JP2003017922A - Method for manufacturing dielectric antenna - Google Patents

Abstract

PROBLEM TO BE SOLVED: To drastically improve the manufacturing yield of a dielectric antenna by obtaining a desired center frequency and a desired impedance through simple trimming. SOLUTION: In the method for manufacturing the dielectric antenna 10, that comprises a process of trimming an antenna pattern 14 formed to a dielectric substrate 12, when the width W1 of a 1st line 30 is made thin, the dielectric antenna can be adjusted to have a high impedance (in the case of the antenna in a parallel resonance mode) and a low center frequency, when the width W2 of a 2nd line 32 is made thin, the dielectric antenna can be adjusted to have a low center frequency without almost changing the impedance, and when the widths W3, W4 of 3rd and 4th lines 34, 36 are made thin, the dielectric antenna can be adjusted to have a low impedance (in the case of the antenna in a parallel resonance mode) and a low center frequency.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a dielectric antenna in which an antenna pattern made of an electrode film is formed on a dielectric substrate.

[0002]

2. Description of the Related Art Heretofore, in order to miniaturize an antenna device and a communication device, for example, many dielectric antennas have been proposed in which an antenna pattern formed of an electrode film is formed on the surface of a dielectric substrate. Japanese Patent Laid-Open No. 9-1626
No. 33, No. 10-32413, No. 1
0-41722).

Many of these dielectric antennas can be directly mounted on a wiring board for use, which is one of the advantages.

[0004]

In such a dielectric antenna, however, it is difficult to form an antenna pattern matching a preset center frequency on the dielectric substrate in a single film forming process.

Therefore, conventionally, the antenna pattern is trimmed after the antenna pattern is formed on the dielectric substrate.

The present invention has been made in view of the above points, and a desired center frequency and impedance can be obtained by simple trimming, and the yield of the dielectric antenna can be greatly improved. It is an object to provide a method for manufacturing an antenna.

[0007]

A method of manufacturing a dielectric antenna according to the present invention comprises a first step of forming an antenna pattern on a dielectric substrate and a second step of trimming the antenna pattern. In the method for manufacturing a dielectric antenna having the second step, in the second step, at least a first part of the antenna pattern in which the center frequency and impedance simultaneously change by trimming and a second part in which the center frequency changes by trimming are included. After detecting and, the first and second parts are selectively trimmed.

Generally, a dielectric antenna is
The impedance is adjusted to 50Ω or other than 50Ω. In this case, in the present invention, since the impedance can be selectively adjusted in addition to the adjustment of the center frequency, the impedance can be easily adjusted in addition to the adjustment of the center frequency according to various specifications. You can

That is, in the present invention, the impedance can be selectively adjusted when the center frequency is adjusted, and the yield of the dielectric antenna can be greatly improved.

In the first step, the antenna pattern is formed on the dielectric substrate so that the center frequency is higher than at least the set center frequency, and the second pattern is formed.
In the step of (3), after detecting a part of the first and second parts where the center frequency is lowered by trimming, the part may be trimmed.

Here, the frequency and the impedance of the dielectric antenna can be adjusted by adjusting the width of the line that is long in the vertical direction. Generally, linear antennas used at high frequencies (monopole, dipole)
Cannot ignore the line width with respect to the total length (λ / 4, λ / 2), and the line width affects the center frequency and impedance. Theoretically, the wider the line width, the higher the center frequency and the wider the band.

As a method of trimming the antenna pattern, there are: a method of first forming an antenna pattern (a linear antenna pattern) so that the center frequency becomes low, and then a method of shortening the length of the antenna pattern. ,: A method is conceivable in which the antenna pattern is first formed so that the center frequency becomes high, and then the width of the antenna pattern is narrowed.

By adopting one of these methods, it is possible to easily adjust the set center frequency (desired center frequency) by trimming the antenna pattern formed on the dielectric substrate.
Since the impedance can be selectively adjusted,
The yield of the dielectric antenna can be improved.

Then, trimming may be performed on the detected portion so that the line width becomes narrow.

In particular, when the antenna pattern has a meander line shape, the following method can be adopted.

That is, the detected portion may be a first line of the antenna pattern that extends continuously in one direction from the feeding portion. In this case, the center frequency can be adjusted to be low while increasing the impedance (in the case of the parallel resonance mode antenna).

Of the one or more lines parallel to the first line extending continuously in one direction from the feeding part of the antenna pattern, the second line closest to the feeding part is narrowed. It may be included. In this case, the center frequency can be adjusted low without changing the impedance.

Further, of the two or more lines parallel to the first line that continuously extends in one direction from the feeding part of the antenna pattern, the width of the line except the second line closest to the feeding part is narrowed. You may make it include the process to do. In this case, the center frequency can be adjusted to be low while lowering the impedance (in the case of the parallel resonance mode antenna).

