JP2008252158A - Antenna block, antenna device, and radio communication equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a compact and efficient antenna device capable of reducing an influence of a surrounding ground pattern. <P>SOLUTION: A first pad electrode 121 of an antenna block 100 is connected to a first land pattern 212, and a second pad electrode 122 is connected to a second land pattern 213. A first radiation conductor 123 formed on the first side of a substrate 110 is formed vertically to a ground surface at the farthest position from a third edge line 220c of the ground pattern in an antenna mount region 211, thus minimizing an influence to the first radiation conductor from the ground pattern 220. A recess 117 is formed on a bottom surface 112 at the side of a second side 114 in the substrate 110, and air having low permittivity is interposed between the first radiation conductor 123 and the third edge line 220c of the ground pattern, thus further suppressing deterioration in antenna characteristics caused by the influence of the grand pattern. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an antenna block and an antenna device using the same, and more particularly to a conductor pattern shape of a surface mount type antenna device. The present invention also relates to a wireless communication device configured using such an antenna device.

A small antenna device built in a small wireless communication device such as a cellular phone has attracted attention. This type of antenna device is required to be as small as possible and have a high antenna gain, and various structures have been proposed. For example, Patent Document 1 proposes an antenna device in which a feeding end side portion of a radiation electrode formed on the bottom surface of a rectangular parallelepiped base and an open end side portion formed on the top surface of the base are arranged to face each other. ing. According to this antenna device, the distance between the feeding end side portion and the open end side portion of the radiation electrode can be widened, and the coupling between the feeding side portion and the open end side portion of the radiation electrode is suppressed. Therefore, it is possible to prevent a decrease in antenna gain (deterioration of antenna characteristics) due to the coupling strength between the feeding end side portion and the open end side portion of the radiation electrode while reducing the size of the base. .
Japanese Patent No. 3788306

  In general, this type of antenna device is susceptible to the influence of the surrounding ground pattern. Therefore, it is necessary to reduce the influence as much as possible to prevent a decrease in antenna gain. However, in the conventional antenna device described above, the feeding end side portion and the open end side portion of the radiation electrode have an asymmetric structure, and either one portion is always close to the ground pattern, so that the influence of the ground pattern is not affected. There is a problem that the antenna characteristics deteriorate.

  The present invention has been made to solve the above-described problem, and an object of the present invention is to provide a small and highly efficient antenna device that can reduce the influence of the surrounding ground pattern. It is another object of the present invention to provide a small and high-performance wireless communication device configured using such an antenna device.

  The object of the present invention is to provide a base made of a dielectric or magnetic material, first and second pad electrodes formed at both ends in the longitudinal direction of the bottom surface of the base, and a first of the base parallel to the longitudinal direction. Formed on at least one of the first radiating conductor formed on the side surface and having both ends connected to the first and second pad electrodes, respectively, and the second side surface or the upper surface of the substrate facing the first side surface, And a second radiating conductor connected to the second pad electrode.

  According to the present invention, the first radiation conductor, which is the part most contributing to the emission of radio waves, is formed on the side surface of the base. Therefore, when the antenna device is mounted in an appropriate direction, the first radiation conductor Can be kept away from the ground pattern on the printed circuit board, and deterioration of antenna characteristics due to the influence of the ground pattern can be suppressed.

  That is, the above-described object of the present invention includes an antenna block and a printed circuit board having an antenna block mounting area. The antenna block is formed on a base made of a dielectric material or a magnetic material, and at both longitudinal ends of the bottom surface of the base. A first radiating conductor formed on the first side surface of the base parallel to the longitudinal direction and having both ends connected to the first and second pad electrodes, respectively, A printed circuit board comprising: a second radiating conductor formed on at least one of the second side surface or the upper surface of the base opposite to the first side surface and having one end connected to the second pad electrode; A power supply line connected to the electrode and a ground pattern provided around the antenna block mounting area, and the ground pattern is arranged in at least one direction around the antenna block mounting area. It is provided with an open area where the over down absent, the first radiation conductor is also achieved by an antenna apparatus characterized by facing the open region side.

