JPS6243909A - Resonator and filter using it - Google Patents

Abstract

PURPOSE:To improve the Qo value and the electric characteristic, especially the insertion loss by connecting both spiral line electrodes electrically via a through hole provided to a dielectric base. CONSTITUTION:Two counter electrodes 7a, 7b are provided to both surfaces of a dielectric base 1 while interposing the base 1 in-between. Then spiral line electrodes 8a, 8b of, e.g., one turn wound in the same direction are connected respectively to the counter electrodes 7a, 7b and the tip of both the spiral line electrodes 8a, 8b is connected electrically via the through hole 9 provided to the dielectric base 1. A current flowing to the spiral line electrodes 8a, 8b is made the same direction between lines 81a and 81b and between lines 82a and 82b, they cause mutual inductance to attain magnetic field coupling. Since the increase in the stored magnetic field energy to the increase in the conductor loss is sufficiently larger than the case with a single line or one turn line electrode, resulting that the Qo of the resonance system is increased.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a resonator having electrodes formed on both surfaces of a dielectric substrate, and a filter using the resonator.

[Conventional technology and its problems]

Conventionally, when using a bandpass filter configuration for a microstrip line filter or a printed filter, as the filter becomes smaller, the Q value of the resonator (resonant element) that makes up the filter decreases, increasing the insertion loss of the filter and causing electrical There was a problem of deteriorating the physical characteristics.

For example, an example of a comb-shaped microstrip line filter is shown in FIG.
A ground electrode 2 is formed on one side, and an input/output electrode 3.5 and a plurality of comb-shaped electrodes 4 are formed on the other side. The width W of the comb-shaped electrode 4 and the thickness T of the dielectric substrate 1 are each about 1.0 m, for example. In such a microstrip line filter, for example, Q at 400MHz is
The 0 value was only around 100. Furthermore, in the case of blind fill, in which a filter is constructed by printing an electrode pattern on a dielectric substrate, the ao (direction) is almost the same as this.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a resonator and a filter using the resonator in which the electrical characteristics, particularly the insertion loss, are improved by changing the Q0 value.

[Failure to solve the problem]

In this invention, counter electrodes and spiral line electrodes connected to each other and wound in the same direction are provided on both surfaces of a dielectric substrate, and a through hole provided in the dielectric substrate is provided between the two spiral line electrodes. This is a filter using a resonator and a warp, which are electrically connected to each other.

(Operation) Capacitance is formed between the opposing electrodes, and inductance is formed between both spiral line electrodes.
．． A C resonant circuit is formed. Moreover, since the increase in the energy of the stored magnetic field is sufficiently larger than the increase in the loss of conductor 111 due to the connection of both spiral line electrodes, the Q0 value increases in the 1- direction, thereby improving the electrical characteristics.
In particular, it is hoped that the case against the insertion will be defeated.

〔Example〕

FIG. 1 is a perspective view showing an embodiment of a resonator according to the present invention. Two opposing electrodes 7a and 7b are provided on both surfaces of the dielectric substrate 1 with the dielectric substrate 1 in between. The shape of the opposing electrodes 7a and 7b may be, for example, a square as shown in the figure, or another shape such as a circle. One of the opposing electrodes 7a and 7b (for example, the opposing electrode 7b) is
For example, it is used as a ground electrode. And counter electrodes 7a, 7
For example, one-turn spiral line electrodes Vi8a and 8b wound in the same direction are connected to b, respectively, and the tips of both spiral line electrodes 8a and 8b are connected to through poles 9 provided on the dielectric substrate 1. electrically connected via. In this way, the resonator 6 is formed.

1- In the resonator 6, as shown in FIG. 2, an electrostatic field C is formed between the opposing electrodes 7a and 7b, and an inductance of 1. is formed, thereby forming a parallel LC resonant circuit.

Moreover, in the resonator 6, the number of turns can be doubled (
In this example, there are 2 turns), so there is a large inductance 1. can be taken. In other words, with reference to FIG. 3, the current flowing through spiral line electrodes 8a, 8b is between lines 81a and 81b and between lines
and 82b are in the same direction, causing mutual induction and magnetic field coupling. Note that M indicates lines of magnetic force. Therefore, compared to the case of a single wire or one turn, for example, the energy of the magnetic field stored increases (theoretically four times that of one turn) for an increase in conductor loss (theoretically twice that of one turn).
is sufficiently larger, and as a result, the 00 value of the resonance system increases.

