JPH0514006A - Stripline resonator and filter - Google Patents

Abstract

(57) [Summary] (Modified) [Purpose] To obtain a small unadjusted resonator and filter that can be used in the high frequency range of 100 MHz or higher. [Structure] Conductor strip lines 11 to 14 having one or more turns are formed on one surface or both surfaces of a dielectric substrate 10 having a relatively high dielectric constant, and the conductor strip line 11 is formed.
˜14 are arranged close to each other or face each other so that a line capacitance is generated. Conductor strip lines 11-14
The LC parallel resonance circuit is composed of the inductance component of and the capacitance component of the line capacitance, and a filter can be obtained by forming the LC parallel resonance circuit in multiple stages. Conductor strip lines 11-1
It is also possible to change the pass band characteristic, the attenuation characteristic and the like depending on the shape of 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stripline resonator or filter that can be used in a high frequency band exceeding 100 MHz, and has a conductor pattern of one turn or more formed on the surface of a dielectric substrate. And filters.

[0002]

2. Description of the Related Art There is an increasing demand for resonators and filters that can be used in a band of several hundred MHz for mobile communication devices. Conventionally, helical resonator (filter), dielectric resonator (filter)
Etc. are used, but there is a limit to miniaturization because the size is restricted by the wavelength of the resonance frequency. Moreover, adjustment is often necessary due to the problem of dimensional accuracy during firing.
Moreover, it requires a lot of man-hours in the assembly process,
There is a demand for a resonator and a filter that have high accuracy and are easy to manufacture.

Further, in the helical filter and the dielectric filter, there is a problem that a harmonic wave three times as high as the fundamental frequency is generated, and how to remove this is a big problem.

[0004]

SUMMARY OF THE INVENTION The present invention provides a resonator and a filter which can be miniaturized and can be easily manufactured and which can be used in a high frequency range. Further, it is possible to provide a resonator and a filter that can obtain high accuracy, require almost no adjustment, and have stable characteristics.

[0005]

According to the present invention, a conductor pattern having at least one turn is formed on the surface of a dielectric substrate having a relatively high dielectric constant, and a plurality of conductor patterns are arranged to capacitively
By inductively coupling, a resonator and a filter are configured to solve the above problems.

That is, at least one surface of the dielectric substrate is provided with a circulating inductor conductor pattern, the conductor patterns are arranged in close proximity, and one end of the conductor pattern is connected to the input / output end and the other end. Is characterized by being grounded.

[0007] Specifically, a conductor pattern for an inductor, which is connected to the front and back surfaces of the dielectric substrate by through holes and circulates, is provided. The conductor patterns are arranged so as to overlap on the front and back surfaces, and one end of the conductor pattern is arranged. Is connected to the input / output end and the other end is grounded.

[Action]

The self-resonance generated by the inductance component of the conductor pattern (strip line) and the inter-line (distributed) capacitance component between the conductor patterns is positively utilized as a resonator and a filter.

[0009]

EXAMPLES Examples of the present invention will be described below.

FIG. 1 is a plan view showing an embodiment of the present invention.
(A) shows the upper surface and (b) shows the lower surface. On the front and back of the ceramic substrate 10 with a relatively high dielectric constant of about 90,
Conductor striplines 11, 12 are formed. The conductor strip lines 11 and 12 are connected to each other by through holes formed in the substrate 10 to form one continuous strip line. In this example, a stripline of connected conductors
The length of 11 and 12 was 35.4 mm. The width of the conductor strip lines was 0.2 mm, and the spacing was also 0.2 mm.

The conductor strip line 11 is formed as a conductor pattern that circulates on the surface side for about one and a half turns. The conductor strip line 12 on the back surface, which is connected by a through hole, is also formed as a conductor pattern that slightly circulates for two turns, and the end portion is extended to the side surface of the substrate. The front and back conductor patterns are formed so as to overlap and oppose each other on the front and back surfaces. Since the conductor patterns are formed so as to extend in the same direction, it is impossible that all the conductor patterns completely overlap and face each other, but most of them can be overlapped. This is to give capacitance between the conductor patterns. Of course, it is desirable to arrange the conductor patterns close to each other so that capacitance can be obtained between the conductor patterns on the same surface. In addition, in order to increase the capacity,
As mentioned above, it is necessary to use a substrate made of a material having a relatively high dielectric constant.