  Thus, according to the present invention, the first radiating conductor, which is the main radiating conductor, is disposed away from the ground pattern and is disposed perpendicular to the ground plane. Thus, a small and highly efficient antenna device can be realized.

  In the present invention, the antenna block preferably further includes a recess formed in a part of the bottom surface on the second side surface side of the base. According to this, since the low dielectric constant air is interposed between the first radiation conductor and the ground pattern, it is possible to further suppress the deterioration of the antenna characteristics due to the influence of the ground pattern.

  The above object of the present invention is also achieved by a wireless communication device comprising the antenna device having the above characteristics.

  As described above, according to the present invention, it is possible to reduce the influence of the surrounding ground pattern, and to provide a small and highly efficient antenna block and antenna device. In addition, according to the present invention, a small and high-performance wireless communication device configured using such an antenna device can be provided.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 is a schematic perspective view showing a configuration of an antenna block 100 according to a preferred embodiment of the present invention, and FIG. 2 is a development view of the antenna block 100.

  As shown in FIGS. 1 and 2, the antenna block 100 includes a base 110 made of a dielectric and a plurality of conductor patterns provided on the surface of the base 110.

  The base 110 has a substantially rectangular parallelepiped shape in which the A direction is the longitudinal direction and the B direction is the width direction. The top surface 111 and the bottom surface 112 are parallel to both the A direction and the B direction, and are parallel to the A direction. The first side surface 113 and the second side surface 114 are orthogonal to the direction, and the third side surface 115 and the fourth side surface 116 are orthogonal to the A direction and parallel to the B direction. The size of the base 110 may be appropriately set according to the target antenna characteristics.

  Although it does not specifically limit as a material of the base | substrate 110, Ba-Nd-Ti type material (relative dielectric constant 80-120), Nd-Al-Ca-Ti type material (relative dielectric constant 43-46), Li—Al—Sr—Ti (relative permittivity 38 to 41), Ba—Ti based material (relative permittivity 34 to 36), Ba—Mg—W based material (relative permittivity 20 to 22), Mg—Ca— Ti-based materials (relative permittivity 19 to 21), sapphire (relative permittivity 9 to 10), alumina ceramics (relative permittivity 9 to 10), cordierite ceramics (relative permittivity 4 to 6), and the like can be used. . The base 110 is produced by firing these materials using a mold.

What is necessary is just to select a dielectric material suitably according to the target frequency. As the relative dielectric constant ε _r increases, a greater wavelength shortening effect can be obtained, so that the length of the radiation conductor can be shortened. However, this is not necessarily the case where the relative dielectric constant ε _r is large, and an appropriate value is obtained. Exists. Therefore, for example, when the target frequency is 1.575 GHz, it is preferable to use a material having a relative dielectric constant ε _r of about 20 to 25. According to this, the radiation conductor can be reduced in size while securing a sufficient gain. Preferred examples of the material having a relative dielectric constant ε _r of about 20 to 25 include Mg—Ca—Ti dielectric ceramics. As the Mg—Ca—Ti dielectric ceramic, it is particularly preferable to use a Mg—Ca—Ti dielectric ceramic containing TiO ₂ , MgO, CaO, MnO, and SiO ₂ .

  The base body 110 is provided with a concave portion 117 formed by hollowing out a part of the bottom surface 112 on the second side surface 114 side. Although details will be described later, the recess 117 is formed in order to improve the antenna characteristics, and is provided in a region on the base 110 where the conductor pattern is avoided. Note that “formed by being cut through” expresses the shape of the recess in an easy-to-understand manner, and does not intend to limit the processing method. Therefore, for example, the recess 117 can be formed from the beginning by powder molding.

