JPH08222916A - Microstrip line resonator - Google Patents

Abstract

PURPOSE: To provide a microstrip line resonator by which revision of a resonance frequency is facilitated without changing the length of a microstrip line nor revision of a parallel capacitance with respect to the line. CONSTITUTION: In the microstrip line resonator where a microstrip line 14 with a folded pattern whose one end connects to a ground conductor 12 is formed in a dielectric board 10 with the ground conductor 12 provided thereto, plural pairs of solder lands 20 for mounting capacitive elements are formed along a side ridge to which the microstrip line 14 opposes. Then capacitive elements 22 are connected in parallel to the solder lands 20.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a microstrip line resonator composed of a dielectric substrate provided with a ground conductor and a microstrip line.

[0002]

2. Description of the Related Art Conventionally, a quarter-wave microstrip line is provided on the surface of a dielectric substrate, a ground conductor is provided on the back surface of the dielectric substrate, one end of the microstrip line is opened, and the other end is grounded. A microstrip line type resonator having a structure connected to is used in the field of high frequency circuits.

However, the resonance frequency in this type of microstrip line resonator is determined by the length of the microstrip line and the relative permittivity of the dielectric substrate. For this reason, conventionally, a microstrip line is formed to be long so as to resonate at a frequency lower than a target resonance frequency, and then the microstrip line is cut to obtain a desired resonance frequency, and the length is reduced. The method of setting by shortening the length is adopted.

Therefore, according to the conventional method of adjusting the resonance frequency in the microstrip line resonator,
The resonance frequency can be raised by shortening the length of the microstrip line, but it cannot be lowered. Therefore, if a part of the microstrip line is removed and the width is narrowed, the characteristic impedance changes and the resonance frequency changes. Therefore, a part between the feeding point of the microstrip line and the connection end to the ground conductor is changed. The method of adjusting the resonance frequency by shortening the length of the microstrip line and the method of adjusting the resonance frequency by narrowing the width of a part of the microstrip line based on the fact that the There has been proposed a microstrip line resonator configured so that a desired resonance frequency can be accurately obtained by combining the above (Japanese Patent Application Laid-Open No. 5-211403).

In addition, the surface of the dielectric substrate has a resonance wavelength of 1 /
A microstrip line having a folded (U-shaped) pattern set to a length of 4 is provided, and one end of the microstrip line is connected to a ground conductor provided on the back surface of the dielectric substrate via a first connection conductor. In addition, the other end of the microstrip line is connected to the second connection conductor, and by connecting a capacitive element such as a capacitor element in parallel to a required length position of the folded pattern of the microstrip line, A microstrip line resonator configured to obtain a desired resonance frequency has also been proposed (Japanese Utility Model Laid-Open No. 4-114205).

[0006]

However, in the above conventional microstrip line resonator, when the resonance frequency is changed, the length of the microstrip line is changed, or a capacitive element connected in parallel to the microstrip line is tried. It is necessary to adjust it by erroneously moving it or changing its capacitance value. Therefore, according to these adjustment methods, it is necessary to change the line length or change the setting position of the capacitive element and the used capacitance each time the design of the resonator is changed, which complicates the design change work. There are difficulties.

Therefore, an object of the present invention is to make it possible to easily change the resonance frequency without changing the length of the microstrip line or changing the parallel capacitance value for the line. To provide.

[0008]

In order to achieve the above object, a microstrip line resonator according to the present invention comprises:
In a microstripline resonator in which a folded microstrip line is formed by connecting one end to a grounding conductor on a dielectric substrate with a grounding conductor, the required spacing along the opposite side edges of the microstripline. It is characterized in that a plurality of pairs of soldering lands for mounting the capacitive element are formed separately from each other, and the capacitive element is selectively connected in parallel to the opposing soldering lands.

In this case, a chip capacitor or a varactor diode can be preferably used as the capacitive element connected to the soldering land.

[0010]

According to the microstrip line resonator of the present invention, a plurality of pairs of soldering lands for mounting the capacitive element are formed along the opposite side edges of the microstrip line at a required distance. By selectively connecting the capacitive elements in parallel to the opposing soldering lands, it is possible to easily achieve the preset selection of a plurality of resonance frequencies without changing the capacitive elements.
That is, there is an advantage that the design of the resonator can be easily changed.

