JP2000068718A - Connecting structure of microstrip line device, high frequency filter, transmission/reception multicoupler and communication equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce a conductor loss due to the edge effect of a microstrip line and to improve a degree of freedom on designing for obtaining a prescribed filter characteristic. SOLUTION: Connecting electrodes 5, 6 and lines 31 to 34 as a resonator are formed on the surface of a dielectric board 1. The lines 31 and 34 are made of the aggregate of plural conductor lines and the end parts of the respective conductor lines are formed in a recessed/projected state to fit to the recessed/projected part of the electrode of its connecting opposite side while keeping a prescribed interval.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coupling structure of a microstrip line device, and a high-frequency filter, a duplexer and a communication device using the coupling structure.

[0002]

2. Description of the Related Art Conventionally, as a transmission line for a high-frequency circuit, a microstrip line has been used, which makes use of the advantages of being easy to manufacture, and capable of being reduced in size and thickness.

However, in a normal microstrip line, current is concentrated on the edge of the line due to the so-called edge effect, and the conductor loss at the edge becomes significant. Most of this conductor loss occurs in the area of several μm at the edge of the line, and the loss characteristics and power handling characteristics of the transmission line are governed by the edge effect. Accordingly, the applicant of the present invention has proposed a high-frequency transmission line and a dielectric resonator for the purpose of alleviating the current concentration at the edge of the electrode as disclosed in Japanese Patent Application No. Hei.
No. 276813.

FIG. 13 is an enlarged perspective view of a microstrip line in which the edge effect has been mitigated. The ground electrode 2 is formed on the lower surface of the dielectric plate 1 in the drawing, and the upper surface of the dielectric plate 1 in the drawing. 3a and 3b, conductor lines for a microstrip line are formed. By providing a plurality of gaps 4 at the edge of the track in this way, 3
This constitutes a thin sub-conductor line shown by b.

FIG. 14 is a comparative example of current densities of the microstrip line shown in FIG. 13 and a conventional microstrip line. As shown in (A), current concentrates on the respective edges of the conductor wires 3a and 3b.
As a whole, it is dispersed at a plurality of locations, so that the maximum current density is suppressed. On the other hand, in the conventional microstrip line shown in (B), a large current concentration occurs at the edge of the line 3, and the conductor loss at this portion becomes large.

[0006]

As described above, when the line used as the resonator is constituted by an aggregate of a plurality of conductor lines, in order to make the current phases flowing through the respective conductor lines the same,
For example, the ends of the resonator line and the coupling electrode are opposed to each other, or the ends of the resonator line are opposed to each other. However, such a structure has a problem that strong coupling cannot be obtained, and the degree of freedom in design when used as a filter is extremely low.

In order to sequentially couple a plurality of resonators, a method of arranging resonator lines in parallel with each other as shown in FIG. 15 can be adopted. However, the resonator lines are formed of an aggregate of a plurality of conductor wires. When configured, the electromagnetic field may be disturbed between adjacent lines.

An object of the present invention is to reduce the conductor loss due to the edge effect of a microstrip line and to increase the degree of freedom in design for obtaining predetermined filter characteristics and the like. , A high-frequency filter, a duplexer, and a communication device using the structure.

[0009]

SUMMARY OF THE INVENTION The present invention relates to a coupling structure of a line and an electrode provided on a surface of a dielectric, wherein each of the lines is constituted by an aggregate of a plurality of conductor wires. The ends of the conductor wires and the ends of the electrodes are made uneven, and the uneven portions are fitted with a predetermined gap therebetween.

With this structure, the resonator line or the transmission line and the coupling electrode, or the resonator lines form irregularities at the ends of the plurality of conductor wires and fit into the irregularities of each other. As a result, the capacitance of the gap increases, and strong external coupling or strong resonator-to-resonator coupling is obtained.

Further, in the present invention, the lengths of the plurality of conductor lines are made substantially constant, and the arrangement positions of the conductor lines are alternately shifted in the longitudinal direction of the conductor lines. With this structure, the length of each of the plurality of conductor wires is substantially constant, and the electrodes facing each other form an uneven shape and fit into the uneven portions of each other, so that the current phases of the respective conductor wires are aligned. . As a result, the disturbance of the electromagnetic field is small, and the effect of dispersing the current density flowing to the edge of each conductor wire due to the skin effect works effectively, thereby obtaining low loss characteristics.

Further, in the present invention, the line is constituted by a main conductor line arranged at the center and a plurality of sub-conductor lines arranged at an edge portion thereof, and an end of the main conductor line is made uneven on the other side. In accordance with the shape portion, both are formed in an uneven shape that fits into each other. With this structure, the current concentration at the edge is reduced, and the increase in conductor loss due to the decrease in the conductor portion within a certain line width is suppressed. The capacitance at the ridges is increased and a strong coupling is obtained.

