JPS6390818A - Resonator - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a resonator suitable for filters, oscillation elements, etc. used in frequency ranges including and exceeding the UHF band.

Resonators used for filters, oscillation elements, etc. in the above frequency range are required to have a relatively high sharpness (hereinafter referred to as Q), and such resonators have conventionally been made using dielectric There are body coaxial resonators, strip lines, etc. However, these resonators have a problem in that they have a complicated structure and are large in size, resulting in high costs.

Therefore, in order to solve these problems, the applicant of the present invention proposed a small and low-cost resonator as described below (Japanese Patent Application No. 61-97312).

As shown in FIG.
Coil patterns 12a and 13a are provided on 1a and back surface 11b.
, and two capacitor electrode patterns 14a, 14b, L5a, 15b are formed at both ends thereof, respectively.

This capacitor electrode pattern consists of 14a, 15a and 1
4b and 15b face each other on both sides of the substrate 11, forming capacitors C11 and C12.

Further, the coil patterns 12a and 13a form a coil in terms of high frequency.

By the way, in the above configuration, the dielectric constant ε is 80 and the thickness is 4.
00 μm group (using anti-11, f r = 504 M
In order to resonate at llz, the capacitance of the capacitor is C11.
= 18 pF, Cl2 = 53 pF, and the inductance of the coil is L11 = L12 = 2.77 nH. In order to obtain these values, capacitor electrode patterns 14a, 14b, 15a that constitute capacitors C11 and CI2 are used.
, 15b is A11=7 m, j!
12=1.5 mm, l 13=7
mm, ! ! 14 = Coil patterns 12a and 13a formed in the size of 3.5 dragons and forming a coil
is formed with a thickness of 7!15 = 116 = 6.0 mm, and compared to dielectric coaxial resonators, strip lines, etc., this resonator has a simple structure and can be made smaller. .

However, in recent years, there has been a strong demand for smaller and lighter electronic equipment bodies, and the above-mentioned resonators still pose an obstacle to making the equipment bodies smaller and lighter.

In view of these problems, it is an object of the present invention to provide a resonator that is even smaller and lower in cost.

Means for Resolving the Problems In order to achieve the above object, a resonator according to the present invention includes a substrate, a first coil pattern formed on the surface of the substrate, and a coil pattern extending from both ends of the first coil pattern. two lower capacitor electrode patterns formed as above, two dielectrics formed respectively on the lower capacitor electrode patterns, and two upper capacitor electrode patterns formed respectively on the dielectrics. , a second coil pattern formed between the upper capacitor electrode patterns;
Its structural feature is that it consists of:

According to the above configuration, the lower capacitor electrode pattern is formed on the substrate surface, the dielectric is formed on it, and the upper capacitor electrode pattern is further formed on it, so that the lower and upper capacitor electrode patterns are The distance between the capacitor electrode patterns is only the thickness of the dielectric material interposed between them, and the facing distance can be significantly reduced compared to conventional ones, increasing the capacitance by placing them close together. Therefore, if the capacitors have the same capacity, the area of the capacitor electrode pattern can be reduced, and a pair of coils and two capacitors can be appropriately electrically coupled to obtain a desired resonator circuit.

Figure 1 shows a resonator as an embodiment of the present invention, and Figure (
A) is a front view, figure (B) is an x-xvA sectional view, figure (c) is
is a cross-sectional view taken along the line Y-Y in Figure (A).

In the figure, reference numeral 1 denotes an insulating substrate formed to have a thickness of, for example, 400 μm, and a linear first coil pattern 2 is formed on the surface of the insulating substrate 1. 2a.

2b is a lower capacitor electrode pattern extending from both ends of the first coil pattern 2, and a dielectric made of CK material is provided on the upper surface of the lower capacitor electrode patterns 2a and 2b so as to cover these. 3 are laminated in the form of a thin film. The upper capacitor electrode pattern 4a is on the upper surface of the dielectric 3 laminated on the upper surface of the lower capacitor electrode pattern 2a, and the upper capacitor electrode pattern 4a is on the upper surface of the dielectric 3 laminated on the upper surface of the lower capacitor electrode pattern 2b. Upper capacitor electrode patterns 4b are formed respectively, and a second coil pattern 4 is further formed between upper capacitor electrode patterns 4a and 4b. First coil pattern 2, lower capacitor electrode patterns 2a, 2b, and second coil pattern 4, upper capacitor electrode pattern 4
a and 4b are each formed in a U-shape. Note that, for example, silver paste or the like is used as the material for the first coil pattern 2, the second coil pattern 4, the lower capacitor electrode patterns 2a, 2b, and the upper capacitor electrode patterns 4a, 4b. The capacitor electrode patterns 2a and 2b are also connected to the second coil pattern 4 and the upper capacitor electrode patterns 4a and 4b.
are formed one by one by a method such as screen printing.

As the material of the dielectric 3, CK material or the like can be used. Further, the reason why the tip of the lower capacitor electrode pattern 2b is made to protrude from the dielectric 3 is to facilitate the connection of the lead wire.

In the above configuration, the lower capacitor electrode pattern 2a and the upper capacitor electrode pattern 4a, which face each other with the dielectric 3 in between, and the lower capacitor electrode pattern 2b and the upper capacitor electrode pattern 4b are each connected to the capacitor C1.
, C2 are the permittivity ε, thickness t, and thickness of the dielectric 3, respectively.
Determined by the facing area of the capacitor electrode pattern. In addition, the first coil pattern 2 and the second coil pattern 4 are
Since a coil is formed in terms of high frequency, assuming that the inductance thereof is Ll and L2, this resonator has a coil LL on both sides of the capacitor C1, as shown in FIG.

