DE69630258T2 - Radio transmission filter for low temperature operation - Google Patents

Description

The invention relates to a small format Integrated high-performance filter device in the transmission section a base station in a mobile communication system for performing the Communication with multiple, adjacent transmission frequency channels used , cooling an overall filter element for use, and in particular a filter device operating at low temperatures for high-performance transmission, in which a superconductor is used as the electrode material.

A dielectric resonator filter with high Q-value is in mobile communication as a high-performance transmission filter for one Base station in a frequency band from 800 MHz (megahertz) to 1.5 GHz (Gigahertz) have been widely used. There is a filter for each channel needed. Usually becomes a machine used in which 16 filters for 16 channels are housed as a group. Each filter is for use cooled with air or water, because with an input power of ten watts or more, there is an insertion loss of has about 40%.

A distributor type heavy current filter device used for the transmitting section of the base station has one in 13 structure shown (see "The Basis of Mobile Communications": The Institute of Electronics, Information and Communication Engineers, by Yoshihisa Okumura et al., pp. 255-256). In 13 are 16-channel transmitters with changing frequencies within a frequency band via isolating switches 541 with resonator filters 542 connected. Any resonator filter 542 is formed by a dielectric resonator and is designed so that it passes a signal transmitted by the connected transmitter within a kilohertz (kHz) to 100 kHZ frequency band.

Considering the space requirement and The installation cost in mobile communication becomes an antenna usually together used. For this reason, a branch or distributor is used. The distributor combines the outputs several bandpass filters with different passband frequencies and closely adjacent resonance frequencies for sharing an output transmission line. The prior art distributor is at the exit end a microwave filter connected to a cavity, one dielectric resonator or the like, and uses one Coaxial line or the like.

In 13 becomes a distributor 543 used to connect 16-channel signals to a line while performing impedance matching. As in 13 are branch lines formed by coaxial cables in the distributor 543 hierarchically connected. More specifically, the branch lines 544 with a length of λ / 4 (ie about a quarter wavelength) are connected to the output sides of 16 resonator filters. 4 branch lines each 544 are combined into one and connected to four union or mixing points. Branch lines are connected to the mixing points 545 connected with a length of λ / 2. Two branch lines each 545 are combined into one and connected to two mixing points. In addition, branch lines 546 with a length of λ / 2 connected to the two mixing points. The two branch lines 546 are connected to each other at a mixing point to which the output line of a high-performance circulator is connected. To prevent the transmission of interference signals outside the pass band, the high-performance circulator is connected to an antenna via a band filter.

The principle of operation of the distributor is the following. Seen from the mixing point, those in resonance take over Filters the impedance match, and other resonators are shorted. Accordingly, when output signals are separated by (2n + 1) λ / 4 from Output end of the filter are mixed, the impedance of the Branch line in non-resonance state at the mixing point infinite. When the output signal passes through the branch line that is in a distance of (m + 1) λ / 2 from the mixing point the impedance does not. As a result, there is no mismatch loss, even if the signal outputs be brought together again in the same position. As a result, low loss transmission lines be shared. is λ a wavelength at the mean resonance frequency of the filter (electrical length), and n and m are 0 or natural Numbers.

The impedance of each resonator filter, seen from the mixing point of the coaxial cable with a length of λ / 4 is for the frequency of a pass band equal to the characteristic impedance of an output line and is for other frequencies much higher. Therefore, the characteristics of other filters are hardly affected. consequently can the output signals of the resonators are easily brought together.

In the filter device after State of the art are dielectric resonator filters for the number of the channels in one housing unit housed, and signals from the filters are through one of Coaxial cable branch lines formed distributor to an output line merged. As a result, it increases the device.

In a high-performance filter device, a plurality of filters of the flat or planar circuit type are formed by normally conductive metal electrodes which are not integrated by the distributor and which have a coaxial line structure according to the prior art and are operated at normal temperature because of a low Q value and a high insertion loss. Even if such a filter device is used in practice each filter should be mounted on a shield housing and connected to the distributor by a connector. As a result, the size of the device increases and connector attenuation occurs on each connector.

A planar circuit filter, the one Filter electrode with a recent developed superconducting thin film is due to a high Q value, a low loss and characterized a high output but should be on cooled a low temperature to work in the superconducting state. traditionally, becomes a su praleit filter unit, which is housed in a shield housing is on the cold head of a cryostat to perform laboratory-scale assessment experiments. To the The shield housing is used as an example by a common surface-mounted (SMA) connectors or the like with a semi-rigid cable connected, and the other end of the semi-rigid cable is connected to one Connector connected to the wall of a heat insulating container is attached so that the Signal of the filter is input and output. However, it is about none Example has been reported in which several superconducting planar circuit filters used to build the high-performance filter, such as. B. for one Mobile communication base station or the like.

A filter device in which several dielectric resonator filters are housed, has a high Performance loss on. An insertion loss at a frequency of about 1.5 GHz is, for example, 2 to 3 decibels (DB). Consequently, the Filter device in a large Rack to be cooled with air or water. The dimensions of each resonator are approximately 100 mm ∅ × 120 mm H. The 16-channel filter section is 25 centimeters wide (cm), a depth of 25 cm and a height of 1 meter (m). Taking the room in which a cooling system for air or water cooling is included, then the dimensions of the entire filter device magnified even more. Besides, is the power requirement for a predetermined transmission power so large that the filter device is uneconomical is.

If due to a change in temperature of the filter changes a resonance frequency, there is the possibility that the Operation of a mobile communication system becomes difficult. consequently is the temperature stability a necessary design restriction for the filter device, the generally increases the cost of the filter device.

In addition, each filter should a channel frequency setting / tuning device can be provided, which increases the cost.

A semi-rigid cable, a coaxial cable for high Power or the like is cut into pieces a few cm long, the for a branch line can be used. Therefore is a connecting section difficult to manufacture. The specialist must process, measure and carry out adjustment by hand. For this reason, the distributor is disadvantageous for the reproducibility of the Characteristic curve, the production, the costs and the like.

If high-power microwaves occur a superconducting filter according to the prior art and are merged or mixed by the distributor, wherein a metal with a temperature close to normal temperature is used the temperature of a superconducting filter element becomes higher than that of the connector part, since the distributor develops heat through conductor damping, so that partially a transition to the normal conductive state (quench). Consequently the section transitioned to the normal conducting state becomes immediate interrupted.

Even if the distributor through a Cable with small dimensions is formed, such as. B. a semi-rigid Cable to cool the entire filter unit becomes the size of the filter device due to the smallest bending radius of the semi-rigid cable (downwards) limited and cannot be reduced. A heavy current also flows to the cable and to the filter connector, So that the Temperature of the superconducting thin film as a result of being developed by contact resistance loss and conductor resistance loss Joule heat increases. This reduces the value of the critical current, so that the maximum output power is limited.

