 4 is a diagram showing the relationship between the directional characteristics and the conductive portion of the parasitic element of the antenna device according to the second embodiment of the present invention. The upper part of FIG. 4 is a diagram showing a conductive portion of the parasitic element. Of the eight parasitic element pieces 201 located in the rhombus, those in the conductive state are indicated by thick lines. The lower part of FIG. 4 is a simulation result of the directivity characteristics of the parasitic element shown in the upper part. 4A shows a state in which all connection means 202 are turned off, FIG. 4B shows a state in which only the connection means 202e is turned on, and FIG. 4C shows a state in which the connection means 202b and 202d are turned on. is there. The operation of the antenna device having the above configuration will be described below.

  By turning off all the connection means 202, the parasitic element pieces 201a to 201h become linear conductors of a quarter wavelength, and the influence on the directivity from the radiation element 101 is negligible. As shown in FIG. 4A, the characteristic is a directivity characteristic of an axis object with the radiating element 101 corresponding to the radiating element as an axis.

  By turning on only the connecting means 202e, the parasitic element pieces 201d and 201e are brought into conduction, and a reflector having an electrical length and a half wavelength is formed. As shown in FIG. 4B, the reflecting operation of the reflector switches to directivity characteristics in the direction of the parasitic element pieces 201a and 201b on the opposite side across the radiation element 101. Similarly, when only the connection means 202a is turned on, the directivity characteristic is turned downward.

  By turning on only the connecting means 202b and 202d, the parasitic element pieces 201a and 201b and 201c and 201d are respectively connected to form a two-wavelength, half-wavelength reflector on the right side in the drawing. Due to the reflecting operation of the reflector, the directivity is switched in the direction facing the connecting means 201a, 201b and 201c, 201d as shown in FIG. Similarly, by turning on only the connection means 202f and 202h, the directivity characteristics are switched to the right in the figure. Further, when only the connecting means 202b is turned on, the parasitic element pieces 201a and 201b are connected to each other to form a reflector having an electrical length of half wavelength in the upper right direction of 45 degrees in the figure with respect to the radiating element, and to the lower left direction. Directional characteristics change.

  As described above, by changing the position where the reflector is formed by the on / off control of the connecting means 202, the directivity can be switched not only before and after the radiating element but also right and left and diagonally.

  In addition, although the structure which forms a reflector was explained, the operation which makes a directional characteristic incline in the direction of a director by using a parasitic element piece shorter than a quarter wavelength and forming a director shorter than a half wavelength. May be used. Further, the directivity may be switched by using both the operations of the director and the reflector.

  Further, the radiating element is provided with a corresponding frequency changing means for changing the corresponding frequency by changing the mounting reactance, for example, and by changing the mounting reactance between the connection points of the parasitic element pieces in the means for controlling the impedance, the corresponding frequency is changed. The antenna device may be configured to control the directivity.

  In addition, although the radiation | emission element and the parasitic element piece showed the example of a linear conductor, in this case, an antenna apparatus is comprised by connecting between linear conductors by a feed terminal and a connection means. Further, the radiating element and the parasitic element piece may be formed of a strip-shaped conductor, for example, a metal pattern formed on a substrate may be used. Further, a radiating element or a parasitic element piece having a microstrip antenna structure such as a patch antenna may be used.

  Although three examples of directivity characteristics have been shown, the on / off control of the connecting means is not limited to this. Further, when the connecting means 202c and 202g are arranged, more types of directional characteristics can be switched, but it is not necessary to arrange them.

  Note that a plurality of the antenna devices of the present invention can be used as an array antenna by arranging a plurality of antenna devices in a linear shape, a lattice shape, or a circular shape at regular intervals, or randomly arranging them. Direction required by the array by controlling the directivity of the array by controlling the amplitude and phase of the input and output signals to each antenna device, and simultaneously switching the directivity of each antenna device to a directivity suitable for the array directivity Since the directivity of each of the antenna devices is improved, better array directivity can be obtained.

