JP2002335114A - Chip antenna and method of adjusting characteristics thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a chip antenna which can be changed adaptively and easily in resonance frequency, corresponding to the specifications demanded for antenna. SOLUTION: A chip antenna is equipped with an antenna conductor 1, which is formed of a previously patterned metal plate and embedded in a dielectric chip 2 or laminated on the surface of the dielectric chip 2, and a plurality of terminals 3 which are extracted out from the different parts of the antenna conductor 1 and protrude from the dielectric chip 2. Only the terminals, which are capable of setting up the desired resonance frequency, are selected from among the entire terminals, and the parts of the selected terminals extending from the dielectric chip 2 are cut in proper lengths, so as to make fine adjustment of the resonance frequency.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chip antenna whose resonance frequency can be adaptively set according to customer specifications, and a method of adjusting the characteristics of the chip antenna.

[0002]

[Related Background Art] Recently, an antenna conductor formed of a flat conductor or a meandering conductor has been embedded in a dielectric chip or provided on the surface of a dielectric chip as an antenna built in various information communication devices. Attention has been focused on stacked chip antennas. This type of chip antenna is realized as having an outer dimension of, for example, about 2 mm in height, 4 mm in width, and about 10 mm in length, and is used by being mounted on a printed wiring circuit board or the like.

[0003]

When a chip antenna is mounted on a wireless device such as a portable telephone, it is necessary that the chip antenna has a predetermined resonance frequency. Therefore, the required antenna specifications differ for each device to be mounted. In particular, its resonance frequency is tuned to the customer's application. However, re-designing the antenna conductor pattern in response to various customer requirements will inevitably require a great deal of expense. Adjusting the resonance frequency by trimming the antenna conductor has also been proposed. However, there is a problem that the trimming device is expensive and the adjustment (trimming) is troublesome.

The present invention has been made in view of such circumstances, and has as its object to provide a plurality of types having characteristics tuned according to various antenna specifications required for each customer from a common model. An object of the present invention is to provide a chip antenna that can easily realize the chip antenna described above.
Another object of the present invention is to provide a chip antenna characteristic adjustment method that can easily tune the antenna characteristics of a common model chip antenna according to various antenna specifications required for each customer. I do.

[0005]

In order to achieve the above-mentioned object, a chip antenna according to the present invention is made of, for example, a metal plate patterned in advance in a meander shape, and is embedded in a dielectric chip or provided on a surface of the dielectric chip. It is characterized by comprising an antenna conductor provided in a stacked manner, and a plurality of terminals which are respectively derived from different portions of the antenna conductor and project from the dielectric chip and are selectively used.

[0006] The resonance frequency of the chip antenna is selectively set by using only the terminal capable of setting a desired resonance frequency among the plurality of terminals. At this time, the resonance frequency may be finely adjusted by cutting a terminal which is selectively used among the plurality of terminals by adjusting a protruding length from the dielectric chip.

A method for adjusting the characteristics of a chip antenna according to the present invention includes a terminal derived from an antenna conductor made of a metal plate which is embedded in a dielectric chip or laminated on the surface of the dielectric chip. This is a method for adjusting the characteristics of a chip antenna, characterized in that the length of the terminal of the chip antenna protruding from the dielectric chip is adjusted so as to have desired characteristics and cut off.

That is, an antenna conductor made of a metal plate is provided by being embedded in a dielectric chip or laminated on the surface of the dielectric chip. The cutting is performed to adjust the resonance frequency.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. [Embodiment 1] FIG. 1 is a perspective view showing a schematic configuration of a chip antenna according to a first embodiment. Reference numeral 1 denotes an antenna conductor formed of a flat conductor plate (metal plate), and a dielectric having a predetermined size. It is provided embedded in the chip 2. 3 (3a,
Reference numerals 3b, 3c) denote a plurality (for example, three) of feed terminals which are respectively derived from different portions on one end side of the antenna conductor 1 and protrude from the end surface of the dielectric chip 2. These feed terminals 3 (3a, 3b, 3c) are selectively used in accordance with antenna specifications required for the chip antenna, particularly, a resonance frequency to be set. still,
Unused power supply terminals 3 may be cut off.

The antenna conductor 1 is formed by patterning a conductor plate by punching or etching, for example, as shown in FIG. The conductor pattern has a meandering shape. The feed terminals 3a, 3b, 3c are respectively connected to the first, second, and third folded portions A1, at one end of the antenna conductor 1.
The antenna conductors 1 are derived in parallel from A2 and A3, respectively, and have different distances (line lengths) from the other end B of the antenna conductor 1.

