JP2008160411A - Antenna device and portable radio - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an antenna device having high radiation efficiency even if a loss medium exists, and having wide band characteristics. <P>SOLUTION: A metal plate 3 is provided so as to contact a side A where a reverse L antenna 2 of a rectangular conductor base plate 1 is provided, and thus, electromagnetic waves to be radiated from the reverse L antenna 2 are hardly sneak to the backside of the rectangular conductor base plate 1 and the radiation is inclined to the surface side of the rectangular conductor base plate 1. Further, the surrounding length of the metal plate 3 is set at 1/2 wavelength of an operation frequency, and the metal plate 3 resonates with the reverse L antenna 2, and thus, input impedance of the reverse L antenna 2 becomes wide band. Thus, even if the reverse L antenna 2 as a low posture antenna is used, the broadband characteristics of the antenna device can be improved. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an antenna device and a portable wireless device.

  In recent years, portable wireless devices have become smaller and thinner, and it has become essential to incorporate antenna devices in portable wireless devices. However, when the antenna device is built in the portable wireless device, there is a problem that the distance between the antenna and the human body cannot be increased, and the radiation efficiency of the electromagnetic wave is remarkably deteriorated to deteriorate the communication quality.

  In order to solve this problem, the directivity of the antenna may be directed in the direction opposite to the human body. As an antenna device that directs the directivity of an antenna in a specific direction, an antenna device in which a rectangular conductor plate is disposed at a quarter wavelength away from the antenna is known (see, for example, Patent Document 1).

  The antenna device described in Patent Document 1 includes a rectangular conductor plate and a dipole antenna disposed near the center of the rectangular conductor plate. By making the distance between the rectangular conductor plate and the dipole antenna a quarter wavelength, it is possible to match the input impedance. Also, by arranging the dipole antenna near the center of the rectangular conductor plate, the rectangular conductor plate functions as a reflector, and the directivity of the dipole antenna is the side on which the dipole antenna of the rectangular conductor plate exists (hereinafter, the front side of the rectangular conductor plate). Can be directed to.

In this way, by directing the directivity of the dipole antenna toward the front side of the rectangular conductor plate, on the opposite side of the dipole antenna across the rectangular conductor plate (hereinafter referred to as the back side of the rectangular conductor plate), for example, a human body or the like. Even in the presence of a lossy medium, highly efficient radiation characteristics can be realized.
JP 2002-141742 A

  However, in the antenna device described in Patent Document 1, the distance between the rectangular conductor plate and the dipole antenna needs to be a quarter wavelength. If this distance is shortened and the posture of the dipole antenna is lowered, there arises a problem that the input impedance of the dipole antenna is narrowed. When the input impedance of the dipole antenna is narrowed, it is difficult for a wideband signal to be input to the dipole antenna, and the antenna device is difficult to transmit and receive a wideband signal.

  In addition, if the dipole antenna is placed close to the side of the rectangular conductor plate to improve the narrowing of the input impedance, electromagnetic waves are likely to leak into the back side of the rectangular conductor plate where lossy media exist, resulting in lossy properties. Radiation efficiency is reduced when a medium is present.

  The present invention has been made to solve the above-described problems of the prior art, and an object thereof is to provide an antenna device having high radiation efficiency even in the presence of a lossy medium and having broadband characteristics. .

  In order to achieve the above object, an antenna device of the present invention includes a conductor ground plane, a feeding point provided in the vicinity of one side of the conductor ground plane, an antenna connected to the conductor ground plane via the feeding point, a conductor A metal plate is provided so as to be in contact with the one side of the ground plate, and the perimeter of the metal plate is about ½ wavelength of the operating frequency of the antenna.

  The antenna device of the present invention includes a conductor ground plate, a feeding point provided near one side of the conductor ground plate, an antenna connected to the conductor ground plate via the feeding point, and both ends of one side of the conductor ground plate. The loop length of the linear conductor element including the one side of the conductor ground plane is approximately ½ wavelength of the operating frequency of the antenna.

  A portable wireless device according to the present invention includes the antenna device described above.

  According to the antenna device of the present invention, it is possible to provide an antenna device having high radiation efficiency when a lossy medium is present and having broadband characteristics.

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

  The antenna device according to the first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a diagram illustrating the configuration of the antenna device according to the present embodiment.

