JP2006129537A - Diversity antenna and radio communications apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a strong diversity antenna against a difference in polarization, closing each directivity to nondirectivity, while lessening the gain differences of a horizontally polarized wave and a vertically polarized waves in each antenna. <P>SOLUTION: Each central axis of a first long conductor portion 11 and a 2nd long conductor portion 21 becomes mutually substantially perpendicular. Each central axis of a first conductor portion 13 for power supply and a second conductor portion 23 for power supply becomes mutually substantially parallel, and a first stretcher conductor portion 11 and a 2nd long conductor portion 21 turn to the outside. A first printed circuit board 14 and a 2nd printed circuit board 24 are made to face and become substantially parallel, and a first reverse F (female) mold antenna 10 and a second reverse F (female) mold antenna 20 are arranged. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a diversity antenna and a wireless communication apparatus including the diversity antenna.

  With recent advances in communication technology, wireless communication devices have been downsized, and one of the small antennas used in this wireless communication device is an inverted F-type antenna. The inverted F-type antenna is convenient for miniaturization because the length of the element can be reduced to ¼ wavelength and the feeding point can be in the middle of the element. There is a diversity antenna using two inverted F antennas.

  FIG. 7 is an external perspective view showing a conventional diversity antenna. The conventional diversity antenna 50 includes a plate-like inverted F-type antenna 60 and a plate-like inverted F-type antenna 70. The plate-like inverted F-type antenna 60 and the plate-like inverted F-type antenna 70 are arranged on the upper surface of the casing 51 of the wireless communication device.

  The inverted F-type antenna 60 includes a plate 61, a ground plate 62, a feed line 63, and a feed point 64, and the inverted F-type antenna 70 includes a plate 71, a ground plate 72, a feed line 73, and a feed point 74.

  Each of the plates 61 and 71 is made of a rectangular metal conductor, and the length of each side of the rectangle is determined according to the frequency to be used. The ground plates 62 and 72 are metal conductors, respectively, and ground the plates 61 and 71 to the casing 51 of the wireless communication device. The feed lines 63 and 73 excite the plates 61 and 71 by applying a quasi-microwave current to the feed points 64 and 74, respectively. The feeding points 64 and 74 are points that can supply the largest current to the plates 61 and 71, respectively. The casing 51 of the wireless communication device is box-shaped.

  In FIG. 7, a plane parallel to the upper surface of the casing 51 of the wireless communication device in which the inverted F-type antenna 60 and the inverted F-type antenna 70 are arranged is a horizontal plane H, and the upper surface of the casing 51 of the wireless communication device is A direction perpendicular to the vertical axis V is defined as a vertical axis V.

FIG. 8 is a diagram showing a directivity pattern of the conventional diversity antenna 50 of FIG. FIG. 8A is a diagram showing a directivity pattern with respect to the vertical axis V in the inverted F-type antenna 60. The directivity pattern for vertical polarization is indicated by a solid line, and the directivity pattern for horizontal polarization is indicated by a dotted line. Show. FIG. 8B is a diagram showing a directivity pattern with respect to the vertical axis V in the inverted F-type antenna 70. The directivity pattern with respect to the vertical polarization is shown by a solid line, and the directivity pattern with respect to the horizontal polarization is shown. Shown with dotted lines.
JP 63-0318826 A Japanese Patent Laid-Open No. 08-186429 JP-A-62-0209904 JP 09-0167214 A

  However, the above prior art has the following problems. That is, as apparent from the directivity pattern of the vertical axis V reference of the inverted F-type antenna 60 in FIG. 8A and the inverted F-type antenna 70 in FIG. With respect to the upper surface of the casing 51 of the wireless communication apparatus in which the type antenna 60 and the inverted F type antenna 70 are arranged, the lower gain is smaller than the upper gain, and the null point is in the vertical axis V direction. have. In addition, the gain of horizontal polarization indicated by a dotted line is smaller than the gain of vertical polarization indicated by a solid line. Such an antenna always has a small gain direction and a weak polarization plane even if they are combined to provide diversity. It is effective in the case where the usage state and direction of the system equipped with these antennas is constant and only a constant polarization is transmitted and received, but since the usage state and direction are not constant, all polarizations are transmitted and received in all directions. It becomes a problem when it must be possible.

