JP3380165B2 - High frequency filter device, duplexer and communication device - 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 filter device in a microwave band or a millimeter wave band used for wireless communication, a duplexer, and a communication device using the same.

[0002]

2. Description of the Related Art In a microwave band or millimeter wave band high frequency filter device used for wireless communication, particularly a high frequency filter device used for a base station of a mobile communication system,
Despite handling a large amount of power, it is required to be compact, low loss, and low cost. In such a high-frequency filter device that handles a large amount of electric power, a dielectric resonator having a high unloaded Q and a small size is used. However, as the device becomes smaller, its heat radiation efficiency decreases, and measures against temperature rise are taken. Is a serious problem.

Therefore, Japanese Unexamined Patent Publication No. 6-37513 proposes a device using a superconductor as an electrode material. An example of the configuration is shown in FIG. 9A is a top view, and FIG. 9B is a cross-sectional view taken along the line AA in FIG. In this way, the entire surface ground electrode is formed on the lower surface of the dielectric substrate, and the microstrip line is formed on the upper surface. These electrodes are the superconductor thin film,
The high heat resistant metal thin film and the high conductivity metal thin film are formed in this order.

By forming the electrode in which the superconductor thin film and the high conductivity metal thin film are combined in this way, the conductivity of the superconductor thin film becomes extremely large in the normal state, the conductor loss is small, and the Q is high. Acts as a resonator (microstrip resonator). When the electrode temperature rises above the superconducting transition temperature of the superconductor material (hereinafter simply referred to as the "transition temperature"), the conductivity of the superconductor thin film drops sharply. Loss is kept low and no fatal deterioration of characteristics occurs.

[0005]

However, the conventional device shown in FIG. 24 has a low loss property as compared with the case where each of the superconductor or the normal conductor (metal conductor) is formed as a single electrode. However, it is considered inferior in terms of reliability and power resistance. In other words, by forming a metal thin film on the superconductor thin film, the physical properties of the superconductor thin film may be changed. It is considered that the power consumption is deteriorated and a problem occurs in the power resistance characteristic. In addition, the insertion loss as a filter when the temperature of the electrode rises above the transition temperature is smaller than that when the electrode is composed only of a superconductor thin film, but the conductor loss when the temperature exceeds and does not exceed the transition temperature. Is not small, and the change of the unloaded Q as the dielectric resonator and the characteristic change as the filter cannot be sufficiently suppressed.

The object of the present invention is to solve the above-mentioned various problems, maintain low loss in a normal state, high reliability, and high power resistance, and even when the temperature of the electrode rises above the transition temperature. 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 characteristic deterioration.

[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. A high-frequency filter device is configured by combining the superconducting filter according to 1. and the normal conducting filter including a resonator having a normal conductor as an electrode material. In particular, normal conduction
Filter that determines the characteristics near the center of the frequency characteristics
And a superconducting filter for the normal conducting filter
Connected to the relationship that strengthens the characteristics near the end of the frequency characteristics.
That make up the filter apparatus is.

A resonator using a superconductor as an electrode material has a characteristic that the unloaded Q is extremely high in a normal use state in which the electrode exhibits superconductivity, and when the temperature rises above the transition temperature, this resonator is used. The no-load Q of is greatly reduced. On the other hand, although the electric conductivity of the normal conductor has temperature dependence, it does not change sharply near the transition temperature unlike the superconductor. Therefore, in the resonator using the normal conductor as an electrode material, the unloaded Q of the resonator is stable regardless of whether the transition temperature of the superconductor is exceeded or not.

Therefore, in the normal state where the superconductor exhibits superconductivity, the high unloaded Q characteristic of the resonator using the superconductor as an electrode material is utilized, and the electrode temperature rises above the transition temperature. In that case, the filter characteristics are exhibited by the resonator using the normal conductor as the electrode material. Therefore, even if the temperature of the electrode rises above the transition temperature, the main part of the filter characteristics is determined by the resonator using the normal conductor as the electrode material so that fatal characteristic deterioration does not occur. If the resonator made of the electrode material is used to enhance the filter characteristics, it will not cause a fatal characteristic deterioration when the temperature is raised above the transition temperature.