  The antenna device shown in FIG. 1 includes a rectangular conductor ground plane 1, an inverted L antenna 2 disposed on a side A of the rectangular conductor ground plane 1, and a metal plate 3 connected to the side A of the rectangular conductor ground plane 1. Yes. Hereinafter, the side of the rectangular conductor ground plane 1 where the inverted L antenna 2 is installed is referred to as the front side of the rectangular conductor ground plane 1, and the side where the inverted L antenna 2 is not installed is referred to as the back side of the rectangular conductor ground plane 1.

  The rectangular conductor ground plane 1 of the antenna device is made of a conductive material such as copper. However, the material is not limited to copper and may be any metal having conductivity such as gold, silver, and aluminum. Further, a layered dielectric may be provided on both surfaces of the metal or between the metal like a circuit board.

  Next, the inverted L antenna 2 has one end connected to the vicinity of the side A of the rectangular conductor ground plate 1 via the feeding point 4 and a first linear element 2-1 that is substantially perpendicular to the side A, and substantially parallel to the side A. The extended second linear element 2-2 is provided, and the other end of the first linear element 2-1 and one end of the second linear element 2-2 are connected. The element length of the inverted L antenna 2 including the first linear element 2-1 and the second linear element 2-2 is approximately ¼ wavelength of the operating frequency. Therefore, the element length of the first linear element 2-1 corresponding to the attitude of the antenna is shorter than about ¼ wavelength. The inverted L antenna 2 is made of a conductive material, like the rectangular conductor ground plane 1.

  The metal plate 3 is a rectangular conductor plate made of the same material as the rectangular conductor ground plate 1. One side of the metal plate 3 is connected to the side A of the rectangular conductor ground plate 1 by soldering or the like so that the corner of the metal plate 3 and the feeding point 4 are in contact with each other. The peripheral length of the metal plate 3 is about twice the element length of the inverted L antenna 2, that is, about ½ wavelength of the operating frequency.

  If the peripheral length of the metal plate 3 is about twice the element length of the inverted L antenna 2, the length of each side of the metal plate 3 is arbitrary, but the side of the metal plate 3 connected to the rectangular conductor ground plane 1. It is desirable that the length is substantially equal to the element length of the second linear element 2-2, and the length of a side substantially perpendicular to this side is substantially equal to the element length of the first linear element 2-1.

  Here, the case where the metal plate 3 is connected to the rectangular conductor ground plate 1 by soldering or the like has been described. However, for example, as shown in FIG. 2, the metal plate 3 and the rectangular conductor ground plate 1 are combined into one metal plate. It may be realized with. This is processed by, for example, cutting or etching.

  Subsequently, the operation principle of the antenna device according to the present embodiment will be described with reference to FIGS. 3 and 4. FIG. 3 is an enlarged view of a part of the antenna device shown in FIG. FIG. 4 is a side view of the antenna apparatus shown in FIG.

  First, when a high-frequency current is input from the feed point 4 to the inverted L antenna 2, the current is excited in the inverted L antenna 2 to radiate electromagnetic waves. At this time, the metal plate 3 resonates with the inverted L antenna 2 and a current flows mainly along the side of the metal plate 3. The current flowing along the side of the metal plate 3 is weaker than the current flowing through the inverted L antenna 2.

  As described above, when a high-frequency current is input from the feed point 4 to the inverted L antenna 2, the metal plate 3 resonates with the inverted L antenna 2. This corresponds to connecting two resonant circuits of the inverted L antenna 2 and the metal plate 3 in parallel when viewed from the feeding point 4. Therefore, the input impedance of the inverted L antenna 2 is widened.

  Here, the length of the side connected to the rectangular conductor ground plane 1 of the metal plate 3 is substantially equal to the element length of the second linear element 2-2, and the length of the side substantially perpendicular to this side is the first linear element 2. −1, the input impedance of the inverted L antenna 2 viewed from the feeding point 4 is substantially equal to the input impedance of the metal plate 3 viewed from the feeding point 4, and the inverted L antenna 2 and the metal plate 3 tends to resonate. Therefore, compared with the case where the length of each side of the metal plate 3 is arbitrary, the input impedance of the inverted L antenna 2 becomes wider.

