JP3048509B2 - High frequency circuit element - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-frequency circuit device basically composed of a resonator, such as a filter or a duplexer, used in a high-frequency signal processing device such as a communication system.

[0002]

2. Description of the Related Art In a high-frequency communication system, a high-frequency circuit element composed basically of a resonator including a filter, a duplexer and the like is an essential element. In particular, in a mobile communication system or the like, a narrow band filter is required for effective use of a frequency band. Further, in a base station of mobile communication, a communication satellite, and the like, there is a strong demand for a filter capable of withstanding a large power with a narrow band, low loss, small power, and the like.

As high-frequency circuit elements such as resonator filters currently used, those using a dielectric resonator, those using a transmission line structure, and those using a surface acoustic wave element have become mainstream. I have. Among them, the one using the transmission line structure is small and can be applied to high frequencies in the microwave and millimeter wave ranges, and is a two-dimensional structure formed on a substrate. It is widely used because it can be easily combined with. Conventionally, as this type of resonator, a half-wavelength resonator using a transmission line has been most commonly used.
A high-frequency circuit element such as a filter is formed by coupling a plurality of half-wavelength resonators (detailed examples / practices microwave circuit Tokyo Denki University Press).

Another conventional example uses a planar circuit structure. As a typical example, there is a type in which a filter is used by using a disk-type resonator and providing a projection on a part of the outer periphery thereof to couple a dipole mode [Transactions of the Institute of Electronics, Communication and Communication Engineers ^, 72 / 8 Vol. Five
5-B No. 8 `` Analytical treatment of microwave planar circuits (A
nalysis of Microwave Planar Circuit)
Takashi Ogoshi].

[0005]

However, in a resonator having a transmission line structure such as a half-wavelength resonator, since the high-frequency current in the conductor is partially concentrated, the loss due to the resistance of the conductor is relatively large. In the resonator, the Q value is degraded, and the loss is increased when a filter is formed. In addition, when a half-wavelength resonator having a microstrip line structure, which is generally used, is used, the influence of loss due to radiation from a circuit to space also becomes a problem.

Further, in a resonator having a planar circuit structure of a type in which a projection is provided on a disk resonator, current concentration occurs at the projection, and further, the discontinuity of the structure at the projection is caused by the fact that a signal wave has a spatial Therefore, the Q value also deteriorates in this type of resonator, and the loss increases even when a filter is formed by this type of resonator.

[0007] These effects become more pronounced as the structure is reduced in size or the operating frequency is increased. Dielectric resonators are used as resonators having relatively small loss and excellent power durability. However, since they have a three-dimensional structure and are large in size, dielectric resonators are used. This is a problem for miniaturization.

Further, it is possible to reduce the loss of these high-frequency circuit elements by using a superconductor. However, in the above-mentioned conventional structure, the superconductivity is increased due to excessive concentration of current. It is difficult to use large power signals because they are destroyed. Even in an actual measurement example, the maximum input power is about several tens of mW, which does not reach a practical level.

[0009] From the above, at high frequencies such as microwaves and millimeter waves, a compact, two-dimensional structure, good matching with other circuits and elements, and a high performance resonator filter, etc. In order to realize a high-frequency circuit element, it is extremely important to solve such a problem of a resonator having a transmission line structure or a planar circuit structure.

In order to solve the above-mentioned problems in the prior art, the present invention realizes a resonator having a small loss due to the resistance of a conductor and a high Q value with a small structure, and a high-performance high-frequency circuit element using the same. The purpose is to provide.

In order to achieve the above object, a first configuration of a high-frequency circuit device according to the present invention comprises a conductor having an elliptical shape formed on a surface of a substrate, and has a microstrip line structure, a strip line structure, and a coplanar structure. Comprising a resonator having a structure selected from the group consisting of a waveguide structure,
At least one input / output terminal formed of a transmission line on the outer periphery of a conductor forming the resonator is capacitively coupled to the conductor forming the resonator.

Also, the first high-frequency circuit element of the present invention
In the configuration of the above, on the outer periphery of the conductor constituting the resonator,
Of the resonance modes of the resonator, two different points at which only one of two mutually orthogonal dipole modes is excited are input / output coupling points 1 and 2,
At the input / output coupling points 1 and 2, it is preferable that the input / output terminals are respectively coupled to the resonator.

[0013] The first high-frequency circuit device of the present invention may be configured as follows.
In the configuration of the above, on the outer periphery of the conductor constituting the resonator,
Of the resonance modes of the resonator, two different points at which only one of two mutually orthogonal dipole modes is excited are input / output coupling points 1 and 2,
Preferably, two different points at which only the other mode is excited are input / output coupling points 3 and 4, and at the input / output coupling points 1 to 4, the input / output terminals are respectively coupled to the resonator.

Further, the first high-frequency circuit device of the present invention has
In the configuration of the above, on the outer periphery of the conductor constituting the resonator,
Of the resonance modes of the resonator, two mutually orthogonal dipole modes can be excited equally, and two points in a positional relationship adjacent to each other are input / output coupling points 1 and 2,
At the input / output coupling points 1 and 2, it is preferable that the input / output terminals are respectively coupled to the resonator.

Further, the first high-frequency circuit device of the present invention has
In the configuration of the above, on the outer periphery of the conductor constituting the resonator,
Of the resonance modes of the resonator, two mutually orthogonal dipole modes can be excited equally, and two points in a positional relationship facing each other are input / output coupling points 1 and 2,
At the input / output coupling points 1 and 2, it is preferable that the input / output terminals are respectively coupled to the resonator.

Further, the first high-frequency circuit element of the present invention has the following features.
In the configuration of the above, on the outer periphery of the conductor constituting the resonator,
A point at which two mutually orthogonal dipole modes can be excited equally among the resonance modes of the resonator is defined as an input / output coupling point 1, and a point at which only one of the dipole modes is excited is defined as an input / output coupling point. 2. It is preferable that a point where only the other mode is excited is an input / output coupling point 3, and that at the input / output coupling points 1 to 3, the input / output terminals are respectively coupled to the resonator.