  As described above, the radiating element and the connecting means for connecting between the adjacent parasitic element pieces and the quarter-wavelength parasitic element pieces arranged in a rhombus shape inclined at 45 degrees in the main polarization plane of the radiating element; The antenna device is configured with the directivity control means for controlling the connection means, and the on / off control of the connection means allows easy switching of the directivity characteristics in the main polarization plane in the front, rear, left, and right directions of the radiating element. A low-profile antenna can be realized by control.

(Embodiment 3)
FIG. 5 is a block diagram of an antenna apparatus according to the third embodiment of the present invention. In FIG. 5, the antenna device includes parasitic element pieces 301 a and 301 b made of linear conductors having an electrical quarter wavelength, parasitic element pieces 302 a to 302 h made of linear conductors having an electrical length of 1/8 wavelength, and adjacent elements. A plurality of connecting means 303a to 303j for connecting the parasitic element pieces to be connected. The plurality of parasitic element pieces 301 and 302 are arranged in a hexagonal shape in the main polarization plane of the antenna device.

  FIG. 6 is a diagram showing the relationship between the conduction portion of the parasitic element of the antenna device and the directivity. The upper part of FIG. 6 is a diagram showing a conduction portion of the parasitic element. Of the six parasitic element pieces 301 and 302 located in the hexagonal shape, the conductive state is indicated by a thick line. The lower part of FIG. 6 is a simulation result of the directivity characteristics of the parasitic element shown in the upper part.

  6A turns off all the connecting means 303, FIG. 6B turns on only the connecting means 303e and 303f, FIG. 6C turns on only the connecting means 303f and 303g, and FIG. d) shows a state in which only the connection means 303f, 303g, 303i, and 303j are turned on. The operation of the antenna device having the above configuration will be described below.

  By turning off all the connection means 303, the parasitic element pieces 301a and 301b become quarter-wavelength linear conductor pieces, and 302a to 302h become quarter-wavelength linear conductor pieces, and direct from the radiation element. Since the influence on the characteristic is slight, the directivity characteristic of the antenna device is the directivity characteristic of the axis object about the radiation element 101 corresponding to the radiation element as shown in FIG.

  By turning on only the connection means 303e and 303f, the parasitic element pieces 301b, 302d, and 302e are connected to form a reflector having an electrical length and a half wavelength. Due to the reflection operation of the reflector, the directivity is switched to the opposite side across the radiating element 101 as shown in FIG. Similarly, when only the connection means 303a and 303j are turned on, the directivity characteristic in the direction of the parasitic element piece 301b is switched.

  FIG. 6C shows only the connection means 303f and 303g turned on. The parasitic element pieces 301b, 302e, and 302f are connected to form a reflector having an electrical length and a half wavelength. By the reflection operation of the reflector, the directional characteristics in the direction of the parasitic element pieces 301a, 302a, and 302b are switched. Similarly, when only the connecting means 303i and 303j are turned on and the connecting means 303d and 303e are turned on in the diagonally lower right direction in the figure, only the parasitic element pieces 301a, 302g and 302h and only the connecting means 303a and 303b are connected. When turned on, the directivity characteristics in the directions 301b, 302e, and 302f are switched.

  FIG. 6D shows only the connection means 303f, 303g, 303i, and 303j turned on. A reflector having an electrical length and a half wavelength connected to the parasitic element pieces 301b, 302e, and 302f and a reflector having an electrical length and a half wavelength connected to the parasitic element pieces 301a, 302g, and 302h are formed. By the reflection operation of the reflector, the directional characteristics directed to the parasitic element pieces 302a, 302b, 302c, and 302d are switched. Similarly, when only the connection means 303a, 303b, 303d, and 303e are turned on, the directional characteristics toward the parasitic element pieces 302e, 302f, 302g, and 302h are switched.

  Although four examples of directivity characteristics are shown, the on / off control of the connection means 303 is not limited to this. Further, when the connection means 303c and 303h are arranged, more types of directivity switching can be performed, but it is not necessary to arrange them.