Further, in the present invention, a dielectric is filled in or brought close to the uneven portion of the conductor wire. As a result, the capacitance of the gap between the concave and convex portions increases, and the strength of the coupling increases.

Further, in the present invention, at least one of the conductor wires is a thin-film multilayer electrode composed of a laminate of a thin-film conductor layer and a thin-film dielectric layer. As a result, current concentration is further alleviated, and overall conductor loss is reduced.

According to the present invention, at least one of the conductor wires is made of a superconductor. This reduces the overall conductor loss.

Further, in the present invention, the line is a resonator, and the high-frequency filter is configured as an input / output unit for coupling the electrode to the resonator.

A transmission filter and a reception filter are constituted by the high frequency filter, a transmission filter is provided between the input port and the input / output port, and a reception filter is provided between the input / output port and the output port. Is configured. Further, the communication device is configured by providing the dielectric filter or the duplexer in the high frequency unit.

[0018]

FIG. 1 shows the configuration of a high-frequency filter according to a first embodiment. FIG. 1 shows only the electrode pattern formed on the upper surface of the dielectric plate. A ground electrode is formed on the entire lower surface of the dielectric plate, and a microstrip line is formed by the ground electrode and an electrode on the upper surface sandwiching the dielectric plate. However, the central portion of the microstrip line is omitted, and the omitted portion is indicated by a wavy line. In FIG.
A portion indicated by is a line used as a resonator, and is composed of a main conductor line 3a having a relatively large line width at the center and a plurality of sub-conductor lines 3b having a small line width arranged at an edge portion thereof. Both ends of the main conductor wire 3a and the sub conductor wire 3b are arranged so as to form irregularities. The line length of the line 3 is a half wavelength of the resonance frequency to constitute a microstrip line resonator having both ends open. Hereinafter, this resonator is referred to as a “thin-film multi-wire resonator”.

Reference numerals 5 and 6 denote coupling electrodes, respectively, and the comb-shaped electrodes 5b and 6b protrude so as to fit into the uneven portions formed by the ends of the main conductor line 3a and the sub-conductor line 3b. For example, the line width of the main conductor 3a is several μm to 100 μm, the line width of each conductor of the sub-conductor 3b is 1.5 μm, the number of sub-conductors is on the order of 100, and the width of the entire line 3 is It is about 400 μm. With this structure, the coupling electrodes 5 and 6 and both ends of the line 3 are coupled by electrostatic capacitance (hereinafter, referred to as “capacitive coupling”). In this way, a high-frequency filter in which the coupling electrodes 5 and 6 operate as signal input / output terminals and the line 3 operates as a resonator is obtained.

The pattern of the resonator line and the coupling electrode is formed by various patterning methods such as etching after forming an electrode film on the entire surface of the dielectric plate.

When there are a plurality of conductor wires acting as resonators other than the ground electrode as described above, resonance modes are generated by the number of the conductor wires, and among these, the fundamental resonance mode having the lowest resonance frequency is used. Thereby, the resonator can be operated with low loss.

According to the first embodiment, low-loss operation of the thin-film multi-wire electrode resonator is not impaired, and large-capacity coupling can be ensured in a small area. In addition, since a concave-convex portion between the end of the resonator line and the end of the coupling electrode is fitted with a predetermined gap, Qe (external coupling Q) is set to 1
It can be as strong as about 0-100. In a structure in which the ends of the line and the electrode are simply butted, Qe is only about one thousand to several thousand, and only weak external coupling can be obtained.

FIG. 2 is a diagram showing a configuration of a high frequency filter according to the second embodiment, and shows only an electrode pattern portion on a dielectric plate. In this example, a concave portion is formed by providing the comb-shaped electrodes 3c at both ends of the main conductor line 3a of the line 3. On the other hand, the comb-like electrodes 5c and 6c corresponding to the concave portions at both ends of the main conductor wire 3a are formed on the coupling electrodes 5 and 6, respectively. With this structure, the capacitive coupling between the coupling electrodes 5 and 6 and both ends of the line 3 can be increased.
Conversely, a convex comb-shaped electrode may be formed at both ends of the main conductor wire 3a, and a concave comb-shaped electrode may be formed on the side of the coupling electrodes 5 and 6 opposite thereto.