  The present invention has been made to solve the above-described problems. When the directivity pattern based on the vertical axis V is viewed, each of the first and second antennas exists in the vertical axis V direction. The null point is eliminated, and both vertical polarization and horizontal polarization have gain in all directions, that is, close to omnidirectionality, and the gain of vertical polarization shown by the solid line In comparison with this, it is improved that the gain of the horizontally polarized wave indicated by the dotted line is small. Furthermore, when the diversity is operated, the improved horizontal polarization of the first and second antennas is used to strengthen the difference in polarization.

  In order to solve the above-described problem, the diversity antenna of the present invention is formed by bending a single metal plate, and has a first longitudinal conductor portion and a first side surface of the first longitudinal conductor portion. A first grounding conductor portion provided substantially perpendicular to the first longitudinal conductor portion, and a first ground conductor portion provided substantially perpendicular to the first longitudinal conductor portion on the other side surface of the first longitudinal conductor portion. The first inverted F-type antenna composed of the power supply conductor portion, a single metal plate bent, a second longitudinal conductor portion, and one of the side surfaces of the second longitudinal conductor portion. A second grounding conductor portion provided substantially perpendicular to the second longitudinal conductor portion, and provided on the other side surface of the second longitudinal conductor portion substantially perpendicular to the second longitudinal conductor portion. A diversity antenna comprising a second inverted F-type antenna comprising a second feeding conductor The central axes of the first and second longitudinal conductor portions are substantially perpendicular to each other, and the central axes of the first and second feeding conductor portions are substantially parallel to each other, In addition, the first longitudinal conductor portion and the second longitudinal conductor portion are arranged with a sufficient space between the first and second inverted F antennas so that the first longitudinal conductor portion and the second longitudinal conductor portion are opposed to each other. To do.

  In the present invention, the first inverted F-type antenna includes a first printed circuit board, and the first grounding conductor is electrically connected to a ground pattern of the first printed circuit board. The first feeding conductor portion is electrically connected to a feeding point of the first printed circuit board, and the second inverted F-type antenna includes a second printed circuit board, and the second grounding conductor is provided. Is electrically connected to the ground pattern of the second printed circuit board, and the second power supply conductor is electrically connected to the power supply point of the second printed circuit board. The second printed circuit board is arranged to face each other so as to be substantially parallel.

  The present invention is characterized in that the outer circumferences of the first printed board and the second printed board have substantially the same length as the wavelength of the radio wave to be used.

  In the present invention, the first printed circuit board is provided with the first longitudinal conductor portion with respect to the center where the first printed circuit board and the second printed circuit board are arranged to face each other. Further, the surface of the second printed circuit board on which the second longitudinal conductor portion is provided is arranged so as to face the outside.

  Further, according to the present invention, the first longitudinal conductor portion of the first inverted F-type antenna is arranged substantially vertically with the first feeding conductor portion on the upper side, and the second inverted conductor portion is the second inverted conductor portion. The second longitudinal conductor portion of the F-type antenna is characterized in that its central axis is arranged substantially horizontally.

  Further, the present invention is characterized in that the second longitudinal conductor portion of the second inverted F-type antenna is disposed so as to be above the horizontal central axis of the second printed circuit board. To do.

  In the wireless communication apparatus including the diversity antenna and the transmission / reception circuit board unit to which the diversity antenna is connected, the first inverted F antenna and the second inverted F antenna are The transmission / reception circuit board unit is disposed so as to be substantially symmetrical about the center thereof.