  In addition, although the structure which forms a reflector was demonstrated, it was guided by the waveguide formed by using a parasitic element piece shorter than a quarter wavelength and connecting a parasitic element piece to a length shorter than a half wavelength. You may use the operation | movement in which a directional characteristic inclines in a vessel direction.

  As described above, the connecting means for connecting between the radiating element and the adjacent parasitic element piece and the quarter-wave and eighth-wavelength parasitic element pieces arranged in a hexagonal shape in the main polarization plane of the radiating element. The antenna device is composed of a parasitic element having a directivity characteristic control means for controlling the connection means, and by connecting two or three parasitic element pieces by on / off control of the connection means, an electrical length of half wavelength is obtained. By forming the reflector and changing the position at which the reflector is formed, it is possible to realize a low-profile antenna by simple control capable of switching the directivity in the main polarization plane.

(Embodiment 4)
FIG. 7 is a functional block diagram of a wireless communication apparatus according to the fourth embodiment of the present invention. In FIG. 7, the wireless communication device includes an antenna device 100, a reception unit 401, and directivity characteristic control signal generation means 403. In addition, the reception unit 401 includes reception intensity detection means 402 that detects the intensity of a signal received by the reception unit wireless communication apparatus. The configuration of antenna apparatus 100 is the same as that of the antenna apparatus of the first embodiment. The operation of the wireless communication apparatus having the above configuration will be described below.

  First, when the radiating element 101 receives incident radio waves that reach the wireless communication device, an output signal is sent from the power supply port 102 to the receiving unit 401. Then, the direction and intensity of the incident radio wave are detected by the reception intensity detection unit 402 included in the reception unit 401.

  An incident radio wave including a frequency component corresponding to the antenna device 100 is often referred to as a received signal, and is also referred to as a high-frequency signal or an RF signal. As an operation during reception, the RF signal is demodulated to obtain digital data.

  The directivity characteristic control signal generation unit 403 switches the directivity characteristic at a timing with little influence on the transmission / reception operation of digital data based on the output of the reception unit 401, and is the best based on the output of the reception intensity detection unit 402. The directivity characteristic that provides the received signal strength is set as the directivity characteristic suitable for the communication situation. Then, a control signal for operating the directivity control unit 105 in accordance with the setting is generated, and the control signal is sent to the directivity control unit 105. In the transmission / reception operation of digital data, better communication quality can be obtained by using the directivity characteristics. For example, by switching the directivity within the symbol period in synchronization with the symbol period of the received signal, the direct influence of the change in the communication transmission path due to the directivity switching is limited to one symbol, and directivity control Can minimize the influence on the reception characteristics. Further, by switching the directivity within the time interval between symbols, it is possible to reduce the influence of the change in transmission characteristics due to directivity control during the symbol period.

  Also, in the configuration where the wireless communication device uses the same frequency for the reception operation and the transmission operation, the propagation characteristics of the radio signal are almost equal, so the directivity characteristic suitable for the communication situation of the reception operation and the directivity characteristic suitable for the communication situation of the transmission operation Are almost equal. That is, good communication quality can be obtained in the transmission operation by using the directivity obtained in the reception operation.

  Even if the wireless communication device uses different frequencies for the reception operation and the transmission operation, the positional relationship with the counterpart wireless communication device does not change, so the directivity obtained by the reception operation can be used. Also, good communication quality according to the reception operation can be obtained. Furthermore, by returning the arrival state of the transmission signal from the wireless communication device from the partner wireless communication device, the directivity characteristics suitable for the communication status of the transmission operation are detected by the same operation as the directivity switching operation in the reception operation. May be. Thereby, better communication quality can be obtained.