Further, the second aspect of the high-frequency circuit element according to the present invention
Is provided with a plurality of resonators formed of a conductor having an elliptical shape formed on the surface of the substrate, and the resonators are coupled to each other.

Further, the second aspect of the high-frequency circuit device according to the present invention
In the configuration of the above, on the outer periphery of the conductor constituting the resonator,
Of the resonance modes of the resonator, two mutually orthogonal dipole modes can be excited equally, and two points in a positional relationship adjacent to each other are input / output coupling points 1 and 2,
The plurality of resonators are connected in series to each other via the input / output coupling points 1 and 2, and the input / output coupling points belonging to resonators located at both ends of the plurality of resonators Of these, it is preferable that two input / output terminals formed of a transmission line are capacitively coupled to the resonators located at both ends at a coupling point that is not coupled to an adjacent resonator.

Further, a first high-frequency circuit device according to the present invention
Alternatively, in the second configuration, the tip portion of the transmission line formed on the substrate surface is capacitively coupled by opposing the outer periphery of the conductor forming the resonator with a gap therebetween. preferable.

Further, a first high-frequency circuit device according to the present invention
Alternatively, in the second configuration, it is preferable to use a superconductor as the conductor material.

[0021]

[0022]

[0023]

[0024]

[0025]

According to the first structure of the high-frequency circuit device of the present invention, the high-frequency circuit device is formed of a conductor having an elliptical shape formed on the surface of the substrate, and has a microstrip line structure, a strip line structure, and a coplanar waveguide structure. A resonator having a structure selected from a group, wherein at least one input / output terminal formed of a transmission line is capacitively coupled to the conductor forming the resonator on the outer periphery of the conductor forming the resonator. Since the resonator as an element has an elliptical shape, two non-degenerate orthogonal dipole modes are used as resonance modes. Therefore, two resonance modes are simultaneously excited and used. Thus, a high-frequency circuit element having excellent functionality, such as a two-stage bandpass filter, can be realized while being a single resonator. In addition, since the resonator as a component is formed of a conductor having an elliptical shape formed on the surface of the substrate, and the contour of the resonator is very smooth, the high-frequency current is partially excessively concentrated, and the signal Waves do not radiate into space. As a result, a high Q (no-load Q) can be realized. Further, since the high-frequency current is uniformly spread and distributed two-dimensionally, the maximum current density when the resonance operation is performed by the high-frequency signal having the same power can be suppressed to be low. In this case as well, it is possible to prevent adverse effects due to excessive concentration of high-frequency current, such as deterioration of the conductor material due to heat generation, and as a result, it is possible to further handle high-frequency signals of electric power.

Further, since a resonator having a structure selected from the group consisting of a microstrip line structure, a strip line structure and a coplanar waveguide structure is used, there are the following advantages. That is, the microstrip line structure has a simple structure and good matching with other circuits. Further, since the stripline structure has a very small radiation loss, a high-frequency circuit element with a small loss can be realized. In addition, the coplanar waveguide structure can manufacture all structures including the ground plane on one side of the substrate, so that the manufacturing process can be simplified and high-temperature superconductivity that is difficult to form on both sides of the substrate It is particularly useful when a thin film is used as a conductor material.

[0027]

[0028]

Further, the first high-frequency circuit element of the present invention
In the configuration of the above, two different points where only one of two orthogonal dipole modes among the resonance modes of the resonator are excited are input and output on the outer periphery of the conductor forming the resonator. According to a preferred example in which the input and output terminals are coupled to the resonator at the input and output coupling points 1 and 2 respectively, the transmission characteristics between the input and output terminals are changed to the resonance of the excited mode. The high-frequency circuit element can be put to practical use as a band-pass filter by appropriately setting the degree of coupling at the input / output coupling points 1 and 2 so as to exhibit a resonance characteristic having a peak at a frequency.

[0030]

Further, the first high-frequency circuit element of the present invention
In the configuration of the above, two mutually orthogonal dipole modes (resonant frequencies f _A and f _B ) among the resonance modes A and B of the resonator can be equally excited on the outer periphery of the conductor forming the resonator, and , Two points adjacent to each other in a positional relationship are defined as input / output connection points 1 and 2, and the input / output connection points 1 and 2
According to the preferred example, in which the input / output terminals are respectively coupled to the resonators, two resonators having different resonance frequencies f _A and f _B with different input / output characteristics between the input / output terminals are connected in parallel. Since the characteristics are the same as those in the case, the bandwidth | f _A −
It can be operated as a two-stage bandpass filter of about f _B |. The two-stage bandpass filter can be realized by a simple configuration in which the input / output terminal is coupled to one conductor, so that the size of the element can be reduced.

The first high-frequency circuit element of the present invention
In the configuration described above, two mutually orthogonal dipole modes (resonance frequencies f _A and f _B ) such as resonance modes A and B of the resonator can be equally excited on the outer periphery of the conductor forming the resonator, and According to a preferred example, two points having a positional relationship facing each other are input / output coupling points 1 and 2, and at the human output coupling points 1 and 2, input / output terminals are respectively coupled to the resonator. Since this is the same as when the phases between the resonators are inverted and connected in parallel, the outputs of the two resonators interfere with each other, the transmittance becomes maximum at the frequencies f _A and f _B , and the frequency (f _A + f _B ) / 2, it is possible to realize a high-frequency circuit element having filter characteristics such that the transmittance takes a minimum value.