  As described above, the present invention is formed by bending a single metal plate, and the first longitudinal conductor portion is formed on the first longitudinal conductor portion and one of the side surfaces of the first longitudinal conductor portion. A first grounding conductor portion provided substantially perpendicularly to the first grounding conductor portion and a first feeding conductor portion provided on the other side surface of the first longitudinal conductor portion substantially perpendicularly to the first longitudinal conductor portion. A first inverted F-type antenna formed by bending a single metal plate, a second longitudinal conductor portion, and a second longitudinal conductor portion on one of the side surfaces of the second longitudinal conductor portion. A second grounding conductor provided substantially perpendicular to the conductor, and a second power supply provided substantially perpendicular to the second longitudinal conductor on the other side of the second longitudinal conductor. Diversity antenna composed of a second inverted F-type antenna comprising a conductor portion for use, wherein the first longitudinal conductor portion and the second longitudinal conductor The respective central axes are substantially perpendicular to each other, and the respective central axes of the first feeding conductor portion and the second feeding conductor portion are substantially parallel to each other, and the first longitudinal conductor portion and the second feeding conductor portion are substantially parallel to each other. The first and second inverted F-type antennas are arranged with a sufficient gap so as to be opposed to each other.

  Therefore, according to the present invention, a diversity antenna corresponding to both vertical polarization and horizontal polarization is provided by reducing the difference between the gain of vertical polarization and the gain of horizontal polarization. Can do. In addition, since the first and second inverted F-type antennas are formed by bending a single metal plate, the diversity antenna can be easily manufactured.

  In the present invention, the first inverted F-type antenna includes a first printed circuit board, and the first grounding conductor is electrically connected to a ground pattern of the first printed circuit board. The first feeding conductor portion is electrically connected to a feeding point of the first printed circuit board, and the second inverted F-type antenna includes a second printed circuit board, and the second grounding conductor is provided. Is electrically connected to the ground pattern of the second printed circuit board, and the second power supply conductor is electrically connected to the power supply point of the second printed circuit board. The second printed circuit board is arranged to face each other so as to be substantially parallel.

  Therefore, according to the present invention, each of the first and second antennas does not have a null point in the direction of the vertical axis V, and has gain in all directions, that is, omnidirectional. Further, since the respective central axes are arranged so as to be perpendicular to each other, the difference in the polarization plane becomes strong when operated as diversity.

  The present invention is characterized in that the outer circumferences of the first printed board and the second printed board have substantially the same length as the wavelength of the radio wave to be used.

  Therefore, according to the present invention, the radio waves wrap around the back surfaces of the first and second printed circuit boards on which the first and second long conductor portions are provided, and the first and second inverted F antennas. The directivity pattern becomes more omnidirectional, and the difference between the gain of vertical polarization and the gain of horizontal polarization is reduced.

  In the present invention, the first printed circuit board is provided with the first longitudinal conductor portion with respect to the center where the first printed circuit board and the second printed circuit board are arranged to face each other. The surface of the second printed circuit board on which the second longitudinal conductor portion 21 is provided is arranged so as to face the outside.

  Therefore, according to the present invention, even when an obstacle or the like is arranged between the first printed circuit board of the first inverted F antenna and the second printed circuit board of the second inverted F antenna. It is possible to provide a diversity antenna that is less affected by the obstacles.

  Further, according to the present invention, the first longitudinal conductor portion of the first inverted F-type antenna is arranged substantially vertically with the first feeding conductor portion on the upper side, and the second inverted conductor portion is the second inverted conductor portion. The second longitudinal conductor portion of the F-type antenna is characterized in that its central axis is arranged substantially horizontally.

  Therefore, according to the present invention, by making each of the central axes coincide with the polarization planes of the vertical polarization and the horizontal polarization, the difference in polarization is enhanced when operated as diversity. Further, by arranging the first feeding conductor portion connected to the feeding point through which the most current flows to the upper side and the central axis thereof being arranged substantially vertically, obstacles to the lower side of the first inverted F-type antenna can be obtained. It is possible to provide a diversity antenna in which the influence is reduced. That is, when a system including these antennas is installed on a wall or a desk, the influence thereof can be reduced.

  Further, the present invention is characterized in that the second longitudinal conductor portion of the second inverted F-type antenna is disposed so as to be above the horizontal central axis of the second printed circuit board. To do.

