JPH11330803A - High frequency filter device, shared device and communication equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To constitute a high frequency filter device, a shared, device and communication equipment in which low loss, high reliability, and high power resistance in a normal state can be maintained, and fatal characteristic deterioration will not be accompanied, even when the temperature of an electrode is raised above a transition temperature. SOLUTION: A high frequency filter device is constituted by combining a superconducting resonator Rs , using a superconductor as an electrode material with a normal conducting resonator Rn using a normal conductor as an electrode material. Especially, each resonance frequency is set so that band rejection filters superconducting band-pass filter(SBEF) 1 and 2 constituted of the superconducting resonator Rs can be provided in the neighborhood of the both edges of the pass band, and a band-pass filter normal conductive band-pass filter(NBPF) constituted of the normal conductive resonator Rn can be provided at the central part of the pass band. Thus, even when the temperature of an electrode is increased beyond the transition temperature, the band-pass characteristics as a whole can be maintained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-frequency filter and a duplexer in a microwave band or a millimeter wave band used for wireless communication and the like, and a communication device using them.

[0002]

2. Description of the Related Art In microwave and millimeter wave band high frequency filter devices used for wireless communication, high frequency filter devices used particularly for base stations of mobile communication systems are known.
In spite of handling large power, small size, low loss and low cost are required. In such a high-frequency filter device handling large power, a small dielectric resonator having a high no-load Q and a small size is used. Is a serious problem.

Therefore, Japanese Patent Application Laid-Open No. 6-37513 proposes an apparatus using a superconductor as an electrode material. FIG. 24 shows an example of the configuration. 3A is a top view, and FIG. 3B is a cross-sectional view taken along line AA in FIG. Thus, the ground electrode is formed entirely on the lower surface of the dielectric substrate, and the microstrip line is formed on the upper surface. These electrodes are made of a superconductor thin film,
The layers are formed in the order of a highly heat-resistant metal thin film and a highly conductive metal thin film.

By forming an electrode in which a superconductor thin film and a high-conductivity metal thin film are combined as described above, the conductivity of the superconductor thin film becomes extremely large in a normal state, the conductor loss is small, and the Q is high. Acts as a resonator (microstrip resonator). When the temperature of the electrode rises above the superconducting transition temperature of the superconductor material (hereinafter, simply referred to as “transition temperature”), the conductivity of the superconductor thin film rapidly decreases. Loss is kept low, and no fatal characteristic deterioration occurs.

[0005]

However, the conventional device shown in FIG. 24 has a lower loss compared with a case where each of a superconductor or a normal conductor (metal conductor) is formed as a single electrode. , Reliability and power durability. That is, the physical properties of the superconductor thin film may be changed by laminating a metal thin film on the superconductor thin film, and when the electrode is heated to a transition temperature or higher, the reliability of the electrode is increased due to the heat generated by each layer of the electrode. It is considered that the power consumption decreases and a problem is caused in the power handling characteristics. Also, compared to the case where the electrode is composed of only a superconductor thin film, the insertion loss as a filter when the electrode is heated to the transition temperature or higher is smaller, but the conductor loss between when the electrode exceeds the transition temperature and when it does not exceed the transition temperature. Is not small, and the change of the no-load Q as the dielectric resonator and the change of the characteristic as the filter cannot be sufficiently suppressed yet.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned various problems, maintain low loss, high reliability, and high power durability in a normal state. An object of the present invention is to provide a high-frequency filter device, a duplexer, and a communication device that do not cause fatal deterioration of characteristics.

[0007]

In order to solve the above-mentioned problems caused by using an electrode composed of a laminate of a superconductor thin film and a metal thin film, the present invention provides a resonator using a superconductor as an electrode material. And a resonator using a normal conductor as an electrode material to form a high-frequency filter device.