[0011]

Embodiments of the microstrip line resonator according to the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 is a schematic plan view showing an embodiment of a microstrip line resonator according to the present invention. That is, in FIG. 1, reference numeral 10 is a dielectric substrate, and 12 is a dielectric substrate.
Is a ground conductor formed on the back surface of the dielectric substrate 10,
Are microstrip lines (strip conductors) formed on the surface of the dielectric substrate 10, respectively. However, the dielectric substrate 10 can be made of, for example, a ceramic containing barium titanate as a main component and having a thickness of about 1 mm. Further, the ground conductor 12 and the microstrip line 14 can each be formed of a metal conductor film formed by appropriately applying a silver (Ag) paste and baking it.

The microstrip line 14 has a first portion 14a and a second portion 14 which extend parallel to each other.
b and a third part 14c connecting these parts to each other
And a U-shape.
At the one end of the microstrip line 14, that is, at the end of the first portion 14a, a through hole 16 that penetrates the dielectric substrate 10 is also provided, and a conductor substance 18 is provided in the through hole 16. By filling, one end of the microstrip line 14 and the ground conductor 12 are electrically connected to each other.

Therefore, in the present invention, the microstrip line 14 having the above-described structure extends in parallel with each other, and is spaced by a predetermined distance at a position where the first portion 14a and the second portion 14b are opposed to each other. Plural pairs of soldering lands 20 and 20 (three in the illustrated example) for mounting the capacitor element 22 (shown by a chain line) and connecting it are provided. In this case, each soldering land 20,
20 can be formed of a solder resist or glass.

However, the resonance frequency f is f = 1 / (2
π√LC), the capacitance C of the capacitive element is determined by the position of any one of the soldering lands 20, 20.
Preset inductance L without changing
Can be obtained. In this case, soldering land 2
The positions 0 and 20 are the third position of the microstrip line 14.
The resonance frequency can be set to increase as it approaches the portion 14c.

In the present invention, chip capacitors can generally be used as the capacitors mounted on the soldering lands 20, 20. Moreover, the modulation sensitivity can be changed by using a varactor diode (variable capacitance diode) instead of the capacitor.

As described above, according to the present embodiment, the resonance frequency depending on the positions of the soldering lands 20, 20 is obtained and set by assuming that the capacitive element having the predetermined capacitance C is used in advance. The chip capacitor can be easily mounted to obtain the required resonance frequency. Moreover, in this case, the design change of the resonance frequency can be easily achieved by changing the positions of the soldering lands 20, 20 without changing the capacitance of the capacitor. The microstrip line 14 can also be formed by forming a thick film of copper (Cu).

Although the preferred embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and many design changes can be made without departing from the spirit of the present invention. For example, in the above-described embodiment, the case of the unbalanced type in which the microstrip line is placed on the dielectric substrate formed on the ground conductor is shown.
It is needless to say that the microstrip line resonator of the present invention described above can be applied to a balanced type in which a dielectric substrate is sandwiched by ground conductors and microstrip lines are inserted and arranged in the dielectric substrate. is there.

[0019]

As is apparent from the above-described embodiments, according to the microstrip line resonator of the present invention,
In a microstrip line resonator formed by forming a microstrip line having a folded pattern, one end of which is connected to a ground conductor, on a dielectric substrate provided with a ground conductor,
A structure in which a plurality of pairs of soldering lands for mounting the capacitor are formed along the opposite side edges of the microstrip line with a required space therebetween, and the capacitor is selectively connected in parallel to these opposing soldering lands. By doing so, it is possible to easily achieve selective setting of a plurality of preset resonance frequencies without changing the capacitive element.

That is, according to the present invention, a plurality of resonance frequencies can be easily selected by a microstrip line having one pattern (U-shape). Therefore, there is an advantage that the design of the resonator can be easily changed.

[Brief description of drawings]

FIG. 1 is a schematic plan perspective view showing an embodiment of a microstrip line resonator according to the present invention.

[Explanation of symbols]

 10 Dielectric Substrate 12 Ground Conductor 14 Microstrip Line 14a First Part 14b Second Part 14c Third Part 16 Through Hole 18 Conductive Material 20 Soldering Land 22 Capacitive Element

Claims (3)

[Claims] 1. A microstrip line resonator comprising a dielectric substrate provided with a ground conductor and a microstrip line having a folded pattern, one end of which is connected to the ground conductor, formed along a side edge of the microstrip line opposite to each other. Microstripline resonance, characterized in that a plurality of pairs of soldering lands for mounting capacitive elements are formed at required intervals and the capacitive elements are selectively connected in parallel to the opposing soldering lands. vessel. 2. The microstrip line resonator according to claim 1, wherein the capacitive element connected to the soldering land is a chip capacitor. 3. The microstrip line resonator according to claim 1, wherein the capacitive element connected to the soldering land is a varactor diode.