JP4514361B2 - Chip antenna and its characteristic adjustment method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a chip antenna capable of adaptively setting a resonance frequency according to customer specifications and a method for adjusting the characteristics thereof.
[0002]
[Related background]
Recently, chip antennas that have been embedded in dielectric chips or laminated on the surface of dielectric chips have attracted attention as antennas built into various information and communication equipment, such as flat conductors or meandering conductors. Has been. This type of chip antenna is realized, for example, as having an outer dimension of about 2 mm in height, 4 mm in width, and 10 mm in length, and is used by being mounted on a printed circuit board or the like.
[0003]
[Problems to be solved by the invention]
By the way, since the chip antenna is required to have a predetermined resonance frequency when mounted on a wireless device such as a mobile phone, the required antenna specifications are different for each mounted device. In particular, the resonance frequency is tuned according to the application at the customer site. However, it cannot be denied that a great deal of cost is required to redesign the antenna conductor pattern in accordance with various customer requirements. It has also been proposed to adjust the resonance frequency by trimming the antenna conductor, but there is a problem that the trimming apparatus is expensive and the adjustment (trimming) takes time.
[0004]
The present invention has been made in consideration of such circumstances, and the object thereof is a plurality of types of chip antennas having characteristics tuned according to various antenna specifications required for each customer from a common model. It is an object of the present invention to provide a chip antenna that can easily realize the above.
It is another object of the present invention to provide a chip antenna characteristic adjustment method capable of easily tuning the antenna characteristics of a common model chip antenna according to various antenna specifications required for each customer. To do.
[0005]
[Means for Solving the Problems]
The chip antenna according to the present invention to achieve the above-mentioned object is made of, for example, a metal plate previously patterned in a meander shape, embedded in a dielectric chip, or laminated on the surface of the dielectric chip, and an antenna conductor, The antenna conductor includes a plurality of terminals which are respectively derived from different portions of the antenna conductor and protrude from the dielectric chip and selectively used.
[0006]
The resonance frequency of the chip antenna is selectively set by using only a terminal capable of setting a desired resonance frequency among the plurality of terminals. At this time, the resonant frequency may be finely adjusted by cutting the selectively used terminals of the plurality of terminals by adjusting the protruding length from the dielectric chip.
[0007]
The chip antenna characteristic adjusting method according to the present invention includes a chip antenna having a terminal derived from an antenna conductor made of a metal plate embedded in a dielectric chip or laminated on the surface of the dielectric chip. A method for adjusting the characteristics, characterized in that the protruding length of the terminal of the chip antenna from the dielectric chip is adjusted and cut so as to have a desired characteristic.
[0008]
That is, an antenna conductor made of a metal plate is embedded in the dielectric chip or laminated on the surface of the dielectric chip, and the protruding length of the terminal derived from the antenna conductor from the dielectric chip is adjusted and cut. Thus, the resonance frequency is adjusted.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[Embodiment 1]
FIG. 1 is a perspective view showing a schematic configuration of the chip antenna according to the first embodiment. Reference numeral 1 denotes an antenna conductor made of a flat conductor plate (metal plate), which is embedded in a dielectric chip 2 having a predetermined size. Provided. Reference numerals 3 (3 a, 3 b, 3 c) denote a plurality of (for example, three) feeding terminals that are respectively led out from different portions on one end side of the antenna conductor 1 and protruded from the end face of the dielectric chip 2. . These feed terminals 3 (3a, 3b, 3c) are selectively used according to the antenna specifications required for the chip antenna, particularly the resonance frequency to be set. In addition, you may make it cut off the electric power feeding terminal 3 which is not used.
[0010]
Incidentally, the antenna conductor 1 is obtained by, for example, patterning a conductor plate by punching or etching as shown in FIG. 2, and meanders in a meandering manner in which lines are provided in parallel at a predetermined pitch through folded portions over several turns. Form a conductor pattern. The feeding terminals 3a, 3b and 3c are led out in parallel from the first, second and third folded portions A1, A2 and A3 on one end side of the antenna conductor 1, respectively. The distance (line length) from the other end side B is different.
[0011]
In FIG. 2, a two-dot chain line 4 indicates a region where the antenna conductor 1 is embedded by the dielectric chip 2. In FIG. 2, the antenna conductor is connected via bridge portions 5a, 5b, and 5c obtained by extending the power supply terminals 3a, 3b, and 3c, and a bridge portion 5d extended from the other end of the antenna conductor 1, respectively. 1 shows a state in which 1 is supported by an outer frame 6. The outer frame 6 is for positioning the antenna conductor 1 with respect to the dielectric injection mold when the antenna conductor 1 is embedded by the dielectric chip 2. The bridge portions 5a, 5b, to 5d are cut after the antenna conductor 1 is embedded with the dielectric chip 2. The antenna conductor 1 embedded in the dielectric chip 2 is separated from the outer frame frame 6 by cutting the bridge portions 5a, 5b, to 5d.