Further, the first high-frequency circuit element of the present invention
In the configuration of the above, a point where two mutually orthogonal dipole modes (resonance frequencies f _A and f _B ) among the resonance modes A and B of the resonator can be excited equally on the outer periphery of the conductor forming the resonator. One of the dipole modes, mode A (resonant frequency f _A ), as input / output coupling point 1
The point at which only the second mode B is excited is designated as the input / output coupling point 2, and the point at which only the other mode B (resonance frequency f _B ) is excited is designated as the input / output coupling point 3. According to a preferable embodiment of the terminal is coupled with each of said resonators, when inputting a high frequency signal input and output terminal coupled to the resonator at the input and output coupling points 1, frequencies around the frequency f _a of the high frequency signal The component couples with mode A, and frequency components near frequency f _B couple with mode B. The frequency component coupled to mode A is output only to the input / output terminal coupled to the resonator at the input / output coupling point 2, and the frequency component coupled to mode B is coupled to the input / output coupling point 3 at the input / output coupling point 3. It is output only to the input / output terminal that is connected to the device. Therefore, the present high-frequency circuit element functions as a duplexer for separating the frequency component of the input signal. Since this duplexer can be realized using only a resonator made of one conductor, the size of the element can be reduced. An input / output terminal coupled to the resonator at the input / output coupling point 2 and an input / output terminal coupled to the resonator at the input / output coupling point 3 are used for signal input. If an input / output terminal coupled to the resonator is used for signal output, it can function as a multiplexer.

Also, the second high-frequency circuit element of the present invention
According to the configuration, a plurality of resonators formed of conductors having an elliptical shape formed on the surface of the substrate are provided, and the resonators are coupled to each other, and the resonator as a component is formed into an elliptical shape. Since the two non-degenerate orthogonal dipole modes are used as resonance modes, the two resonance modes are simultaneously excited to be used. And a high-frequency circuit element excellent in the above. In addition, since the resonator as a component is formed of a conductor having an elliptical shape formed on the surface of the substrate, and the contour of the resonator is very smooth, the high-frequency current is partially excessively concentrated, and the signal Waves do not radiate into space. As a result, a high Q (no-load Q) can be realized. In addition, since the high-frequency current is spread two-dimensionally and uniformly, the maximum current density when the resonance operation is performed by the high-frequency signal of the same power can be suppressed low.
Even when dealing with high-power high-frequency signals, it is possible to prevent adverse effects due to excessive concentration of high-frequency current, such as deterioration of conductor materials due to heat generation, and as a result, it is possible to handle high-frequency signals of power further. Become.

The first high-frequency circuit element of the present invention
Alternatively, in the second configuration, according to a preferred example of using a superconductor as a conductor material, it is possible to improve power handling performance (maximum signal power that can be input to an element) limited by a critical current density of the superconductor. Can be.

[0036]

[0037]

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. (Embodiment 1) FIG. 1 is a plan view showing an embodiment of a resonator according to the present invention. As shown in FIG. 1, an elliptical conductor 2 made of a metal film is formed on a substrate 1 made of a dielectric single crystal or the like by using, for example, vacuum deposition and etching. Note that a ground plane 13 is formed on the back surface of the substrate 1 as necessary (see FIG. 14).

In such a configuration, if a high-frequency signal is coupled to the conductor 2 by an appropriate method, a resonance operation can be performed and a resonator can be operated. In FIG. 1, the directions in which the high-frequency current flows in the two modes having the lowest resonance frequencies (herein, referred to as mode A and mode B, and the respective resonance frequencies are f _A and f _B ) are schematically indicated by arrows. Was. Such a resonance mode electromagnetic field and its associated potential distribution can be predicted to some extent by calculation. By the way, in these two modes A and B, as shown by the arrow in FIG. 1, the direction in which the current flows is directed to two axes of the ellipse perpendicular to each other. Such a mode is called a “dipole mode” in a normal disc-shaped resonator, but is also referred to in the same manner. Since these dipole modes can exist independently at the same time, it can be considered that two resonators exist. Here, if the conductor 2 is perfectly circular, the two dipole modes are in a degenerate state, and the resonance frequencies of the two modes are completely equal. However, in the case of an elliptical shape as shown in FIG. 1, both modes are not degenerate, and a difference occurs between the resonance frequencies of mode A and mode B. The resonance frequencies of these two modes can be arbitrarily set based on the lengths of the major axis and the minor axis of the ellipse. Then, by using both modes separately, it is possible to function as two resonators having different resonance frequencies while being a single resonator. Therefore, effective use of the area of the resonator circuit, that is, The size can be reduced.

FIG. 21 shows the change of the resonance frequency of both modes with respect to the ratio of the minor axis to the major axis (minor axis length / major axis length) when the area of the conductor 2 is kept constant when the circle is a perfect circle (minor axis). Length / long axis length = 1). In the resonator of the present invention, since a difference occurs in the resonance frequency, the coupling between the two dipole modes is very small, and when the resonance frequency of both modes is very close (short axis length / long axis length ≒ 1). Except for these, it can be considered that the two resonance modes exist almost independently. That is, in the present invention, "not degenerate" means that the shape of the resonator is not substantially symmetric. For example, when an elliptical resonator is used as in the first embodiment, the ellipticity is preferably 0.1 to 1.

In the case of the conventional disk resonator, since the distribution of the high-frequency current spreads two-dimensionally and relatively uniformly, the conductor loss is small and the influence of the radiation loss is small. Therefore, it has a very high Q (unloaded Q) as compared with a resonator having another shape of the same planar circuit structure or a transmission line resonator such as a normal half-wavelength resonator. On the other hand, in the case of the resonator of the present invention, as shown in FIG. 21, the difference between the major axis and the minor axis required to provide a 10% difference in the resonance frequency between mode A and mode B is as follows. , About 10%, it is predicted that the current distribution actually has substantially the same as that of the disk resonator except that the resonance frequency difference between the modes has to be very large. be able to. Accordingly, also in the resonator of the present invention, a very high Q can be realized because the high-frequency current spreads relatively uniformly and the influence of radiation loss is small.