  Further, as shown in FIG. 4, the metal plate 3 is connected to the side A of the rectangular conductor ground plate 1 so as to be in contact with the feeding point 4. For this reason, the second linear element 2-2 of the inverted L antenna 2 is blocked by the metal plate 3, and is difficult to see directly from the back side of the rectangular conductor ground plate 1 (for example, the point X shown in FIG. 4).

  Here, in the vicinity of the inverted L antenna 2 such as the back side of the rectangular conductor ground plane 1, the second linear element 2-2 contributes to radiation from the inverted L antenna 2. Since the second linear element 2-2 is blocked by the metal plate 3 and is difficult to see from the back side of the rectangular conductor ground plate 1, the electromagnetic wave radiated from the inverted L antenna 2 is blocked by the metal plate 3, and the rectangular conductor ground plate The electromagnetic wave radiated | emitted toward the back side of 1 is reduced. That is, the metal plate 3 functions as a shielding plate that prevents the electromagnetic wave radiated from the inverted L antenna 2 from wrapping around. Therefore, the directivity of the inverted L antenna 2 is inclined to the front side of the rectangular conductor ground plane 1.

  In the present embodiment, one side of the metal plate 3 is described as being connected to the side A of the rectangular conductor ground plate 1 by soldering or the like so that the corner of the metal plate 3 and the feeding point 4 are in contact with each other. In order to prevent the electromagnetic wave from wrapping around, it is sufficient that the second linear element 2-2 of the inverted L antenna 2 is difficult to see directly from the back side of the rectangular conductor ground plate 1, so that the metal plate 3 has the side A of the rectangular conductor ground plate 1. It only has to be connected to. However, the length of the side connected to the rectangular conductor ground plane 1 of the metal plate 3 is substantially equal to the element length of the second linear element 2-2, and the length of the side substantially perpendicular to this side is the first linear element 2- 1 is substantially equal to the element length of 1, as described above, when one side of the metal plate 3 is connected to the side A of the rectangular conductor ground plate 1 so that the corner of the metal plate 3 and the feeding point 4 are in contact with each other, The element length of the two-line element 2-2 is equal to the length of one side of the metal plate 3, and the second line element 2-2 is more difficult to see from the back side of the rectangular conductor ground plane 1.

  As described above, according to the first embodiment, by arranging the metal plate 3 so that the side A where the inverted L antenna 2 of the rectangular conductor ground plate 1 is installed and one side of the metal plate 3 are connected, the rectangular conductor Electromagnetic waves that wrap around the back side of the ground plane 1 can be reduced, and when a lossy medium exists on the back side of the rectangular conductor ground plane 1, the radiation efficiency when this lossy medium exists can be improved.

  Further, by setting the perimeter of the metal plate 3 to be about ½ wavelength of the operating frequency of the inverted L antenna 2, the metal plate 3 and the inverted L antenna 2 resonate, and the input impedance of the inverted L antenna 2 is widened. can do. That is, it is possible to widen the antenna device using the inverted L antenna 2 which is a low-profile antenna.

  Next, an antenna apparatus according to a second embodiment of the present invention will be described with reference to FIGS. The antenna device according to the present embodiment has substantially the same configuration as the antenna device shown in FIG. 1, except that the metal plate 5 is inclined toward the inverted L antenna 2 by an angle θ. Therefore, the same components as those of the antenna device shown in FIG.

  The metal plate 5 of the antenna device shown in FIG. 5 is a rectangular conductor plate made of a conductive material, like the metal plate 3 shown in FIG. One side of the metal plate 5 is connected to the side A of the rectangular conductor ground plate 1 by soldering or the like so that the corner of the metal plate 5 and the feeding point 4 are in contact with each other. At this time, the metal plate 5 is disposed to be inclined from the rectangular conductor ground plate 1 by the angle θ toward the inverted L antenna.

  The peripheral length of the metal plate 5 is about twice the element length of the inverted L antenna 2, that is, about ½ wavelength of the operating frequency. If the peripheral length of the metal plate 5 is about twice the element length of the inverted L antenna 2, the length of each side of the metal plate 5 is arbitrary, but the side of the metal plate 5 connected to the rectangular conductor ground plane 1. It is desirable that the length is substantially equal to the element length of the second linear element 2-2, and the length of a side substantially perpendicular to this side is substantially equal to the element length of the first linear element 2-1. As in the first embodiment, the rectangular conductor base plate 1 and the metal plate 5 may be realized by a single metal plate.