  Therefore, according to the present invention, the second longitudinal conductor portion is disposed on the upper side of the horizontal central axis of the second printed circuit board, so that the lower side of the second inverted F-type antenna is disposed on the lower side. It is possible to provide a diversity antenna in which the influence of an obstacle is reduced. That is, when a system including these antennas is installed on a wall or a desk, the influence thereof can be reduced.

  In the wireless communication apparatus including the diversity antenna and the transmission / reception circuit board unit to which the diversity antenna is connected, the first inverted F antenna and the second inverted F antenna are The transmission / reception circuit board unit is disposed so as to be substantially symmetrical about the center thereof.

  Therefore, according to the present invention, the distance between the first inverted F-type antenna and the second inverted F-type antenna is ensured inside the miniaturized wireless communication apparatus, and the transmission / reception circuit board unit is connected to the first inverted F-type antenna. By disposing the antenna between the F-type antenna and the second inverted F-type antenna, it is possible to provide a radio communication apparatus including a diversity antenna that is less affected by the transmission / reception circuit board unit.

  FIG. 1 is a diagram showing a diversity antenna composed of a first inverted F-type antenna and a second inverted F-type antenna according to an embodiment of the present invention, and FIG. 2 relates to the embodiment of the present invention. FIG. 3 is an external perspective view showing a first inverted F-type antenna, FIG. 3 is an external perspective view showing a second inverted F-type antenna according to an embodiment of the present invention, and FIG. 4 is an embodiment of the present invention. It is a figure which shows the directivity pattern of the diversity antenna concerning. Hereinafter, embodiments of the present invention will be described with reference to FIGS. 1 to 4.

  FIG. 2 is an external perspective view showing the first inverted F-type antenna 10 of the present embodiment. The first inverted F-type antenna 10 is formed, for example, by cutting a metal plate into an appropriate shape and bending it. The first inverted F-type antenna 10 is provided substantially perpendicular to the first longitudinal conductor portion 11 on the first longitudinal conductor portion 11 and one of the side surfaces of the first longitudinal conductor portion 11. The first grounding conductor portion 12 and the first feeding conductor portion 13 provided on the other side surface of the first longitudinal conductor portion 11 substantially perpendicular to the first longitudinal conductor portion 11. .

  Further, the first inverted F-type antenna 10 includes a first printed circuit board 14 provided to face the first longitudinal conductor 11, and the first printed circuit board 14 includes a ground pattern 15 and a feeding point. 16 is disposed. The tip of the first grounding conductor 12 is electrically connected to the ground pattern 15 of the first printed circuit board 14 by soldering or the like, and the tip of the first power supply conductor 13 is The first printed circuit board 14 is electrically connected to the feeding point 16 by soldering or the like.

  The outer periphery of the first printed circuit board 14 has substantially the same length as the wavelength of the radio wave used. For example, if the frequency to be used is 2.4 GHz, the outer circumference is about 12 cm, and if the outer shape of the first printed circuit board 14 is a square, the size is about 3 cm.

  In an inverted F-type antenna that normally requires a wide ground, the outer circumference of the first printed circuit board 14 is set to have approximately the same length as the wavelength of the used radio wave, so that the radio wave is transmitted through the first longitudinal direction of the first printed circuit board 14. The directivity pattern of the first inverted F-type antenna 10 extends to the negative side of the vertical axis V as shown in FIG. The null point existing in the direction of the vertical axis V disappears and becomes nearly omnidirectional, and the difference between the gain of vertical polarization and the gain of horizontal polarization is reduced.

  As described above, in the embodiment of the present invention, the first inverted F-type antenna 10 is formed by cutting out and bending a metal plate into an appropriate shape, but the present invention is not limited to this, and the inverted F antenna is formed by other methods. A mold antenna may be formed.

  Moreover, although the external shape of the 1st printed circuit board 14 is a square, it is not limited to this, You may deform | transform a substantially square shape, a polygon, or one part.