If using the distributor a coaxial line is formed, as described above, the dimensions of the device, and a large amount of heat supplied from the coaxial line is removed. Out for this reason, the dimensions of the entire facility including one necessary large refrigeration machine considerably larger, and the facility is becoming more expensive.

In "Fabrication and Evaluation of Superconducting Devices "(manufacturing and assessment of superconductor components) by R. Babbit et al., Microwave Journal 34 (1991), No. 4, pp. 40-48, becomes a facility for low temperature operation discloses a shield housing block, a heat insulating Container, in which the shield housing block is housed, and one provided in the heat insulating container cooling plate having. The shield housing block is attached to the cooling plate.

There is a solution to the above problems Object of the present invention therein is a high-performance filter device to provide that for a Mobile communication base station or the like is used and excellent temperature stability and frequency selectivity, a low insertion loss, small size, low power and low Costs.

The task is characterized by the characteristics of the To sayings solved.

According to a first construction has a filter device for Low temperature operation on: a shield housing block with signal input and - exit sections and several closed rooms with between the signal input and -Assembly sections connected filter elements, a heat insulating Container, in which the shield housing block and a cooling plate, provided in the heat insulating container in which the shield case block in thermal contact condition or heat conductive on the cooling plate is attached.

With such a construction are several filter elements in the shield housing block housed, and the shield housing block is in the heat insulating container in thermal contact condition on the cooling plate attached. As a result, can the dimensions of the overall device are reduced while a temperature change each filter element can be regulated to a minimum. Self when a temperature change is caused by the distance of the resonant frequencies of the filters kept almost constant as long as the filter element is the same Has temperature characteristic (such a construction can easily be achieved. Accordingly, the frequency stability can be improved by the known means of surveillance the resonance frequency of the filter can be applied to the temperature the cooling plate to regulate.

The shield housing block preferably has several signal input and output sections and is by several shield housings formed with at least one enclosed space. Also are the signal input and output lines of the filter element preferably via a Connection point on the substrate of the filter element or via a wiring element embedded in the substrate with the signal input and output portions of the shield housing block connected.

In addition, the closed Space for accommodating the filter element kept in a vacuum state, so that Filter element cooled stably can be. Furthermore, the closed room with dry helium, Neon or a mixture of helium and neon filled so that the filter element without liquefaction evenly a temperature of about 30 Kelvin (K) can be cooled. If the closed room with dry argon, nitrogen, or oxygen is filled with a mixture of argon, nitrogen and oxygen, the filter element can spread evenly without liquefaction the temperature of liquid Nitrogen (77.3 K) are cooled, that can be easily reached.

Each planar filter element is preferably almost arranged in parallel, a cylindrical bore with an axis, which are almost parallel to the surface each filter element penetrates the shield housing block, a mobile body is provided, the movable body being a threaded or screw portion has, which in a spiral Groove is screwed into at least part of the inner peripheral surface the cylinder bore is formed, and by rotation in the Axial direction of the cylinder bore moves, the outer end portion of the moving body a section for transmission an external force has to transmit the torque to the movable body, and wherein the inner End section of the movable body has an earth rod made of a conductor, which Volume (electrical volume) of the closed room changed. at Such a construction is the corresponding to the filter elements intended moving bodies outside of the shield case block rotated and shifted in the axial direction so that the resonance frequency of the Filter elements can be set individually. In particular let yourself the characteristic curve during the cooling easily fine-tune. Also at the top of the grounding bar attached a dielectric layer or a dielectric block, so that the adjustable frequency range according to the dielectric constant be enlarged can.

The transmission section is more preferred for an external force rotated by a drive device on the outside of the heat insulating container (stronger preferably a rod with a low heat transfer coefficient is used, a thermal insulation effect to reach). As a result, the characteristic curve during the Cryogenic operation precise can be set.

Preferably the filter element through a thin film electrode formed, which is applied to a dielectric substrate. In this case, the temperature change easily reach the characteristic of each filter element, and the dimensions the facility can be made smaller. Furthermore, the thin film electrode consists of a superconducting material, in particular from an oxide high-temperature superconductor material, so that he can easily obtain a filter element with a high Q value. Besides, can a high critical current density can be achieved, so that a small format Filters with an output of a few tens of watts at a frequency can be implemented in the 2 GHz band.

In addition, the inside of the heat insulating container is kept in a vacuum state, and the cooling plate is connected to a heat transfer section to dissipate the heat of the shield case block from the heat insulating container to the outside, so that the filter element can be stably cooled by the cooling plate. A coolant can be filled into the heat-insulating container to cool the cooling plate and the shield housing block. With egg In such a construction, cooling can be carried out easily and at low cost.

According to a second construction The present invention is the filter element that the filter device forms, characterized in that a filter electrode, the from a superconducting thin film exists, and one connected to the output end of the filter electrode Thin film coupling line with a length from (2m + 1) λ / 4 (where m = 0 or a natural Number and λ one Signal wavelength is formed on the same level that a filter coupling line block, that of two ground electrodes above a dielectric is held, layered to a filter block is that the other ends of the thin-film coupling lines the filter coupling line block by a conductive connection device connected, which extends in the lamination direction by one Form coupling section, and that an output coupling line with the same characteristic impedance as that of the Thin film coupling line is connected to the coupling section.

With such a construction are the filter electrode consisting of a superconducting thin film and the thin-film coupling line connected at its output end the same level is formed around a filter coupling line block to form by the dielectric of two vertical ground electrodes is held. As a result, a small format filter can be used high Q value and low loss integrated with the coupling line become. The manufacturing steps of the filter are standardized, and the fine adjustment of the frequency characteristic is standardized, So that the Working hours for manufacturing and other costs can be reduced.

By laminating the filter coupling line blocks to Formation of the filter block is achieved by the coupling between the filter coupling line blocks avoided the ground electrode, and the dimensions of the overall device can be made smaller. Furthermore, the other ends of the thin-film coupling lines with a length from (2m + 1) λ / 4 the filter coupling line block by a conductive connection device connected, which extends in the lamination direction, d. H. by a contact hole (a through hole) around a coupling portion to build. The output coupling line, which is the same characteristic Impedance like the thin-film coupling line has, is connected to the coupling section, so that several Filters through a thin-film laminate structure can be united.

Preferably, the superconducting thin existing filter electrode through a superconducting oxide thin layer educated. In this case, cooling is easy to do because the operating temperature approximately to the temperature of liquid Nitrogen can be adjusted. Even more preferred is if in the superconducting oxide thin film with low thermal conductivity by using the superconducting electrode with one on the superconducting oxide thin film trained metallic thin film a partial quench occurs (i.e. a loss of superconducting properties), the shunt over the metallic thin present so that Burning of the superconducting oxide thin film can be prevented can.