In FIG. 2, a two-dot chain line 4 indicates a region where the dielectric conductor 2 embeds the antenna conductor 1. In FIG. 2, the power supply terminals 3a,
Bridge portions 5a, 5b, which are extended 3b, 3c, respectively.
5C shows a state in which the antenna conductor 1 is supported on the outer frame 6 via a bridge portion 5d extending from the other end of the antenna conductor 1. The outer frame 6 holds the antenna conductor 1 against the dielectric injection molding die when the antenna conductor 1 is embedded by the dielectric chip 2.
For positioning without deviation. Each of the bridge portions 5a, 5b, to 5d is cut after the antenna conductor 1 is embedded in the dielectric chip 2. By cutting these bridge portions 5a, 5b, to 5d, the antenna conductor 1 embedded in the dielectric chip 2 is moved to the outer frame 6
Disconnected from

In particular, the bridge portions 5a, 5b, 5c extending from the power supply terminals 3a, 3b, 3c, respectively, are cut along the ends of the dielectric chip 2 except for, for example, selectively used power supply terminals. Only the bridge portion extending from the selectively used power supply terminal is cut by projecting the power supply terminal from the end of the dielectric chip 2 by a predetermined length. The bridge 5 d extending from the other end of the antenna conductor 1 is, for example, the dielectric chip 2.
Cut along the edge of the

[0013] Incidentally, the power supply terminal 3 selectively used.
(3a, 3b, 3c) are selected according to the tuning state required for the chip antenna (according to the resonance frequency to be set), and feed points A1, A2, A3 for the antenna conductor 1 are selected. Plays a role in deciding where in each of the folded portions described above. Such a power supply terminal 3
The effective antenna length of the antenna conductor 1 is determined by the selection of a, 3b, 3c and the selection and setting of the feeding points A1, A2, A3 for the antenna conductor 1, whereby the resonance frequency is selectively set. For example, the aforementioned power supply terminal 3a
Is set for a center frequency of 2.192 GHz, the power supply terminal 3b is set for a center frequency of 2.318 GHz, and the power supply terminal 3c is set for a center frequency of 2.330 GHz.

As described above, a plurality of power supply terminals 3 (3a, 3b,
According to the chip antenna configured with 3c), after the antenna conductor 1 is embedded in the dielectric chip 2 to form a chip antenna of a common model, the antenna specifications requested by a customer (customer) or the like, particularly, Unnecessary ones among the plurality of power supply terminals 3 (3a, 3b, 3c) are cut off according to the resonance frequency, and only the necessary power supply terminals 3 are left, so that the resonance frequency is easily tuned and supplied to the customer. can do. In addition, without changing the pattern of the antenna conductor 1 embedded in the dielectric chip 2 or trimming the antenna conductor 1 to adjust its resonance frequency, it is not necessary to simply use the plurality of feed terminals 3 (3a, 3b, 3c). A chip antenna having an antenna specification (resonance frequency) required by a customer or the like can be realized only by cutting off a simple antenna. Therefore, the manufacturing cost is kept low,
A chip antenna capable of adaptively responding to a plurality of types of tuning requests can be provided.

In the embodiment described above, of the plurality of power supply terminals 3a, 3b, 3c, those other than those selected according to the antenna specifications are cut off so as not to be used erroneously. However, when there is no possibility that the plurality of power supply terminals 3a, 3b, 3c may be used by mistake, it is also possible to omit the above-described cutting of unnecessary terminals and leave them as surplus terminals that are not used.

[Embodiment 2] FIG. 3 shows another example of a conductor pattern of an antenna conductor 1 used in a chip antenna according to a second embodiment. In this chip antenna, the antenna conductor 1 bent in a meandering shape is used.
Power supply terminals 3 (3a, 3b) are provided at two places on one end side of
Further, three short-circuiting terminals 8 are provided at a portion extending from the one end side.
(8a, 8b, 8c). These short-circuit terminals 8 (8a, 8b, 8c) are provided at predetermined intervals in the extension direction. At the other end of the antenna conductor 1, a fixing terminal 9 is provided. Other configurations are the same as those of the above-described first embodiment, and a description thereof will be omitted.

According to the chip antenna having such a structure, power is supplied by selectively using one of the power supply terminals 3 (3a, 3b) to meet the antenna specifications in the short-circuit terminal 8 (8a, 8b, 8c). The antenna characteristic is tuned by electrically connecting the one selected accordingly to the ground plane of the mounting board. Therefore, the power supply terminal 3 (3a,
By selecting 3b) and selecting the short-circuit terminal 8 (8a, 8b, 8c), the antenna characteristics (resonance frequency) of the chip antenna can be easily fine-tuned.