  The conductor pattern on the substrate 110 includes first and second pad electrodes 121 and 122 formed on the bottom surface 112 of the substrate 110, a first radiation conductor 123 formed on the first side surface 113 of the substrate 110, and A second side surface 114 facing the first side surface 113 and a second radiation conductor 124 formed on the upper surface 111 are provided. These conductor patterns can be formed by applying an electrode paste material by a method such as screen printing or transfer and then baking under a predetermined temperature condition. Silver, silver-palladium, silver-platinum, copper, or the like can be used as the electrode paste material. In the present embodiment, the conductor pattern is not formed on the third and fourth side surfaces 115 and 116 of the base 110, but may be formed as necessary.

  The first and second pad electrodes 121 and 122 are conductor patterns for electrically and mechanically connecting the antenna block 100 to the printed circuit board, and are formed at both ends of the base 110 in the longitudinal direction. . Both the first and second pad electrodes 121 and 122 are formed over the entire surface in the width direction, thereby enabling connection with a first radiating conductor 123 and a second radiating conductor 124 described later. Therefore, the first and second pad electrodes 121 and 122 also contribute to antenna characteristics and function as part of the radiation conductor. Although details will be described later, when the antenna block 100 is mounted, the first pad electrode 121 is connected to the power supply line.

  The first radiating conductor 123 is the portion closest to the feeding point in the conductor pattern formed on the exposed surface of the base 110, and is the portion most contributing to radio wave radiation. The first radiation conductor 123 is formed on the entire surface of the first side surface 113 of the base 110. Thereby, one end of the first radiation conductor 123 is connected to the first pad electrode 121, and the other end is connected to the second pad electrode 122. As described above, since the first radiating conductor 123 is formed on the side surface of the base 110, when the antenna block 100 is mounted in an appropriate direction, the first radiating conductor 123 is removed from the ground pattern on the printed circuit board. The antenna characteristics can be kept away from each other, and deterioration of the antenna characteristics due to the influence of the ground pattern can be suppressed. Current path of one conductor pattern constituting the antenna

  The second radiation conductor 124 is a conductor pattern extending in the longitudinal direction of the base 110. One end of the second radiation conductor 124 is connected to the second pad electrode 122, and the other end is open. The second radiating conductor 124 has a first conductor portion 124a formed on the second side surface 114 of the base 110 and a second conductor portion 124b formed on the upper surface 111 of the base body. The width of the second conductor portion 124b is preferably substantially equal to the width of the first radiation conductor 123 in order to facilitate antenna design.

  With the above configuration, the first pad electrode 121, the first radiating conductor 123, the second pad electrode 122, and the second radiating conductor 124 constitute one continuous conductor pattern.

  FIG. 3 is a schematic perspective view showing an example of a pattern layout of the printed circuit board 200 on which the antenna block 100 is mounted.

  As shown in FIG. 3, on the surface of the printed circuit board 200, there are a clearance area 210 that is an insulating area provided near the outer periphery of the board, an antenna mounting area 211 provided in the clearance area 210, and a clearance area 210. A ground pattern 220 provided on the outside, first and second land patterns 212 and 213 provided on both ends of the antenna mounting region 211 in the longitudinal direction, and a feed line 214 connected to the first land pattern 212, respectively. Is provided. Further, a clearance area 230 that covers substantially the same area as the clearance area 210 on the front surface side is provided on the back surface of the printed circuit board 200. Further, various circuit components constituting the wireless communication device are mounted at appropriate positions on the front and back surfaces of the printed circuit board 200.

  In the present embodiment, three directions around the antenna mounting region 211 are surrounded by the ground pattern 220. That is, the antenna mounting area 211 is surrounded by the first and second edge lines 220a and 220b of the ground pattern orthogonal to the longitudinal direction and the third edge line 220c of the ground pattern parallel to the longitudinal direction. . The remaining one direction is an end of the printed circuit board 200, which is an area where no ground pattern exists (open area 240).