Hierarchically around the outputs of the multi-channel filters merge and an exit similar to obtain a distributor according to the prior art, the Filter block preferably divided into several groups consisting of several filter coupling line blocks consist; the other ends of the thin film coupling lines through a first conductive Connection device connected, which is in the direction of lamination extended to form a first coupling section for each group; a first Output coupling line with a length of nλ / 2 (n is a natural number and λ is a signal wavelength), whose characteristic impedance is equal to that of the thin-film coupling line is connected to the first coupling section, the others Ends of the first output coupling lines of each group are through a second conductive Connection device connected, which is in the direction of lamination extends to form a second coupling portion, and on the second coupling section becomes a second output coupling line with the same characteristic impedance as that of the first output coupling line connected. That way it possible a very small format filter device with low loss, high Q value and thin layer structure to implement in the the filter circuit and the distributor according to the status of technology are integrated.

Differentiate more preferred either the dielectric constant or the thickness of the dielectric that is the output coupling line includes, or both sizes of that of the filter block, so that the width of the output coupling line while maintaining a predetermined characteristic impedance is enlarged. As a result, an increase the current density when merging of the signals are reduced so that the performance of the entire superconducting filter device can be increased.

According to a third construction of the present invention, the filter device for low-temperature operation is characterized in that the filter element which forms the filter device has a construction in which a superconducting filter, which consists of a superconducting thin layer applied to a carrier material A, is connected to a distributor which consists of a thin-film conductor applied to a carrier material B; that a conductive transmission line that forms the distributor has the same characteristic Im has such a transmission line that forms the superconducting filter, and that the cross-sectional area of the transmission line that forms the distributor is larger than the conductor cross-sectional area of the transmission line that forms the superconducting filter.

According to the above construction implemented a high-performance superconducting filter device which includes the superconducting filter and the distributor. More accurate said the transmission line, that forms the distributor is larger than that transmission line forming the filter, that on a different substrate is applied so that the transmission conductor has a larger cross-sectional area. In particular, the carrier material of the distributor thicker than that of the filter, and the dielectric constant of the distribution carrier material is set lower than that of the filter support material, around the transmission line to enlarge so that the Cross sectional area of the transmission conductor is enlarged. In a thin film type distributor, where the cross-sectional area of the transmission conductor by enlarging the transmission line is enlarged, If a metal is used as a thin-film conductor, heat can develop be prevented. Furthermore, when using a superconductor as a thin film conductor prevents current flow that exceeds a critical current. Preferably the thin film conductor through the oxide superconductor, a metal or through a layer structure of oxide superconductor and metal formed so that a higher performance can be used.

According to a fourth construction the filter device according to the invention for low temperature operation the filter element has a structure in which a filter unit, which is formed by several planar circuit filters that are made up of a superconducting thin-film filter electrode exist, connected to a distributor by several connection connections through a branch line attached to a substrate is formed, wherein the filter unit is attached so that it with the common cooling surface in contact comes, and wherein the distributor is arranged so that a level that includes the distributor, the area each planar circuit filter intersects, each connection terminal one Connecting conductor, which at one end to the surface of the Planar circuit filter parallel first contact surface and at the other end one to the surface of the distributor has a parallel second contact surface.

According to such a construction Is it possible, a small-sized filter device with low loss, high Implement performance and high Q value in the filter in three Dimensions are provided. Furthermore, the temperature fluctuation low under the filters, which contributes to the stability of the characteristic. each Planar circuit filter cuts a flat or planar distribution unit, preferably they are almost perpendicular to each other and their connection takes place through a connecting conductor (connection terminal) with first and second contact areas at both ends. As a result, the structure can be three-dimensional Arrangement for reducing the dimensions with the continuity of the impedance the connecting section (the reduction of a Joule loss, by contact resistance, conductor loss and the like arises) be compatible.

The first contact area is parallel to the surface of the Planar circuit filter, and the second contact area is parallel to the surface the distribution unit. As a result, the filter electrode of the Planar circuit filter and the first contact surface and the branch line the distribution unit and the second contact surface in contact with one another come so that continuity the impedance at the connection section can be achieved.

In addition, between the first contact area and the filter electrode of each planar circuit filter and / or between the second contact surface and the branch line of the distributor preferably a conductive material provided such. B. a metal, a superconductor or a conductive resin. As a result, the contact resistance at each connection section stronger be reduced, and the stability of the electrical characteristics each connection section can be used for those caused by cooling temperature change be improved.

According to a fifth construction of the filter device according to the invention for low-temperature operation, a filter element contained in each filter element 11 illustrated manifold at least one of the structures in which are arranged in the order given below: filter output connection sections 401 . 402 . 403 and 404 , a first union or mixing point 406 at a distance of (2n + 1) λ / 4 from the filter output connection sections 401 and 402 , a second mixing point 407 at a distance of (2n + 1) λ / 4 from the filter output connection sections 403 and 404 and at a level through the filter output connection sections 401 and 402 and the first mix point 406 is spanned, and a third mixing point 408 at a distance of (m + 1) λ / 2 from the first and second mixing points 406 and 407 and at the (same) level, with at least three of the filter output connection sections 401 . 402 . 403 and 404 with the first, second and third mix points 406 . 407 and 408 are connected by straight branch lines, which have the form of a thin layer applied to a carrier material and the same characteristic impedance (where λ is a wavelength at the mean resonance frequency of a filter and n and m are 0 or natural numbers).

With such a structure, the manifold can be formed on the plane by one isosceles triangular structure for merging the filter output connection sections 401 and 402 to the first mixing point 406 , an isosceles triangular structure for merging the filter output connection sections 403 and 404 to the second mixing point 407 and an isosceles triangular structure for merging the first and second mixing points 406 and 407 to the third mixing point 408 be used. The transmission lines of the same width, which are formed on the carrier material, which is uniform and has no layer thickness distribution, have the same characteristic impedance and phase constant. As a result, a real length is proportional to an electrical length. Accordingly, a coupling line with an electrical length of (2n + 1) / λ can be formed using the three isosceles structures. In this way, it is possible to implement a small format, low loss, thin film type distributor.

According to the fifth construction, the filter outlet connecting portions are 401 . 402 . 403 and 404 preferably arranged at regular intervals on a straight line, and the third mixing point 408 is arranged in a position where a straight line for connecting the filter output connecting portion 401 with the first mix point 406 a straight line for connecting the filter output connection section 404 with the second mix point 407 cuts. Consequently, the occurrence of radiation loss due to bending of the branch lines at the first and second mixing points can occur 406 and 407 be prevented.

The distributor has at least one fan-shaped structure in which at least two filter output connection sections arc are arranged and the centers of the arc through a straight line Branch line in the form of a thin layer applied to a carrier material and with a length from (2n + 1) / λ / 4 whose characteristic impedance is the same (where λ is a wavelength at the average resonance frequency of a filter and n equals 0 or a natural one Number is).

