JPH05121918A - Microstrip line resonator - Google Patents

Abstract

(57) [Summary] [Objective] In a microstrip line resonator used for resonators such as oscillators and filters of several 100 MHz to several GHz, it is possible to solve the difficulty of resonance frequency correction, and to achieve a high precision resonance frequency with a small number of steps. The object is to realize a tunable microstrip line resonator. A microstrip line 2 formed on a dielectric substrate 1, a conductor pattern 4 formed on a surface of the dielectric substrate 1 opposite to the microstrip line 2, a microstrip line 2, and a conductor pattern 4 are arranged in parallel. When the microstrip line 2 is trimmed, the resonance frequency change amount per unit trimming amount does not suddenly increase by providing the through-hole wirings 6a and 6b connected to the. The frequency can be adjusted.

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 used as a resonator such as an oscillator or a filter of several 100 MHz to several GHz.

[0002]

2. Description of the Related Art In recent years, there is a strong demand for miniaturization and thinning of oscillators, filters and the like used in mobile terminal equipment such as mobile phones and mobile communication equipment, and microstrip line resonators are often used as these resonators. It is used.

FIG. 7 shows an example of a circuit in which this microstrip line resonator is used in a single tuning filter circuit. The resonance capacitor 14 is provided in the microstrip line 15.
The output coupling capacitor 16 is also connected, and the transistor 12, the input coupling capacitor 11, and the drive circuit including the bias system (not shown) are connected by the coupling capacitor 13. The tuning frequency of such a filter is determined mainly by the resonance frequency determined by the microstrip line 15 and the resonance capacitor 14, and the factors determining the resonance frequency are the microstrip line 15 and the resonance frequency.
The main factors are the line length, the line width, the material of the substrate on which the microstrip line 15 is formed, the substrate thickness, the capacitance value of the resonance capacitor 14, and the like.

The structure of a conventional microstrip line resonator will be described below. 8A and 8B show the structure of a conventional microstrip line resonator, where 1 is a dielectric substrate, 2 is a microstrip line formed on the surface of the dielectric substrate 1, and 3 is a dielectric. Body board 1
A ground conductor 5 formed on the back surface of the dielectric substrate 1 and a conductor pattern 7a, 7b formed on the front surface of the dielectric substrate 1 for connecting the resonance capacitor 8 connected to the microstrip line 2 and the back ground conductor 3 to each other. Is a through hole for connecting the conductor pattern 5 formed on the surface of the dielectric substrate 1 and the microstrip line 2 to the ground conductor 3, and 8 is a resonance capacitor.

[0005]

In the microstrip line resonator having the above-mentioned structure, the line length and line width of the microstrip line 2 are mainly varied, and the capacitance value of the resonance capacitor 8 is further varied. Since the variation of the resonance frequency occurs due to the variation of the assembly, the resonance frequency is adjusted to correct the variation.

A conventional method of adjusting the resonance frequency is shown in FIG.
A description will be given using (a) and (b). Conventionally, the resonance frequency of a resonator using a microstrip line is adjusted by a laser method for a part of the microstrip line 2.
It was removed by a trimming method such as a sandblast method, and the line length and line width of the microstrip line 2 were changed equivalently. FIGS. 9A and 9B are views showing an example of a conventional microstrip line trimming method. FIG. 9A is a method example 1, which is an example in which the trimming portion 9 is formed by performing trimming over a wide range of the microstrip line 2. Figure 9
(B) is a method example 2, in which the microstrip line 2 is used.
This is an example in which the width of the trimming portion 9 is expanded in advance to increase the trimable range. However, in the above-mentioned configuration, the trimming amount is large and it takes a lot of man-hours to adjust the frequency. Further, as shown in the resonance frequency change data of FIG. As the number decreases, the change in the resonance frequency per unit trimming amount increases, making it difficult to adjust the resonance frequency with high accuracy.
Variations in filter characteristics increase. Further, since trimming equipment requires very high control accuracy, there is a problem that productivity is lowered and equipment cost is increased.

The present invention solves the above-mentioned conventional problems, and provides a microstrip line resonator capable of highly accurate resonance frequency adjustment with a small number of steps.