[0008] A resonator using a superconductor as an electrode material exhibits an extremely high no-load Q in a normal use state in which the electrode exhibits superconductivity. Will be greatly reduced. On the other hand, although the conductivity of the normal conductor depends on the temperature, the conductivity does not suddenly change near the transition temperature unlike the superconductor. Therefore, in a resonator using a normal conductor as an electrode material, the no-load Q of the resonator is stable regardless of whether the transition temperature of the superconductor is exceeded or not.

Therefore, in the normal state in which the superconductor exhibits superconductivity, the high unloaded Q characteristics of the resonator using the superconductor as an electrode material are utilized to raise the electrode temperature above the transition temperature. In this case, the filter characteristics of a resonator using a normal conductor as an electrode material will be exhibited. Therefore, even if the temperature of the electrode rises above the transition temperature, the main part of the filter characteristics is determined by a resonator using a normal conductor as the electrode material, and the superconductor is used in order to prevent fatal deterioration of the characteristics. If a resonator made of an electrode material is used to enhance the filter characteristics, there will be no catastrophic deterioration of the characteristics when the temperature rises above the transition temperature.

For example, a resonator using a superconductor as an electrode material is used as a filter for passing frequencies near one or both ends of a pass band, and a resonator using a normal conductor as an electrode material is used near a center of the pass band. It is a filter that passes the frequency. As a result, a band-pass characteristic can be provided by a resonator using a normal conductor as an electrode material regardless of the temperature of the electrode. In a normal use state in which the superconductor exhibits superconductivity, the resonator does not pass. Since frequencies near one end or both ends of the band are passed, a steep attenuation characteristic can be provided at the upper end, lower end, or both ends of the pass band. Therefore, even if the temperature of the electrode rises above the transition temperature of the superconductor, only the attenuation characteristic at one end or both ends of the band-pass characteristic becomes moderate, and the band-pass characteristic can be maintained as a whole.

Further, for example, a resonator using a superconductor as an electrode material is used as a filter for blocking frequencies near one or both ends of a pass band, and a resonator using a normal conductor as an electrode material is used as a filter in the center of the pass band. A filter that passes nearby frequencies. Also in this case, regardless of the temperature of the electrode, a band-pass characteristic can be provided by a resonator using a normal conductor as an electrode material. In a normal use state in which the superconductor exhibits superconductivity, the resonator does not pass. Since frequencies near one or both ends of the band are blocked, a steep attenuation characteristic can be provided on the upper, lower, or both sides of the pass band.

Further, in the present invention, a part or all of the electrode made of a normal conductor is a thin film multi-layer electrode made of a laminate of a thin film conductor layer and a thin film dielectric layer. This alleviates the concentration of the current density in the electrode portion, reduces the conductor loss as a whole, and obtains a resonator having a high no-load Q. Therefore, even when the temperature of the electrode rises and the superconductor does not show superconductivity, the high no-load Q characteristic of the resonator using the electrode made of the normal conductor is utilized, and the high-frequency filter device with low insertion loss is used. Is obtained.

Further, in the present invention, any of the above high-frequency filter devices is provided between the common port and other individual ports to constitute a duplexer. For example, between a common port and an individual certain port, a high-frequency filter device as a transmission filter for transmitting a transmission signal is provided,
If a high-frequency filter device is provided between the common port and another individual port as a reception filter for passing a reception signal, transmission and reception of an antenna duplexer or the like having a small characteristic change with respect to a temperature change before and after the transition temperature as a whole is provided. A duplexer is obtained. Further, if a high-frequency filter device as a transmission filter for transmitting a transmission signal is provided between one common port and another plurality of individual ports, transmission sharing with a small characteristic change with respect to a temperature change around a transition temperature as a whole is provided. A vessel is obtained.

Further, according to the present invention, a communication device is provided by providing any one of the above-described high-frequency filter devices in a transmission unit or a reception unit of a communication signal. For example, the high-frequency filter device is used for each channel filter and antenna filter in a transmission duplexer used in a base station of a mobile communication system. As a result, a small, low-loss, low-cost and highly reliable communication device can be obtained.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The configuration of a high-frequency filter device according to a first embodiment will be described with reference to FIGS.