According to such a construction the filter outlet connection sections are arranged in an arc shape, and the mixing points are the centers of the arcs so that the filter output connection sections at equal intervals are arranged from the mixing points to form the fan-shaped structure. In addition, many can Filter output connection sections simultaneously to a mix point together become. The transmission lines of the same width, which are formed on a carrier material, that is even and has no layer thickness distribution, have the same characteristic Impedance and the same phase constant. As a result, one real length proportional to an electrical length. Accordingly, by Using the fan-shaped structure the coupling lines with an electrical length of (2n + 1) / λ on the be trained on the same level. Consequently, a small format Thin film type distributor be implemented with high performance (low loss). Besides, can a sufficient one between the filter output connection sections Distance to be maintained, so that a filter on the same support material how the distributor can be designed.

The distributor preferably has at least one of the structures in which at least two fan-shaped structures are provided on the same plane, with the arc centers by branch lines of the same characteristic impedance which are in the form of a on a carrier material applied thin film and a length from (m + 1) / λ / 2 have (where m is 0 or a natural number).

According to the structure of the distributor, in the case of using LaAlO ₃ , SrTiO ₃ , LaGaO ₃ , NdGaO ₃ and the like as the carrier material, the mismatch of a lattice constant between the carrier material and the branch line (the oxide superconductor) is reduced, so that the crystal properties of the branch line (Oxide superconductor) can be improved. As a result, a critical temperature and a critical current density can be improved so that the performance of a refrigerator can be reduced. High power microwaves can also be used. By forming the branch line together with the layer structure of the oxide superconductor and the metal, the transmission through the metal can be ensured even if the superconductor loses its superconductivity due to failure of the refrigerator. As a result, the functions are not completely lost, so that the stability of the distributor can be improved.

As described above, the present invention a small-sized device for low-temperature operation with low loss and high performance, which is excellent temperature stability and has frequency characteristics. In particular, a small format Filter element with low loss, high Q value and high performance provided in which a resonator filter and a section that corresponds to a distributor, using a superconducting Materials through thin film technology are integrated so that the Size reduction and performance improved even further can be. Furthermore, several planar circuit filters, in which each filter electrode consists of a superconducting thin-film material, and a distribution unit arranged in three dimensions, so that a small format Filter device for Low temperature operation with low loss and excellent cooling performance can be implemented.

1 Fig. 14 is a partially cut-out perspective view showing the overall structure of a low-temperature operation filter device according to a first example of the present invention;

2 FIG. 12 is a partially cut-out perspective view showing a concrete example of a shield case block that is shown in FIG 1 filter device shown forms for low-temperature operation;

3 shows a sectional view, which typically shows in side view a superconducting filter element of a filter device for low-temperature operation according to a second example of the present invention (section BB in 4 );

4 a sectional view showing the superconducting filter element in 3 seen from the top (section AA in 3 );

5 Fig. 14 is a sectional side view showing another typical example of the structure of the superconducting filter element;

6 (A) shows a plan view, and 6 (B) Fig. 14 is a sectional view schematically showing the structure of the superconducting filter element according to a third example of the present invention;

7 Fig. 12 is a partially cut-out perspective view illustrating a shield case block of a low-temperature operation filter device according to a fourth example of the present invention.

8th FIG. 12 is a plan view typically showing the connection portion of a distribution unit to the filter of the shield case block in FIG 7 represents;

9 shows a side view that typically shows the connecting portion in FIG 8th represents;

10 Fig. 12 is a perspective view illustrating a connection conductor that forms a connection terminal;

11 Fig. 12 is a plan view typically illustrating the manifold of a cryogenic filter device according to a fifth example of the present invention;

12 Fig. 12 is a plan view typically showing a manifold according to a sixth example of the present invention; and

13 Fig. 12 is a view showing an example of a high performance filter device according to the prior art.

Below are preferred embodiments of the present invention with reference to the drawings described.

1 shows the overall construction of a filter device for low temperature operation. The filter device for low-temperature operation has four filter elements. The four filter elements are in a closed space inside a shield housing block 1 accommodated. The shield block 1 has four signal input sections 2a and four signal output sections 2 B on (see 2 ). The bottom of the shield case block 1 is in the thermal contact state on a cooling plate 3 attached that heat transfer is easily achievable. In a thermal contact mounting section between the shield case block 1 and the cooling plate 3 a grease is pressed in, so that the thermal conductivity is improved. The cooling plate 3 is with one end of a heat conducting section 5 in a heat-insulating container 4 connected and attached to it. As a result, the shield housing block 1 to the cooling plate 3 transferred heat to a low temperature section 6 derived from the other end of the heat-conducting section 5 connected is.

The heat-conducting section 5 is about a heat insulating material 9 on the heat-insulating container 4 attached so that the heat does not come from the heat-insulating container 4 to the heat-conducting section 5 is transmitted. The interior of the heat-insulating container 4 is placed under vacuum around the shield case block 1. As a result, effective thermal insulation is possible. The low temperature section 6 is cooled by a chiller. Instead of thermal insulation and cooling, a coolant such as. B. liquid nitrogen, in the heat-insulating container 4 a be filled to the cooling plate 3 and the shield case block 1 to cool. Such a construction is practical and effective.

Four signal input sections 2a are over four cables 7a with four input connections 8a connected to the heat insulating container 4 are provided. Four signal output sections 2 B are over four cables 7b with four output connections 8b connected to the heat insulating container 4 are provided. Accordingly, a signal passes through one of the input ports 8a is entered, the cable 7a and the signal input section 2a and then one of the filter elements in the shield housing block 1 , Furthermore, the signal from one of the output terminals 8b via one of the signal output sections 2 B and one of the cables 7b output. In this case, only a signal in the pass band of the filter element passes through the filter element to the output terminal 8b ,

According to the present example, there are four filter elements in the shield housing block 1 accommodated. The occurrence of crosstalk between the filter elements must be prevented. The space for accommodating each filter element is closed, and each filter element is connected to the filter input section by a cable 2a and the filter output section 2 B connected. Consequently, such a construction is characterized in that a connection between filter is avoided and the corresponding filter elements are stable.

2 Fig. 12 is a partially cut-out perspective view showing the construction of the shield case block 1 represents. In the shield housing block 1 are four closed rooms 10 , each one of the signal input sections 2a and one of the signal output sections 2 B have, combined into one unit. The filter elements 11 are individually in each closed room 10 accommodated. The planar filter elements 11 are arranged almost parallel to each other. The signal input line 22a of the filter element 11 is with the signal input section 2a connected. The signal output line 22b is with the signal input section 2 B connected. The heat conductive grease or the like is bonded. The heat conductive grease or the like is applied to reduce heat resistance so that the filter element 11 by press contact with a screw, spring or the like on the shield case block 1 is attached. As a result, the radiation power of the filter element increases 11 developed heat, so that the operational stability of the filter element 11 can be improved.