  Next, the operation principle of the antenna device according to the present embodiment will be described with reference to FIG.

  In the antenna device shown in FIG. 5, similarly to the antenna device shown in FIG. 1, when a high-frequency current is input from the feed point 4 to the inverted L antenna 2, the metal plate 5 resonates with the inverted L antenna 2, and the inverted L antenna. The input impedance of 2 becomes wider.

  At this time, the metal plate 5 is installed at an angle θ from the rectangular conductor ground plate 1 toward the inverted L antenna 2, so that the path of the current flowing along the side of the metal plate 5 is from the plane including the rectangular conductor ground plate 1. Leave (see FIG. 6). Therefore, the radiation due to the current flowing through the metal plate 5 occurs away from the plane including the rectangular conductor ground plane 1, and the radiation pattern of the antenna device including the metal plate 5 is inclined to the front side of the rectangular conductor ground plane 1.

  Also in the antenna device shown in FIG. 5, the metal plate 5 is connected so as to be in contact with the side A of the rectangular conductor ground plate 1, similarly to the antenna device shown in FIG. 1. For this reason, the electromagnetic waves radiated from the second linear element 2-2 of the inverted L antenna 2 are blocked by the metal plate 5 and are unlikely to go around to the back side of the rectangular conductor ground plate 1. That is, the metal plate 5 functions as a shielding plate that prevents the electromagnetic wave radiated from the inverted L antenna 2 from wrapping around.

  In the present embodiment, similarly to the first embodiment, in order to prevent the electromagnetic wave from wrapping around, the second linear element 2-2 of the inverted L antenna 2 is difficult to see directly from the back side of the rectangular conductor ground plane 1. The metal plate 5 only needs to be connected to the side A of the rectangular conductor ground plate 1.

  Next, the angle θ between the rectangular conductor base plate 1 and the metal plate 5 will be described with reference to FIGS. 6 and 7.

  FIG. 6 is a side view of the antenna device shown in FIG. When the metal plate 5 is tilted toward the inverted L antenna 2, the current flowing along the side of the metal plate 5 is away from the plane including the rectangular conductor ground plane 1 as described above, so that the radiation pattern of the inverted L antenna 2 is rectangular. Inclined to the front side of the conductor ground plane 1.

  On the other hand, when the metal plate 5 is tilted toward the inverted L antenna 2, the side of the metal plate 5 approaches the inverted L antenna 2 as indicated by the arrow in FIG. 6. When the distance between the metal plate 5 and the inverted L antenna 2 is shortened, they appear to be short-circuited, and electromagnetic waves are not easily input to the feeding point 4.

  Therefore, the input impedance of the inverted L antenna 2 as viewed from the feeding point 4 is reduced, and as shown in FIG. 1, the broadband characteristic is higher than the case where the metal plate 3 and the rectangular conductor ground plane 1 exist on the same plane. It will deteriorate slightly.

  However, when the angle θ between the rectangular conductor ground plane 1 and the metal plate 5 is 0 ° <θ <45 °, the radiation characteristic in the presence of the lossy medium is improved and the deterioration of the broadband characteristic is suppressed. Can do.

  This will be described with reference to FIG. FIG. 7 is an enlarged view of a part of the antenna device shown in FIG. Here, the length of the side of the metal plate 5 substantially perpendicular to the side A of the rectangular conductor base plate 1 is L, and the angle between the rectangular conductor base plate 1 and the metal plate 5 is θ.

  At this time, Lsin θ is the distance between the side B of the metal plate 5 parallel to the side A and the plane including the rectangular conductor ground plane 1. Lcos θ is a distance between a straight line B ′ obtained by projecting the side B of the metal plate 5 onto a plane including the rectangular conductor ground plane 1 and the side A of the rectangular conductor ground plane 1. This distance is referred to as the distance between the inverted L antenna 2 and the side B of the metal plate 5.

  Here, when θ is 0 ° <θ <45 °, the change rate of sin θ is smaller than the change rate of cos θ. That is, when 0 ° <θ <45 °, L cos θ changes greatly, and the distance between the plane including the rectangular conductor base plate 1 and the side B of the metal plate 5 increases. On the other hand, the change in Lsin θ is small, and the distance from the side B of the metal plate 5 to the inverted L antenna 2 does not change greatly.