  FIG. 3 is an external perspective view showing the second inverted F-type antenna 20 of the present embodiment. The second inverted F-type antenna 20 is formed, for example, by cutting a metal plate into an appropriate shape and bending it. The second inverted F-type antenna 20 is provided on the first longitudinal conductor portion 21 and one of the side surfaces of the second longitudinal conductor portion 21 so as to be substantially perpendicular to the second longitudinal conductor portion 21. The second grounding conductor portion 22 and the second feeding conductor portion 23 provided on the other side surface of the second longitudinal conductor portion 21 substantially perpendicularly to the second longitudinal conductor portion 21. .

  Further, the second inverted F-type antenna 20 includes a second printed circuit board 24 provided to face the second longitudinal conductor portion 21, and the second printed circuit board 24 includes a ground pattern 25 and a feeding point. 26 is arranged. The tip of the second grounding conductor 22 is electrically connected to the ground pattern 25 of the second printed circuit board 24 by soldering or the like, and the tip of the second feeding conductor 23 is The second printed circuit board 24 is electrically connected to the feeding point 26 by soldering or the like.

  The outer periphery of the second printed circuit board 24 has substantially the same length as the wavelength of the radio wave used. For example, if the frequency to be used is 2.4 GHz, the outer circumference is about 12 cm, and if the outer shape of the second printed circuit board 24 is a square, the size is about 3 cm.

  In an inverted F-type antenna that normally requires a wide ground, the outer circumference of the second printed circuit board 24 is set to be approximately the same length as the wavelength of the used radio wave, so that the radio wave is transmitted through the second longitudinal direction of the second printed circuit board 24. As shown in FIG. 4B, which will be described later, the directivity pattern of the second inverted F-type antenna 20 extends to the negative side of the vertical axis V as it goes around the back surface of the surface on which the conductor portion 21 is provided. The null point existing in the direction of the vertical axis V disappears and becomes nearly omnidirectional, and the difference between the gain of vertical polarization and the gain of horizontal polarization is reduced.

  As described above, in the embodiment of the present invention, the second inverted F-type antenna 20 is formed by cutting out and bending a metal plate into an appropriate shape. A mold antenna may be formed.

  The outer shape of the second printed circuit board 24 is a square, but the outer shape is not limited to this, and a substantially rectangular shape, a polygon, or a part thereof may be deformed.

  FIG. 1 is a diagram showing a diversity antenna 1 of the present embodiment. The diversity antenna 1 includes the first inverted F antenna 10 shown in FIG. 2 and the second inverted F antenna 20 shown in FIG. The first inverted F-type antenna 10 is the same as the description of FIG. 2, and the second inverted F-type antenna 20 is the same as the description of FIG. Therefore, the description here is omitted.

  The diversity antenna 1 of FIG. 1 includes a central axis X1 of the first longitudinal conductor portion 11 of the first inverted F-type antenna 10 and a central axis X2 of the second longitudinal conductor portion 21 of the second inverted F-type antenna 20. Are substantially perpendicular to each other, and the central axis Y1 of the first feeding conductor portion 13 of the first inverted F-type antenna 10 and the second feeding of the second inverted F-type antenna 20 The conductor part 23 is disposed so that the central axes Y2 thereof are substantially parallel to each other.

  In addition, the first printed circuit board 14 provided to face the first longitudinal conductor portion 11 of the first inverted F-type antenna 10 and the second longitudinal conductor portion 21 of the second inverted F-type antenna 20 The second printed circuit board 24 provided so as to be opposed is disposed so as to be substantially parallel to the second printed circuit board 24.

  In addition, the first printed circuit board 14 of the first inverted F-type antenna 10 and the second printed circuit board 24 of the second inverted F-type antenna 20 are arranged so as to face each other. The surface of the printed board on which the first longitudinal conductor portion 11 is provided and the surface of the second printed board on which the second longitudinal conductor portion 21 is provided are arranged so as to face each other.

  Further, the first longitudinal conductor portion 11 of the first inverted F-type antenna 10 is arranged so that the central axis X1 thereof is substantially vertical with the first feeding conductor portion 13 on the upper side, and the second inverted F-type antenna. The 20 second long conductor portions 21 have a central axis X2 arranged substantially horizontally.