The shield housing block 1 can be divided vertically into two sections, so that the assembly work for the installation of the filter element in the closed space of the shield housing block 1 can be carried out more easily. In this case, the shield case block 1 divided into two sections, and the filter element, the signal input section 2a and the signal output section 2 B are then installed in every closed room. After that, the shield case block 1 assembled and sealed. As a result, the shield case block is obtained 1 , Furthermore, the shield housing block 1 be designed as an aggregate of shielding housings. In this case, each filter element is attached and sealed for each shield case. Then the shield case becomes the shield case block 1 united. In this way, the assembly work can be carried out easily.

The closed space of the shield case block 1 can be with dry He gas, Ne gas or a mixture of dry He gas and Ne gas, or with dry Ar gas, N ₂ gas, O ₂ gas or a mixture of dry Ar gas, N ₂ -Gas and O ₂ -Gas are filled to maintain the temperature stability of the filter element 11 to improve. In the case of a vacuum, the gas can be used within all temperature ranges. In the case of using Ar gas, N ₂ gas, O ₂ gas or a mixture of Ar gas, N ₂ gas and O ₂ gas for operation at a temperature higher than the temperature of liquid Nitrogen, the gases are not liquefied and the filter element is effectively cooled by convection. The above effects can be achieved before He gas, Ne gas, or a mixture of He gas and Ne gas is liquefied at a temperature lower than the temperature of the liquid nitrogen. In particular, the He gas can be used until the temperature of liquid He (4.2 K) is reached.

As in 2 shown, pins come from the signal input section 2a and the signal input section 2 B protrude inward on a dielectric substrate 12 in contact with the signal input section 2a or the signal output section 2 B so that the signal input line 22a and the signal output line 22b of the filter element 11 with the signal input section 2a and the signal output section 2 B of the shield case block 1 get connected. The signal input line 22a and the signal output line 22b of the filter element 11 can be by a wiring element (such as a flexible wiring board or a lead wire) that is connected to the dielectric substrate 12 of the filter element 11 put together or in the substrate 12 is embedded, connected to each other.

As in 2 are shown on the top wall of the shield housing block 1 four through holes are formed. There are cylindrical elements on the through holes 1a appropriate. The cylindrical element 1a also has a through hole that includes an axis that is almost parallel to the substrate surface of the filter element 11 is. A moving element 31 for fine adjustment of the frequency characteristic of the filter element 11 is in the through hole of the cylindrical element 1a used. The moving element 31 has a screw 34 on that in a spiral groove 33 is screwed, which is provided on a part of the through hole. At the outer end of the movable element 31 is a transmission section 35 designed for an external force to apply a rotational force to the movable member 31 transferred to. A lubricant is introduced between the movable member and the other part of the through hole, so that a sliding portion 32 is trained. As a result, the closed space remains 10 in the shield housing block 1 hermetically sealed, and the shield housing block 1 becomes electrical via an electrostatic capacity using a grounding rod 36 of the movable element 31 connected. An earth rod 36 , which consists of a conductor that is the volume of the enclosed space 10 is changed at the inner end (one end on the side of the closed space 10 ) intended. At the top of the grounding stick 36 is a dielectric block 37 attached.

A cylindrical section with a larger diameter than that of the screw section 34 is on the inside of the through hole of the cylindrical element 1a educated. At the be Movable element, a piston section is provided which is fitted into the cylinder section. The sliding section 32 is formed by the cylinder section and the piston section.

The outer power transmission section 35 has the shape of a hexagon screw. When on the outer power transmission section 35 when a tool is attached and rotated, the earthing rod moves 36 by the screw movement of the screw section 34 and the spiral groove 33 the through hole in the closed space 10 in or out of it. The shape of the closed space 10 is caused by the movement of the grounding rod 36 changed, and that in the enclosed space 10 trained distribution of the electric field is changed by a signal that is a filter element 11 happens. The frequency characteristic of the filter element 11 is fine-tuned. In this way, the frequency characteristic can be fine-tuned. According to such a construction, the frequency characteristics for the filter elements can be finely adjusted in the same direction. As a result, fine adjustment can be easily performed on the filter element cooled to the operating temperature.

A rotating mechanism that is connected to the outer power transmission section 35 Connected by a rod made of a highly heat-insulating PTFE (polytetrafluoroethylene) resin, is used as a means for transmitting a torque from outside the heat-insulating container 4 on the outer wall surface of the heat-insulating container 4 provided so that the characteristic can be fine-tuned during the cooling process. This makes the adjustment easier.

The cylindrical element is used for easy assembly 1a so provided that the piece of the through hole that is attached to the movable member 31 slides, is enlarged as much as possible, and is after the previous screwing of the movable element 31 attached to the hole in the housing wall. Accordingly, the cylindrical member 1a not always required. The spiral groove and the sliding portion can be formed on the through hole made in the housing wall around the movable element 31 insert directly into the through hole. The number of moving elements 31 there is no restriction for each filter element. Several movable elements are provided in different places, so that the adjustment can be carried out much more precisely.

The dielectric block 37 can be replaced by a dielectric layer or is not necessary in some cases. However, since the dielectric constant of the dielectric 37 is high (about 3 in the case of Teflon (trademark), about 9 in the case of alumina), an electric field is concentrated on the inside of the dielectric 37 , In the case where the isolator 37 is provided, the setting amount of the frequency characteristic per displacement unit of the movable member can be compared to the case where the dielectric 37 is not intended to be enlarged.

The filter element 11 has a thin film electrode 13 similar to a stripline filter structure on the surface of a dielectric substrate 12 is formed, and ground electrodes formed over the rear. If an electrode material such. B. Cu, Ag or Au as the material of the thin film electrode 13 is used at an operating temperature close to an ordinary temperature, the Q value of the filter element is at most a few hundred. When the electrode material is cooled to a low temperature, e.g. B. on the temperature of liquid nitrogen (77.3 K), then the specific resistance is significantly reduced, so that the Q value increases at a frequency of about 2 GHz to a few thousand. In addition, in the case where a superconducting material is used as the material of the thin film electrode 13 is used by cooling in the superconducting state, the Q value increases at a frequency of about 2 GHz to several tens of thousands. In the case where the superconducting material is the thin film electrode 13 an oxide high temperature superconductor material is used, such as e.g. B. a bismuth system, an yttrium system or a thallium system, the operating temperature, ie the temperature in the superconducting operating state, can be increased much more than with a low-temperature superconducting material such. B. Nb, Nb-Ti or Nb ₃ Sn. As a result, the cooling can be carried out more easily. Since the critical current density is high, ie about 10 ⁵ to 10 ⁷ A / cm ² , a high-performance filter can be formed.