In the resonator of the present invention, the fact that the high-frequency current is spread two-dimensionally means that the maximum current density when the resonance operation is performed by the high-frequency signal of the same power can be suppressed. Means Therefore, even when handling high-power high-frequency signals, it is possible to prevent adverse effects due to excessive concentration of high-frequency current, such as deterioration of conductive materials due to heat generation, and as a result, to handle higher-power high-frequency signals. It becomes possible.

It is more effective to use a superconductor as the material of the conductor 2 of the resonator of the present invention. In general,
If a superconductor is used as the conductor material of the resonator, the conductor loss becomes very small, and the Q value of the resonator can be greatly improved. However, when a superconductor is used, when the maximum current density in the conductor exceeds the value of the critical current density with respect to the high-frequency current of the superconducting material, the superconductivity is destroyed, and as a resonator, Operation becomes impossible. As described above, in the resonator of the present invention, since the maximum current density can be suppressed to a low level, the conductor 2 is made of a superconductor, so that a high-frequency signal having a larger power than that of a resonator having a conventional structure is handled. As a result, it is possible to realize a resonator having a high Q value even for a high-power high-frequency signal, so that the effectiveness is very high.

The above-described effectiveness of the resonator of the present invention is similarly exerted in a high-frequency circuit device using the resonator described below. When the Q value of the resonator is high, when a high-frequency circuit element is configured using the Q value,
Since the loss can be reduced, it is very effective for a high-frequency circuit element.

(Embodiment 2) FIG. 2 shows an embodiment of a high-frequency circuit device using a resonator according to the present invention. In order to put the resonator shown in FIG. 1 into practical use, it is necessary to excite a desired resonance mode (dipole mode) by an appropriate method and to exert an expected function. As a method of exciting the desired mode, a method of coupling the input / output terminal to the conductor 2 at an appropriate position on the outer peripheral portion 3 of the conductor 2 is very simple, and it is also necessary to excite the desired mode reliably. It is effective. In this case, only the mode A of the resonator is excited, and the mode B is not excited in the mode B.
The input / output terminals 71 and 72 are connected to these input / output connection points 61 and 62, respectively. One of the input / output terminals 71 and 72 is used as an input side of a high-frequency signal, and the other is used as an output side. The positions of the input / output coupling points 61 and 62 may be selected where the axis of symmetry of the ellipse intersects the outer peripheral portion 3, and there are two positions in each dipole mode. However, when the conductor 2 has an arbitrary shape, the input / output coupling point 6
In order to determine the positions of the first and second capacitors, in the capacitive coupling method (for example, when a connection is made using a capacitor or the like), the potential distribution of mode A is obtained and the outer peripheral portion 3 is determined based on the potential distribution.
In this case, the potential may be set to a maximum (current is 0). Conversely, inductive coupling methods that excite current (eg,
In the case of connection using a device having an inductance such as a tap, etc.), the potential distribution of mode A is obtained, and based on the potential distribution, the potential may be set at a position where the potential becomes zero (maximum current) in the outer peripheral portion 3. .

The input / output terminal 7 having such a configuration
The transmission characteristics between the input and output coupling points 61 and 62 show the resonance characteristic which peaks at the resonance frequency f _A of the mode A.
By appropriately setting the degree of coupling in the above, the high-frequency circuit element can be put to practical use as a band-pass filter.

(Embodiment 3) FIG. 3 shows another embodiment of a high-frequency circuit element using the resonator according to the present invention. In addition to the configuration of FIG. 2, only the mode B is excited, and the position where the mode A is not excited is defined as input / output connection points 63 and 64, and input / output terminals 73 and 74 are connected to these input / output connection points 63 and 64. I have. As described above, since the mode A and the mode B are not degenerated, coupling between the two modes hardly occurs. Therefore, as a resonator of the resonance frequency f _A is between output terminals 71 and 72, so can be operated independently as a resonator of the resonance frequency f _B between input and output terminals 73 and 74, the high-frequency circuit element of the present invention In addition to the advantages of the resonator of the present invention described above, the area of the resonator can be effectively used, and as a result, the size of the element can be reduced.

(Embodiment 4) FIG. 4 shows still another embodiment of the high-frequency circuit device using the resonator according to the present invention. Of the input / output connection points 61 to 64 in FIG. 3, near the center of two adjacent input / output connection points (for example, the position near the center of the input / output connection points 61 and 63), the mode A and the mode B are exactly the same. There are a total of four positions that can be excited equally. In the high-frequency circuit device shown in FIG. 4, two adjacent locations among the four locations on the outer periphery where both modes can be excited equally can be defined as input / output coupling points 61 and 62, and these input / output coupling points 6 and 6 can be used.
Input / output terminals 71 and 72 are coupled to 1 and 62, respectively. In this case, the input / output characteristics between the input / output terminals 71 and 72 are the same as the characteristics when two resonators having the resonance frequency f _A and the resonance frequency f _B are connected in parallel. By setting it appropriately, the bandwidth | f _A −f _B |
It can be operated as a stage bandpass filter. A commonly used two-stage band-pass filter is formed by coupling two half-wavelength transmission line resonators, whereas the high-frequency circuit element of the present invention enters one elliptical conductor 2. This can be realized by a simple and compact configuration in which the output terminals 71 and 72 are simply coupled. Also,
Since the resonator of the present invention has a higher Q value than a normal half-wavelength transmission line type resonator, it is possible not only to reduce the size of the filter but also to reduce the loss.