Experimentally, the Q is about 30% compared to when using a single wire.
It was confirmed that the 0 value increased by one. Therefore, in the resonator 6 as described above, it is possible to improve the electrical characteristics, especially the insertion and setting, by about 30% while keeping the same size compared to the conventional printed filter. This means that product value increases and market competitiveness is strengthened.

Furthermore, in the resonator 6, since the inductance I can be made large, even at the same resonant frequency, the capacitance C
In other words, the dimensions of the opposing electrodes 7a and 7b can be made small, and thereby the dimensions of the resonator 6 can also be made small. Furthermore, by using the dielectric substrate 1 with a high dielectric constant, the dimensions of the opposing electrodes 7a and 7b and, by extension, the dimensions of the resonator 6 can be further reduced.

FIG. 4 is a plan view partially showing an embodiment of the filter according to the present invention. In this filter, a plurality of the above-mentioned resonators 6 (only two are shown in the figure) are arranged on the same dielectric substrate 1 with their opposing electrodes 7a and 7b close to each other. 6 are coupled by capacitance C3. As a result, a ladder-shaped bandpass filter as shown in FIG. 5, for example, is formed.

In this case, various ways of arranging and coupling the resonators 6 may be used in addition to those shown in the drawings.

For example, the capacitance C8 can be further increased by not only bringing the adjacent opposing electrodes 7a closer to each other, but also by combing part or all of the opposing sides as shown in the figure to increase the opposing area. You can also do it. In addition, in adjacent resonators 6, one counter electrode (for example, counter electrode 7a) of one resonator 6 and the other counter electrode (for example, counter electrode 7b) of the other resonator 6 are both slightly enlarged so that the substrate By arranging the resonators 6 to face each other across the electrodes, it is possible to couple adjacent resonators 6 by the capacitance between the electrodes.Also, contrary to the illustration, each resonator 6 has the same spiral line electrode 8a18b. You can also arrange them so that they are on the side.
In that case, in addition to the main electric field coupling, it is also possible to cause magnetic field coupling between the adjacent spiral line electrodes 8a and 8b.

Even in the filter as described above, the same effect as in the case of the resonator 6 described above can be obtained. That is, by improving the Q0 value, the electrical characteristics, especially the insertion loss, are improved, and the dimensions are also reduced.

〔Effect of the invention〕

As described above, in the resonator according to the present invention and the filter using the same, the electrical characteristics, particularly the insertion and heating characteristics, are improved by improving the QO (af), and the size is also reduced.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing an embodiment of a resonator according to the present invention. FIG. 2 is an equivalent circuit diagram of the resonator of FIG. 1. FIG. 3 is a partial cross-sectional view taken along line m--m in FIG. FIG. 4 is a plan view partially showing an embodiment of the filter according to the present invention. FIG. 5 is an equivalent circuit diagram of the filter of FIG. 4. FIG. 6(A) is a plan view showing an example of a conventional microstrip line filter, and FIG. 6(B) is a sectional view taken along the line BB. 1...Dielectric substrate, 6...Resonator, ? a, 7b...
- Counter electrode, 8a, 8b... spiral line electrode,
9...Through hole Figure 1 Figure 2 Figure 3 A b Figure 4 Figure 5

Claims (2)

[Claims] (1) A counter electrode and spiral line electrodes connected to it and wound in the same direction are provided on both surfaces of the dielectric substrate, and electrical connection is made between both spiral line electrodes via a through hole provided in the dielectric substrate. A resonator characterized by being connected to each other. (2) A counter electrode and spiral line electrodes connected to it and wound in the same direction are provided on both surfaces of the dielectric substrate, and electrical connection is made between both spiral line electrodes via a through hole provided in the dielectric substrate. A filter characterized in that a plurality of connected resonators are formed on the same dielectric substrate, and adjacent resonators are coupled by at least capacitance.