An equivalent circuit is formed by connecting another capacitor C2 in parallel to an LC series circuit in which L2 is connected in series. The first coil pattern 2 and the second coil pattern 4 should have appropriate lengths to enable magnetic coupling with other resonators, and should be formed as close to the end of the insulating substrate 1 as possible. It is desirable that the first coil pattern 2 and the second coil pattern 4 be separated from each other as much as possible in the same resonator so that they are not magnetically coupled or have capacitance.

Note that the above equivalent circuit is a circuit configuration in which lead wires are connected to both sides of the capacitor C2. For example, if the lead wires are connected to the center of the coil, it is possible to create a circuit in which the coils are connected in series on both sides of the capacitor. It is also possible to configure circuits connected in parallel.

To make the above resonator resonate at fr=504MHz,
For example, if C1=18pF, LL and L2 are given by the following equations.

Here, if LL=L2, then L1=L2=2.77nH. C2 can be selected depending on the impedance used, regardless of the resonance frequency. In this example, when the impedance was 50Ω, Q was maximized at C2=53pF, so 53pF was selected. Here dielectric 3
If the dielectric constant ε of is 80 and the thickness [ is 20 μm, CI,
The capacitance of C2 is 1 1 = 0.13 iris,
l 2=14=4 嘗■, f 3 =
This can be obtained by setting the value to 0.30. Also, Ll.

The inductance of L2 is l 5 =6. This can be obtained by setting it to On. The widths Wl and W2 of the first coil pattern 2 and the second coil pattern 4 are not related to the inductance value, but the larger the width, the smaller the resistance, and therefore the higher the Q, which is preferable.

In this example, W 1 =W 2 =1.5 x*.

The resonance characteristics of the resonator formed with the above dimensions are as follows:
As shown in the figure, in this case, a very high value of Q of 148 was obtained.

As mentioned above, in the resonator of this example, the interval between the capacitor electrode patterns can be formed at a distance of 1720 mm (this example: conventional example = 20 μm: 400 μm) compared to the resonator shown in the conventional example, so that the capacitor capacitance can be reduced. If they are the same, the area occupied by the capacitor electrode pattern can also be reduced to 1/20. Therefore, the volume of the resonator itself can be significantly reduced, which has a great effect on miniaturizing the resonator.

In the above embodiment, the lower capacitor electrode patterns 2a, 2b and the upper capacitor electrode patterns 4a, 4b
The distance between C1 and C2 can be changed by changing the thickness t of the dielectric 3, which changes the capacitance of the capacitors C1 and C2.
Since the resonant frequency can be changed, it can be set to an appropriate value in relation to the frequency used.

Further, the dielectric 3 may be laminated to cover the upper surface of the first coil pattern 2 and the lower surface of the second coil pattern 4 as well.

As explained above, in the resonator according to the present invention, a coil pattern is formed on the surface of a substrate, and a thin film is formed between capacitor electrode patterns extending from both ends of each coil pattern. By interposing a dielectric material that can be formed into a capacitor, if the capacitor capacitance is the same, the area occupied by the capacitor electrode pattern that makes up the capacitor can be reduced. In addition to contributing to the miniaturization of electronic devices used,
It has a high Q suitable for filters, oscillation elements, etc. used at frequencies above the 0MI (z band plate), and requires less electrode material than conventional methods, resulting in lower costs.

In addition, since the coil pattern and dielectric material that make up the capacitor and coil are formed only on the surface of the substrate, the spacing between the capacitor electrode patterns can be determined without being affected by the thickness of the substrate. , the advantage is that the thickness of the substrate can be set freely.

Furthermore, when connecting a lead wire to this resonator, it can be done only on the front surface side of the board, making it easy to attach it to a printed circuit board or the like.

[Brief explanation of the drawing]

FIG. 1(a) is a front view showing a resonator as an embodiment of the present invention, FIG. 1(b) is a sectional view taken along the line X-X, and FIG. 1(c) is a Y -Y line sectional view, Figure 2 is a diagram showing the equivalent circuit of the resonator, Figure 3 is a diagram showing the resonance characteristics of the resonator, and Figure 4 (A) is a front view showing the conventional resonator. , FIG. 4(b) is a side view, and FIG. 4(c) is a rear view. 1... Insulator substrate, 3... Dielectric, 2.4.
...Coil pattern, 2a, 2b...Lower capacitor electrode pattern, 4a,
4b... Upper capacitor electrode pattern, C1, C2
...Capacitor, L 1. L2...Coil.

Claims (2)

[Claims] (1) A substrate, a first coil pattern formed on the surface of the substrate, two lower capacitor electrode patterns extending from both ends of the first coil pattern, and above the lower capacitor electrode pattern. two dielectrics respectively formed on the dielectrics, two upper capacitor electrode patterns respectively formed on the dielectrics, and a second coil pattern formed between the upper capacitor electrode patterns. Features a resonator. (2) A patent characterized in that the first coil pattern and the two lower capacitor electrode patterns, and the second coil pattern and the two upper capacitor electrode patterns are each formed in a U-shape. Claims No. (
The resonator described in section 1).