[0008]

To achieve this object, a microstrip line resonator of the present invention comprises a microstrip line formed on a dielectric substrate and a microstrip line formed on the dielectric substrate. It has a configuration including a conductor pattern formed on the opposite surface or an inner layer of the dielectric substrate, and a plurality of through-hole wirings that connect the microstrip line and the conductor pattern in parallel.

[0009]

With this configuration, even when the trimming of the microstrip line is advanced, the resonance frequency change amount per unit trimming amount does not suddenly increase, and the resonance frequency can be adjusted with high accuracy with a small number of steps. It was done.

[0010]

(Embodiment 1) An embodiment of the present invention will be described below with reference to the drawings. 1 (a) and 1
1 (b) and 1 (c) show a microstrip line resonator according to the first embodiment of the present invention.
1A is a plan view, FIG. 1B is a cross-sectional view seen from the front, and FIG. 1C is a cross-sectional view seen from the side. 1 (a)-
In (c), 1 is a dielectric substrate, 2 is a microstrip line formed on the surface of the dielectric substrate 1, 3 is a ground conductor formed on the back surface of the dielectric substrate 1, and 4 is the back surface of the dielectric substrate 1. To connect the resonance capacitor 8 connected to the microstrip line 2 and the ground conductor 3 on the back surface with the conductor patterns 5 connected by through-hole wirings 6a and 6b formed in parallel with the microstrip line 2. Conductor patterns formed on the front surface, 6a and 6b are through-hole wirings that connect the microstrip line 2 and the conductor pattern 4 formed on the back surface of the dielectric substrate 1 in parallel, and 7a and 7b are conductors formed on the surface. Through-hole wiring for connecting the pattern 5 and the microstrip line 2 to the ground conductor 3 on the back surface, and 8 for a resonance capacitor.

The operation of the microstrip line resonator configured as described above will be described with reference to FIG. 2A and 2B are enlarged views of the central portion of the microstrip line 2 in FIG.
FIG. 2A is a plan view, and FIG. 2B is a cross-sectional view seen from the side surface. Reference numeral 9 in FIG. 2A shows a trimming portion of the microstrip line 2 formed by a laser method, a sandblast method, or the like. With this configuration, the through-hole wirings 6a, 6
When trimming between b, as the trimming amount increases and the remaining width of the microstrip line 2 decreases, the line length and the wiring width of the microstrip line 2 between the through-hole wirings 6a and 6b are Conductor pattern 4 connected in parallel to line 2
The ratio determined by is increased, and when the microstrip line 2 is cut, it is completely determined by the conductor pattern 4. As a result, the change characteristic of the resonance frequency with respect to the trimming amount of the microstrip line resonator in this embodiment starts to be more gradual than when the trimming amount increases and the influence of the conductor pattern 4 begins to appear, and the microstrip line 2 is disconnected. It will be constant at the time when it is done.

The characteristics of the microstrip line resonator according to this embodiment and the characteristics of the conventional microstrip line resonator are shown in comparison with FIG.

As is apparent from FIG. 3, the microstrip line resonator according to this embodiment has an excellent effect in adjusting the resonance frequency.

4 (a) and 4 (b) show the first embodiment.
It is an application example based on and is an enlarged front view of a central portion of a microstrip line to be trimmed. FIG. 4A shows an application example (1) in which a thin microstrip line 2 is used, and the variable amount of the resonance frequency is small. FIG. 4B shows an application example (2) in which the width of the trimming portion is increased and the conductor pattern 4 connected in parallel with the microstrip line 2 is made thin and long. It is a large number. The characteristics of the microstrip line according to these application examples are shown in FIG.

As described above, according to this embodiment, the microstrip line 2 provided on the dielectric substrate 1 and the conductor pattern 4 provided on the opposite surface thereof are connected by a plurality of through hole wirings 6a and 6b. As a result, it is possible to prevent the resonance frequency change amount per unit trimming amount from suddenly increasing, and it is possible to adjust the resonance frequency with high accuracy.