As another example, lanthanum aluminate (LaAlO ₃ , lattice constant: a-axis 5.365 Å, c-axis 13.11 Å, dielectric constant: about 24) is used as the material of the dielectric substrate 12 used, and a thallium 2212 phase (critical temperature ~ 110 K) is used as the material of the thin film electrode 13 used so that a round filter structure with a diameter of about 24 mm is formed. In this way the filter element 11 educated. The shield housing block 1 is through that with the low temperature section 6 the cooling plate connected to the refrigerator 3 cooled to about 70 K and then put into operation. As a result, the electrical loss of a pass signal in a frequency band of about 2 GHz can be reduced to several tens of watts.

The example above is true in which a strip line type filter and a round filter as a thin film filter can be used, but the same effects can also be used when using other thin film filters can be achieved such. B. a coplanar filter.

The dimensions of the shield housing seblocks 1 with four filter elements according to the present example are approximately 50 mm W × 30 mm D × 30 mm H (width × depth × height). The outer dimensions of the heat-insulating container are approximately 70 mm ∅ × 60 mm H. Since a filter device with the same performance, which uses a dielectric resonator according to the prior art, has dimensions of approximately 200 mm W × 200 mm D × 150 mm H , their size can be reduced to about half the capacity ratio. If as a cooling device for the cooling plate 3 a Stirling refrigerator is used, the space has dimensions of about 120 mm W × 70 mm D × 170 mm H. In this case too, the size can generally be reduced to about 1/3 or less.

An example is described above in which the low-temperature filter device has four filter elements in the shield housing block , but the present invention is not limited to this. To the An example is a filter device within the scope of the present invention for low temperature operation included in the multiple filters and distributors in one below shield housing block to be described are installed.

In the above example, although the oxide high-temperature superconductor thin film of the thallium 2212 phase has been used as the superconducting thin film, other oxide high-temperature superconductor thin films with the same functions can also be used. Although the thin film resonator was used in the above example, the present invention is not limited to this. A dielectric resonator can be used in the enclosed space 10 inside the shield case block 1 be accommodated. In this case, the dimensions increase.

A filter device for low-temperature operation according to a second example of the present invention, in which filter elements are integrated, is described below. 3 Fig. 12 is a sectional side view showing filter elements according to the present example. 4 shows a sectional plan view illustrating the filter elements according to the present example. 3 is a sectional view taken along BB in 4 , 4 is a sectional view taken along AA in 3 , In 3 the vertical dimension (in the thickness direction) is exaggerated.

As in 3 shown, the filter element has a four-layer structure in which a superconducting thin layer is used as the filter electrode material for the filter element. How out 4 recognizable, the top layer has a structure in which a superconducting filter electrode 101 and a thin-film coupling line 103a with a length of λ / 4 with an output end 102 is connected, are formed on the same level (AA level). The superconducting filter electrode 101 and the thin film connection line 103 are vertical over a dielectric 104 of two ground electrodes 105 held so that a filter coupling line block 106a is formed. In view of the characteristic is sufficient if the coupling line 103a the same characteristic impedance ( 50 Ω) as the input line 121 and has a length of (2m + 1) λ / 4 (m is 0 or a natural number, and λ is a signal wavelength). According to the present example, the length λ / 4 corresponds to the value m = 0.

Correspondingly, filter coupling line blocks can be placed on the other three layers 106b to 106d with the same structure. The filter coupling line blocks 106a to 106d are laminated to a filter element. It is not always necessary for the ground electrodes 105 be glued together. A ground electrode 105 can be shared by the vertically attached filter coupling block. It is desirable to use the superconducting thin film as the contact electrode material because it has excellent filtering properties. It is also desirable to use a metallic thin film as the contact electrode material, since it is cooled to a low temperature, so that the resistance is considerably reduced and the filter properties can be improved extraordinarily compared to the operation at normal temperature.

According to the present example, the filter elements are divided into two groups, each with two filter coupling line blocks ( 106a and 106b . 106c and 106d ). The other ends of the coupling lines 101 and 101d are through contact holes (through holes) 107a and 107c connected as a first conductive coupling device, which extends in the lamination direction, so that first coupling sections 108a and 108b be formed. To the first coupling sections 108a and 108b are the first output coupling lines 109a and 109c with a length of λ / 2 and the same characteristic impedance as that of the thin-film coupling lines 103a and 103d connected. In view of the characteristic curve, it is sufficient if the first output coupling lines 109a and 109c have a length of nλ / 2 (n is a natural number and λ is a signal wavelength). According to the present example, the length λ / 2 corresponds to the value n = 1.

In addition, the other ends of the first output coupling lines 109a and 109c each group through a contact hole 117 connected as a second conductive connecting device which extends in the lamination direction, so that a second coupling section 118 is formed. A second output trunk 120 with the same characteristic impedance as that of the first output coupling lines 109a and 109c is with the second coupling section 118 connected.

According to the above construction, a filter block and an element corresponding to a manifold are into a filter element having the structure of one integrated superconducting electrode. The filter block is formed by laminating a plurality of filter coupling line blocks with a superconducting filter electrode and a thin-film coupling line. The element that corresponds to the distributor is formed by hierarchical connection of the output coupling lines. The ground electrode 105 that on a section with through holes 107a . 107c and 117 is provided, has holes with suitable diameters for insulation against the contact holes. The ground electrodes are connected to one another by other contact holes (not shown).

Referring to the top view (sectional view AA) of 4 the filter coupling line block is added 106a described. As in 4 shown is an input line 121 with the input side of the superconducting filter electrode 101 connected. Input lines are corresponding 121b to 121d with additional filter coupling line blocks 106b to 106d connected (see 3 ). A thin-film coupling line 103a with a length of λ / 4 and the same characteristic impedance (50 Ω) as that of the input line 121 is with the exit end 102 the superconducting filter electrode 101 connected. The contact hole 107a is at the other end (a first coupling section 108a ) provided and with the first output coupling line 109a connected, which has a length of λ / 2 and the same characteristic impedance as that of the input line 121 having. A contact hole 117 is at the top at the other end (the second coupling section 108b ) the output coupling line 109a provided with which the output line 120 (50 Ω) with the same characteristic impedance as that of the input line 121 connected is.

The superconducting filter electrode 101 is in the form of a five-pole strip line type resonator filter. If the same function is achieved, the superconducting filter electrode can 101 take any form of structured thin film. The positions of the input lines 121 to 121d each filter coupling line block are alternately shifted and arranged in a zigzag shape so that a transmitter can be more easily connected to an amplifier.

The output line 120 can be attached to any filter coupling block. In the case where the output line 120 provided on the top layer, it can be easily connected to an output cable. The lengths of the thin-film coupling line and the output coupling line must be designed taking into account the length of the contact hole. The contact hole is usually much shorter than any lead. If the number of layers is increased so that the contact hole becomes much longer, the length must be regulated by changing the line structure of each filter coupling line block.