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments in which the method for manufacturing a dielectric antenna according to the present invention is applied to, for example, a parallel resonance mode dielectric antenna will be described below with reference to FIGS.

Dielectric antenna 10 according to the present embodiment
As shown in FIG. 1, has a dielectric substrate 12 formed by laminating and firing a plurality of plate-shaped dielectric layers, and an antenna pattern 14 formed on the upper surface of the dielectric substrate 12. Is configured. The antenna pattern 14 is formed in a meander line shape by an electrode film.

In the following description, in order to clarify the direction of the dielectric antenna 10, among the respective surfaces of the dielectric substrate 12,
The open end side surface of the antenna pattern 14 is referred to as a front end surface 12a, and the opposite side surface is referred to as a rear end surface 12b.

Dielectric antenna 10 according to this embodiment
1, an input / output terminal 16 made of an electrode film is formed on the rear end surface 12b of the dielectric substrate 12, and the input / output terminal 16 and the rear end of the antenna pattern 14 are the dielectric substrate. It is electrically connected to the strip line electrode 18 formed inside 12 via a via hole 20. The strip line electrode 18 and the via hole 20 form an input portion 22 of the antenna pattern 14. Also, of the antenna pattern 14, the via hole 2
The portion to which 0 is connected becomes the power feeding portion 14a.

Specifically, the dielectric substrate 12 is formed as shown in FIG.
As shown in, the first to tenth dielectric layers S1 to S10 are laminated in this order from the top. These first to tenth dielectric layers S1 to S10 are composed of, for example, one or a plurality of layers.

The antenna pattern 14 and the strip line electrode 18 are formed in regions on the dielectric substrate 12 which are separated from each other in plan view.
Is formed on the upper surface of the first dielectric layer S1, and the stripline electrode 18 is formed on the sixth dielectric layer S6. In addition, the one end 18a of the strip line electrode 18 and the feeding portion 14a of the antenna pattern 14 are the first to fifth parts.
Are electrically connected through the via holes 20 formed in the dielectric layers S1 to S5, and the other end of the strip line electrode 18 and the input / output terminal 16 (see FIG. 1) are directly connected.

The dielectric antenna 10 according to this embodiment is constructed such that the stripline electrode 18 in the input section 22 is sandwiched by at least two ground electrodes 24A and 24B via a dielectric layer. There is. Specifically, a first ground electrode 24A is formed on a portion of the upper surface of the dielectric substrate 12 corresponding to the stripline electrode 18, and a portion of the lower surface of the dielectric substrate 12 corresponding to the stripline electrode 18 is formed. To the second ground electrode 24B
Are formed. Further, in this embodiment, a third ground electrode 24C is formed on a portion of the right side surface 12c of the dielectric substrate 12 corresponding to the strip line electrode 18, and a strip of the left side surface 12d of the dielectric substrate 12 is stripped. The fourth ground electrode 24 is provided on the portion corresponding to the line electrode 18.
D is formed.

That is, in this embodiment, the strip line electrode 18 is surrounded by the first to fourth ground electrodes 24A to 24D via the dielectric layer.

An electrode 24E which is in an electrically floating state is formed on the front end face 12a of the dielectric substrate 12. The electrode 24E is used as a ground electrode and connected to the antenna pattern 14 via a capacitor. You may do it.

When manufacturing the dielectric antenna 10 according to this embodiment, first, the antenna pattern 14 made of an electrode layer is formed on the dielectric substrate 12. Particularly, in this embodiment, the meander line-shaped antenna pattern 14 is formed on the dielectric substrate 12 so that the center frequency is higher than the set center frequency.

After that, in the present embodiment, the impedance is selectively adjusted when adjusting the set center frequency by trimming the antenna pattern 14.

Here, one experimental example will be shown. This experimental example is to see how the center frequency and the impedance change depending on the trimmed portion of the antenna pattern 14. The experimental results are shown in FIGS. 3 and 4.

The results of these experiments will be described with reference to the plan view of FIG. 5. The solid line L in FIGS.
a represents the frequency and impedance in the initial state, and the broken line Lb is the first extending continuously in one direction from the feeding portion 14a of the antenna pattern 14 as shown in FIG.
3 shows the characteristics when the width W1 of the line 30 of FIG.
The dotted line Lc in FIG. 4 indicates three lines 32, 34 and 36 parallel to the first line 30 as shown in FIG.
Among them, the characteristics when the width W2 of the second line 32 closest to the power feeding portion is narrowed are shown.

As shown in FIG. 5, the alternate long and short dash line Ld in FIGS. 3 and 4 shows the characteristic when the width W3 of the third line 34 of the three lines 32, 34 and 36 is narrowed, As shown in FIG. 5, the chain double-dashed line Le in FIGS. 3 and 4 indicates one of the three lines 32, 34, and 36.
The characteristic when the width W4 of the fourth line 36 is reduced is shown.