  Therefore, when the angle θ between the rectangular conductor ground plane 1 and the metal plate 5 is 0 ° <θ <45 °, the radiation characteristics when the lossy medium existing on the back side of the rectangular conductor ground plane 1 is present are improved. Therefore, it is possible to suppress the deterioration of the broadband characteristics.

  As described above, according to the second embodiment, the same effects as those of the first embodiment can be obtained, and the metal plate 5 is installed at an angle θ from the rectangular conductor ground plate 1 and inclined toward the inverted L antenna 2 side. Thus, for example, when a lossy medium exists on the back side of the rectangular conductor ground plane 1, the current flowing along the side of the metal plate 5 can be kept away from the lossy medium, and the radiation efficiency when the lossy medium exists is present. Can be further improved.

(Modification 1)
A modification of the antenna device according to the present embodiment will be described with reference to FIG. The antenna device shown in FIG. 8 has substantially the same configuration as the antenna device shown in FIG. 5, but the rectangular conductor ground plate 1 and the metal plate 5 are not connected by soldering but connected via a spring 6. Is different.

  Even if a force is applied to the metal plate 5 from the front side of the rectangular conductor ground plate 1 by connecting the rectangular conductor ground plate 1 and the metal plate 5 via the spring 6, the connection between the rectangular conductor ground plate 1 and the metal plate 5 is achieved. Will not come off.

(Modification 2)
Subsequently, a modification of the antenna device according to the present embodiment will be described with reference to FIGS. 9 to 11.
The antenna device shown in FIG. 9 has substantially the same configuration as the antenna device shown in FIG. 5 except that an inverted F antenna 7 is used instead of the inverted L antenna 2. In this case, the peripheral length of the metal plate 5 is about twice the length from the short-circuit point C to the tip D of the inverted F antenna 7 with the rectangular conductor ground plate 1.

  The antenna device shown in FIG. 10 has substantially the same configuration as the antenna device shown in FIG. 5 except that a plate-like inverted F antenna 8 is used instead of the inverted L antenna 2. The plate-shaped inverted F antenna 8 includes a plate-shaped conductor 8-1, a short-circuit wire 8-2 that short-circuits the plate-shaped conductor 8-1 and the rectangular conductor ground plane 1, and one end of the rectangular conductor ground plane via the feeding point 4. 1 and the other end connected to a plate-like conductor 8-1. In this case, the peripheral length of the metal plate 5 is about ½ wavelength of the operating frequency.

  If the peripheral length of the metal plate 5 is about ½ wavelength of the operating frequency of the plate-shaped inverted L antenna 8, the length of each side of the metal plate 5 is arbitrary, but the rectangular conductor ground plate of the metal plate 5 The length of the side connected to 1 is substantially equal to the length of the side substantially parallel to the side A of the rectangular conductor ground plate 1 of the rectangular conductor 8-1, and the side substantially perpendicular to the side A of the rectangular conductor ground plate 1 of the metal plate 5 Is preferably substantially equal to the element length of the short-circuit line 8-2 or the feeder line 8-3.

  Furthermore, the antenna shown in FIG. 11 has substantially the same configuration as the antenna device shown in FIG. 5 except that a patch antenna 9 is used instead of the inverted L antenna 2. The patch antenna 9 includes a plate-shaped conductor 9-1 and a feeder 9-2 having one end connected to the rectangular conductor ground plane 1 and the other end connected to the plate-shaped conductor 9-1. In this case, the peripheral length of the metal plate 5 is about ½ wavelength of the operating frequency.

  If the peripheral length of the metal plate 5 is about ½ wavelength of the operating frequency of the patch antenna 9, the length of each side of the metal plate 5 is arbitrary, but it is connected to the rectangular conductor ground plane 1 of the metal plate 5. The length of the obtained side is substantially equal to the length of the side substantially parallel to the side A of the rectangular conductor ground plane 1 of the rectangular conductor 9-1 and the length of the side substantially perpendicular to the side A of the rectangular conductor ground plane 1 of the metal plate 5 However, it is desirable that the element length is substantially equal to the element length of the feeder line 9-2.