  The first and second land patterns 212 and 213 are conductor patterns provided corresponding to the first and second pad electrodes 121 and 122 of the antenna block 100, respectively. The first land pattern is provided on the first edge line 220a side of the ground pattern, and the second land pattern is provided on the second edge line 220b side. A power supply line 214 is connected to the first land pattern 212, and a matching circuit 215 including a series inductor 215 a and a parallel inductor 215 b is inserted on the power supply line 214. The antenna frequency can be adjusted by adjusting the element value of the matching circuit 215.

  The distance between the antenna mounting area 211 and the third edge line 220c of the ground pattern is preferably as narrow as possible as long as desired antenna characteristics can be obtained. This is because the smaller the width, the smaller the area occupied by the antenna, and the smaller the entire wireless communication device.

  FIG. 4 is a schematic perspective view showing a configuration of the antenna device 10 according to a preferred embodiment of the present invention, and shows a part of a wireless communication device using the antenna device 10 according to the present embodiment.

  As shown in FIG. 4, the antenna device 10 has the antenna block 100 mounted on a printed circuit board 200, and the first and second pad electrodes 121 and 122 of the antenna block 100 are first and second, respectively. The land patterns 212 and 123 are connected. At this time, the antenna block 100 is arranged such that the first radiation conductor 123 faces the open region 240 side. That is, the first radiating conductor 123 formed on the first side surface of the base body 110 faces the side opposite to the third edge line 220c side of the ground pattern parallel to the first radiating conductor 123 in the antenna mounting region 211. . Thus, since the first radiation conductor 123 is formed perpendicular to the ground plane at the position farthest from the third edge line 220c of the ground pattern, the ground pattern 220 becomes the first radiation conductor 123. The influence that it has can be minimized. In addition, a recess 117 is formed in the bottom surface 112 on the second side surface 114 side of the base 110, and air with a low dielectric constant is provided between the first radiation conductor 123 and the third edge line 220c of the ground pattern. Therefore, the deterioration of the antenna characteristics due to the influence of the ground pattern 220 can be further suppressed.

  As described above, according to the present embodiment, the first radiation conductor 123, which is the portion most contributing to radio wave radiation, is formed on the side surface of the base 110, and the first radiation conductor 123 is Since the layout is sufficiently separated from the edge line 220c of the ground pattern parallel to one radiation conductor 123 and escapes from the ground pattern 220 as much as possible, a small and highly efficient antenna device can be realized.

  Further, for example, when the first radiating conductor 123 is parallel to the ground plane, a portion far from the ground pattern and a portion close to the ground pattern are present in the same conductor pattern, and the entire first radiating conductor 123 is placed in the ground pattern. It is difficult to keep away from. However, if the first radiating conductor 123 is perpendicular to the ground plane as in the present embodiment, the entire first radiating conductor 123 can be moved away from the ground plane. Therefore, the influence of the ground pattern on the first radiation conductor 123 can be minimized.

  In addition, according to the present embodiment, the concave portion 117 formed by cutting a part of the bottom surface 112 on the second side surface 114 side of the base 110 is provided, and the first radiation conductor 123, the ground pattern 220, and the like are provided. Since air with a low dielectric constant is interposed between them, deterioration of antenna characteristics due to the influence of the ground pattern 220 can be further suppressed.

  Although the present invention has been described based on the preferred embodiments, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention. Needless to say, these are also included in the scope of the present invention.

  For example, in the above-described embodiment, the case where the first radiation conductor 123 is formed on the entire surface of the first side surface 113 of the base 110 has been described. However, the present invention is not limited to such a case. Alternatively, it may be partially formed on the first side surface 113. The second radiating conductor 124 includes a first conductor portion 124a formed on the second side surface 114 of the base 110 and a second conductor portion 124b formed on the upper surface 111 of the base body. The conductor pattern extending in the longitudinal direction may be provided only on the upper surface 111, or may be provided only on the second side surface 114.

  In the antenna device in each of the above embodiments, the base 110 has a rectangular parallelepiped shape, but it is not essential that the base 110 is a strict rectangular parallelepiped. For example, a taper for specifying the direction of the corner of the rectangular parallelepiped is provided. It may be provided.

