JPH09232846A - Method for tuning glass antenna - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a tuning method by which the glass antenna formed by a conductive tape and the glass antenna formed by a printed wire are capable of obtaining substantially the same characteristics. SOLUTION: In the tuning method for the glass antenna in which an antenna pattern is formed on glass by a silver print, the antenna pattern is formed by a conductive tape 1 and a tuning is performed by coating substance 4 with high dielectric constant on the upper part of the conductive tape 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a glass antenna for forming an antenna pattern on a window glass for vehicles or a window glass for construction by silver printing so as to obtain preferable performance in a reception frequency band. Regarding tuning method.

[0002]

2. Description of the Related Art Recently, radio broadcast waves such as AM and FM,
There has been a demand for a glass antenna for vehicles for receiving TV broadcast waves. In particular, a glass antenna provided on a rear window glass or a side window glass is an antenna obtained by printing and firing silver paste by screen printing. It is necessary to adjust (tune) the optimum length, optimum spacing, etc. of each element of the antenna pattern, but it is possible to cut the printed line formed by silver paste (hereinafter abbreviated as silver print), Make it longer
It is virtually impossible to add.

Therefore, a conductive tape having an adhesive formed thereon is attached to the back surface of a copper foil having a thickness of about 35 μm and a width of about 1 mm to form an antenna pattern, and other parts of the pattern are moved. The current situation is to change the length and substitute it.

[0004]

However, there is a difference in characteristics between a glass antenna tuned by a conductive tape and an antenna formed by a printed wire actually mounted on a window glass of a vehicle or the like. It is known to those skilled in the art that it is difficult to approximate even if the thickness of the copper foil which is the conductive tape is changed or the width is changed, and there is no suitable method to approximate it. There has been a demand for a tuning method capable of obtaining a performance similar to that of an antenna formed by printing a conductive paste.

The present invention has been made in view of the above circumstances, and provides a tuning method by which a glass antenna formed of a conductive tape and a glass antenna formed of a printed wire can obtain substantially the same characteristics. The purpose is to provide.

[0006]

The present inventors have made the present invention by paying attention to the fact that the deviation of the characteristics is almost equivalent to the deviation of the resonance frequency.

That is, the present invention focuses on the fact that the resonance frequency can be approximated to the wavelength shortening rate of the glass antenna formed by the printed wire by changing the wavelength shortening rate based on the speed of the received radio wave on the antenna. The wavelength shortening rate of the glass antenna formed by the printed wire is
Since it is smaller than the wavelength shortening rate of the glass antenna formed of the conductive tape, in order to increase the wavelength shortening rate of the glass antenna formed of the conductive tape, it is possible to cut it by covering the conductive tape with a substance having a high dielectric constant. By using a conductive tape that is extremely easy to tune by attaching or pasting, it is possible to obtain the characteristics almost equivalent to those of the glass antenna formed by the printed wire.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION As the conductive tape, a metal foil such as iron, copper, aluminum or an alloy containing them as a main component and having an adhesive formed thereon can be suitably used.

In the case of an iron tape, its width varies depending on the relative permittivity and thickness of the dielectric material, but is R manufactured by Shin-Etsu Chemical.
When TV paste is used, it is preferable to set the thickness to 1 mm to 3.5 mm, as will be apparent from the examples described later, because it can be approximated to a glass antenna formed by a printed line. In this case, it is actually possible to approximate even if it exceeds 3.5 mm, but the distance between the antenna patterns is 5 mm.
If the width is narrow, it is difficult to form the antenna pattern itself, so the upper limit is 3.5 mm.

In the case of a copper tape, its width varies depending on the relative permittivity and thickness of the dielectric, but is R manufactured by Shin-Etsu Chemical.
When TV paste is used, it is preferable to set it to 0.4 mm to 2 mm, as will be apparent from the examples described later, because it can be approximated to a glass antenna formed by a printed line. In this case, even if it is actually smaller than 0.4 mm, it can be approximated, but since workability deteriorates, it is 0.4 mm.
Is the lower limit.

In the present invention, a substance having a high dielectric constant means a substance having a relative dielectric constant of 3 or more. The upper limit of the relative permittivity is practically 1
It is about 4. Therefore, a material having a relative dielectric constant in the range of 3 to 14 may be appropriately selected. For example, a powder of polyvinyl butyral is dissolved in methyl ethyl ketone to form a paste (hereinafter referred to as PVB paste. 13), further dried PVB paste (relative permittivity 4.0), a plurality of laminated dielectric films (relative permittivity: 13.8) in which titanate whiskers are dispersed in a thermoplastic polyester resin, Shin-Etsu Chemical RT
Each conductive tape is coated with a paste such as V paste (KE3417) or a film made of a substance having a high dielectric constant, such as phenol resin (relative dielectric constant: 4.0 to 7.0), urea resin (Relative permittivity: 6.
0-8.0), melamine resin (relative dielectric constant: 7.2-8.
4), polyester resin (relative dielectric constant: 5.2-6.
4), acrylic resin (relative permittivity: 3.8 to 4.5), epoxy resin (relative permittivity: 4.1), vinyl chloride resin (relative permittivity: 3.3 to 4.5), etc. Sheet to cover a plurality of elements of the antenna pattern formed by the conductive tape, or the conductive tape 1
You may coat every book.

