JP3079694B2 - Microstrip line resonator - Google Patents

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 for a resonator such as an oscillator or a filter of several hundred MHz to several GHz.

[0002]

2. Description of the Related Art In recent years, there has been a strong demand for downsizing and thinning of oscillators, filters, and the like used in portable terminal devices of mobile communication devices such as cellular phones. Used.

FIG. 7 shows an example of a circuit in which this microstrip line resonator is used in a single-tuned filter circuit. The microstrip line 15 includes a resonance capacitor 14.
An output coupling capacitor 16 is connected, and the transistor 12 and the input coupling capacitor 11 are connected to a drive circuit including a bias system (omitted in the drawing) by a 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 resonance frequency is determined by the microstrip line 15.
The main factors are the line length, 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.

[0004] The structure of a conventional microstrip line resonator will be described below. FIGS. 8A and 8B show the structure of a conventional microstrip line resonator, wherein 1 is a dielectric substrate, 2 is a microstrip line formed on the surface of the dielectric substrate 1, and 3 is a dielectric substrate. Body substrate 1
A conductor pattern 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, 7a, 7b Is a through hole for connecting the ground pattern 3 to the conductor pattern 5 and the microstrip line 2 formed on the surface of the dielectric substrate 1, and 8 is a resonance capacitor.

[0005]

In the microstrip line resonator configured as described above, the line length and line width of the microstrip line 2 vary, the capacitance of the resonance capacitor 8 varies, and furthermore, Since the resonance frequency varies due to the assembly variation, the resonance frequency is adjusted and the variation is corrected.

FIG. 9 shows a conventional method of adjusting the resonance frequency.
This will be described with reference to (a) and (b). Conventionally, the resonance frequency of a resonator using a microstrip line has been adjusted by using a laser method,
Removal is performed by a trimming method such as a sand blast method, and equivalently, the line length and line width of the microstrip line 2 are changed. FIGS. 9A and 9B are views showing an example of a conventional microstrip line trimming method. FIG. 9A is a method example 1 in which the trimming unit 9 is formed by performing trimming over a wide range of the microstrip line 2. FIG.
(B) is a method example 2, and the microstrip line 2
This is an example in which the width of the trimming section 9 is increased in advance to increase the trimming possible range. However, in the above-described configuration, the trimming amount increases and it takes time and effort to adjust the frequency. Further, as shown in the change data of the resonance frequency in FIG. As the number decreases, the change of the resonance frequency per unit trimming amount increases, so it is difficult to adjust the resonance frequency with high accuracy,
Variations in filter characteristics increase. Further, since very high control accuracy is required for the trimming equipment, 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 adjusting the resonance frequency with high accuracy and with a small number of steps.

[0008]

In order to achieve the above object, a microstrip line resonator according to the present invention comprises a microstrip line formed on a dielectric substrate and a microstrip line formed on the dielectric substrate. a ground conductor formed on the inner layer of the opposite surface or the dielectric substrate and the conductive pattern, birds of the microstrip line
A plurality of through-hole wirings for connecting the conductor patterns in parallel on both sides of the portion to be trimmed;
The microstrip line between the
It is a thing which was a mining part.

[0009]

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

[0010]

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

The operation of the microstrip line resonator configured as described above will be described with reference to FIG. FIGS. 2A and 2B are enlarged views of the central portion of the microstrip line 2 in FIG.
2A is a plan view, and FIG. 2B is a cross-sectional view as viewed from a side. Reference numeral 9 in FIG. 2A indicates a trimming portion of the microstrip line 2 by a laser method, a sand blast method, or the like. With such a configuration, the portion to be trimmed of the microstrip line 2, that is, the through-hole wiring 6a,
6b, the length and width of the microstrip line 2 between the through-hole wirings 6a and 6b become smaller as the trimming amount increases and the remaining width of the microstrip line 2 decreases. Conductor pattern 4 connected in parallel to line 2
Becomes higher, and is completely determined by the conductor pattern 4 when the microstrip line 2 is cut. 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 become gentler than the point where the trimming amount increases and the effect of the conductor pattern 4 starts to appear, and the microstrip line 2 is cut. It becomes constant at the point of time.