  In addition, the second longitudinal conductor portion 21 of the second inverted F-type antenna 20 is disposed on the upper side of the horizontal central axis C <b> 1 of the second printed circuit board 24.

  FIG. 4 is a diagram showing a directivity pattern of the diversity antenna 1 of the present embodiment. FIG. 4A shows the first printed circuit board 14 in the first inverted F-type antenna 10 of FIG. 2 so that the first longitudinal conductor portion 11 is positioned below the first printed circuit board 14. Is a diagram showing a directivity pattern with respect to the vertical axis V in a state where the horizontal axis is horizontal, the directivity pattern with respect to vertical polarization is indicated by a solid line, and the directivity pattern with respect to horizontal polarization is indicated by a dotted line. FIG. 4B shows the second printed circuit board in the second inverted F-type antenna 20 of FIG. 3 so that the second longitudinal conductor portion 21 is positioned above the second printed circuit board 24. It is a figure which shows the directivity pattern of the vertical axis V reference in the state where 24 was leveled, the directivity pattern with respect to vertical polarization is shown as the continuous line, and the directivity pattern with respect to horizontal polarization is shown with the dotted line.

  Here, FIG. 8 showing the directivity of the conventional diversity antenna 50 is compared with FIG. 4 showing the directivity pattern of the diversity antenna 1 of the present embodiment. The directivity pattern of the conventional inverted F-type antenna 60 in FIG. 8A and the directivity pattern of the inverted F-type antenna 70 in FIG. The lower gain is smaller than the upper gain relative to the upper face of the casing 51 of the wireless communication apparatus in which the inverted F-type antenna 70 is disposed, and has a null point in the vertical axis V direction. Further, the gain of the horizontal polarization indicated by the dotted line is smaller than the gain of the vertical polarization indicated by the solid line.

  On the other hand, in the first inverted F-type antenna 10 of the present embodiment, the first printed circuit board 14 is placed so that the first longitudinal conductor portion 11 is positioned below the first printed circuit board 14. In FIG. 4A showing the directivity pattern in a horizontal state, the vertical gain and horizontal polarization are not significantly different from each other by comparing the upper and lower gains with reference to the first printed circuit board 14. The null point in the direction of the vertical axis V disappears and has a gain in all directions, that is, close to omnidirectionality. Further, comparing the gain of the vertically polarized wave indicated by the solid line and the gain of the horizontally polarized wave indicated by the dotted line, there is no significant difference as compared with the prior art.

  Further, in the second inverted F-type antenna 20 of the present embodiment, the second printed circuit board 24 is leveled so that the second longitudinal conductor portion 21 is positioned above the second printed circuit board 24. 4B showing the directivity pattern in FIG. 4B, the vertical gain and the vertical polarization are not significantly different from each other by comparing the upper and lower gains with reference to the second printed circuit board 24, and the vertical axis V direction. The null point disappears and gains in all directions, that is, close to omnidirectionality. Further, comparing the gain of the vertically polarized wave indicated by the solid line and the gain of the horizontally polarized wave indicated by the dotted line, there is no significant difference as compared with the prior art.

  Further, in FIG. 4A, the gain of horizontal polarization is larger than that of vertical polarization, and in FIG. 4B, the opposite is true, that is, the polarization directions that the two antennas are good at are different. It will be strong against the difference in polarization when operated as.

  FIG. 5 is a block diagram showing the internal circuit configuration of the wireless communication apparatus according to the embodiment of the present invention, and FIG. 6 is a perspective view showing the installation state of the diversity antenna inside the wireless communication apparatus according to the embodiment of the present invention. It is. Hereinafter, embodiments of the present invention will be described with reference to FIGS. 5 and 6. FIG. 5 is a block diagram illustrating an internal circuit configuration of the wireless communication device 2 according to the present embodiment. The wireless communication device 2 of the present embodiment shown in FIG. 5 has the following circuit configuration. The wireless communication device 2 includes a diversity antenna 1 and a transmission / reception circuit board unit 30. The transmission / reception circuit board unit 30 includes an input unit 31, an encoding circuit 32, a modulation circuit 33, a transmission circuit 34, a reception circuit 35, a demodulation circuit 36, a decoding circuit 37, and an output unit 38.