FIG. 2 is a block diagram showing components constituting the high frequency filter device. In the figure, K is a coupling circuit, Rs is a resonator using a superconductor as an electrode material (hereinafter referred to as “superconducting resonator”), and Rn is a resonator using a normal conductor as an electrode material (hereinafter “normal conduction”). Resonator ").
PS is a phase shifter, which shifts the phase by π, for example. (Fi) indicates that the resonator has a resonance frequency of fi. For example, Rs (f1) represents a superconducting resonator having a resonance frequency of f1, and Rn (f8) represents a normal conduction resonator having a resonance frequency of f8.

FIG. 1 shows the relationship between the resonance frequency of each resonator and the pass band. In this example, two superconducting resonators at resonance frequencies f1 and f2 carry frequencies near the lower end of the passband, and six normal conducting resonators at resonance frequencies f3 to f8 carry frequencies near the upper end from the center of the passband. . Therefore, in a normal use state, as shown in FIG. 1A, the lower side of the pass band exhibits a steep attenuation characteristic. The temperature (temperature of the electrode) of the superconducting resonator rises above the transition temperature, and the no-load Q (Qo) of the superconducting resonator having the resonance frequencies f1 and f2.
, The insertion loss increases, so that the attenuation characteristic on the lower side of the passband becomes slightly gentle as shown in FIG. However, since the characteristics of the normal conduction resonators responsible for f3 to f8 hardly change, the bandpass characteristics are maintained as a whole.

In order to sharpen the attenuation characteristic on the upper end side of the pass band, for example, a superconducting resonator may be used as two resonators having resonance frequencies f7 and f8.

As shown in FIG. 2, when the resonance frequencies of the respective resonators are arranged in order, the adjacent resonators having the resonance frequencies are connected in parallel via a phase shifter PS which shifts the phase by, for example, π. Thus, the two resonators having adjacent resonance frequencies have a very large impedance as viewed from the branch point, and therefore, mutual interference can be prevented.

In FIG. 2, each resonator is a circular TM mode dielectric resonator having electrodes formed on the upper and lower surfaces of a cylindrical dielectric pillar as shown in FIG.
Is, for example, a loop or probe coupled to the circular TM mode dielectric resonator. The phase shifter PS is, for example, a line having an electrical length having a phase difference π.

FIG. 18A shows an example in which a dielectric column is mounted on the bottom surface in a shielding cavity.
(B) shows an example in which dielectric pillars having electrodes formed on the upper and lower surfaces are laminated and integrated, and the electrodes on the outer surface are respectively joined between the top surface and the bottom surface in the shielding cavity. In each case, the dielectric resonator acts as a circular TM mode dielectric resonator. However, a superconducting resonator is formed by making the electrode a superconductor, and a normal conduction resonator is formed by making the electrode a normal conductor.

Other examples of the resonator include a TM dual-mode dielectric resonator as described later with reference to FIG.
A short-circuit type dielectric resonator as shown in FIGS. 19 to 22 can be used. In these figures, (A) is a perspective view,
(B) is a sectional view of the AA part in (A). In the example shown in FIG. 19, an electrode is formed on the outer surface of a rectangular parallelepiped dielectric block to function as a TM mode dielectric resonator. In the example of FIG. 20, a void is formed around the dielectric portion so as to form a prismatic dielectric portion at the center, and the dielectric portion acts as a TM mode dielectric resonator.
Similarly, in the example shown in FIG. 21, an electrode is formed on the outer surface of a cylindrical dielectric block to function as a circular TM mode dielectric resonator. In the example of FIG.
A void is formed around the dielectric portion so as to form a cylindrical dielectric portion in the center, and the dielectric portion acts as a circular TM mode dielectric resonator. In any case, a superconducting resonator is formed by making the electrode a superconductor, and a normal conducting resonator is formed by making the electrode a normal conductor.