In the case of coating with a resin sheet, the conductive tape may be coated one by one, but since the entire conductive tape (generally a large number) can be coated, workability is remarkably improved. To be improved.

Further, in this case, if an air layer (relative permittivity of 1) is present between the dielectric material and the conductive tape, the antenna characteristics may be greatly changed due to the influence of the air layer. Need to be adhered so that there is less.

The tuning is carried out by forming a predetermined antenna pattern with a conductive tape and applying the above-mentioned paste or the like to each of the conductive tapes alone, or by sticking the conductive tape upper part with a resin sheet. By measuring the antenna characteristics with a thing, by changing the interval between the antenna filaments formed by the conductive tape, or by changing the length of each filament of the conductive tape,
If suitable tuning is performed, and based on the result, a glass antenna having the same shape and the same spacing and length of each filament is formed by silver printing, a glass antenna having substantially the same characteristics as those at the time of tuning can be obtained.

When tuning, when shortening the length of each filament, the unnecessary portion may be simply cut off with a knife or the like, and when lengthening it, a conductive tape may be connected, but the conductive portion to be connected. Solder to connect securely.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A case where a standard dipole antenna is used as an antenna pattern will be described below with reference to the drawings.

FIG. 1 is a plan view of essential parts showing a glass antenna used in the test of the present invention, and FIG. 2 is a first embodiment, a second embodiment,
Sectional drawing of the antenna filament formed by the conductive tape used for the tuning in Example 4 and Example 5,
3 is a cross-sectional view of the conductive tape used for tuning in Example 3, and FIG. 4 is a frequency characteristic diagram of each antenna. (1) is Example 1, (2) is Example 2, and (S) is A printed reference antenna and a comparative example in which (c) is a copper foil are shown.

Example 1 Polyvinyl butyral (PVB) powder was mixed in a solvent methyl ethyl ketone (MEK) at a weight ratio of about 1:10 to form a paste-like PVB paste as a dielectric substance (having a relative dielectric constant of 10 to 13) will be exemplified.

As shown in FIGS. 1 and 2, a conductive tape 1 having a width of 1 mm and a thickness of 35 μm, such as a copper foil with an adhesive, is attached to the glass plate 2 so that each one-side element has a length of 600 mm. A dipole antenna 3 is formed, and a PVB paste is applied on the dipole antenna 3 as a substance 4 having a high dielectric constant so as to have a thickness of about 2 mm.

The characteristics of the glass antenna thus obtained were connected to an impedance measuring device (not shown) from the feeding portions 3 ₁ , 3 ₁ 'and the resonance frequency and the resistance were measured.
As shown in Table 1, the power supply units 3 ₁ and 3 ₁ ′ were connected to a network analyzer (not shown), and the reception gain (frequency characteristic) for each frequency was measured.
As shown in (1), the frequency characteristics of a glass antenna (referred to as a reference antenna) with a width of 1 mm and a thickness of 10 μm obtained by printing and firing with silver paste are shown in Table 1 and (s) of FIG. 4, respectively. Therefore, it can be seen that the antenna formed of the conductive tape of the present example has a resonance frequency and a frequency characteristic that are much closer to those of the reference antenna than the comparative example formed only of copper foil described later.

In this embodiment, when shortening the filament formed by the conductive tape, it may be cut with a knife and the unnecessary portion may be wiped off, and when the filament is lengthened, a new copper foil is made of glass. It is attached so that it contacts the copper foil formed on the board, the copper foils are soldered together, and PV
The B paste was applied and tuned.

[0022] Example 2 A conductive tape having the same structure as that of Example 1 was attached, and PV was used.
It was coated with B paste and then dried, and has a relative dielectric constant of about 4.0.

The characteristics of the glass antenna thus obtained are 92.
3MHz and 55.5Ω, the frequency characteristics of Fig. 4
As shown in (2), the degree of approximation with the reference antenna is similar to that of the first embodiment.

Example 3 As shown in FIG. 3, after a copper foil 1 having the same dimensions as in Example 1 was attached, whiskers of titanate were dispersed in a thermoplastic polyester resin (dielectric constant: 13. 8)
Are laminated on each other as a dielectric substance 4, and a transparent adhesive tape 5 is adhered on the dielectric substance 4.

The characteristics of the glass antenna thus obtained are 92.
It was 6 MHz and 53.7 Ω, which was similar to that of the first embodiment and similar to the reference antenna.