[0012]
In particular, the bridge portions 5a, 5b, and 5c extending from the power supply terminals 3a, 3b, and 3c are cut along the ends of the dielectric chip 2 except for the power supply terminals that are selectively used, for example. Only the bridge portion extending from the power supply terminal used in general is cut by projecting the power supply terminal from the end of the dielectric chip 2 by a predetermined length. Further, the bridge portion 5d provided to extend from the other end side of the antenna conductor 1 is cut along the end portion of the dielectric chip 2, for example.
[0013]
Incidentally, the power supply terminal 3 (3a, 3b, 3c) used selectively is selected according to the tuning state required for the chip antenna (according to the resonance frequency to be set). It plays a role of determining where the feeding points A1, A2, and A3 for the conductor 1 are located in each of the folded portions described above. The effective antenna length of the antenna conductor 1 is determined by the selection of the feed terminals 3a, 3b, 3c and the selection of the feed points A1, A2, A3 for the antenna conductor 1, and the resonance frequency thereof is selectively set. Is done. For example, the above-described feeding terminal 3a is set for the center frequency 2.192 GHz, the feeding terminal 3b is set for the center frequency 2.318 GHz, and the feeding terminal 3c is set for the center frequency 2.330 GHz.
[0014]
As described above, according to the chip antenna including the plurality of power supply terminals 3 (3a, 3b, 3c) used by cutting off unnecessary power supply terminals, the antenna conductor 1 is embedded in the dielectric chip 2. After forming the common model chip antenna, the antenna specifications required by customers (customers), etc., especially unnecessary ones in the plurality of feed terminals 3 (3a, 3b, 3c) are cut off according to the resonance frequency, By leaving only the necessary power supply terminal 3, the resonance frequency can be easily tuned and supplied to the customer. In addition, the antenna conductor 1 embedded in the dielectric chip 2 does not need to be changed, or the antenna conductor 1 is trimmed to adjust its resonance frequency, and is simply unnecessary in the plurality of power supply terminals 3 (3a, 3b, 3c). A chip antenna having an antenna specification (resonant frequency) requested by a customer or the like can be realized simply by cutting off the object. Therefore, it is possible to provide a chip antenna that can keep the manufacturing cost low and can adaptively respond to a plurality of kinds of tuning requests.
[0015]
In the above-described embodiment, the power supply terminals 3a, 3b, and 3c other than those selected in accordance with the antenna specifications are cut off so as not to be used accidentally. However, when there is no possibility that the plurality of power supply terminals 3a, 3b, and 3c are erroneously used, it is possible to omit the above-described unnecessary terminal cut-off and leave it as an unused unused terminal.
[0016]
[Embodiment 2]
FIG. 3 shows another example of the conductor pattern of the antenna conductor 1 used in the chip antenna according to the second embodiment. In this chip antenna, feed terminals 3 (3a, 3b) are provided at two locations on one end side of the antenna conductor 1 bent in a meander shape, and three shorting terminals 8 (8a, 8b, 8c). These shorting terminals 8 (8a, 8b, 8c) are provided at predetermined intervals in the extending direction. A fixing terminal 9 is provided on the other end side of the antenna conductor 1. Since other configurations are the same as those of the first embodiment described above, description thereof is omitted.
[0017]
According to the chip antenna having such a structure, power is fed selectively using one of the feed terminals 3 (3a, 3b), and selected according to the antenna specifications in the short-circuit terminals 8 (8a, 8b, 8c). The antenna characteristics are tuned by electrically connecting one of them to the ground plane of the mounting board. Therefore, the antenna characteristics (resonance frequency) of the chip antenna can be easily finely tuned (tuned) by selecting the feeding terminal 3 (3a, 3b) and selecting the shorting terminal 8 (8a, 8b, 8c). .
[0018]
[Embodiment 3]
FIG. 4 is a view for explaining an embodiment of a characteristic adjustment method for a chip antenna. The chip antenna is schematically connected to the antenna conductor 1 embedded in the dielectric chip 2, the feed terminal 3 connected to one end side of the antenna conductor 1, and the other end side of the antenna conductor 1. And an open-side terminal 7. The antenna conductor 1, the feeding terminal 3, and the open side terminal 7 are formed by a single metal conductor plate.