Further, the resonator is not limited to a dielectric resonator, but may be a strip resonator. Also in this case, a superconducting resonator is formed by using an electrode as a superconductor, and a normal conducting resonator is formed by using an electrode as a normal conductor.

Next, the configuration of a high-frequency filter device according to a second embodiment will be described with reference to FIGS.

FIG. 6 is a block diagram showing the entire structure of the high-frequency filter device. In the figure, SBP
F1 is a bandpass filter using a superconducting resonator (hereinafter referred to as “superconducting bandpass filter”), and NBPF is a bandpass filter using a normal conducting resonator (hereinafter referred to as “normal conducting bandpass filter”). ), PS is a phase shifter, which shifts the phase by, for example, π.

FIG. 3 shows the pass characteristics of the normal conduction band pass filter NBPF, and FIG. 4 shows the respective pass characteristics of the superconducting band pass filters SBPF1 and SBPF2. The normal bandpass filter NBPF shown in FIG.
To f3 as pass bands, the superconducting band pass filter SBPF1 shown in FIG.
The BPF 2 has f3 to f4 as pass bands.

The normal conduction resonator has a higher Q than the superconducting resonator.
Since o is small, the attenuation characteristics at both ends of the pass band of the normal conduction band pass filter are relatively gentle. On the other hand, since the Qo of the superconducting resonator is extremely high, the attenuation characteristics at both ends of the passband of the superconducting bandpass filter become steep.

By connecting these three resonators in parallel as shown in FIG. 6, the overall characteristics are as shown in FIG. That is, the superconducting bandpass filter SBPF1 is responsible for the lower band (f1 to f2) of the passband, and the superconducting bandpass filter SBP is for the higher band (f3 to f4) of the passband.
F2 is carried, and the center part (f2 to f3) of the pass band is carried by the normal conduction band pass filter NBPF. Therefore, a filter characteristic having steep attenuation characteristics at both ends of the pass band can be obtained.

If the electrodes of the superconducting resonator constituting the superconducting band-pass filter do not show superconductivity because of the transition temperature or higher, the insertion loss of the superconducting band-pass filter increases and the attenuation characteristics become gentle. However, due to the operation of the normal-conducting band-pass filter, the insertion loss near the center of the pass band is suppressed to a slight increase, and the fatal deterioration of the filter as a whole does not occur.

Next, the configuration of a high frequency filter device according to a third embodiment will be described with reference to FIGS.

FIG. 10 is a block diagram showing the entire structure of the high frequency filter device. In the figure, SB
EF1 is a band rejection filter using a superconducting resonator (hereinafter referred to as “superconducting band rejection filter”), and NBPF is a normal conduction bandpass filter.

FIG. 7 shows the pass characteristics of the normal conduction band pass filter NBPF, and FIG. 8 shows the respective pass characteristics of the superconducting band reject filters SBEF1 and SBEF2. The normal conduction bandpass filter NBPF shown in FIG.
To f3 as pass bands, the superconducting band rejection filter SBEF1 shown in FIG.
BEF2 sets f3 to f4 as a stop band.

By connecting these three resonators in series as shown in FIG. 10, the overall characteristics are as shown in FIG. That is, the superconducting band rejection filter SBEF1 abruptly attenuates the lower side (f1 to f2) of the passband, and the superconducting band rejection filter SBEF2 abruptly attenuates the higher side (f3 to f4) of the passband. Therefore, a filter characteristic having steep attenuation characteristics at both ends of the pass band can be obtained.

If the electrodes of the superconducting resonator constituting the superconducting band rejection filter have a transition temperature or higher and no longer exhibit superconductivity, the superconducting band rejection filters SBEF1, SEF1
Although the amount of attenuation of the BEF 2 is reduced, the insertion loss in the pass band is suppressed to a slight increase due to the operation of the normal conduction band pass filter, and no fatal deterioration of the characteristics of the filter as a whole is caused.