FIG. 3 shows a comparison between the characteristics of the microstrip line resonator according to the present embodiment and the characteristics of the conventional microstrip line resonator.

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

FIGS. 4A and 4B show the first embodiment.
FIG. 7 is an application example based on FIG. 5, 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 reduced. 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 thinner and longer. It is the one that increased. FIG. 5 shows the characteristics of the microstrip line according to these application examples.

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 are connected by a plurality of through-hole wirings 6a and 6b. Accordingly, it is possible to prevent the amount of change in the resonance frequency per unit trimming amount from suddenly increasing, and it is possible to adjust the resonance frequency with high accuracy.

(Embodiment 2) A second embodiment of the present invention will be described below with reference to the drawings. FIGS. 6A and 6
(B) is a diagram of a microstrip line resonator showing the second embodiment, and both figures are enlarged views of a central portion of the microstrip line. FIG. 6A is a plan view, and FIG. 6B is a cross-sectional view as viewed from the front. FIG.
6 (a) and FIG. 6 (b), 1 is a dielectric substrate, 2 is a microstrip line, 3 is a ground conductor on the back surface, 6a,
Reference numeral 6b denotes a through-hole wiring, which has the same configuration as that of FIG. The difference from the configuration of FIG.
Is provided in the inner layer of the dielectric substrate 1 and 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, except that the microstrip line resonator is connected to the inner layer of the dielectric substrate 1 in parallel with the microstrip line 2. Conductor pattern 1
By forming 0, the space on the back side can be used effectively.

[0018]

As described above, the present invention relates to a microstrip line formed on a dielectric substrate, a ground conductor provided on a surface of the dielectric substrate opposite to the microstrip line, comprising a conductor pattern formed in the inner layer of the dielectric substrate, and a plurality of through-hole wiring that connects the conductor patterns on both sides of the trimming scheduled portion of the microstrip line in parallel, the double
The microstrip between several through-hole wires.
Because it is a rimming part, it realizes an excellent microstrip line resonator that can adjust the resonance frequency with high accuracy with a small number of man-hours, and provides a small, high-performance, high-productivity high-frequency oscillator, filter, etc. Is of great industrial value.

[Brief description of the drawings]

FIG. 1A is a plan view of a microstrip line resonator according to a first embodiment of the present invention. FIG. 1B is a cross-sectional view of the microstrip line resonator according to the first embodiment as viewed from the front. Sectional view from the side of the microstrip line resonator in the embodiment of FIG.

FIG. 2A is an enlarged plan view of a central portion of a microstrip line for explaining the operation of the microstrip line resonator according to the first embodiment; FIG. 2B is a plan view of the microstrip line resonator according to the first embodiment; Cross-sectional view of the center of the microstrip line for operation explanation, enlarged from the side

FIG. 3 is a diagram showing resonance frequency characteristics according to the amount of trimming of the microstrip line resonator 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. FIG. 4B is an application example (2) based on the first embodiment. Plan view of the center 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.

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

FIG. 7 is a circuit diagram of a single-tuned filter circuit using a microstrip line resonator for explaining a circuit operation;

8A is a plan view showing the structure of a conventional microstrip line resonator. FIG. 8B is a cross-sectional view showing the structure of the conventional microstrip line resonator viewed from a side.

9A is a diagram showing a first example of a trimming method for explaining the operation of a conventional microstrip line resonator. FIG. 9B is a diagram showing a second example of a trimming method for explaining the operation of a conventional microstrip line resonator.

[Explanation of symbols]

 Reference Signs List 1 dielectric substrate 2 microstrip line 3 ground 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)

(57) [Claims] A microstrip line formed on a dielectric substrate; a ground conductor and a conductor pattern formed on a surface of the dielectric substrate opposite to the microstrip line ;
And a plurality of through-hole wiring that connects the conductor patterns in parallel on both sides of the constant portion, the plurality of through-holes
Trimming section for microstrip line between wires
And the microstrip line resonator. 2. The microstrip line resonator according to claim 1, wherein a conductor pattern connected by a plurality of through-hole wirings is provided on an inner layer of the dielectric substrate in parallel with the microstrip line.