According to the example above, the filter element has a structure in which a filter block composed of four filter coupling line blocks is divided into two groups, each group having two filter coupling line blocks and the outputs of the four superconducting filter electrodes through the thin film coupling line and the first and second Output coupling lines are gradually brought together and then one of the output lines 120 to reach. The present invention is not limited to the above example. In other words, the numbers of the output coupling lines and thin-film coupling lines which are connected through the contact holes at connection points can be selected. A one-stage connection in which a plurality of thin-film coupling lines are connected to one another via contact holes and connected directly to the output line (the last output coupling line), and an at least three-stage connection are included in the scope of the present invention.

An example of a manufacturing method for a filter element according to the above example is described below. In this example, an oxide high temperature superconductor material is used as the superconducting electrode material, and two dielectric substrates are used as the dielectric 104 glued together. First, lanthanum aluminates (LaAlO ₃ , lattice constant: a-axis 5.365 Å, c-axis 13.11 Å, dielectric constant: about 24) are used, on which an oxide high-temperature superconductor thin-film material with a thallium 2212 phase (critical temperature ~ 110 K) is trained. Using the known technology, the oxide high temperature superconductor thin film material becomes one in 4 displayed, desired structure processed. The structure is related to the substrate dimension used at the contact hole 107a divided into two parts. If a large substrate is used, the structures can be integrated.

The structure of the superconducting filter electrode of the filter coupling line block is designed so that it has passband frequencies which differ somewhat from one another. The filter coupling line blocks 106b to 106d do not have a superconducting thin-film line structure, that of the second output coupling line 120 equivalent. In addition, the filter coupling line blocks have 106b and 106d no superconducting thin-film line structure that corresponds to the first output coupling line.

An oxide high temperature superconductor thin film is deposited on the surface of another dielectric substrate to form a ground electrode. The oxide high-temperature superconductor thin film with the through hole is processed by Ar ion beam etching. A slightly larger hole is formed so that it has a smaller floating electrostatic capacity has. Further, a through hole having a dimension whose characteristic impedance is close to that of the thin film coupling line is made by machining with a carbon dioxide gas laser processing machine on the dielectric substrate on which the superconducting thin film electrode of the filter is formed and a portion of the dielectric substrate which is the ground electrode with the through hole.

The substrate for the formation of the filter electrode of the filter coupling line block and the substrate for the formation of the ground electrode are glued to one another in the direction that one in 3 structure shown, so that each filter coupling line block is manufactured. The characteristic curve is measured by cooling and adjusted by gradually scraping off the superconducting filter electrode, laser adjustment using YAG laser radiation or the like. When the substrates are glued together, a gap section with a dielectric constant of approximately 1 is formed on a section without a superconducting thin-film electrode structure. Because of the very small thickness of the superconducting thin-film electrode (a few hundred nm), the characteristic curve is rarely influenced. Dielectric material having the same dielectric constant as that of the dielectric substrate is formed, planed and polished on the superconducting thin film electrode by sputtering. The substrates are glued together with optical precision. As a result, the influence on the characteristic can be eliminated.

The bonded substrates are divided again. A normally conductive metal, such as. B. Cr / Au, Cu or Ag is formed as a thin layer on the contact hole portion. According to another method, a superconducting thin film can be formed in the contact hole or the contact hole can be filled with a conductive paste, a conductive resin or the like. Furthermore, a conductor such. B. a metal or a superconducting rod used and connected by a metallic thin film, a conductive paste, a resin or the like. In this way, the substrates with the contact hole sections incorporated therein are glued together again to form a filter coupling line block. The filter coupling line blocks are arranged one above the other so that the filter block is formed. The contact is sufficient to connect the contact holes between the adjacent filter coupling line blocks. The connection can be ensured even better when using metal foils, conductive pastes or resins. The metallic thin layer is deposited on the substrate end faces of the input lines 121 to 121d and the second output coupling line 120 formed so that a connection to an input / output line can be made by press contact. If the connection can be made without the metallic thin layer (deposition layer), there is no problem.

This in 3 Superconducting filter element with 4-channel filter shown has dimensions of approximately 65 mm W × 35 mm D × 4 mm D (width × depth × thickness) for 1.5 GHz. The superconducting filter element is housed in the shield case, which has an input-output connector. The shield housing is mounted on the heat-insulating container so that a filter device for low-temperature operation is created. If the refrigerator is grounded and operated at about 70 K, a higher performance than that of a dielectric resonator filter device according to the prior art can be achieved. The volume of the overall system including the refrigerator is approximately 1/3 of the volume of the dielectric resonator filter device with the same function according to the prior art. As a result, the size can be reduced significantly. The insertion loss is less than a few watts per channel for an input signal of about 10 watts. The power consumption is less than half the value of the prior art device. In addition, taking into account the power loss of the amplifier of a transmitter or the like for the entire transmission section of a mobile communication base station system, the power consumption can be greatly reduced.

As a variant of the example above shows 5 another example of the superconducting filter element. With respect to the superconducting filter element, the filter block (up to the thin-film coupling line) is separated from the output coupling line section. The dielectric constant and the thickness (distance between the ground electrodes) of the dielectric surrounding the output coupling line are chosen so that they differ from the values of the filter block, so that the width of the output coupling line is increased, the characteristic impedance being equal to that of the input line and the like.

The output coupling line receives a signal with a power which is equal to the sum of the signal line of the thin-film coupling lines which are connected to one another at the coupling sections. Accordingly, if the width of the output switch is the same as that of the thin film interconnect, then the current density of the signal transmitted on the output switch is equal to the multiple current density of the thin film switch. If the coupling line consists of a superconducting material, then the critical current density of the line determines the maximum usable signal power. Accordingly, the width of the output coupling line is increased and the current density of the signal transmitted on the line is reduced, so that the Leis used for the superconducting filter device can be increased in the same way as in the present example.

How out 5 recognizable, two thin-film coupling lines unite 103a and 103b (or 103c and 103d ) on the first coupling section 108a (or 108c ) with an output coupling line 109a (or 109c ). As a result, the thickness of one around the output coupling line 109a (or 109c ) applied dielectric, ie the distance between the vertical ground electrodes 135 , compared to a dielectric applied around the thin-film coupling line. In fact, the distance between the vertical ground electrodes 135 the output coupling line to the distance between the converging vertical mass electrodes for two thin-film coupling lines (ie to the thickness of the two filter connecting line blocks), so that the dimensions of the output coupling lines are adjusted 109a and 109c can be achieved. This can be done by causing the substrate thickness of the dielectric 134 used in the output coupling line section differs from that of the dielectric used in the filter block section 104 different. A connection of the end face of the filter block thin-film coupling line (of the first coupling section) to the output coupling line can be produced by press contact, wire bonding, metal foils, silver pastes, conductive resins or the like.