[0019]
Incidentally, this chip antenna is manufactured as follows. That is, first, a metal plate is punched to produce a conductor pattern shown in FIG. This conductor pattern has a structure in which the antenna conductor 1, the feeding terminal 3, and the open-side terminal 7 are connected to the outer frame 6 via bridge portions 5e and 5f, respectively. In this conductor pattern, the power supply terminal 3 and the bridge portion 5e are formed to have the same width, and the length thereof is set as a sufficiently long length in consideration of a tuning process described later. The open terminal 4 and the bridge portion 5f are also formed to have the same width, and the length thereof is set sufficiently long.
[0020]
Thereafter, the conductor pattern is set in a mold, a dielectric is injection molded, and the antenna conductor 1 is embedded in the dielectric chip 2. Thereafter, a portion from the power supply terminal 3 of the conductor pattern to the bridge 5e and a portion from the open-side terminal 7 to the bridge portion 5f are cut, respectively, and the portions connected to the antenna conductor 1 are connected to the feed terminal 3 and the open-side terminal 7 respectively. And
[0021]
In this cutting step, the cutting positions C1, C2,... On the power supply terminal 3 side and the open side terminal 7 side are set so that the chip antenna manufactured here is in the tuning state desired by the customer (customer). Cutting positions D1, D2,... Are selected respectively. In other words, the lengths of the power supply terminal 3 and the open-side terminal 7 and the protruding lengths of the terminals 3 and 7 from the dielectric chip 2 are adjusted.
[0022]
According to the chip antenna manufacturing method executed in this way, when cutting a conductor pattern formed from a metal plate, tuning is performed by adjusting the lengths of the feed terminal 3 and the open terminal 7 respectively. Therefore, if a model as one common chip antenna is made, then the cutting position of the feeding terminal 3 and the open-side terminal 7 can be changed according to the customer specifications, and the customer specifications can be changed. A chip antenna with tuned characteristics can be easily manufactured.
[0023]
In the structure described above, the antenna conductor 1 and the terminals 3 and 7 are made of a metal plate, and the protruding portion from the dielectric chip 2 is stable in strength and hardly deformed. If the resonance frequency is set, the antenna characteristic (resonance frequency) can be stably maintained. Therefore, unless an unintentional external force is applied to the chip antenna, there is an advantage that the chip antenna can be used stably over a long period of time.
[0024]
In this example, the power supply terminal 3 and the open-side terminal 7 are used for characteristic adjustment, but only one of them may be used for characteristic adjustment. The open-side terminal 7 can be used as a fixing terminal for fixing the chip antenna to the mounting substrate. Moreover, it is good also as a structure which does not provide the open side terminal 7 at all. Furthermore, the cutting process for adjusting the characteristics can of course be performed as a separate process after the antenna conductor 1 is cut out from the conductor pattern.
[0025]
By the way, when mounting a chip antenna with one power supply terminal 3 cut off from the other power supply terminal 3 as in the above-described chip antenna embodiment on a printed circuit board, the power supply terminal is selected according to the mounting state. 3 may be appropriately cut off to adjust the protruding length from the dielectric chip 2, thereby finely adjusting the resonance frequency. In this case, the power supply terminal 3 is left in advance, and the resonance frequency thereof may be adjusted while the protrusion length of the power supply terminal 3 is gradually shortened by cutting the tip. Further, instead of adjusting the length of the feeding terminal 3 as described above, for example, a conductor portion extending as the bridge portion 5d from the other end side of the antenna conductor 1 is left as an adjustment terminal, and the length of the adjustment terminal is adjusted. It is also useful to finely adjust the resonance frequency.
[0026]
Further, the terminals 3 and 7 of the antenna chip mounted on the printed circuit board 10 are bent into a “Z” shape or the like as shown in FIG. 6, for example, and connected to the conductor portion of the printed circuit board 10. It is also possible to shorten the length of protrusion of the terminals 3 and 7 from the dielectric chip 2 by adjusting the bending shape. By processing the protruding length of the power supply terminal 3 and the like from the dielectric chip 2 in this way, the mounting state of the antenna chip on the printed circuit board 10 can be made more compact.
[0027]
[Others]
By the way, when the unnecessary one of the plurality of power supply terminals 3 is cut off as described above, or the resonance frequency is selectively set by adjusting the protruding length of the adjustment terminal from the dielectric chip 2, for example, FIG. A cutting machine as shown in FIG.