FIG. 3 is a view showing a configuration of a high-frequency filter according to the third embodiment, and shows only an electrode pattern on a dielectric plate. Unlike the first and second embodiments, in this example, the main conductor line 3a and the sub-conductor line 3b of the line 3 have the same line length, and the arrangement position is set in the longitudinal direction of the line (the horizontal direction in the figure). ). In accordance with this, the protruding length of the comb-like electrodes 5b, 6b of the coupling electrodes 5, 6 is made constant. According to this structure, the resonance frequencies of the main conductor line 3a and the sub conductor line 3b of the line 3 can be matched, the phases of the currents flowing through the conductor lines are uniform, and the edge of each conductor line due to the skin effect The effect of dispersing the density of the current flowing through the portion works effectively. Therefore, the thin-film multi-wire resonator can be operated with low loss near the design center.

Next, the configuration of a high-frequency filter according to a fourth embodiment is shown in FIG. FIG. 4A shows the entire electrode pattern on the dielectric plate, and FIG. 4B is an enlarged view of a portion B in FIG. In the first to third embodiments, a single line is used to form a high-frequency filter using a single-stage resonator, but in this example, a high-frequency filter using two resonators using lines 3 and 7 is used. The structure of the coupling part between the coupling electrode 5 and the resonator line 3 and the structure of the coupling part between the resonator line 7 and the coupling electrode 6 are the same as those in the first to third embodiments. . The abutting portions of the lines 3 and 7 are, as shown in (B), a main conductor line 3a and a sub conductor line 3b of the line 3.
Are arranged unevenly, and correspondingly, the ends of the main conductor line 7a and the sub-conductor line 7b of the line 7 are also arranged so that they fit into each other. With this structure, two resonators constituted by the lines 3 and 7 are capacitively coupled.

FIG. 5 is a diagram showing a configuration of a coupling portion between resonators of a high-frequency filter according to a fifth embodiment. In this manner, the comb-shaped electrodes 3c and 7c may be provided on the main conductor lines 3a and 7a of the two lines, respectively, so that the concave and convex portions are fitted. According to this structure, the strength of the coupling between the resonators can be further increased.

FIG. 6 is a view showing a structure of a coupling portion between a coupling electrode and a line of a high frequency filter according to a sixth embodiment. As shown in the drawing, the opposing portions of the coupling electrode 5 and the main conductor line 3a and the sub-conductor line 3b of the line 3 have a shape in which the concave and convex portions are fitted with a predetermined gap therebetween, and are formed in the gap portions. A dielectric 8 is formed. With this structure,
The capacitance between the coupling electrode 5 and the end of the line 3 increases. Such a dielectric 8 may be formed by a thick film printing method.

FIG. 7 is a view showing a structure of a coupling portion between resonators of a high frequency filter according to a seventh embodiment. (B) is an enlarged view of a B part in (A). Track 3 and Track 7
The shape of the opposing portion is the same as that shown in FIG. 5 in that the concavo-convex portion is fitted with a predetermined gap kept therebetween, and the dielectric 8 is formed in the gap. With this structure, the capacitive coupling between the resonators can be further increased. Further, by providing the dielectrics 9 and 10 in the gaps between the sub-conductor lines of the lines 3 and 7, current concentration due to the skin effect can be reduced, and overall conductor loss can be reduced. Note that the entire coupling portion between the resonators may be covered with a dielectric. Similarly, the surface may be covered with a dielectric over the adjacent sub-conductor line.

FIG. 8 is a diagram showing a configuration of a high frequency filter according to the eighth embodiment. (A) is an electrode pattern on a dielectric plate, (B) is a cross-sectional view of the BB portion in (A). The patterns of the coupling electrodes 5 and 6 and the line 3 as a plan view are the same as those shown in FIG. 3, but the main conductor line 3a and the sub-conductor line 3b of the line 3 are as shown in FIG. It is provided as a thin-film multilayer electrode composed of a laminate of a thin-film conductor layer and a thin-film dielectric layer. In FIG. 8B, reference numeral 2 denotes a single-layer ground electrode formed on the lower surface of the dielectric plate 1, and the main conductor lines 3a and the sub-conductor lines 3b are formed by alternately laminating thin-film conductor layers and dielectric layers, respectively. are doing. Here, the thickness of the thin-film conductor layer and the thickness of the thin-film dielectric layer are each on the order of the skin depth or less.

With this structure, unlike the case of the single-layer electrode, the current does not concentrate only on the surface portion due to the skin effect.
The current is dispersed in each thin-film conductor layer portion. For this reason, the current concentration due to the edge effect is dispersed in the surface direction of the dielectric plate 1, and the current concentration due to the skin effect in the thickness direction of the electrode is reduced at the same time.