  As described above, as shown in the present modification, the antenna device according to the second embodiment is not limited to the inverted L antenna, and various antennas can be used.

  Next, an antenna apparatus according to a third embodiment of the present invention will be described with reference to FIG. The antenna device according to the present embodiment has substantially the same configuration as the antenna device shown in FIG. 5, but differs in that a linear element 10 is used instead of the metal plate 5. Therefore, the same components as those of the antenna device shown in FIG.

  The linear element 10 of the antenna device shown in FIG. 12 is made of a conductive material as with the rectangular conductor ground plane 1. The linear element 10 has one end connected to the rectangular conductor ground plane 1, extends substantially perpendicular to the side A of the rectangular conductor ground plane 1, bends so as to be substantially parallel to the side A, and bends so as to be substantially perpendicular to the side A. After that, the other end is electrically connected to the side A of the rectangular conductor base plate 1 by soldering or the like.

  The element length of the linear element 10 is a combination of twice the element length of the first linear element 2-1 of the inverted L antenna 2 and the element length of the second linear element 2-2. That is, the loop length of the linear element 10 including the side A (the length of the path indicated by the dotted line in FIG. 12) is about twice the element length of the inverted L antenna 2 and about ½ wavelength of the operating frequency. Yes. Further, the plane including the linear element 10 is inclined by the angle θ toward the front side of the rectangular conductor ground plane 1.

Next, the operation principle of the antenna device according to the present embodiment will be described with reference to FIG.
When the metal plate 5 is connected to the rectangular conductor base plate 1, the current input to the metal plate 5 flows along the side of the metal plate 5. In the case of the antenna device shown in FIG. 12, the linear element 10 is disposed in a portion corresponding to the side of the metal plate 5. For this reason, the current path of the linear element 10 is substantially equal to the current path of the metal plate 5, and the linear element 10 resonates with the reverse antenna 2 in the same manner as the metal plate 5.

  Further, since the linear element 10 is inclined to the front side of the rectangular conductor ground plane 1 by an angle θ, the linear element 10 is separated from the plane including the rectangular conductor ground plane 1. As a result, the electromagnetic wave is radiated from the linear element 10 at a position away from the back side of the rectangular conductor ground plane 1 where the lossy medium exists, and the radiation characteristics when the lossy medium exists are improved.

  As described above, according to the third embodiment, even when the linear element 10 is used instead of the metal plate 5, the broadband characteristic and the radiation characteristic when a lossy medium is present are improved. Furthermore, the linear element 10 is lighter than the metal plate 5, and only one place is required for soldering. Therefore, the antenna device can be reduced in weight and can be easily manufactured.

  Next, an antenna apparatus according to a fourth embodiment of the present invention will be described with reference to FIG. The antenna device according to the present embodiment has substantially the same configuration and operation as the antenna device shown in FIG. 5, but differs in that a cut is provided in the metal plate 11. About the same structure and operation | movement as the antenna apparatus shown in FIG. 5, the same code | symbol is attached | subjected and description is abbreviate | omitted.

  The metal plate 11 of the antenna device shown in FIG. 13 is made of a conductive material like the rectangular conductor ground plane 1. One side of the metal plate 11 is connected to the side A of the rectangular conductor ground plate 1 by soldering or the like. The rectangular conductor base plate 1 and the metal plate 11 may be realized by a single metal plate.

  The metal plate 11 is installed at an angle θ on the front side of the rectangular conductor ground plate 1. Further, a notch 12 is provided on one side of the metal plate 11, and the perimeter including the notch 12 of the metal plate 11 is about twice the element length of the inverted L antenna 2. For this reason, the metal plate 11 resonates with the inverted L antenna 2 and the input impedance of the inverted L antenna 2 is widened.

  As described above, according to the fourth embodiment, the same effects as those of the second embodiment can be obtained, and the metal plate 11 can be reduced in size and weight by providing the notches 12 in the metal plate 11. it can.

(Modification 3)
A modification of the antenna device according to the present embodiment will be described with reference to FIG. The antenna device shown in FIG. 14 has substantially the same configuration and operation as the antenna device shown in FIG. Is different. The peripheral length of the metal plate 13 is also about twice the element length of the inverted L antenna 2, that is, about ½ wavelength of the operating frequency of the inverted L antenna 2.