For example, a resonator using a superconductor as an electrode material is used as a filter that passes frequencies near one or both ends of the pass band, and a resonator using a normal conductor as an electrode material is used near the center of the pass band. Use a filter that passes frequencies. As a result, the resonator using the normal conductor as the electrode material can have bandpass characteristics regardless of the temperature of the electrode, and the resonator will pass through in normal use where the superconductor exhibits superconductivity. Since frequencies near one end or both ends of the band are passed, a sharp attenuation characteristic can be provided at the upper end, the 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, the attenuation characteristic at one end or both ends of the bandpass characteristic becomes gentle, and the bandpass characteristic can be maintained as a whole.

Further, for example, a resonator having a superconductor as an electrode material is used as a filter for blocking frequencies near one or both ends of the pass band, and a resonator having a normal conductor as an electrode material is used as a center of the pass band. Use a filter that passes frequencies in the vicinity. Also in this case, the resonator using the normal conductor as the electrode material can have the bandpass characteristic regardless of the temperature of the electrode, and in the normal use state in which the superconductor exhibits superconductivity, the resonator passes through the resonator. Since frequencies near one end or both ends of the band are blocked, a steep attenuation characteristic can be provided on the upper side, the lower side, or both sides of the pass band.

Further, in the present invention, a part or the whole of the electrode made of a normal conductor is a thin film multilayer electrode composed 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 with a high unloaded Q. Therefore, even in a state where the electrode temperature rises and the superconductor does not exhibit 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, according to the present invention, one of the above high frequency filter devices is provided between a common port and other individual ports to form a duplexer. For example, between a common port and a certain individual port, a high-frequency filter device as a transmission filter for passing a transmission signal is provided,
By installing a high-frequency filter device as a reception filter that passes the reception signal between the common port and other individual ports, the transmission / reception of an antenna duplexer, etc. with little characteristic change due to temperature change around the transition temperature as a whole A shared device can be obtained. Further, if a high-frequency filter device as a transmission filter that allows transmission signals to pass through is provided between one common port and a plurality of other individual ports, the transmission sharing can be reduced as a whole with little change in characteristics due to temperature changes before and after the transition temperature. You get a bowl.

Further, according to the present invention, any one of the above-mentioned high frequency filter devices is provided in a communication signal transmitting section or a receiving section to constitute a communication apparatus. 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-sized, low-loss, low-cost and highly reliable communication device can be obtained.

[0015]

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 each part of the high-frequency filter device. In the figure, K is a coupling circuit, Rs is a resonator having a superconductor as an electrode material (hereinafter referred to as “superconducting resonator”), and Rn is a resonator having a normal conductor as an electrode material (hereinafter “normal conduction”). "Resonator".),
PS is a phase shifter, and shifts the phase by π, for example. Further, (fi) indicates that the resonance frequency is fi. For example, Rs (f1) represents a superconducting resonator having a resonance frequency of f1, and Rn (f8) represents a normal conducting 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 having resonance frequencies f1 and f2 bear the frequencies near the lower end of the pass band, and six normal conducting resonators having resonance frequencies f3 to f8 take the frequencies near the upper end of the pass band. . Therefore, in a normal use state, as shown in FIG. 1A, the low frequency side of the pass band exhibits a steep attenuation characteristic. The unloaded Q (Qo) of the superconducting resonator, in which the temperature of the superconducting resonator (the temperature of the electrode) rises above the transition temperature and bears the resonance frequencies f1 and f2.
, The insertion loss increases, so that the attenuation characteristic on the low frequency side of the pass band becomes slightly gentle as shown in FIG. However, since the characteristics of the normal conduction resonator responsible for f3 to f8 hardly change, the band pass characteristics are maintained as a whole.

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

As shown in FIG. 2, when the resonance frequencies of the respective resonators are arranged in order, adjacent resonators of the resonance frequencies are connected in parallel via a phase shifter PS that shifts the phase by, for example, π. As a result, the impedance of the two resonators adjacent to each other at the resonance frequency when viewed from the branch point becomes very large, so that 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 column as shown in FIG.
Is a loop or probe coupled to the circular TM mode dielectric resonator, for example. The phase shifter PS is, for example, a line having an electrical length that gives a phase difference π.