Embodiment 5 FIG. 5 shows a resonator according to the present invention.
Another embodiment of a high-frequency circuit element using the present invention will be described. Book
In the high-frequency circuit element having the configuration, the mode A and the mode B are equivalent.
Of the four input / output coupling points of the outer peripheral portion 3 of the conductor 2 which can be excited to
Input and output connection of two points located opposite each other
Points 61 and 62 are set. Also in this configuration, the configuration of FIG.
The resonance frequency f_AAnd the resonance frequency f_BThe two
This is the same as when the resonators are connected in parallel, but in FIG.
Unlike the case, the phase between the two resonators is reversed and
The output of the two resonators is
Interfere with each other, frequency f_A, F _B, The transmittance becomes maximum,
Frequency (f_A+ F_B) / 2 so that the transmittance takes the minimum value
High frequency circuit element with excellent filter characteristics
Can be.

(Embodiment 6) FIG. 6 shows still another embodiment of the high-frequency circuit device using the resonator according to the present invention. In FIG. 6, the position where the two dipole modes (mode A and mode B) of the resonator are excited equally is set to the input / output coupling point 6.
1 and the position where only mode A is excited is input / output coupling point 6
2. A position where only mode B is excited is defined as an input / output coupling point 63. The input / output terminals 71 to 73 are connected to the input / output connection points 61 to 63, respectively. In this arrangement, by inputting a high-frequency signal to the input terminal 71, the frequency component near frequency f _A of the high frequency signal is combined with the mode A, the frequency component near frequency f _B binds to mode B. The frequency component coupled to mode A is output only to input / output terminal 72, and the frequency component coupled to mode B is output only to input / output terminal 73. Therefore, the high-frequency circuit element of the present invention functions as a duplexer for separating the frequency component of the input signal. Also, the input / output terminal 7
If 2, 73 are used for signal input and the input / output terminal 71 is used for signal output, it can function as a multiplexer. In the conventional duplexer, it was necessary to use at least two resonators. However, the high-frequency circuit device of the present invention can be realized using only a resonator composed of one elliptical conductor. In addition to the advantages of the resonator of the present invention,
The size of the device can be reduced.

(Embodiment 7) In the above-described embodiments 2 to 6, the case where the high-frequency circuit element is constituted by using the resonator composed of a single elliptical conductor has been described. Thus, a new high-frequency circuit element can be formed. The high-frequency circuit element of FIG.
Although the operation as a band-pass filter of a stage has already been described, if a sharper change in insertion loss is required at the boundary between the pass band and the stop band, it is necessary to increase the number of stages of the filter.

FIG. 7 shows a resonance composed of a plurality of elliptical conductors.
One embodiment of a two-stage or more band-pass filter using a filter
Show. Here, three conductors 21 to 23 are used to form a six-stage
A bandpass filter was constructed. The conductors 21 and 2 of FIG.
In 3, the two dipole modes can be excited equally.
Of the four locations on the circumference, two adjacent locations are connected to junction points 81 to 8
It is 6. Then, the conductors 21 and 23 at both ends are connected.
Input / output terminals 71 and 72 are connected to joint points 81 and 86, respectively.
Have been. In addition, the conductors 21 and 23 are connected at connection points 82 to 8.
5 and directly connected to the conductor 22. This configuration
Then, the coupling degree of the coupling points 81 to 86 and the coupling degree of the conductors 21 to 23
The resonance frequency of the two dipole modes (f _A, F_B)
One-stage and two-stage bandpass filters, if set appropriately
Band with a steeper transmission characteristic compared to
A pass filter can be configured.

In the seventh embodiment, a six-stage band-pass filter has been described as an example. However, the number of stages is not limited to six, and may be increased. Generally, when n resonators are used, a 2n-stage bandpass filter can be configured. Therefore,
By employing the structure of the high-frequency circuit element of the present invention, it is possible to reduce the size of a band-pass filter having an increased number of stages as compared with a conventional band-pass filter.

(Embodiment 8) FIG. 8 shows still another embodiment of the resonator according to the present invention. As shown in FIG.
Is provided with a slit 15 at the center thereof. Also in this case, similarly, the conductor 2 operates as a resonator. By changing the direction and length of the slit 15,
The resonance frequencies of the two resonance modes can be changed. Therefore, the slit 15 is newly formed after the resonator is manufactured, or the slit 1 already formed is formed.
By extending the length of 5, the resonance frequencies of the two resonance modes can be finely adjusted. When the direction of the slit 15 matches the current direction of one of the resonance modes (in the case of mode A in FIG. 8), the presence of the slit 15 does not affect the current distribution of the mode. Has little effect, but the other mode (FIG. 8)
In this case, since the current distribution in the mode B) is greatly affected by the slit 15, the resonance frequency also changes. actually,
If the length of the slit 15 is made longer, the resonance frequency changes in the direction of decreasing. Therefore, by forming the slit 15 in a direction perpendicular to the current direction of one of the modes, the resonance frequency can be finely adjusted only for that mode, and the fine frequency difference between the two modes can be finely adjusted. Adjustment and the like can be easily performed. Further, if the two slits are formed so as to be perpendicular to the current directions of both modes, the two modes can be finely adjusted individually. Normally, in order to change the resonance frequency in a disk resonator, it is necessary to change the radius of the disk, and it has been very difficult to fine-tune the resonance frequency after manufacturing the resonator. However, if the configuration of the present invention is adopted, it is possible to finely adjust the resonance frequencies of the two resonance modes separately by forming slits of an appropriate length and direction after manufacturing the resonator. Above is useful.

(Embodiment 9) When the resonator has a microstrip line structure or a strip line structure, as shown in FIG. 9, a ground electrode 16 is formed around the conductor 2 constituting the resonator and used. It is also possible.
By adopting such a configuration, it is possible to prevent electromagnetic waves from leaking and to make the operation unstable, so that the effectiveness is high. In particular,
In the case where a material with a small loss such as a superconductor is used as the material of the conductor 2, the effect of the very small leakage often greatly affects the characteristics. Is particularly large. When inputting and outputting data in this configuration, the ground electrode 16 may be partially cut, and the input / output terminal may be led to the conductor 2 (see FIG. 18A).