[0028]
In this cutting machine, when the antenna conductor 1 is embedded with the dielectric chip 2 using a molding device, the above-described bridge portions 5a, 5b, 5c, and 5d are cut to separate the chip antenna from the outer frame frame 6. For example, a lower die 21 that forms a base and an upper die 22 that is provided so as to be movable up and down facing the lower die 21 and to which a pressing force is applied from above by a press machine. In such a lower mold 21 and an upper mold 22, a pair of upper and lower portions whose cutting portions (cutter positions) are set in advance according to the power supply terminal 3 to be cut or the length-adjusted power supply terminal 3 or the open-side terminal 7. The replacement pieces 23 and 24 are mounted. Then, the bridge chip 5a, 5b, 5c, 5d is cut at a time by sandwiching the antenna chip instructed by the outer frame 6 described above between these replacement pieces 23, 24 and operating the cutting machine. You can do it.
[0029]
Incidentally, the pair of replacement pieces 23 and 24 are prepared in advance for a plurality of types as those corresponding to a plurality of types of antenna specifications, respectively, and selectively with the lower mold 21 according to the designated antenna specifications. Used by attaching to the upper mold 22. Therefore, by simply selecting a pair of replacement pieces 23 and 24 according to the antenna specifications, the antenna chip with the unnecessary feed terminals 3 cut off and the lengths of the terminals 3 and 7 adjusted as described above, that is, the resonance frequency is adjusted. (Tuned) antenna chip can be easily manufactured.
[0030]
The present invention is not limited to the embodiment described above. For example, the antenna conductor 1 is not limited to one having a meandering meandering line, but may be one having a flat microstrip antenna. In the embodiment, three power supply terminals 3 (3a, 3b, 3c) are provided and two unnecessary power supply terminals are cut off. However, two or four or more power supply terminals 3 are provided and used. You may make it cut off other power supply terminals, leaving only one power supply terminal. Further, various modifications can be made to the portions where the power supply terminals 3a, 3b, and 3c are taken out. The present invention can be applied not only to a chip antenna having a structure in which the antenna conductor 1 is embedded in the dielectric chip 2 but also to a chip antenna having a structure in which the antenna conductor 1 is laminated on the surface of the dielectric chip 2.
[0031]
As the dielectric chip 2, for example, PPS (polyphenylene sulfide) mixed with BaO—Nd ₂ O ₃ —TiO ₂ ceramic powder may be used. As for the dielectric constant, although it depends on the antenna specification, for example, a dielectric constant of about [20] may be used. In addition, the present invention can be variously modified and implemented without departing from the scope of the invention.
[0032]
【The invention's effect】
As described above, according to the present invention, it is possible to inexpensively manufacture a chip antenna that adaptively copes with various antenna specifications from a single common model, and the characteristics thereof can be easily met according to requests from customers and the like. It is possible to achieve great effects in practice, such as being able to be tuned.
[Brief description of the drawings]
FIG. 1 is a perspective view showing a schematic configuration of a chip antenna according to an embodiment of the present invention.
FIG. 2 is a diagram showing an antenna conductor used in the chip antenna shown in FIG. 1 and a structure of an outer frame frame that supports the antenna conductor.
FIG. 3 is a diagram showing another example of an antenna conductor used for a chip antenna.
FIG. 4 is a diagram for explaining an embodiment of a characteristic adjustment method for a chip antenna.
FIG. 5 is a diagram showing an example of adjusting the cutting position of the terminal in the chip antenna characteristic adjusting method;
FIG. 6 is a view showing an example of mounting a chip antenna on a printed circuit board.
FIG. 7 is a diagram illustrating an example of a cutting machine used for selective cutting of a power feeding terminal and length adjustment of the power feeding terminal.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Antenna conductor 2 Dielectric chip | tip 3,3a, 3b, 3c Feeding terminal 4 Embedded area | region 5a, 5b, 5c, 5d of antenna conductor by dielectric chip Bridge part 6 Outer frame frame 7 Open side terminal 8a, 8b, 8c, 8d Short-circuit terminal 10 Printed circuit board 21 Lower mold 22 Upper mold 23, 24 Replacement piece (cutter)

Claims (3)

An antenna conductor made of a metal plate embedded in a dielectric chip or laminated on the surface of the dielectric chip, and each antenna conductor is derived from a different part of the antenna conductor and protrudes from the dielectric chip for selective use. A chip antenna , wherein the plurality of terminals are power supply terminals for the antenna conductor . An antenna conductor made of a metal plate embedded in a dielectric chip or laminated on the surface of the dielectric chip, and each antenna conductor is derived from a different part of the antenna conductor and protrudes from the dielectric chip for selective use. a method of adjusting the characteristics of the chip antenna and a plurality of terminals that are to from the plurality of terminals in the chip antenna, and selects the used terminal so that the characteristics of the desired Chip antenna characteristic adjustment method. 3. The chip antenna characteristic adjustment method according to claim 2, wherein at least one unnecessary terminal other than the selected use terminal is cut out of the plurality of terminals.

Images