FIG. 9 is a view showing the configuration of a high-frequency filter according to the ninth embodiment, showing an electrode pattern portion on the surface of a dielectric plate. Here, each of the main conductor line 3a and the sub conductor line 3b of the line 3 is made of a superconductor. In such a thin-film multi-wire electrode resonator, the maximum current density is suppressed, so that a large current can flow through the entirety within a range not exceeding the critical current density at which superconductivity breaks down. Will be able to handle signals.

Next, FIG. 10 shows a configuration example of a high frequency filter according to the tenth embodiment. (A) is a top view of the whole,
(B) is a sectional view of a BB portion in (A), (C) is an enlarged view of a C portion in (A), and (D) is an enlarged view of a D portion in (A). In FIG. 10, 31, 32,
Reference numerals 33 and 34 denote hairpin-shaped lines, respectively. The ends of the lines are, as shown in (C) and (D), the edges of the main conductor line in the same manner as in the above-described embodiment. A plurality of sub-conductor wires are provided at the end. The length of each line is a half wavelength of the resonance frequency, and each line acts as a so-called hairpin type resonator. Therefore, in this example, the filter functions as a band-pass filter composed of four stages of resonators. In the above configuration, since the strength of the coupling between the resonators and the external coupling can be increased, the passband can be broadened easily. In each of the above-described embodiments, one set of lines is configured from the main conductor line and the plurality of sub-conductor lines arranged at the edge of the main conductor line.
All the conductor lines may be formed as conductor lines having the same narrow line width as the sub-conductor line shown in each embodiment, and only a plurality of these conductor lines may be arranged to form a set of lines. Also,
The line width of the main conductor line may be made as thin as the line width of the sub conductor line.

Next, FIG. 11 shows a configuration example of a duplexer using the above high-frequency filter. Here, the transmission filter and the reception filter are band-pass filters having the configuration of the dielectric filter. The transmission filter passes the frequency of the transmission signal, and the reception filter passes the frequency of the reception signal. The connection position between the output port of the transmission filter and the input port of the reception filter is such that the electrical length from the connection point to the equivalent short-circuit surface of the resonator at the last stage of the transmission filter is 1 at the wavelength of the frequency of the reception signal. The relationship that the electric length from the connection point to the equivalent short-circuit plane of the first-stage resonator of the receiving filter is an odd multiple of 1/4 wavelength at the wavelength of the transmission signal. And As a result, the transmission signal and the reception signal are surely branched.

As described above, by providing a plurality of dielectric filters between ports commonly used and individual ports, a diplexer or a multiplexer can be similarly configured.

FIG. 12 shows the duplexer (duplexer).
FIG. 2 is a block diagram illustrating a configuration of a communication device using the communication device. As described above, the transmission circuit is connected to the input port of the transmission filter, the reception circuit is connected to the output port of the reception filter, and the antenna is connected to the input / output port of the duplexer.

In addition, circuit elements such as the diplexer, the multiplexer, the combiner, and the distributor are constituted by a thin-film multi-wire resonator and a coupling electrode coupled thereto, and a communication device is constituted by using these circuit elements. By doing
A small and highly efficient communication device can be obtained.

[0037]

According to the first and second aspects of the present invention, the conductor loss due to the edge effect of the microstrip line is reduced, and a strong external coupling between the resonator line or the transmission line and the coupling electrode is obtained. In addition, since strong inter-resonator coupling is obtained, the degree of freedom in design for obtaining predetermined filter characteristics and the like is increased.

According to the third aspect of the present invention, the length of each of the plurality of conductor wires is substantially constant, and the electrodes facing each other form an uneven shape and fit into the uneven portions of each other.
Since the current phases of the conductor wires are aligned with each other, the effect of dispersing the current density flowing at the edge of each conductor wire due to the skin effect works effectively, and low loss characteristics can be obtained.

According to the fourth and fifth aspects of the present invention, current concentration at the edge is reduced, and an increase in conductor loss due to a decrease in the conductor portion within a certain line width is suppressed. In addition, the conductor loss is efficiently reduced, and the capacitance at the uneven portion is increased, so that a strong coupling can be obtained.

According to the invention described in claim 6, the coupling between the resonator line or the transmission line and the coupling electrode or the coupling between the resonators can be further easily strengthened.

According to the seventh aspect of the present invention, the current concentration at the surface portion of the conductor wire is also reduced, and the overall conductor loss is further reduced.

According to the eighth aspect of the present invention, the conductor loss of the entire conductor wire is reduced, and a large current can be applied to the entire conductor wire within a range not exceeding the critical current density at which the superconductivity fails. However, a relatively high-power signal can be handled.