FIG. 11 is a block diagram showing a more specific configuration example of the whole high frequency filter device. Where Rn
Is a normal conducting resonator, Rs is a superconducting resonator, K is a coupling circuit,
TL is a transmission line. Each of the two superconducting band-stop filters SBEF1 and SBEF2 has four superconducting resonators Rs and λg / λg when the wavelength on the line is λg.
4 or an odd multiple thereof. This provides a band rejection filter characteristic having four attenuation poles. The normal conduction bandpass filter NBPF has bandpass characteristics by sequentially coupling four normal conduction resonators Rn. And two superconducting band-stop filters S
BEF1, SBEF2 and normal conduction bandpass filter NBP
F and a transmission line TL having an electrical length of λg / 4 or an odd multiple thereof. Thereby, the impedance when the fourth stage resonator Rs of the superconducting band rejection filter SBEF1 from the first stage resonator Rn of the normal conduction bandpass filter NBPF to the fourth stage resonator Rs becomes very high. Similarly, a normal conduction bandpass filter NBPF
From the fourth-stage resonator Rn to the superconducting band-stop filter SB
Since the impedance seen from the resonator Rs in the first stage of the EF2 becomes very high, there is no interference between the two.

FIG. 12 is a perspective view showing a configuration of a main part of a normal conduction resonator constituting the normal conduction bandpass filter described above. In this example, a dielectric core having a shape in which two square pillar-shaped dielectric columns are crossed is integrally formed with a square cylindrical cavity, and electrodes are formed on the outer peripheral surface (four side surfaces) of the cavity. is there. Electromagnetic fields are shielded by providing a metal plate or a ceramic plate on which electrodes are formed on the two opening surfaces of the cavity. With this structure, TM110 mode resonance occurs in each of the vertical direction and the horizontal direction in the drawing, and a TM dual mode dielectric resonator is formed. Then, by combining these two resonance modes, 2
Used as a stage resonator. The coupling with the outside may be performed by inserting a coupling loop into the cavity and magnetically coupling with a predetermined mode.

As a normal conduction bandpass filter, this T
In addition to the M double mode dielectric resonator, an open dielectric resonator shown in FIG. 18, a short-circuited dielectric resonator shown in FIGS. 19 to 22, or a microstrip resonator may be used.

FIGS. 13 and 14 show examples of the configuration of the superconducting band rejection filter. FIG. 13 is an external perspective view thereof. Four superconducting resonators are provided in the shielding cavity, and an input / output connector is provided outside.

FIG. 14A is a plan view showing a state in which the upper surface of the shielding cavity is removed, and FIG.
It is sectional drawing of -A part. Each superconducting resonator has superconductor electrodes formed on the upper and lower surfaces of a cylindrical dielectric ceramic, respectively. These superconducting resonators are mounted on the bottom of the shielding cavity. Also, the shielding cavity has λ
A coupling circuit (probe) is projected through a transmission line having an electrical length of g / 4 (λg is a wavelength on the transmission line). Each coupling circuit is capacitively coupled to the circular TM mode of the superconducting resonator. With this structure, a band rejection filter composed of four stages of resonators is formed.

As the superconducting band rejection filter, a TM double mode dielectric resonator, a short-circuit type dielectric resonator, a strip resonator, or the like may be used.

FIGS. 15 and 16 show examples of the configuration of a normal conduction bandpass filter. FIG. 15 is a perspective view of the appearance, in which four normal-conducting resonators are provided inside the shield cavity, and an input / output connector is mounted outside. FIG.
(A) is a plan view in a state where an upper surface of a shielding cavity is removed, and (B) is a cross-sectional view of an AA portion in (A). Each resonator has thin-film multilayer electrodes formed on the upper and lower surfaces of a cylindrical dielectric ceramic. A coupling capacitor (chip) is attached to the thin film multilayer electrode on the upper surface, and the coupling capacitor is connected to the center conductor of the input / output connector. Also, coupling capacitors of adjacent resonators are connected by a coupling circuit (line). With such a structure, a band-pass filter including four resonators is configured.