(Embodiment 10) As a method for coupling an input / output terminal to a conductor constituting a resonator, it is effective to use one of two coupling methods, capacitive coupling or inductive coupling. It is. FIG. 10 shows an embodiment in which capacitive coupling is used. In this case, the input / output terminals 71, 7
2 is constituted by a transmission line, and capacitive coupling is realized by the capacitance in the gap 10. Since such a capacitive coupling can realize a large external Q, it is easy to achieve matching when the Q value (no-load Q) of the resonator is large, and is effective. In addition to the coupling by such a gap, using a capacitive individual component (capacitor, etc.)
Capacitive coupling can also be realized by directly connecting the input / output terminals 71 and 72 and the outer peripheral portion 3 of the conductor 2. FIG. 11 shows an embodiment in which inductive coupling is used. In this case, inductive coupling is realized by the inductance at the tap 11. Since such inductive coupling can realize a small external Q, matching can be easily achieved when the Q value (no-load Q) of the resonator is small, and is effective. In addition to the connection by the tap 11, the input / output terminals 71 and 72 and the outer peripheral portion 3 of the conductor 2 are directly connected to each other by using an inductive individual component (coil or the like) or a thin lead wire having an appropriate length. The connection can also realize inductive coupling.

(Embodiment 11) In FIG. 10, when a large degree of input / output coupling is required, the interval between the gaps 10 may be reduced. Problems have limitations. In this case, as shown in FIG. 12, by adopting a configuration in which the front end portion 17 of the transmission line as the input / output terminals 71 and 72 is widened at the coupling portion, even when a large degree of input / output coupling is required. Since it is not necessary to reduce the interval between the gaps 10, the above problem can be solved.

(Embodiment 12) In the above Embodiments 1 to 11, the case where a resonator made of an elliptical conductor is used as the resonator has been described as an example, but an elliptical conductor is not necessarily used depending on the application. It is not necessary to use it, and even if it is a planar circuit resonator made of a conductor 12 of an arbitrary shape as shown in FIG. 13, if it has two non-degenerate orthogonal dipole modes as resonance modes, basically Can perform the same operation. However, if the contour of the conductor 12 is not smooth, the high-frequency current is partially excessively concentrated, and the Q value may be reduced due to an increase in loss, or a problem may occur when a high-power high-frequency signal is applied. There is. Therefore, in the case of a shape other than an elliptical shape, the effectiveness can be further enhanced by forming the resonator with the conductor 12 having a smooth contour shape.

Embodiment 13 In the resonator and the high-frequency circuit device of the present invention, the microstrip line structure shown in FIGS. 14, 15 and 16 and the strip line as shown in FIGS. Regardless of the structure or the coplanar waveguide structure, the same excellent characteristics can be exhibited. Among them, the microstrip line structure (FIG. 14) has a relatively large loss due to radiation, but has a simple structure and is generally used most widely, and has good matching with other circuits. Strip line structure (Fig. 15)
Although the structure is complicated, the radiation loss is extremely small, so that a high-frequency circuit element with small loss can be realized. As for the coplanar waveguide structure (FIG. 16), all structures including the ground plane 13 on one surface of the substrate can be manufactured, so that the manufacturing process can be simplified. This is particularly useful when a high-temperature superconducting thin film, which is difficult to form on both surfaces of the substrate, is used as the conductor material.

Further, as the resonator and the high-frequency circuit element of the present invention, as shown in FIG. 17, a structure in which the conductor 2 is arranged between two opposing conductor surfaces 14, 14 can be used. This structure is similar to the strip line structure in FIG. 15, but has a structure in which the substrate 1 in FIG. 15 does not exist and the conductor 2 is floating in space. In this case, since the periphery of the conductor 2 is filled with air (or a vacuum, an appropriate gas) or the like, it is surrounded by a material having a low relative dielectric constant. Therefore, the characteristic impedance of the resonator increases, and the high-frequency current flowing through the conductor 2 can be reduced, so that the loss of the resonator decreases. Therefore, a high Q
This is the most desirable configuration for realizing the value. still,
In order to fix the conductor 2 between the conductor surfaces 14, 14, a method of fixing with a material having a low dielectric constant such as Teflon is effective.

In the high-frequency circuit device of the present invention described so far, a metal thin film is assumed as a conductor material. However, the present invention is not necessarily limited to a metal thin film, and for example, a superconductor thin film can be used. Since a superconductor has much smaller loss than a metal, a resonator having a very large Q can be formed, and the use of the superconductor is effective also in the high-frequency circuit device of the present invention. However, in a superconductor, a superconducting current cannot flow beyond the critical current density. This is a problem when handling high-power high-frequency signals. In the high-frequency circuit element of the present invention,
Since a high-frequency current distribution is spread two-dimensionally and relatively uniformly because a resonator formed by an elliptical conductor is used, the maximum current density when a high-frequency signal of the same power is handled is, for example, 1 /. It becomes smaller than a two-wavelength transmission line resonator or the like. For this reason, when a resonator is constituted by a superconductor having the same critical current density, the resonator of the present invention can handle a high-frequency signal with even higher power. Therefore, also in the high-frequency circuit element of the present invention, by using the superconductor for the conductor portion, it is possible to realize a high-frequency circuit element having excellent characteristics even for high-power high-frequency signals.