  The receiving unit 401 may include a reception error detection unit that detects an error rate of received data that is digital data obtained from incident radio waves. In this case, the directivity characteristic control signal generation unit 403 determines the directivity characteristic suitable for the communication state based on the output of the reception error detection unit, and sends a corresponding control signal to the directivity characteristic control unit 105. In order to detect reception errors, it is necessary to receive a known data sequence, but error detection can be performed by performing directional characteristic determination at a timing when a predetermined data sequence such as a preamble of a communication frame is transmitted. If there is a signal that does not contribute to communication due to multiple wave propagation or interference wave, the intensity of the undesired wave is also added to the received intensity and the accuracy of directional characteristic determination is reduced, but the directional characteristic is determined by the error rate of the received data Thus, directivity characteristics suitable for the communication state can be obtained in the radio signal contributing to the actual communication operation, and better communication quality can be obtained.

  Note that the wireless communication apparatus of this embodiment can be used for a mobile station or a base station. By setting the directivity characteristics that contribute greatly to the communication operation, better communication quality can be obtained and a more efficient mobile radio system can be constructed. In addition, by including a frame for transmitting and receiving data for determining directivity suitable for the communication state in the communication format, it is possible to set the directivity with higher accuracy and obtain better communication quality.

  As described above, the antenna device, the directivity control signal generating means for generating the control signal for controlling the directivity control means, and the reception intensity detecting means for detecting the intensity of the incident radio wave, the directivity control signal When the generation unit is a radio communication device that generates a control signal corresponding to the detection result of the reception intensity detection unit, a radio communication terminal capable of more efficient communication can be realized.

(Embodiment 5)
FIG. 8 is a perspective view of a foldable wireless communication apparatus 500 according to the fifth embodiment of the present invention. FIG. 8A shows a state where the wireless communication apparatus 500 is folded, and FIG. 8B shows a state where the wireless communication apparatus 500 is open. FIG. 9 is a functional block diagram of the wireless communication apparatus 500.

  8 and 9, the wireless communication device 500 includes the antenna device 100, and further, a shape state detection unit 501 that detects the open / closed state of the wireless communication device 500, and a necessary directivity characteristic from the output of the shape state detection unit 501. A directional characteristic control signal generating unit 502 that determines and sends a corresponding control signal to the directional characteristic control unit 105; The configuration of antenna apparatus 100 is the same as that of the first embodiment, and the configuration of receiving section 401 is the same as that of the fourth embodiment. Hereinafter, the operation of the wireless communication apparatus 500 configured as described above will be described.

  In the state where the wireless communication device 500 in FIG. 8A is closed, there is no obstacle in the diagonally upward direction when viewed from the antenna device 100, so that the directivity characteristic corresponding to the radiation element is switched. On the other hand, in the state where the wireless communication in FIG. 8B is opened, the degree of contribution to the communication operation of the directivity characteristic in the direction blocked by the housing of the opened wireless communication device 500 is reduced, so that it is opposite to the housing. By switching to the directivity characteristic directed in the direction, a more desirable directivity characteristic of the wireless communication device 500 is formed in response to the mechanical shape change of the wireless communication device 500.

  In addition, although the wireless communication apparatus 500 is a foldable type and the configuration example using the directivity characteristic control signal generation unit 502 corresponding to the two states of opening and closing is shown, it is not limited to this. In the wireless communication device 500 having a shape in which the contribution of the directivity of the antenna device 100 to the communication operation is biased due to the mechanical shape change, the directivity control signal generation unit 502 that changes the directivity to the directivity that compensates for the bias of the contribution. May be used.

  Note that the wireless communication apparatus 500 of this embodiment can be used for a mobile station or a base station. By setting the directivity characteristics that contribute greatly to the communication operation, better communication quality can be obtained and a more efficient mobile radio system can be constructed. In addition, by including a frame for transmitting and receiving data for determining directivity suitable for the communication state in the communication format, it is possible to set the directivity with higher accuracy and obtain better communication quality.

  As described above, the shape state detection unit 501 that detects a mechanical shape change of the wireless communication apparatus 500, the necessary directivity characteristic is determined from the output of the shape state detection unit 501, and the corresponding control signal is transmitted to the directivity characteristic control unit 105. Wireless communication terminal capable of performing more efficient communication by changing the directivity in response to a mechanical shape change by including the directivity control signal generation means 502 to be sent to the antenna and the antenna device 100 capable of controlling directivity Can be realized.