FIG. 17 is a sectional view showing the structure of the thin-film multilayer electrode. In this example, the thin film conductor layer 3a, the thin film dielectric layer 4a, and the thin film conductor layer 3
The thin-film multilayer electrode 2 is formed by alternately forming the thin-film conductor layers and the thin-film dielectric layers in the order of b. The periphery of each thin-film conductor layer is open. The thickness of each thin film electrode layer is equal to or less than the skin depth at the resonance frequency so that the dielectric resonator formed by each thin film electrode layer and the thin film dielectric layer is coupled to the dielectric resonator formed by the dielectric plate. And

According to such a structure, each of the thin film dielectric layers 4a, 4b and 4c constitutes an extremely thin dielectric resonator together with the thin film electrode layers 3a, 3b and 3c located above and below them. Therefore, by setting the resonance frequency of the dielectric resonator formed in each thin film dielectric layer to be substantially equal to the resonance frequency of the dielectric resonator formed by the dielectric plate, the dielectric resonator formed in each thin film dielectric layer is The directions (phases) of the currents flowing through the upper and lower thin film electrode layers are aligned. As a result, the current concentration in the upper and lower portions of the dielectric plate 1 is reduced, and the current is dispersed to the surface layer. As a result, conductor loss is reduced, and high Qo characteristics are obtained.

Next, an example of the configuration of a transmission duplexer used in a base station of a mobile communication system and a communication apparatus using the same will be described with reference to FIG. In FIG. 23, each channel filter passes the frequency band of each transmission channel, and the isolator prevents the transmission signal from returning to the transmitter for each channel. The power combining circuit combines the power of the transmission signals passing through each channel filter and outputs the combined signal to the antenna filter. This antenna filter outputs the power-combined signal to the antenna. A communication device is constituted by the transmission duplexer and a transmitter for each channel connected thereto.

In such a transmission duplexer, any one of the high-frequency filter devices described above is applied to each channel filter and antenna filter. As a result, a small size, low loss, low cost, and highly reliable transmission duplexer and communication device can be obtained.

The embodiment of the duplexer of the present invention has been described by taking the duplexer as an example. Similarly, the duplexer is constituted by using the high-frequency filter device of the present invention for the transmit filter and the receive filter. be able to.

[0047]

According to the present invention, in the normal state where the superconductor exhibits superconductivity, the high unloaded Q characteristic of the dielectric resonator using the superconductor as the electrode material is utilized, and the electrode temperature is reduced. When the temperature rises above the transition temperature, it exhibits the filter characteristics of the dielectric resonator using the normal conductor as the electrode material. Therefore, if the main part of the filter characteristics is determined by the dielectric resonator using the normal conductor as the electrode material, and the dielectric resonator using the superconductor as the electrode material is used to enhance the filter characteristics, the transition temperature is higher than the transition temperature. When the temperature rises to a high level, no fatal deterioration of characteristics occurs.

According to the present invention, a part or all of the electrode made of a normal conductor is formed as a thin film multilayer electrode composed of a laminate of a thin film conductor layer and a thin film dielectric layer. As a result, the conductor loss is reduced as a whole, and a dielectric resonator having a high unloaded Q can be obtained. Therefore, even in a state where the electrode temperature rises and the superconductor does not show superconductivity, the high no-load Q characteristic of the dielectric resonator using the electrode made of a normal conductor is utilized, and the high frequency of the low insertion loss is obtained. A filter device is obtained.

Further, according to the present invention, it is possible to obtain a duplexer or a duplexer which has a small characteristic change with respect to a temperature change around the transition temperature.