[Embodiment 3] FIG. 4 is for describing an embodiment of a method for adjusting the characteristics of a chip antenna.
This chip antenna is roughly connected to an antenna conductor 1 embedded in a dielectric chip 2, a feed terminal 3 connected to one end of the antenna conductor 1, and connected to the other end of the antenna conductor 1. And an open-side terminal 7. In addition, the antenna conductor 1, the power supply terminal 3, and the open-side terminal 7 are formed of one metal conductor plate.

Incidentally, this chip antenna is manufactured as follows. That is, first, a metal plate is punched to manufacture the conductor pattern shown in FIG. The conductor pattern has a structure in which the antenna conductor 1, the power supply terminal 3, and the open-side terminal 7 are connected to the outer frame 6 via bridge portions 5 e and 5 f, 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 is set to a sufficient length in consideration of a tuning process described later. The open-side terminal 4 and the bridge portion 5f are also formed to have the same width, and their lengths are set sufficiently long.

Thereafter, the conductor pattern is set in a mold, and a dielectric is injection-molded to embed the antenna conductor 1 in the dielectric chip 2. Thereafter, a portion of the conductor pattern extending from the power supply terminal 3 to the bridge 5e and a portion extending from the open side terminal 7 to the bridge portion 5f are cut off, and the portion connected to the antenna conductor 1 is cut into the power supply terminal 3 and the open side terminal 7. And

In this cutting step, the chip antenna manufactured here is brought into the tuning state desired by the customer or the like (customer) so that the cutting position C1,
, And cutting positions D1, D2,
Select each. That is, the length of the power supply terminal 3 and the length of the open-side terminal 7 and the length of protrusion of the terminals 3 and 7 from the dielectric chip 2 are adjusted.

According to the method of manufacturing the chip antenna executed as described above, when cutting the conductor pattern formed from the metal plate, the lengths of the feed terminal 3 and the open-side terminal 7 are adjusted, respectively. Since tuning can be performed, if a model as one common chip antenna is made, only the cutting positions of the power supply terminal 3 and the open side terminal 7 are changed according to customer specifications,
A chip antenna having characteristics tuned according to the customer specification can be easily manufactured.

In the above-described structure, the antenna conductor 1
In addition, since 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 is hardly deformed. (Resonance frequency) can be stably maintained. Therefore, there is an advantage that the chip antenna can be stably used for a long time unless an undesired external force is applied to the chip antenna.

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. Further, the open side terminal 7 can be used as a fixing terminal for fixing the chip antenna to a mounting board. Open side terminal 7
May not be provided at all. Further, as for the cutting step for adjusting the characteristic, it is of course possible to cut out the antenna conductor 1 from the conductor pattern and then to execute the cutting step as a separate step.

By the way, one power supply terminal 3 is left and another power supply terminal 3
When mounting the chip antenna with the cut-off on the printed wiring circuit board, the leading end side of the power supply terminal 3 is appropriately cut off according to the mounting state to adjust the protruding length from the dielectric chip 2, whereby the resonance frequency is adjusted. May be finely adjusted. In this case, the power supply terminal 3 may be left longer in advance, and its resonance frequency may be adjusted by cutting off the tip of the power supply terminal 3 while gradually reducing the protruding length of the power supply terminal 3. In addition, such a power supply terminal 3
Instead of adjusting the length of the antenna conductor 1, for example, a conductor portion extending from the other end of the antenna conductor 1 as the bridge portion 5d is left as an adjustment terminal, and the length of the adjustment terminal is adjusted to reduce the resonance frequency. Adjusting is also useful.

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. By adjusting the bending shape at this time, it is also possible to shorten the length of protrusion of the terminals 3 and 7 from the dielectric chip 2. By processing the length of the power supply terminals 3 and the like protruding from the dielectric chip 2 in this manner, the mounting state of the antenna chip on the printed wiring circuit board 10 can be made more compact.

[Others] By the way, as described above, unnecessary ones of the plurality of power supply terminals 3 are cut off, and furthermore, the resonance frequency is selectively set by adjusting the length of the adjustment terminals protruding from the dielectric chip 2. In doing so, for example, a cutting machine as shown in FIG. 7 may be used.