(Embodiment 6)
FIG. 10 is a perspective view of an antenna device according to a sixth embodiment of the present invention. In FIG. 10A, reference numeral 601 denotes a parasitic element piece obtained by translating the parasitic element piece 201 up and down, 602 denotes connection means for connecting the parasitic element pieces 601, and 603 denotes a main polarization plane of the antenna device. FIG. 10B shows an example in which a reflector is formed by the connecting means 202 and 602, 604 is a reflector formed by connecting the parasitic element pieces 201 by the connecting means 202, and 605 is connected corresponding to the reflector 604. A reflector formed by connecting parasitic element pieces 601 by means 602.

  When the reflector 605 is formed in the vertical direction of the reflector 604 when viewed from the radiation element 101, radiation in the direction of the reflector 605 is suppressed, and thus directivity in the opposite direction of the reflector 604 is further increased. .

  In addition, by forming a reflector above the main polarization plane 603, the directivity characteristics can be switched to the main polarization plane 603 inclined obliquely downward in the opposite direction of the reflector.

  Furthermore, FIG. 11 is a perspective view of another form of antenna device according to Embodiment 6 of the present invention. In FIG. 11, reference numeral 101 denotes a radiating element which is inclined with respect to the main polarization plane 603 and is arranged on a straight line AA ′, 606 is a parasitic element piece arranged in a grid pattern, and 607 is a connection state between the parasitic element pieces 606. Connection means 603 for switching is the main polarization plane of the antenna device.

  By disposing the radiating element 101 obliquely with respect to the main polarization plane 603 of the antenna device, the directivity characteristics with respect to the cross polarization of the antenna device are improved. Furthermore, by arranging the parasitic element pieces in a lattice pattern and switching the connection conditions between the parasitic element pieces to form a reflector or a director, it is possible to switch the directional characteristics for the main polarization and cross polarization. Become. In wireless transmission in urban areas and indoors, the plane of polarization changes due to reflection and scattering from structures such as walls on the transmission path.For example, even if horizontal polarization is radiated, Since some vertical polarization component is generated, better communication quality can be realized by controlling the directivity of cross polarization in addition to the main story.

  As described above, by using the parasitic element pieces 606 arranged in a lattice pattern and the radiating element 101 arranged obliquely on the main polarization plane 603, an incoming wave whose polarization plane has changed due to reflection scattering during propagation is used. However, an antenna device capable of good communication can be realized.

(Embodiment 7)
FIG. 12 is a perspective view of an antenna device according to a seventh embodiment of the present invention. In FIG. 12, reference numeral 701 denotes a reflector. For example, the reflector 701 is arranged in a direction in which the arrival of a signal is not expected due to the peripheral structure of the device in which the antenna device is incorporated.

  When an antenna device is built in a device, it may receive a noise signal from another part in the device, and the direction in which the signal is not expected (for example, the internal direction of the device on which the antenna device is mounted) The signal incident from the center is mainly a noise signal. By disposing the reflector 701, the noise signal from the inside of the device is reduced. For example, when the directivity control is performed based on the received power, the directivity control can be performed more faithfully to the incoming wave. Performance can be improved.

  As described above, by arranging the reflector 701 in a direction in which the arrival of a signal is not expected, the influence of the noise signal can be reduced, and the accuracy of directivity control corresponding to the incoming wave can be improved.

  The antenna device according to the present invention is small and low-profile, and can switch the directivity characteristics in the main polarization plane. Therefore, the antenna device is mainly used in a radio communication system using a microwave band and a millimeter wave band.