In this embodiment, when shortening the filament formed by the conductive tape, it is cut with a knife to remove unnecessary portions, and when the filament is lengthened, a new copper foil is formed on the glass plate. The copper foils were attached so as to be in contact with each other, and the copper foils were soldered to each other, and three dielectric films were stacked on top of each other and adhered together with a transparent adhesive tape, and tuning was performed.

Comparative Example A conventional glass plate is formed by adhering only a copper foil having a thickness of 35 μm and a width of 1 mm to form an antenna. The characteristics of this antenna are as shown in Table 1 in terms of resonance frequency and resistance. ,
The frequency characteristics are 94.7 MHz and 53.9 Ω, and the frequency characteristics are as shown in (c) of FIG. 4, and it can be seen that the characteristics are considerably different from the reference printed antenna.

Example 4 An example will be described in which an iron foil with an adhesive is used for the conductive tape and RTV paste (KE3417) manufactured by Shin-Etsu Chemical is used as a dielectric substance.

The width of the conductive tape is 1 mm, 2 mm, 4 m
In the case of m, the thickness of the dielectric material (including the case where no dielectric material is included for comparison) was changed in each case.

As shown in FIGS. 1 and 2, the conductive tape 1
Is attached to the glass plate 2 with each one-side element having a length of 600 mm to form a dipole antenna 3, and an RTV paste is applied as a substance 4 having a high dielectric constant on the dipole antenna 3.

When the width of the iron tape is 1 mm, 2 mm, and 4 mm, when the dielectric material is not applied, the thickness of the dielectric material is 0.73 mm, the thickness of the dielectric material is 1.14 mm, and 1. When the resonance frequency and the resistance value were measured at 87 mm, the results shown in Table 2 were obtained.

[0032] As is clear from this result, in any case, the coating with the dielectric material tends to approximate the resonance frequency of the reference antenna of 91.3 MHz, and the width is 2 mm.
In the case of, the resonance frequency and the resistance value are the closest, and the width is 1
It can be said that it is an approximate range for both mm and 4 mm.

Example 5 A case where copper foil with an adhesive is used for the conductive tape and RTV paste (KE3417) manufactured by Shin-Etsu Chemical is used as a dielectric material will be exemplified.

The width of the conductive tape is 0.4 mm, 1 mm,
The measurement was performed for the cases of 2 mm and 4 mm, and for each case, the thickness of the dielectric material (including the case without the dielectric material for comparison) was changed.

As shown in FIGS. 1 and 2, the conductive tape 1
Is attached to the glass plate 2 with each one-side element having a length of 600 mm to form a dipole antenna 3, and an RTV paste is applied as a substance 4 having a high dielectric constant on the dipole antenna 3.

When the width of the copper tape was 0.4 mm, 1 mm, 2 mm, and 4 mm, when the dielectric substance was not applied, the resonant frequency and the resistance value were measured by changing the thickness of the dielectric substance. The results shown in Table 3 were obtained.

[0037] As is clear from this result, the width of the conductive tape is 4 m.
In the case of m, it is not preferable because even if the dielectric material is thickened, it is not so close to the reference resonance frequency, but in other widths, by coating the dielectric material, the resonance frequency of the reference antenna becomes 91.3 MHz. It can be seen that they are well approximated.

[0038]

According to the present invention, it is possible to easily tune a glass antenna formed by printing, which has been difficult in the past, with a conductive tape such as an iron foil or a copper foil.

[Brief description of drawings]

FIG. 1 is a plan view of an essential part showing a glass antenna used for a test of the present invention.

FIG. 2 is a cross-sectional view of an antenna wire formed of a conductive tape used for tuning in Examples 1 and 2.

FIG. 3 is a cross-sectional view of an antenna filament formed of a conductive tape used for tuning in Example 3.

FIG. 4 is a frequency characteristic diagram of each antenna, where (1) is Example 1, (2) is Example 2, (S) is a reference antenna printed, and (c) is a comparative example formed of copper foil. Shown respectively.

[Explanation of symbols]

 1 conductive tape 2 glass plate 3 dipole antenna 4 substance with high dielectric constant

Claims (4)

[Claims] 1. A method for tuning a glass antenna, wherein an antenna pattern is formed on a glass plate by silver printing, the antenna pattern is formed by a conductive tape, and a material having a high dielectric constant is coated on the conductive tape. A tuning method for a glass antenna, which is characterized by being tuned. 2. The tuning of a glass antenna according to claim 1, wherein the conductive tape is made of a metal foil such as iron, copper, aluminum or an alloy containing them as a main component, and an adhesive is formed on the back surface. Method. 3. The method of tuning a glass antenna according to claim 1, wherein only the conductive tape is coated with a substance having a high dielectric constant. 4. The method for tuning a glass antenna according to claim 1, wherein the upper part of the conductive tape is covered with a sheet made of a material having a high dielectric constant.