  The input unit 31 is connected to the input of the encoding circuit 32, the output of the encoding circuit 32 is connected to the input of the modulation circuit 33, the output of the modulation circuit 33 is connected to the input of the transmission circuit 34, and the output of the transmission circuit 34 Is connected to the diversity antenna 1. The diversity antenna 1 is connected to the input of the receiving circuit 35, the output of the receiving circuit 35 is connected to the input of the demodulating circuit 36, the output of the demodulating circuit 36 is connected to the input of the decoding circuit 37, and the decoding circuit 37 Are connected to the output unit 38.

  Next, the operation of the wireless communication apparatus 2 of the present embodiment in FIG. 5 will be described. Video data and audio data input from the input unit 31 are encoded by the encoding circuit 32. The encoded data signal is modulated with a carrier wave having a predetermined frequency (for example, 2.4 GHz band) by the modulation circuit 33, amplified by the transmission circuit 34, and radiated as a transmission signal from the diversity antenna 1.

  The received signal received by the diversity antenna 1 is amplified by the receiving circuit 35, and only a signal in a predetermined frequency (for example, 2.4 GHz) band is received by a filter circuit (not shown) provided in the receiving circuit 35. Input to the demodulation circuit 36. The demodulating circuit 36 performs demodulation by detecting the signal from the receiving circuit 35, and the demodulated signal is converted into video data and audio data by the decoding circuit 37 and output from the output unit 38 to the outside.

  FIG. 6 is a perspective view showing an installation state of the diversity antenna 1 inside the wireless communication device 2 of the present embodiment.

  The wireless communication device 2 in FIG. 6 includes the diversity antenna 1 in FIG. 1, a transmission / reception circuit board unit 30 having the internal circuit configuration in FIG. 5 to which the diversity antenna 1 is connected, and a cabinet 40.

  FIG. 6 shows a state in which the diversity antenna 1 and the transmission / reception circuit board unit 30 are installed inside the cabinet 40 as viewed from the lower side of the wireless communication device 2. In order to make the inside visible, a part of the cabinet 40 (a lower cabinet (not shown)) is removed.

  The first inverted F-type antenna 10 of FIG. 2 and the second inverted F-type antenna 20 of FIG. 3 constituting the diversity antenna 1 of FIG. 1 are centered on the transmission / reception circuit board unit 30 therebetween. It arrange | positions so that it may become substantially symmetrical.

  Further, the arrangement of the first inverted F-type antenna 10 of FIG. 2 and the second inverted F-type antenna 20 of FIG. 3 constituting the diversity antenna 1 of FIG. 1 is the same as the arrangement described in the diversity antenna 1 of FIG. The description is omitted here.

  As described above, in the embodiment of the present invention, the case where the wireless communication device 2 has the transmission / reception function has been described. However, the present invention is not limited to this, and the wireless communication device 2 may have only the transmission function or only the reception function.

These are figures which show the diversity antenna comprised by the 1st inverted F type antenna and 2nd inverted F type antenna concerning embodiment of this invention. These are the external appearance perspective views which show the 1st inverted F type antenna concerning embodiment of this invention. These are the external appearance perspective views which show the 2nd inverted F type antenna concerning embodiment of this invention. These are figures which show the directivity pattern of the diversity antenna concerning embodiment of this invention. These are block diagrams which show the internal circuit structure of the radio | wireless communication apparatus concerning embodiment of this invention. These are perspective views which show the installation state of the diversity antenna inside the radio | wireless communication apparatus concerning embodiment of this invention. These are the external appearance perspective views which show the conventional diversity antenna. These are figures which show the directivity pattern of the conventional diversity antenna.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Diversity antenna 2 Wireless communication apparatus 10 1st inverted F type antenna 11 1st longitudinal conductor part 12 1st grounding conductor part 13 1st electric power feeding conductor part 14 1st printed circuit board 15 Ground pattern (1st Printed circuit board)
16 Feeding point (feeding point of the first printed circuit board)
20 Second Inverted F Antenna 21 Second Longitudinal Conductor 22 Second Grounding Conductor 23 Second Feeding Conductor 24 Second Printed Circuit Board 25 Ground Pattern (Second Printed Circuit Board)
26 Feeding point (feeding point of the second printed circuit board)
DESCRIPTION OF SYMBOLS 30 Transmission / reception circuit board unit 31 Input part 32 Coding circuit 33 Modulation circuit 34 Transmission circuit 35 Reception circuit 36 Demodulation circuit 37 Decoding circuit 38 Output part 40 Cabinet