<Specific Examples> The present invention will be described in more detail with reference to specific examples. FIG. 18 shows the configuration of the high-frequency circuit element (filter) manufactured in this example. Desired characteristics were designed such that the center frequency was 5 GHz and the bandwidth was about 2%. The fabrication method is as follows. First, dimensions 12mm x 12mm, thickness 0.5mm
By laminating a 10 nm thick titanium thin film and a 1 μm thick gold thin film in this order on both surfaces of a substrate 1 made of lanthanum alumina (LaAlO ₃ ) single crystal, a conductor thin film having a two-layer structure is formed. Formed. Here, the titanium thin film is for improving the adhesion between the gold thin film and the substrate. Next, the conductor thin film on one surface was patterned into the elliptical conductor 2, the input terminal portions 71 and 72, and the ground electrode 16 by photolithography and argon ion beam etching. The conductor thin film on the back surface of the substrate 1 was used as the ground plane 13 as it was. The pattern shape is such that the major axis diameter of the elliptical conductor 2 is 7 mm, the minor axis diameter is 6.86 mm, and the line width of the input / output terminals 71 and 72 is 0.1.
5 mm. Also, the tip 1 of the input / output terminals 71, 72
7, the line width was increased to 1.22 mm, and the conductor 2
And capacitive coupling was performed with a gap of 20 μm between them.
Note that there is an interval of about 1 mm between the ground electrode 16 and the conductor 2 and between the input / output terminals 71 and 72. For measurement of the microwave characteristics, an HP-8510B network analyzer (manufactured by Hewlett-Packard) was used. FIG.
9 shows the frequency response characteristics of the filter manufactured as described above. As is clear from FIG. 19, this filter shows the characteristics of a two-stage band-pass filter.
The effectiveness of the present invention has been confirmed.

A filter having a similar pattern (FIG. 1)
8) was changed to TlBaCaC on a lanthanum alumina substrate.
It was formed by a uO superconductor thin film (thickness 0.7 μm). The ground plane on the back surface of the substrate was formed by sequentially laminating a titanium thin film having a thickness of 10 nm and a gold thin film having a thickness of 1 μm.
A conductor thin film having a layer structure was used. When measuring the microwave characteristics, as shown in FIG. 22, the prepared filter chip 100 is fixed to a brass jig 101, and it is H
e was attached to the cooling part of the gas circulation refrigerator 102 to control the temperature. In FIG. 22, 103 denotes a cold head, 104 denotes tempered glass for windows, 105 and 106 denote high frequency connectors, and 107 denotes a high frequency cable. For measurement of microwave characteristics, use the HP-8510B
A network analyzer (manufactured by Hewlett-Packard) was used. FIG. 20 shows the input power dependence of the insertion loss at a temperature of 20 Kelvin of the filter manufactured as described above. As is clear from FIG. 20, the insertion loss is about 0.4 dB, and it has been confirmed that the insertion loss does not change even when the input power is 41.8 dBm (about 15 W). Conventionally, a high-frequency filter using a high-temperature superconductor thin film loses superconductivity with respect to a high-frequency signal power larger than about several to several tens of mW, and cannot operate as a filter. It can be seen that the high-frequency circuit element (filter) of the present invention has a structure capable of suppressing concentration of signal current and withstanding large input power.

[0063]

As described above, according to the configuration of the high-frequency circuit element according to the present invention, two resonance modes are simultaneously excited and used, so that, for example, a two-stage A high-frequency circuit element having excellent functionality such as a filter can be realized. Further, since the resonator is formed of a conductor having a smooth contour formed on the surface of the substrate, the high frequency current is partially excessively concentrated, and the signal wave does not radiate to the space. As a result, a decrease in the Q value due to an increase in radiation loss can be suppressed, and a high Q (no-load Q) can be realized. In addition, since the high-frequency current is spread two-dimensionally and uniformly, the maximum current density when the resonance operation is performed by the high-frequency signal of the same power can be suppressed low.
Even when handling high-power high-frequency signals, it is possible to prevent adverse effects due to excessive concentration of high-frequency current, such as deterioration of conductor materials due to heat generation, and as a result, it is possible to handle high-frequency signals with even higher power Becomes

Further, according to the high-frequency circuit device using the resonator according to the present invention, even if the shape of the conductor is incomplete or the input / output coupling point is slightly shifted from a desired position, Since the resonance frequencies of the two dipole modes are different, there is almost no coupling between the two modes. As a result, the deterioration of the resonance characteristics is small, so that even with relatively moderate manufacturing accuracy, a high Q value and operation stability are obtained. Can be realized.

[Brief description of the drawings]

FIG. 1 is a plan view showing a first mode of a resonator according to the present invention.

FIG. 2 is a plan view showing a first mode of the first configuration of the high-frequency circuit device using the resonator according to the present invention.

FIG. 3 is a plan view showing a second mode of the first configuration of the high-frequency circuit device using the resonator according to the present invention.

FIG. 4 is a plan view showing a third mode of the first configuration of the high-frequency circuit device using the resonator according to the present invention.

FIG. 5 is a plan view showing a fourth mode of the first configuration of the high-frequency circuit device using the resonator according to the present invention.

FIG. 6 is a plan view showing a fifth mode of the first configuration of the high-frequency circuit device using the resonator according to the present invention.

FIG. 7 is a plan view showing one embodiment of a second configuration of the high-frequency circuit device using the resonator according to the present invention.

FIG. 8 is a plan view showing a second mode of the resonator according to the present invention.

FIG. 9 is a plan view showing a third mode of the resonator used in the first configuration of the high-frequency circuit device according to the present invention.

FIG. 10 is a plan view showing a sixth mode of the first configuration of the high-frequency circuit device using the resonator according to the present invention.

FIG. 11 is a plan view showing a seventh mode of the first configuration of the high-frequency circuit device using the resonator according to the present invention.

FIG. 12 is a plan view showing an eighth embodiment of the first configuration of the high-frequency circuit device using the resonator according to the present invention.

FIG. 13 is a plan view showing a fourth mode of the resonator according to the present invention.

FIG. 14 is a sectional view showing a fifth mode of the resonator according to the present invention.

FIG. 15 is a sectional view showing a sixth embodiment of the resonator according to the present invention.

FIG. 16 is a sectional view showing a seventh embodiment of the resonator according to the present invention.

FIG. 17 is a sectional view showing an eighth embodiment of the resonator according to the present invention.