In FIG. 18, (A) is an example in which a dielectric column is placed on the bottom surface in a shield cavity (cavity),
(B) is an example in which dielectric columns having electrodes formed on the upper and lower surfaces are laminated and integrated, and the electrodes on the outer surface are respectively bonded between the top surface and the bottom surface in the shielding cavity (cavity). In either case, it functions as a circular TM mode dielectric resonator, but it becomes a superconducting resonator by making the electrode a superconductor, and becomes a normal conducting resonator by making the electrode a normal conductor.

Other examples of the above-mentioned resonator include a TM dual mode dielectric resonator as shown in 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 a portion AA in (A). In the example shown in FIG. 19, electrodes are formed on the outer surface of a rectangular parallelepiped dielectric block so that the dielectric block acts as a TM mode dielectric resonator. In the example of FIG. 20, a void portion is formed around the prismatic dielectric portion so that the dielectric portion is formed in 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 so that the dielectric block acts as a circular TM mode dielectric resonator. In the example of FIG. 22,
A cavity is formed around the columnar dielectric portion so that the columnar dielectric portion is formed in the center so that the dielectric portion acts as a circular TM mode dielectric resonator. In either 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.

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

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

FIG. 6 is a block diagram showing the overall 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 and 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 pass characteristics of the superconducting band pass filters SBPF1 and SBPF2. The normal conduction band pass filter NBPF shown in FIG. 3 has a frequency f2.
To f3 as pass bands, the superconducting band pass filter SBPF1 shown in FIG. 4 has frequencies f1 to f2 as pass bands, and S
The BPF 2 has f3 to f4 as pass bands.

The normal conduction resonator has a Q value as compared with 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 comparatively gentle. On the other hand, since the Qo of the superconducting resonator is extremely high, the attenuation characteristic at both ends of the passband of the superconducting bandpass filter becomes steep.

By connecting these three resonators in parallel as shown in FIG. 6, the overall characteristics are as shown in FIG. That is, the low-frequency side (f1 to f2) of the passband is carried by the superconducting bandpass filter SBPF1, and the high-frequency side (f3 to f4) of the passband is the superconducting bandpass filter SBP.
The normal conduction band pass filter NBPF plays a role of F2, and the central portion (f2 to f3) of the pass band. 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 bandpass filter are above the transition temperature and do not exhibit superconductivity, the insertion loss of the superconducting bandpass filter increases and the attenuation characteristic becomes gentle. However, due to the action of the normal conduction band pass filter, the insertion loss in the vicinity of the center of the pass band is suppressed to an extent that it slightly increases, and the filter as a whole does not have a fatal deterioration in characteristics.

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

FIG. 10 is a block diagram showing the overall structure of the high frequency filter device. SB in the figure
EF1 is a band stop filter using a superconducting resonator (hereinafter referred to as "superconducting band stop 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 pass characteristics of the superconducting band stop filters SBEF1 and SBEF2. The normal bandpass filter NBPF shown in FIG. 7 has a frequency f2.
~ F3 as a pass band, the superconducting band stop filter SBEF1 shown in FIG. 8 has frequencies f1 and f2 as stop bands, and S
BEF2 has f3 to f4 as stopbands.

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 stop filter SBEF1 steeply attenuates the low band side (f1 to f2) of the pass band, and the superconducting band stop filter SBEF2 steeply attenuates the high band side (f3 to f4) of the pass band. 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 stop filter are above the transition temperature and no longer show superconductivity, the superconducting band stop filters SBEF1, SEF are provided.
Although the amount of attenuation of BEF2 becomes small, the insertion loss in the pass band is suppressed to the extent that the insertion loss in the pass band is slightly increased by the action of the normal conduction band pass filter, and the filter as a whole does not suffer a fatal characteristic deterioration.