Top view of the main part of the antenna device according to Embodiment 1 of the present invention Functional block diagram of the antenna device according to the first embodiment Top view of the main part of the antenna device according to the second embodiment The figure which showed the directional characteristic of the antenna apparatus in Embodiment 2 Top view of the main part of the antenna device according to the third embodiment The figure which showed the directional characteristic of the antenna apparatus in Embodiment 3 Functional block diagram of the wireless communication apparatus in the fourth embodiment (A) Perspective view of the wireless communication device in the fifth embodiment in a closed state (b) Perspective view of the wireless communication device in the fifth embodiment in an opened state Functional block diagram of the wireless communication apparatus in the fifth embodiment (A) Perspective view of antenna device in embodiment 6 (b) Perspective view of reflector formed by connecting means 202, 602 in embodiment 6. The perspective view of the other antenna apparatus in Embodiment 6 The perspective view of the antenna apparatus in Embodiment 7 A perspective view of a conventional antenna device

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Antenna apparatus 101 Radiation element 102 Feeding port 103 Parasitic element piece 104 Connection means 105 Directional characteristic control means 106 Control input port 201 Parasitic element piece 202 Connection means 301 Parasitic element piece 302 Parasitic element piece 303 Connection means 401 Reception part 402 Reception intensity detection Means 403 Directivity characteristic control signal generation means 500 Wireless communication apparatus 501 Shape state detection means 502 Directivity characteristic control signal generation means 601 Parasitic element piece 602 Connection means 603 Main polarization plane 604 Reflector 605 Reflector formed by connecting parasitic element pieces 601 by connecting means 602 606 Parasitic element 607 Connecting means 701 Reflector

Claims (21)

An antenna apparatus comprising: a radiating element having a feeding port; a plurality of parasitic element pieces located in a main polarization plane of the radiating element; and a variable impedance connecting means for connecting the plurality of parasitic element pieces. The antenna device according to claim 1, further comprising frequency changing means for changing a corresponding frequency of the radiating element. The antenna device according to claim 1, wherein the plurality of parasitic element pieces are annularly disposed around the radiation element. The antenna device according to claim 1, wherein the plurality of parasitic element pieces are located in a diamond shape around the radiating element. The antenna device according to claim 1, wherein the plurality of parasitic element pieces are arranged in a hexagonal shape around the radiation element. The antenna device according to claim 1, wherein the plurality of parasitic element pieces are arranged in a lattice pattern around the radiation element. The antenna device according to claim 1 or 2, comprising at least one parasitic element piece having an electrical length of a quarter wavelength. The antenna device according to claim 1 or 2, comprising at least one parasitic element piece having an electrical length of 八 wavelength. The antenna device according to claim 1, further comprising at least one parasitic element piece inclined at 45 degrees with respect to the radiating element. The antenna device according to claim 1, wherein at least one reflective element is provided outside the parasitic element piece. The antenna device according to claim 1, wherein the radiating element is located obliquely with respect to a main polarization plane of the antenna device. The antenna device according to claim 1, wherein at least one of the connection means is in a conductive state. The antenna device according to claim 12, wherein a total length of the parasitic element pieces electrically connected by the connection means in a conductive state is different from a length of the radiating element. An antenna device in which the antenna device according to any one of claims 1 to 13 is positioned in an array. 15. The antenna device according to claim 1, further comprising directivity control means for controlling impedance of the connection means. 16. A wireless communication apparatus comprising: the antenna device according to claim 15; and directivity characteristic control signal generation means for generating a control signal for controlling the directivity characteristic control means. 17. The wireless communication apparatus according to claim 16, further comprising reception intensity detection means for detecting the intensity of incident radio waves, wherein the directivity characteristic control signal generation means generates a control signal corresponding to a detection result of the reception intensity detection means. 17. A reception error detection means for detecting an error rate of received data obtained from incident radio waves, wherein the directivity characteristic control signal generation means generates a control signal corresponding to a detection result of the reception error detection means. Wireless communication device. A housing that covers the antenna device and the directivity characteristic control signal generation means; and a shape state detection means that detects a change in the shape of the housing, wherein the directivity control signal generation means detects the shape state detection means. The wireless communication apparatus according to claim 16, wherein a control signal corresponding to the result is generated. The radio communication apparatus according to claim 16, wherein the directivity characteristic control signal generating means generates a control signal in synchronization with a symbol period of communication data. A mobile radio system including a mobile station or a base station comprising the radio communication device according to any one of claims 16 to 20.

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