  Next, a portable wireless device according to a fifth embodiment of the present invention is described with reference to FIG. The portable wireless device according to the present embodiment includes the antenna device shown in FIG. In addition, about the same structure and operation | movement as the antenna apparatus shown in FIG. 5, the same code | symbol is attached | subjected and description is abbreviate | omitted.

  The portable wireless device shown in FIG. 15 is a foldable portable wireless device, and includes a first housing 14-1 and a second housing 14-2, and a rectangular conductor ground plane 1-1 in the first housing. A rectangular conductor ground plane 1-2 in the second housing, a hinge cable 15 for electrically connecting the rectangular conductor ground planes 1-1 and 1-2, and a radio device 16 provided on the rectangular conductor ground plane 1-1. , A feed line 17 that connects the radio device 16 and the feed point 4, an inverted L antenna 2 that is connected to the feed line 17 via the feed point 4, and a metal plate 5 that is connected to one side of the rectangular conductor ground plane 1-1. ing. The rectangular conductor ground plane 1-1 corresponds to the rectangular conductor ground plane 1 shown in FIG.

  The 1st housing | casing 14-1 and the 2nd housing | casing 14-2 are mutually connected so that rotation is possible. When the portable wireless device is used for a telephone call or data communication, the first housing 14-1 and the second housing 14-2 are mainly opened approximately 180 degrees (see FIG. 15 is used in a standby state, and the first casing is bent in the direction of the arrow during standby, and is mainly used in a folded state (not shown).

  Next, similarly to the rectangular conductor ground plane 1-1, the rectangular conductor ground plane 1-2 is made of a conductive material such as copper. However, the material is not limited to copper and may be any metal having conductivity such as gold, silver, and aluminum. Further, a layered dielectric may be provided on both surfaces of the metal or between the metal like a circuit board.

  The radio device 16 provided on the rectangular conductor ground plane 1-1 performs signal processing such as demodulation of a signal received via the inverted L antenna 2 and modulation of a transmission signal. The feeder line 17 inputs a signal processed by the wireless device 16 to the inverted L antenna via the feeding point 4, and inputs a signal received via the inverted L antenna to the wireless device 16.

  Here, a surface where the first housing 14-1 is in contact with the second housing 14-2 when the portable wireless device is folded is referred to as a back surface of the first housing 14-1. The inverted L antenna 2 is provided on the opposite side of the back surface of the first housing 14-1 with the rectangular conductor ground plate 1-1 interposed therebetween. Since the metal plate 5 is installed at an angle θ on the reverse L antenna 2 side, the radiation pattern of the reverse L antenna 2 is inclined on the opposite side to the back surface of the first housing 14-1. When using a portable wireless device such as a telephone call, the lossy medium often exists on the back surface of the first housing 14-1. Therefore, the radiation characteristic when the lossy medium of the portable wireless device is present is improved.

  As described above, according to the fifth embodiment, the antenna device of FIG. 5 is arranged so that the inverted L antenna 2 is located on the opposite side of the back surface of the first housing 14-1 with the rectangular conductor ground plane 1-1 interposed therebetween. By installing, the same effect as the second embodiment can be obtained.

  Although the example in which the antenna device shown in FIG. 5 is mounted on a portable wireless device has been described here, the same effect can be obtained by mounting the antenna device shown in FIGS. In this embodiment, the folding portable wireless device has been described. However, the folding portable wireless device may be mounted on a non-folding portable wireless device.

  In addition, this invention is not limited to the said Example as it is, A component can be deform | transformed and embodied in the range which does not deviate from the summary in an implementation stage. Various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the above embodiments. For example, some components may be deleted from all the components shown in the embodiments. Furthermore, constituent elements over different embodiments may be appropriately combined.