FIG. 11 is a block diagram showing a more specific structural example of the entire 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. The two superconducting band stop filters SBEF1 and SBEF2 each have four superconducting resonators Rs of λg / when the wavelength on the line is λg.
It is configured by connecting via a transmission line TL having an electrical length of 4 or an odd multiple thereof. As a result, it has a band elimination filter characteristic having four attenuation poles. The normal conduction band pass filter NBPF has four normal conduction resonators Rn sequentially coupled to each other to have a band pass characteristic. And two superconducting band stop filters S
BEF1, SBEF2 and normal conduction band pass filter NBP
F is connected to F by a transmission line TL having an electrical length of λg / 4 or an odd multiple thereof. As a result, the impedance seen from the first-stage resonator Rn of the normal conduction band-pass filter NBPF to the fourth-stage resonator Rs of the superconducting band stop filter SBEF1 becomes extremely high, so that they do not interfere with each other. Similarly, a normal conduction band pass filter NBPF
From the fourth stage resonator Rn of the superconducting band stop filter SB
Since the impedance of the first-stage resonator Rs of the EF2 is extremely high, they do not interfere with each other.

FIG. 12 is a perspective view showing a structure of a main part of a normal-conduction resonator constituting the above-mentioned normal-conduction bandpass filter. In this example, a dielectric core having a shape in which two square pillar-shaped dielectric pillars are crossed is integrally molded with a square tube-shaped cavity, and electrodes are formed on the outer peripheral surface (four side surfaces) of the cavity. is there. An electromagnetic field is shielded by providing a metal plate or a ceramic plate on which electrodes are formed on the two opening surfaces of the cavity. This structure causes TM110 mode resonance in the vertical and horizontal directions in the figure, and constitutes a TM double mode dielectric resonator. Then, by combining these two resonance modes,
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 band pass filter, this T
In addition to the M double-mode dielectric resonator, the open type dielectric resonator shown in FIG. 18, the short-circuit type dielectric resonator shown in FIGS. 19 to 22, or the microstrip resonator may be used.

FIG. 13 and FIG. 14 are diagrams showing a configuration example of the superconducting band elimination filter. FIG. 13 is a perspective view of the appearance. Four superconducting resonators are provided in the shield cavity, and input / output connectors are provided outside.

FIG. 14A is a plan view with the upper surface of the shielding cavity removed, and FIG. 14B shows A in FIG.
It is a sectional view of the -A portion. In each superconducting resonator, superconducting electrodes are formed on the upper and lower surfaces of a cylindrical dielectric ceramic. These superconducting resonators are mounted on the bottom of the shield cavity. Also, the shield 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 elimination filter including a four-stage resonator is formed.

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

FIG. 15 and FIG. 16 are diagrams showing a configuration example of the normal conduction band pass filter. FIG. 15 is a perspective view of the appearance thereof, in which four normal conduction resonators are provided inside the shielding cavity and an input / output connector is attached to the outside. FIG.
(A) is a plan view with the upper surface of the shielding cavity removed, and (B) is a cross-sectional view taken along the line AA 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 this coupling capacitor and the central conductor of the input / output connector are connected. In addition, the coupling capacitors of adjacent resonators are connected by a coupling circuit (line). With such a structure, a bandpass filter including four resonators is formed.

FIG. 17 is a sectional view showing the structure of the thin film multilayer electrode. In this example, from the surface of the dielectric ceramics, the thin film conductor layer 3a, the thin film dielectric layer 4a, 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 peripheral portion of each thin film conductor layer is open. The thickness of each thin-film electrode layer is the same as or thinner than the skin depth at the resonance frequency so that the dielectric resonator formed by each thin-film electrode layer and thin-film dielectric layer is coupled to the dielectric resonator formed by the dielectric plate. And

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

Next, a configuration example of a transmission duplexer used in a base station of a mobile communication system and a communication device 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 blocks the transmission signal from returning to the transmitter of each channel. The power synthesis circuit power-synthesizes the transmission signals that have passed through the respective channel filters and outputs them to the antenna filter. This antenna filter outputs the power-combined signal to the antenna. A communication device is constituted by this transmission duplexer and the transmitter for each channel connected to it.