This cutting machine embeds the antenna conductor 1 in the dielectric chip 2 using a molding device, and then cuts the above-mentioned bridge portions 5a, 5b, 5c, 5d respectively, and cuts the chip antenna from the outer frame 6 to the chip antenna. The upper mold 22 is used when cutting off, and includes, for example, a lower mold 21 serving as a base, and an upper mold 22 that is provided to be vertically movable in opposition to the lower mold 21 and is pressed from above by a press machine. . A pair of upper and lower dies whose cutting portions (cutting positions) are set in advance in the lower die 21 and the upper die 22 in accordance with the power supply terminal 3 to be cut or the power supply terminal 3 or the open side terminal 7 whose length is adjusted. Are mounted respectively. Then, the antenna chips indicated by the outer frame 6 described above are sandwiched between these replacement pieces 23, 24, and the cutting machine is operated to thereby form the bridge portions 5a, 5b, 5c, 5d.
May be cut at once.

By the way, the pair of replacement pieces 23, 24
A plurality of types are prepared in advance according to a plurality of types of antenna specifications, and are selectively mounted on the lower die 21 and the upper die 22 according to the specified antenna specifications. Therefore, by simply selecting the pair of replacement pieces 23 and 24 according to the antenna specifications, unnecessary feed terminals 3 are cut off as described above, and the antenna chip whose terminal 3, 7 length is adjusted, that is, the resonance frequency is adjusted. (Tuned) antenna chips can be easily manufactured.

The present invention is not limited to the above embodiment. For example, the antenna conductor 1 is not limited to a meandering meandering line, but may be a flat microstrip antenna. In the embodiment, three power supply terminals 3 (3a,
3b, 3c), and described that two unnecessary power supply terminals are cut off. However, two or four or more power supply terminals 3 are provided, and only one power supply terminal to be used is used, and another power supply terminal is used. You may make it cut off. Furthermore, various modifications can be made to the locations where the power supply terminals 3a, 3b, 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.

For the dielectric chip 2, for example, P
PS (polyphenylene sulfide) and BaO-Nd ₂
A mixture of O ₃ -TiO ₂ ceramic powders can be used. The dielectric constant depends on the antenna specifications, but may be, for example, about [20]. In addition, the present invention can be variously modified and implemented without departing from the gist thereof.

[0032]

As described above, according to the present invention, 1
A chip antenna adaptively coping with various antenna specifications from one common model can be manufactured at low cost, and its characteristics can be easily tuned according to the demands of customers and the like. The effect is achieved.

[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 the structure of an antenna conductor used for the chip antenna shown in FIG. 1 and an outer frame supporting 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 illustrating an embodiment of a method for adjusting the characteristics of a chip antenna.

FIG. 5 is a diagram showing an example of adjusting a cutting position of a terminal in a method for adjusting the characteristics of a chip antenna.

FIG. 6 is a diagram showing an example of mounting a chip antenna on a printed wiring circuit board.

FIG. 7 is a diagram showing an example of a cutting machine used for selectively cutting a power supply terminal and adjusting the length of the power supply terminal.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Antenna conductor 2 Dielectric chip 3, 3a, 3b, 3c Feeding terminal 4 Antenna conductor embedding area by dielectric chip 5a, 5b, 5c, 5d Bridge section 6 Outer frame 7 Open side terminal 8a, 8b, 8c, 8d Short-circuit terminal 10 Printed wiring circuit board 21 Lower mold 22 Upper mold 23,24 Replacement piece (cutter)

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Kennori Waki 2-6-1 Marunouchi, Chiyoda-ku, Tokyo Furukawa Electric Co., Ltd. F-term (reference) 5J046 AA02 AA09 AB06 AB13 PA04 PA07 QA02 5J047 AA02 AA09 AB13 FD01

Claims (4)

[Claims] An antenna conductor made of a metal plate embedded in a dielectric chip or laminated on the surface of a dielectric chip, and each of the antenna conductors is led out from a different part of the antenna conductor and protrudes from the dielectric chip. And a plurality of terminals selectively used. 2. The chip antenna according to claim 1, wherein the plurality of terminals are feed terminals for the antenna conductor. 3. Adjusting the characteristics of a chip antenna having a metal plate antenna conductor embedded in a dielectric chip or laminated on the surface of the dielectric chip and a terminal derived from the antenna conductor. A method of adjusting the characteristics of a chip antenna, comprising: adjusting the length of the terminal of the chip antenna from the dielectric chip so as to have desired characteristics; and cutting the terminal. 4. The method according to claim 3, wherein the terminal is a power supply terminal for the antenna conductor or a terminal provided on an open side.