As can be seen from these results, when the width W1 of the first line 30 is narrowed, the center frequency can be adjusted to be low while increasing the impedance (in the case of the parallel resonance mode antenna). Width W2 of the second track 32
When is thin, the center frequency can be adjusted to be low with almost no change in impedance.

When the widths W3 and W4 of the third and fourth lines 34 and 36 are narrowed, the center frequency can be adjusted to be low while lowering the impedance (in the case of the parallel resonance mode antenna).

As described above, in the method of manufacturing the dielectric antenna 10 according to this embodiment, the impedance is selectively selected when the center frequency is adjusted by trimming the antenna pattern 14 formed on the dielectric substrate 12. I am trying to adjust it.

Normally, the dielectric antenna 10 is designed so that the impedance is adjusted to 50Ω or other than 50Ω depending on the mode. In this case, in the present embodiment,
Since the impedance is selectively adjusted in addition to the adjustment of the center frequency, it is possible to easily adjust the center frequency and impedance according to various specifications such as an antenna alone or an antenna integrated with a filter, for example. Therefore, the yield of the dielectric antenna 10 can be significantly improved.

The dielectric antenna manufacturing method according to the present invention is not limited to the above-described embodiment, and it goes without saying that various configurations can be adopted without departing from the gist of the present invention.

[0038]

As described above, according to the method for manufacturing a dielectric antenna according to the present invention, a desired center frequency and impedance can be obtained by simple trimming, and the yield of the dielectric antenna is greatly improved. Can be made.

[Brief description of drawings]

FIG. 1 is a perspective view showing a dielectric antenna according to the present embodiment when viewed from one direction.

FIG. 2 is an exploded perspective view showing a dielectric antenna according to the present embodiment.

FIG. 3 is a diagram showing a result (reflection characteristic) of an experimental example.

FIG. 4 is a diagram showing a result (Smith chart) of an experimental example.

FIG. 5 is a plan view showing a dielectric antenna according to the present embodiment.

[Explanation of symbols]

10 ... Dielectric antenna 12 ... Dielectric substrate 14 ... Antenna pattern 14a ... Feed part 30 ... 1st track 32 ... 2nd track 34 ... Third track 36 ... Fourth track

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Takami Hirai             2-56, Sudacho, Mizuho-ku, Nagoya-shi, Aichi             Inside Hon insulator Co., Ltd. (72) Inventor Yasuhiko Mizutani             2-56, Sudacho, Mizuho-ku, Nagoya-shi, Aichi             Inside Hon insulator Co., Ltd. (72) Inventor Tainobu Saka             2-56, Sudacho, Mizuho-ku, Nagoya-shi, Aichi             Inside Hon insulator Co., Ltd. (72) Inventor Hitoshi Saito             664-1 Sarukubo, Saku City, Nagano Prefecture Soshin Electric Co., Ltd.             Ceremony Company Chikuma Factory F-term (reference) 5J046 AA00 AB13 PA01 PA04

Claims (6)

[Claims] 1. A method of manufacturing a dielectric antenna, comprising: a first step of forming an antenna pattern on a dielectric substrate; and a second step of trimming the antenna pattern, the second step comprising: In the antenna pattern, at least a first portion where the center frequency and impedance simultaneously change due to trimming and a second portion where the center frequency changes due to trimming are detected, and then the first and second portions are selected. 1. A method of manufacturing a dielectric antenna, which is characterized by trimming. 2. The method for manufacturing a dielectric antenna according to claim 1, wherein in the first step, the antenna pattern is formed on the dielectric substrate so as to have a center frequency higher than at least a set center frequency. In the second step, after detecting a portion where the center frequency is lowered by trimming, of the first and second portions,
A method for manufacturing a dielectric antenna, which comprises trimming the portion. 3. The method for manufacturing a dielectric antenna according to claim 2, wherein trimming is performed on the detected portion so that the line width of the detected portion becomes narrower. 4. The method for manufacturing a dielectric antenna according to claim 1, wherein when the antenna pattern has a meander line shape, the detected part is the antenna pattern. home,
A method of manufacturing a dielectric antenna, which is a first line continuously extending in one direction from a power feeding portion. 5. The method for manufacturing a dielectric antenna according to claim 1, wherein when the antenna pattern has a meander line shape, the antenna pattern is continuous from the feeding portion of the antenna pattern. A method of manufacturing a dielectric antenna, comprising a step of narrowing a width of a second line which is closest to the feeding portion among one or more lines which are parallel to the first line extending in the direction. 6. The method for manufacturing a dielectric antenna according to claim 1, wherein when the antenna pattern has a meander line shape, the antenna pattern is continuous from the feeding portion of the antenna pattern. A method of manufacturing a dielectric antenna, comprising a step of narrowing a width of a line other than a second line closest to the feeding portion among two or more lines parallel to a first line extending in a direction.