In the example shown in FIG. 1, conductor strip lines 13 and 14 are formed on the front and back surfaces of the same substrate in a pattern symmetrical to the conductor strip lines 11 and 12 formed on the front and back surfaces of the ceramic substrate. These dimensions are the same as above. Also,
Conductor patterns 15 and 16 are formed at the ends of the conductor strip line 11 and the conductor strip line 13 so as to face each other, to obtain a structure for obtaining an input / output coupling capacitance. 0.16 mm ² conductor patterns were formed at the ends of the conductor strip lines 11 and 13, and a capacitance was obtained between these and the conductor patterns 15 and 16 on the back surface. Zero the distance between two conductor strip lines.
It was set to 6 mm.

LC by the conductor strip lines 11 and 12
A parallel tank circuit is formed, and the conductor strip lines 13 and 14 form an LC parallel tank circuit.
Between these, capacitive and inductive coupling occurs,
A filter is constructed.

FIG. 2 is an explanatory diagram of pass band characteristics of the filter having the above configuration. It was confirmed that the center frequency was 254 MHz, the insertion loss was 3 dB or less, and excellent attenuation characteristics were obtained. It was also confirmed that the characteristics differ depending on the shape of the conductor pattern. It has been found that when the conductor pattern is formed line-symmetrically as shown in FIG. 1, the inductive coupling becomes large, and when it is point-symmetrical (rotationally symmetric), the capacitive coupling becomes large.

When the stripline resonator and the filter according to the present invention are actually used, a substrate having a high dielectric constant having conductor patterns formed on the front and back surfaces is sandwiched between substrates having a low dielectric constant, and the front and side surfaces of this laminate are It is advisable to form a conductor pattern on. It is desirable to separate only the portions corresponding to the input / output terminals and cover the other portions with a conductor pattern that is grounded. As a result, the shield effect can be obtained.

It is also possible to form three or more sets of conductor strip lines on one substrate, or it is possible to construct a multi-stage filter by stacking dielectric substrates via spacers. The thickness of each dielectric substrate is about 0.2 mm, and it is possible to obtain small and thin filters even if they are stacked with spacers.

[0017]

According to the present invention, it is possible to obtain a compact resonator and filter which can be used in a high frequency range. Moreover, it is possible to obtain a filter in which three times higher harmonics do not appear.

Further, since the conductor can be formed on the fired ceramic substrate by etching, high accuracy can be obtained and desired characteristics can be obtained without adjustment.

[Brief description of drawings]

FIG. 1 is a plan view of an embodiment of the present invention.

FIG. 2 is an explanatory diagram of characteristics of a filter according to the present invention.

[Explanation of symbols]

10 Dielectric substrate 11-14 conductor strip line

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[Procedure amendment]

[Submission date] January 14, 1992

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] Claim 4

[Correction method] Change

[Correction content]

Claims (4)

[Claims] 1. A conductor pattern for an inductor, which circulates on at least one surface of a dielectric substrate, the conductor patterns are arranged close to each other, and one end of the conductor pattern is connected to an input / output end and the other end is A stripline resonator characterized by being grounded. 2. A dielectric substrate is provided with inductor conductor patterns which are connected by through holes and circulate on the front and back surfaces of a dielectric substrate. The conductor patterns are arranged so as to overlap on the front and back surfaces, and one end of the conductor pattern is input / output. A stripline resonator characterized in that it is connected to one end and the other end is grounded. 3. At least two windings on the surface of the dielectric substrate.
Each of the conductor patterns is arranged close to each other, and one end of each conductor pattern is connected to the input / output end via a capacitor.
The other end is a grounded stripline filter. 4. A dielectric substrate is provided with at least two conductor patterns for inductors which are connected by through holes and circulate on the front and back surfaces of the dielectric substrate. The respective conductor patterns are arranged so as to overlap on the front and back surfaces, and the respective conductors are arranged. A stripline resonator, wherein one end of the pattern is connected to an input / output end via a capacitor and the other end is grounded.