Claims (7)

A first metal plate formed by bending a single metal plate and provided on the first longitudinal conductor portion and one of the side surfaces of the first longitudinal conductor portion substantially perpendicularly to the first longitudinal conductor portion. 1st reverse F type which consists of one grounding conductor part and the 1st electric conductor part provided in the other side surface of the 1st longitudinal conductor part substantially perpendicularly with respect to the 1st longitudinal conductor part An antenna,
A second metal plate is formed by bending a single metal plate, and is provided on the second longitudinal conductor portion and one of the side surfaces of the second longitudinal conductor portion so as to be substantially perpendicular to the second longitudinal conductor portion. 2nd reverse F type which consists of 2 grounding conductor parts and the 2nd conductor part for electric power feeding provided in the other side surface of the 2nd longitudinal conductor part substantially perpendicularly with respect to the 2nd longitudinal conductor part A diversity antenna composed of an antenna,
The central axes of the first and second longitudinal conductor portions are substantially perpendicular to each other, and the central axes of the first and second feeding conductor portions are substantially parallel to each other, In addition, the first longitudinal conductor portion and the second longitudinal conductor portion are arranged with a sufficient space between the first and second inverted F antennas so that the first longitudinal conductor portion and the second longitudinal conductor portion are opposed to each other. Diversity antenna.   The first inverted F-type antenna includes a first printed circuit board, the first grounding conductor is electrically connected to a ground pattern of the first printed circuit board, and the first power feeding The conductor part for electrical connection is electrically connected to the feeding point of the first printed circuit board, the second inverted F-type antenna includes a second printed circuit board, and the second grounding conductor part is provided for the second printed circuit board. The second power supply conductor portion is electrically connected to a power supply point of the second printed circuit board, and is electrically connected to the ground pattern of the circuit board, and the first printed circuit board and the second printed circuit board The diversity antenna according to claim 1, wherein the antennas are arranged so as to be substantially parallel to each other.   3. The diversity antenna according to claim 2, wherein outer circumferences of the first printed circuit board and the second printed circuit board have substantially the same length as a wavelength of a radio wave to be used.   A surface of the first printed circuit board on which the first longitudinal conductor portion is provided with respect to a center of the first printed circuit board and the second printed circuit board facing each other; a second printed circuit board; 4. The diversity antenna according to claim 2, wherein the diversity antenna is disposed so as to face outward from a surface of the substrate on which the second longitudinal conductor portion is provided. 5.   The first longitudinal conductor portion of the first inverted F antenna is disposed substantially vertically with the first feeding conductor portion on the upper side, and the second longitudinal axis of the second inverted F antenna is the second of the second inverted F antenna. 5. The diversity antenna according to claim 2, wherein a central axis of each of the longitudinal conductors is arranged substantially horizontally.   The second inverted F-type antenna is arranged so that the second longitudinal conductor portion is located above the horizontal central axis of the second printed circuit board. The diversity antenna according to claim 5.   A wireless communication device comprising the diversity antenna according to any one of claims 1 to 6 and a transmission / reception circuit board unit to which the diversity antenna is connected, wherein the first inverted F antenna and the second antenna The inverted F-type antenna is arranged so as to be substantially symmetric with respect to the transmission / reception circuit board unit.

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