According to the ninth and tenth aspects of the present invention, a low-loss high-frequency filter can be obtained, and a high-frequency filter or a duplexer having a relatively wide passband characteristic can be easily formed. it can.

According to the eleventh aspect, a small and highly efficient communication device can be configured.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a high-frequency filter according to a first embodiment.

FIG. 2 is a diagram illustrating a configuration of a high-frequency filter according to a second embodiment.

FIG. 3 is a diagram showing a configuration of a high-frequency filter according to a third embodiment.

FIG. 4 is an overall view and a partially enlarged view of a main part of a high-frequency filter according to a fourth embodiment.

FIG. 5 is a diagram showing a configuration of a high-frequency filter according to a fifth embodiment.

FIG. 6 is a diagram showing a configuration of a high-frequency filter according to a sixth embodiment.

FIG. 7 is a diagram showing a configuration of a high-frequency filter according to a seventh embodiment.

FIG. 8 is a top view and an enlarged cross-sectional view of a main part of a high-frequency filter according to an eighth embodiment.

FIG. 9 is a diagram showing a configuration of a high-frequency filter according to a ninth embodiment;

FIG. 10 is a diagram showing a configuration of a high-frequency filter according to a tenth embodiment.

FIG. 11 is a block diagram showing a configuration example of a duplexer.

FIG. 12 is a block diagram illustrating a configuration example of a communication device.

FIG. 13 is an enlarged perspective view showing the configuration of a microstrip line using thin-film multi-wire electrodes.

FIG. 14 is a diagram showing an example of current density distribution in the microstrip line and a conventional microstrip line.

FIG. 15 is a diagram showing a configuration example of a high-frequency filter using a conventional coupled line.

[Explanation of symbols]

 Reference Signs List 1-dielectric plate 2-ground electrode 3,7-line 3a, 7a-main conductor line 3b, 7b-sub conductor line 3c, 7c-comb electrode 4-gap 5,6-coupling electrode 5b, 5c, 6b , 6c-comb electrode 8, 9, 10-dielectric 31-34 line

Claims (11)

[Claims] 1. A coupling structure between a line and an electrode provided on a surface of a dielectric, wherein each of the lines is formed of an aggregate of a plurality of conductor lines, and an end of the plurality of conductor lines and the end of the plurality of conductor lines. A coupling structure for a microstrip line device, characterized in that the end portions of the electrodes are made uneven, and the uneven portions are fitted with a predetermined gap therebetween. 2. A coupling structure between lines provided on a surface of a dielectric, wherein each of the lines comprises an aggregate of a plurality of conductor wires, and one end of one of the plurality of conductor wires and the other end of the plurality of conductor wires. A coupling structure for a microstrip line device, characterized in that the end portions of a plurality of conductor wires are each formed into an uneven shape, and the uneven portions are fitted with a predetermined gap therebetween. 3. The micro-micrometer according to claim 1, wherein the length of the plurality of conductor lines is made substantially constant, and the arrangement positions of the conductor lines are alternately shifted in the longitudinal direction of the conductor lines. Combined structure of stripline equipment. 4. The line comprises a main conductor line disposed at the center and a plurality of sub-conductor lines disposed at an edge portion thereof.
2. The coupling structure for a microstrip line device according to claim 1, wherein an end of the main conductor wire and an end of the electrode facing the end are formed in an uneven shape to fit into each other. 5. The line is composed of a main conductor line arranged at the center and a plurality of sub-conductor lines arranged at an edge of the main line. 3. The coupling structure for a microstrip line device according to claim 2, wherein the end of the main conductor line of the other line facing the first line is formed in an uneven shape to fit into each other. 6. The coupling structure for a microstrip line device according to claim 1, wherein a dielectric is filled in or brought into close proximity to the concavo-convex portion of the conductor wire. 7. The thin-film multilayer electrode according to claim 1, wherein at least one of said conductor wires is a thin-film multilayer electrode comprising a laminate of a thin-film conductor layer and a thin-film dielectric layer. Connection structure of microstrip line device. 8. The coupling structure for a microstrip line device according to claim 1, wherein at least one of said conductor lines is made of a superconductor. 9. A high-frequency filter, wherein the line according to claim 1 is a resonator, and the electrode is an input / output unit coupled to the resonator. 10. A transmission filter and a reception filter are constituted by the high-frequency filter according to claim 9, wherein the transmission filter is provided between an input port and an input / output port, and between the input / output port and the output port. A duplexer comprising the receiving filter. 11. A communication device provided with the dielectric filter according to claim 9 or the duplexer according to claim 10 in a high frequency unit.