(Second Embodiment) A second embodiment of the present invention will be described below with reference to the drawings. 6 (a) and FIG.
(B) is a diagram of a microstrip line resonator showing a second embodiment, both of which are enlarged views of the central portion of the microstrip line. FIG. 6A is a plan view, and FIG. 6B is a sectional view seen from the front. Figure 6
In FIG. 6A, 1 is a dielectric substrate, 2 is a microstrip line, 3 is a ground conductor on the back surface, 6a,
Reference numeral 6b is a through hole wiring, and the above is the same as the configuration of FIG. The conductor pattern 10 differs from the configuration of FIG.
On the inner layer of the dielectric substrate 1, which is connected in parallel to the microstrip line 2 by the through-hole wirings 6a and 6b.

The operation of the microstrip line resonator configured as described above is basically the same as that of the first embodiment, but the microstrip line 2 is connected in parallel to the inner layer of the dielectric substrate 1. Conductor pattern 1
By forming 0, the space on the back surface side can be effectively used.

[0018]

As described above, according to the present invention, the microstrip line formed on the dielectric substrate and the conductor formed on the surface of the dielectric substrate opposite to the microstrip line or on the inner layer of the dielectric substrate. By providing a pattern and a plurality of through-hole wirings that connect the microstrip line and the conductor pattern in parallel, an excellent microstrip line resonator capable of highly accurate resonance frequency adjustment with a small number of man-hours is realized, which is small and has high performance. It is also of high industrial value to provide high-frequency oscillators, filters, etc. with high productivity.

[Brief description of drawings]

FIG. 1A is a plan view of a microstripline resonator according to a first embodiment of the present invention. FIG. 1B is a sectional view of the microstripline resonator according to the first embodiment as seen from the front. Sectional View of a Microstripline Resonator from a Side View

FIG. 2A is an enlarged plan view of a central portion of a microstrip line resonator for explaining the operation of the microstrip line resonator according to the first embodiment. FIG. 2B is a microstrip line resonator according to the first embodiment. Cross-sectional view of the central part of the microstrip line enlarged to explain the operation and seen from the side

FIG. 3 is a resonance frequency characteristic diagram according to the trimming amount of the present invention and the conventional microstrip line resonator.

FIG. 4A is an enlarged plan view of a central portion of a microstrip line showing an application example (1) based on the first embodiment. (B) An application example (2) based on the first embodiment. Enlarged plan view of the central part of the microstrip line shown

FIG. 5 is a resonance frequency characteristic diagram according to an application example shown in (a) and (b) of the present invention.

6A is an enlarged plan view of a central portion of a microstrip line resonator of the microstrip line resonator according to the second embodiment. FIG. 6B is a center portion of a microstrip line of the microstrip line resonator according to the second embodiment. Expand the section,
Cross-section view from the front

FIG. 7 is a circuit diagram of a single tuning filter circuit using a microstrip line resonator for explaining the circuit operation.

8A is a plan view showing the structure of a conventional microstripline resonator, and FIG. 8B is a side sectional view showing the structure of a conventional microstripline resonator.

9A is a diagram showing a trimming method example 1 for explaining the operation of a conventional microstripline resonator, and FIG. 9B is a diagram showing a trimming method example 2 for explaining the operation of a conventional microstripline resonator.

[Explanation of symbols]

 1 Dielectric Substrate 2 Microstripline 3 Grounding Conductor 4 Conductor Pattern 5 Conductor Pattern 6a, 6b Through Hole 7a, 7b Through Hole 8 Resonance Capacitor 9 Trimming Point 10 Conductor Pattern 11 Coupling Capacitor 12 Transistor 13 Coupling Capacitor 14 Resonance Capacitor 15 Microstrip line 16 coupling capacitor

Claims (2)

[Claims] 1. A microstrip line formed on a dielectric substrate, a conductor pattern formed on a surface of the dielectric substrate opposite to the microstrip line, and the microstrip line and the conductor pattern are connected in parallel. A microstrip line resonator having a plurality of through hole wirings. 2. The microstrip line resonator according to claim 1, wherein a conductor pattern connected by a plurality of through-hole wirings is provided in parallel with the microstrip line in an inner layer of the dielectric substrate.