Further, according to the present invention, since any one of the above-described high-frequency filter devices is provided in a transmission unit or a reception unit of a communication signal to constitute a communication device, for example, a transmission sharing device used in a base station of a mobile communication system. The communication device using the device can be reduced in size, loss, cost, and reliability.

[Brief description of the drawings]

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

FIG. 2 is a block diagram showing a configuration of the high-frequency filter device.

FIG. 3 is a diagram illustrating characteristics of a filter included in a high-frequency filter device according to a second embodiment.

FIG. 4 is a diagram showing characteristics of another filter included in the high-frequency filter device according to the second embodiment.

FIG. 5 is a diagram showing overall characteristics of the high-frequency filter device.

FIG. 6 is a block diagram showing a configuration of the filter device.

FIG. 7 is a diagram illustrating characteristics of a filter included in a high-frequency filter device according to a third embodiment.

FIG. 8 is a diagram showing characteristics of another filter included in the high frequency filter device according to the third embodiment.

FIG. 9 is a view showing overall characteristics of the high-frequency filter device.

FIG. 10 is a block diagram showing a configuration of the filter device.

FIG. 11 is a block diagram showing a more detailed configuration example of a high-frequency filter device according to a third embodiment.

FIG. 12 is a diagram illustrating a configuration example of a normal conduction bandpass filter.

FIG. 13 is an external perspective view of a superconducting band-stop filter.

FIG. 14 is a diagram showing an internal structure of the superconducting band-stop filter.

FIG. 15 is an external perspective view of a normal conduction bandpass filter.

FIG. 16 is a diagram showing the internal structure of the normal conduction bandpass filter.

FIG. 17 is a diagram showing a configuration of a thin-film multilayer electrode.

FIG. 18 shows an example of an open dielectric resonator.

FIG. 19 shows an example of a short-circuit type dielectric resonator.

FIG. 20 is a diagram showing an example of a short-circuit type dielectric resonator.

FIG. 21 is a diagram showing an example of a short-circuit type dielectric resonator.

FIG. 22 is a diagram showing an example of a short-circuit type dielectric resonator.

FIG. 23 is a diagram illustrating a configuration example of a transmission duplexer and a communication device.

FIG. 24 is a diagram showing a configuration of a conventional superconductor device.

Continued on the front page (72) Inventor Norifumi Matsui 2-26-10 Tenjin, Nagaokakyo-shi, Kyoto Prefecture Inside Murata Manufacturing Co., Ltd. (72) Inventor Shoichi Narahashi 2-1-1 Toranomon, Minato-ku, Tokyo (72) Inventor Toshio Nojima 2-10-1 Toranomon, Minato-ku, Tokyo NTT Mobile Communication Network Co., Ltd.

Claims (6)

[Claims] 1. A high-frequency filter device comprising a combination of a resonator using a superconductor as an electrode material and a resonator using a normal conductor as an electrode material. 2. A resonator using the superconductor as an electrode material is a filter that passes frequencies near one or both ends of a pass band, and a resonator using the normal conductor as an electrode material is used as a filter in a pass band. 2. The high-frequency filter device according to claim 1, wherein the filter that passes frequencies near the center has band-pass characteristics as a whole. 3. A resonator using the superconductor as an electrode material is a filter for blocking frequencies near one or both ends of a pass band, and a resonator using the normal conductor as an electrode material is used as a filter in a pass band. 2. The high-frequency filter device according to claim 1, wherein the filter that passes frequencies near the center has band-pass characteristics as a whole. 4. The thin-film multilayer electrode comprising a laminate of a thin-film conductor layer and a thin-film dielectric layer, wherein a part or all of the normal conductor electrode is a thin-film multilayer electrode. 2. The high frequency filter device according to 1. 5. A duplexer wherein the high-frequency filter device according to claim 1 is provided between a common port and another individual port. 6. A communication device, wherein the high-frequency filter device according to claim 1 is provided in a transmission unit or a reception unit of a communication signal.