  Further, in the above embodiment, the case where the three directions around the antenna mounting area 211 are surrounded by the ground pattern 220 has been described. However, the present invention is not limited to such a case. For example, the antenna mounting area The two directions of the antenna mounting region 211 may be surrounded by the ground pattern 220 by providing 211 at the corners of the printed circuit board 200. In this case, the other two directions are the end portions of the printed circuit board 200, which are open areas where no ground pattern exists. Even if the ground pattern has such a shape, if the first radiating conductor 123 is formed at a position farthest from the edge line of the ground pattern parallel to the first radiating conductor 123, the antenna characteristics are reduced. Can be good.

  Moreover, in the said embodiment, although the recessed part 117 provided in the bottom face 112 of the base | substrate 110 is comprised only by one piece, you may divide | segment into plurality. Further, instead of being provided on the second side surface 114 side of the base body 110, it may be provided at a substantially central portion of the bottom surface 112 of the base body 110.

In the above embodiment, a dielectric is used as the material of the base 110. However, a magnetic material having dielectricity may be used in addition to the dielectric. In this case, since a wavelength shortening effect of 1 / {(ε × μ) ^1/2 } is obtained, a large wavelength shortening effect can be obtained by using a magnetic material having a high magnetic permeability μ. Moreover, since μ / ε determines the impedance of the electrode, the impedance can be increased by using a magnetic material having a high μ. As a result, the Q of the antenna that is too high can be reduced to obtain wideband characteristics.

FIG. 1 is a schematic perspective view showing a configuration of an antenna block 100 according to a first embodiment of the present invention. FIG. 2 is a schematic perspective view showing the configuration of the antenna block 100. FIG. 3 is a schematic perspective view showing an example of a pattern layout of the printed circuit board 200 on which the antenna block 100 is mounted. FIG. 4 is a schematic perspective view showing the configuration of the antenna device 10 according to a preferred embodiment of the present invention.

Explanation of symbols

100 antenna device 110 base 111 upper surface 112 base bottom 113 base first side 114 base second side 115 base third side 116 base fourth side 117 recess 121 first pad electrode 122 2nd pad electrode 123 1st radiation conductor 124 2nd radiation conductor 124a Side surface conductor part 124b Upper surface conductor part 200 Printed circuit board 210 Clearance area 211 Antenna mounting area 212 1st land pattern 213 2nd land pattern 214 Feed line 215 Matching circuit 215a Series inductor 215b Parallel inductor 220 Ground pattern 220a Ground pattern first edge line 220b Ground pattern second edge line 220c Ground pattern third edge line 230 Clearance region 24 Open area

Claims (4)

A substrate made of a dielectric or magnetic material;
First and second pad electrodes formed at both longitudinal ends of the bottom surface of the substrate;
A first radiating conductor formed on a first side surface of the base parallel to the longitudinal direction and having both ends connected to the first and second pad electrodes, respectively;
An antenna comprising: a second radiation conductor formed on at least one of the second side surface or the upper surface of the base opposite to the first side surface, and having one end connected to the second pad electrode. block. An antenna block, and a printed circuit board having a mounting area of the antenna block,
The antenna block is
A substrate made of a dielectric or magnetic material;
First and second pad electrodes formed at both longitudinal ends of the bottom surface of the substrate;
A first radiating conductor formed on a first side surface of the base parallel to the longitudinal direction and having both ends connected to the first and second pad electrodes, respectively;
A second radiation conductor formed on at least one of the second side surface or the upper surface of the base opposite to the first side surface and having one end connected to the second pad electrode;
The printed circuit board is
A power supply line connected to the first pad electrode;
A ground pattern provided around the mounting area of the antenna block,
An open area in which the ground pattern does not exist is provided in at least one direction around the antenna block mounting area;
The antenna device according to claim 1, wherein the first radiating conductor faces the open region side.   The antenna device according to claim 2, further comprising a recess formed in a part of a bottom surface of the base on the second side surface side.   A wireless communication device comprising the antenna device according to claim 2.

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