FIG. 18A is a plan view showing a ninth aspect of the first configuration of the high-frequency circuit device using the resonator according to the present invention,
(B) is a sectional view of (a).

19 is a characteristic diagram showing an example of a measurement result of a frequency response of the high-frequency circuit device shown in FIG.

20 is a diagram illustrating an example of a measurement result of a change in insertion loss with respect to input power when a conductor is formed of a high-temperature superconductor thin film in the high-frequency circuit element illustrated in FIG. 18;

FIG. 21 is a diagram showing the relationship between the ratio of the minor axis to the major axis of the resonator according to the present invention and the resonance frequency in the dipole mode.

22 is a cross-sectional view showing a state in which the high-frequency circuit element shown in FIG. 18 in which a conductor is formed of a high-temperature superconductor thin film is attached to a cooling unit of a He gas circulation refrigerator.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Substrate 2 Conductor 3 Outer peripheral part 10 Gap 11 Tap 12 Conductor 13 Ground plane 14 Conductor surface 15 Slit 16 Ground electrode 17 Tip part 61-64 Input / output connection point 71-74 Input / output terminal 81-86 Connection point

Continuation of the front page (56) References JP-A-58-141002 (JP, A) JP-A-5-251904 (JP, A) JP-A-61-156904 (JP, A) JP-A-51-18454 (JP, A) JP-A-64-1306 (JP, A) JP-A-56-141605 (JP, A) JP-A-56-6501 (JP, A) JP-A-56-141604 (JP, A) 48-38954 (JP, A) JP-A-50-47550 (JP, A) JP-A-61-251203 (JP, A) JP-A-7-147501 (JP, A) JP-B-49-39542 (JP, A) B1) US Pat. No. 3,796,970 (US, A) US Pat. No. 5,210,844 (US, A) * 1991 IEEE MTT Sym p. Digest, pp. 443-446 * IEEE Trans. Micro wave Theory and Tecniques, Vol. MTT-28, No. 6, 1980, p. 573-576 * Takataka Ohkoshi et al., "Planar Circuit" (1975, Ohmsha), page 231 and Fig. 12.22 * MICROWAVES, oct, 1979, PP. 50-63 (58) Fields surveyed (Int. Cl. ⁷ , DB name) H01P 7/08 H01P 1/203 H01P 1/208 JICST file (JOIS) WPI (DIALOG)

Claims (10)

(57) [Claims] 1. A consists conductor having an oval shape formed on the surface of the substrate, comprises a resonator having a structure selected from the group consisting microstrip line structure, a strip line structure and the coplanar waveguide structure, prior Symbol the guide on the outer periphery of the conductor constituting the cavity, less <br/> least one output terminal comprising a transmission line constituting said resonator
A high-frequency circuit element that capacitively couples with the body . 2. The method according to claim 1 , further comprising:
Two orthogonal dies among the resonance modes of the resonator
Only one of the pole modes is excited
The two different points are designated as input / output connection points 1 and 2,
Input / output connection points 1 and 2
2. The high-frequency circuit device according to claim 1, wherein the high-frequency circuit device is coupled to the resonator . 3. The method according to claim 3 , wherein the outer periphery of a conductor forming the resonator is
Two orthogonal dies among the resonance modes of the resonator
Only one of the pole modes is excited
Two different points are designated as input / output connection points 1 and 2, and
Enter and exit two different points where only the mode is excited
Force coupling points 3 and 4 at input / output coupling points 1-4
Wherein the input and output terminals are respectively coupled to the resonator.
2. The high-frequency circuit element according to 1. 4. On the outer periphery of a conductor constituting a resonator, two mutually orthogonal dipole modes among the resonance modes of the resonator can be equally excited and are adjacent to each other.
The two points Ru positional relationship near the input and output coupling points 1 and 2, in the input-output coupling points 1 and 2, the high-frequency circuit device according to claim 1, input and output terminals are coupled with each said resonator. 5. On a periphery of a conductor forming a resonator, two mutually orthogonal dipole modes among resonance modes of the resonator can be equally excited and opposed to each other.
The two points Ru positional relationship near the input and output coupling points 1 and 2, before Symbol <br/> output coupling points 1, 2, the high frequency according to claim 1, input and output terminals are coupled with each said resonator Circuit element. 6. on the outer periphery of the conductor constituting the cavity, wherein one of the resonant modes of the resonator, two dipole modes equally input and output points that can be excited binding point 1 that are orthogonal to each other
And one of the dipole modes
The point where only the light is excited is set to the input / output connection point 2 of the other mode.
Only is input and output bonding points 3 points excited, in the input-output coupling points 1-3, the high-frequency circuit device according to claim 1, wherein the input terminal is coupled with each of said resonators. 7. An elliptical shape formed on a surface of a substrate.
A plurality of resonators made of conductive conductors,
High-frequency circuit device attached to have. 8. On a periphery of a conductor forming a resonator, two mutually orthogonal dipole modes among resonance modes of the resonator can be excited equally and are adjacent to each other.
Positional relationship output the two points binding point 1 in, 2, and a plurality
Are connected to each other via the input / output coupling points 1 and 2.
And the plurality of resonators are connected in series.
Of the input / output coupling points belonging to the resonators located at both ends
Among them, it had your <br/> the point of attachment which is not bound to the adjacent resonators, the two output terminals before Symbol ends consisting of the transmission line
Claim 7 respectively resonator to capacitive coupling located
2. The high-frequency circuit device according to claim 1. 9. A tip of a transmission line formed on a substrate surface.
Part is sandwiched between the outer periphery of the conductor that constitutes the resonator and the gap
Claim has a capacitive coupling by opposing 1
9. The high-frequency circuit device according to any one of items 1 to 8, 10. A high-frequency circuit element according to any one of claims 1 to 9, using a superconductor as the conductor material.