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

Although the transmission duplexer is taken as an example of the duplexer of the present invention, the transmission / reception duplexer is similarly constructed by using the high frequency filter device of the present invention for the transmission filter and the reception 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 an electrode material is utilized to make the electrode temperature higher. When the temperature rises above the transition temperature, it exhibits a filter characteristic by a dielectric resonator using a normal conductor as an electrode material. Therefore, if a dielectric resonator that uses a normal conductor as an electrode material defines the main part of the filter characteristics, and a dielectric resonator that uses a superconductor as an electrode material is used to enhance the filter characteristics, It does not cause a fatal deterioration in characteristics when the temperature is raised to 0.

Further, according to the present invention, a part or the whole of the electrode made of the normal conductor is a thin film multi-layered electrode composed of a laminated body of a thin film conductor layer and a thin film dielectric layer, so that the concentration of the current density at the electrode portion is concentrated. It is alleviated, the conductor loss is reduced as a whole, and a dielectric resonator having a high unloaded Q is obtained. Therefore, even when the electrode temperature rises and the superconductor does not exhibit superconductivity, the high no-load Q characteristic of the dielectric resonator using the electrode made of the normal conductor is utilized, and the high frequency of low insertion loss is achieved. A filter device is obtained.

Further, according to the present invention, it is possible to obtain the duplexer and the duplexer in which the characteristic changes little with respect to the temperature change around the transition temperature.

Further, according to the present invention, since any one of the above high-frequency filter devices is provided in the communication signal transmitting section or the receiving section to configure the communication apparatus, for example, transmission sharing used in a base station of a mobile communication system. It is possible to reduce the size, the loss, the cost, and the reliability of a communication device using a device.

[Brief description of 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 the configuration of the high-frequency filter device.

FIG. 3 is a diagram showing characteristics of a filter included in the high-frequency filter device according to the 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 the configuration of the filter device.

FIG. 7 is a diagram showing characteristics of a filter included in the high-frequency filter device according to the 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 diagram showing overall characteristics of the high frequency filter device.

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

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

FIG. 12 is a diagram showing 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 view showing an internal structure of the superconducting band elimination filter.

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

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

FIG. 17 is a diagram showing the structure of a thin film multilayer electrode.

FIG. 18 is a diagram showing an example of an open type dielectric resonator.

FIG. 19 is a diagram showing an example of a short-circuited dielectric resonator.

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

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

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

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

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

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Norifumi Matsui, No. 26-10 Tenjin, Tenjin, Nagaokakyo, Kyoto Prefecture Murata Manufacturing Co., Ltd. (72) Shoichi Narahashi, No. 10-1, Toranomon, Minato-ku, Tokyo・ In the TTI mobile communication network (72) Inventor Toshio Nojima 2-10-1 Toranomon, Minato-ku, Tokyo NTT Mobile communication network Co., Ltd. (56) Reference JP-A-11-186812 (JP, A) (58) Fields surveyed (Int.Cl. ⁷ , DB name) H01P 1/20-1/219 H01P ^7/ 00-7/10

Claims (6)

(57) [Claims] 1. A resonator using a superconductor as an electrode material
A superconducting filter, the resonators of the normal conductor and the electrode material
High-frequency filter configured by combining
It is a filter device, and the frequency characteristics are
Configure a filter that determines the characteristics near the center, and
A superconducting filter for the filter, with end of frequency characteristics
A high-frequency filter device, characterized in that it is connected in a relationship that strengthens nearby characteristics . 2. A resonator using the superconductor as an electrode material is used as a filter that allows frequencies near one or both ends of the pass band to pass, and a resonator using the normal conductor as an electrode material is used as a filter of the pass band. The high frequency filter device according to claim 1, wherein a band pass characteristic is provided as a whole as a filter that passes frequencies near the center. 3. A resonator using the superconductor as an electrode material is used as a filter for blocking frequencies near one or both ends of the pass band, and a resonator using the normal conductor as an electrode material is used as a filter of the pass band. The high frequency filter device according to claim 1, wherein a band pass characteristic is provided as a whole as a filter that passes frequencies near the center. 4. A thin-film multi-layer 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 multi-layer electrode. The high frequency filter device according to. 5. A duplexer comprising the high-frequency filter device according to claim 1 provided between a common port and other individual ports. 6. A communication device, wherein the high-frequency filter device according to claim 1 is provided in a communication signal transmitter or receiver.