The figure which shows the structure of the antenna apparatus which concerns on 1st Example of this invention. The figure which shows the structural example of the antenna apparatus which concerns on 1st Example of this invention. The enlarged view of the metal plate 3 of the antenna apparatus which concerns on 1st Example of this invention. The side view of the antenna apparatus which concerns on 1st Example of this invention. The figure which shows the structure of the antenna apparatus which concerns on the 2nd Example of this invention. The side view of the antenna apparatus which concerns on the 2nd Example of this invention. The enlarged view of the metal plate 5 of the antenna device which concerns on 2nd Example of this invention. The figure which shows the modification of the antenna apparatus which concerns on 2nd Example of this invention. The figure which shows the modification of the antenna apparatus which concerns on 2nd Example of this invention. The figure which shows the modification of the antenna apparatus which concerns on 2nd Example of this invention. The figure which shows the modification of the antenna apparatus which concerns on 2nd Example of this invention. The figure which shows the structure of the antenna apparatus which concerns on the 3rd Example of this invention. The figure which shows the structure of the antenna apparatus which concerns on the 4th Example of this invention. The figure which shows the modification of the antenna device which concerns on the 4th Example of this invention. The figure which shows the portable radio | wireless machine which concerns on the 5th Example of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Rectangular conductor base plate 2, 7, 8, 9 ... Antenna 3, 5, 11, 13 ... Metal plate 4 ... Feeding point 6 ... Spring 10 ... Linear element 12- .... Cut 14 ... Case 15 ... Hinge cable 16 ... Radio device 17 ... Power supply line

Claims (10)

A conductor ground plane;
A feeding point provided near one side of the conductor ground plane;
An antenna connected to the conductor ground plane via the feeding point;
A metal plate provided so as to be in contact with the one side of the conductor ground plane;
The antenna apparatus according to claim 1, wherein a perimeter of the metal plate is about ½ wavelength of an operating frequency of the antenna.   2. The antenna device according to claim 1, wherein the metal plate is connected to the conductor ground plane at an angle θ toward the antenna with respect to a plane including the conductor ground plane. The antenna includes a first linear element having one end connected to the feeding point and provided substantially perpendicular to the conductive ground plane, and connected to the other end of the first linear element and substantially parallel to the one side of the conductive ground plane. A second linear element provided,
The metal plate is a substantially rectangular metal plate having a short side substantially perpendicular to the one side of the conductor ground plate and a long side substantially perpendicular to the short side,
The element length of the first linear element is substantially equal to the length of the short side of the metal plate, and the element length of the second linear element is substantially equal to the length of the long side of the metal plate. The antenna device according to claim 1 or 2. The antenna includes a linear element having one end connected to the feeding point and provided substantially perpendicular to the conductor ground plane, and a rectangular plate shape connected to the other end of the linear element and provided substantially parallel to the conductor ground plane. Having an element,
The metal plate is a substantially rectangular metal plate having a short side substantially perpendicular to the one side of the conductor ground plate and a long side substantially perpendicular to the short side,
The element length of the linear element is substantially equal to the length of the short side of the metal plate, the side of the rectangular plate element substantially parallel to the one side of the conductor ground plate, and the length of the long side of the metal plate are approximately The antenna device according to claim 1, wherein the antenna devices are equal to each other.   The antenna device according to any one of claims 1 to 4, wherein the metal plate is provided with a cut.   The antenna apparatus according to claim 1, wherein the metal plate has a hexagonal shape.   The antenna device according to any one of claims 1 to 6, wherein the ground conductor plate and the metal plate are formed of a single metal plate. A conductor ground plane;
A feeding point provided near one side of the conductor ground plane;
An antenna connected to the conductor ground plane via the feeding point;
A linear conductor element having both ends connected to one side of the conductor ground plane,
The antenna device according to claim 1, wherein a loop length of the linear conductor element including the one side of the conductor ground plane is about ½ wavelength of an operating frequency of the antenna. The linear conductor element extends substantially perpendicular to the one side from the connection point with the one side of the conductor ground plane, bends at a substantially right angle, and then bends at a substantially right angle to connect to the one side of the conductor ground plane.
The antenna includes a first linear element having one end connected to the feeding point and provided substantially perpendicular to the conductive ground plane, and connected to the other end of the first linear element and substantially parallel to the one side of the conductive ground plane. A second linear element provided,
The length of the portion substantially perpendicular to the one side of the conductor ground plane of the linear conductor element is substantially equal to the length of the first linear element, and the portion of the conductor ground plane of the linear conductor element is substantially parallel to the one side. 9. The antenna device according to claim 8, wherein a length and an element length of the second linear element are substantially equal.   A portable wireless device comprising the antenna device according to any one of claims 1 to 9.

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