If an oxide high temperature superconductor thin film, such as B. lanthanum aluminates or MgO, through a dielectric material can be formed form a superconducting electrode so that the loss at high power can be reduced. It is possible, the normally conductive metal electrode with materials such. B. quartz glass (Dielectric constant: ε = 3.5 to 4.0), sapphire (dielectric constant: ε = 8.6 to 10.6), aluminum oxide ceramics (dielectric constant: ε = 8.0 to 11.0), steatite ceramic (dielectric constant: ε = 6.0 to 7.0), polyethylene fluoride resins (dielectric constant: ε = 2.0) and to combine such things that are not very good for training the oxide superconductor thin film suitable.

According to the above example, the input line, the ground electrode, the thin film coupling line, the output coupling line, the output line, the contact hole and the like are preferably formed from a superconducting material. They can be formed by a normally conductive metallic material, such as. B. Au, Ag, Cu, Al, Pt or the like, if the loss is not very serious. It is possible to use an oxide high temperature superconductor thin film material of the bismuth or yttrium system and an oxide high temperature superconductor thin film material of the thallium 2212 phase as the superconducting thin film electrode material. In this case, operation can be carried out at the temperature of liquid nitrogen. In addition, a low-temperature superconductor material such. B. Nb, Nb-Ti, Nb ₃ Sn or the like can be used at the temperature of liquid helium (4.2 K). In this case, more substrate materials can be used compared to the oxide high temperature superconductor thin film material.

The 6 (A) and 6 (B) show the filter element of a filter device for low temperature operation according to a third example of the present invention. 6 (A) shows a plan view, and 6 (B) shows a sectional view. A superconducting filter 201 is a microstrip line filter which is formed by a superconductor of the Ti system, has a 3 dB bandwidth of 150 kHz at 2 GHz as a characteristic value and is formed on a MgO carrier material. Four superconducting filters 201 are at 5 mm intervals through the filter coupling section to a distributor 203 connected by the thin film type. An oxide superconductor 205 of the Tl system (critical temperature 110 K, critical current density 1.0 × 10 ⁴ A / cm ² ) is as a thin-film conductor on an MgO carrier material 204 educated. The filter element is housed in the shield case, fitted in a heat insulating container and cooled to about 80 K by a refrigerator. On a surface opposite the element formation surface of the carrier materials 202 and 204 Cr is applied with a thickness of 200 Å (20 nm). Au is applied to Cr with a thickness of 10 μm. The carrier materials 202 and 204 come into close contact with a carrier metal to assume the same potential and are short-circuited with the ground electrode. The transmission lines of the superconducting filter and the distributor are connected to one another by Au or Al lines using wire bonding. The carrier material 204 has a thickness of 1.00 mm, ie twice the thickness of the carrier material 202 , The transmission line has a characteristic impedance of 50 Ω. If the characteristic impedances of the transmission lines are set to the same value, the thickness of the substrate is almost proportional to the width of the transmission line. Accordingly, the width of the distributor transmission line is 203 about 0.95 mm, ie about twice as much as the width of the transmission line of the superconducting filter, ie 0.48 mm. As a result, the critical current is doubled, so that a superconducting filter element that can use high-power microwaves can be formed.

Fall in a 2 GHz frequency band Microwaves with a power of 1 W. As a result loses the oxide superconductor as a thin film conductor is not its superconducting properties on the distribution transmission line, so that a transmission with lower loss can be ensured.

It differs according to the example above the thickness of the carrier material 202 from that of the carrier material 204 , Other methods can be used to enlarge the transmission line (the cross-sectional area of the transmission conductor). For example, a method for adjusting the dielectric constant of the carrier material 204 to a smaller value than that of the carrier material 202 be applied. More specifically, as a carrier material 204 MgO with a dielectric constant of 10 is used, and as a carrier material 202 YAlO ₃ with a dielectric constant of 16, LaAlO ₃ with a dielectric constant of 24, LaGaO ₃ or NdGaO ₃ with a dielectric constant of 25 can be used.

In the present example, the oxide superconductor of the Tl system is used as a thin-film conductor, but the type of oxide superconductor is not limited and can be replaced by other superconductors, such as. B. a bi- or y-system. In particular a Bi2223 phase is more advantageous because it is hardly toxic and a higher one critical temperature than 100 K, so that no high-performance refrigerator is required. Besides, can a metal as a thin-film conductor used, such as. B. Au or Pt. If a superconductor metal layer product for cables is used, the transmission be ensured by metals, and then an element will not interrupted when the chiller fails and the superconductor loses its superconducting properties. consequently causes the superconductor metal layer product an improvement in stability the superconducting filter device.

In the example above is the superconducting filter microstrip type, but it can also a superconducting filter of another type, e.g. B. one elliptical type. In particular, in the superconducting Filters of the elliptical type resonate with a microwave Power of more than 10 W detected. It is accordingly possible when using the elliptical type superconducting filter, a To provide superconducting filter device that can handle high-power microwaves.

In the example above, the Connection of the Superconductor filter to the conductor of the distributor transmission line by wire bonding executed can also be done by film bonding or welding.

7 shows the shield housing block of a filter device for low temperature operation according to a fourth example of the present invention. According to the present example, two shield housings 301 and 311 provided to form a shield housing block. The shield case 301 and 311 are in contact with each other and are on a cooling table 306 attached. The shield case 301 and 311 and the cooling table 306 consist of a material such as B. Cu, which has good thermal conductivity at low temperature.

In the shield case 301 are alternately four planar circuit filters 303a to 303d and their cooling plates 304a to 304d accommodated. The four planar circuit filters 303a to 303d are in contact with the cooling plates 304a to 304d , The groups of planar circuit filter and cooling plate are arranged parallel to each other. On each of the planar circuit filters 303a to 303d is a filter electrode made of superconducting material 302 applied and designed for pass frequency characteristics that differ slightly from each other according to the frequency band of each channel. The planar circuit filters 303a to 303d are against each other and to the outside through the cooling plates 304a to 304d and the shield case 301 shielded.

A planar distribution unit 307 (which corresponds to a distributor) is in a second shield housing 311 accommodated. The distribution unit 307 consists of a branch line 307a with lengths of λ / 4 and λ / 2 (λ is a center wavelength), which is formed by a strip line on the substrate. Signal output lines 305a to 305d the planar circuit filter 303a to 303d are via a connection end link 308 with the input end of the branch line 307a connected.

The dimension of the resonance element of the filter of the planar circuit type cannot be set smaller than half a wavelength (electrical length) according to the functional principle. Therefore, it is difficult to connect the planar circuit type filter on the same level to a branch line having a length of λ / 4. The planar circuit filters are arranged parallel to one another in such a way that the ends of the signal output lines are arranged at the same height. The planar distribution unit 307 is connected to the planar circuit filter. As a result, the above problems are solved so that the shield case block can be downsized.

The outlet end of the branch line 307a is with an output connector 309 connected to a shield case 311 is appropriate. The input end of each planar filter is connected to a filter input connector, such as. B. a surface mount connector on the shield housing 301 is appropriate. The interiors of the shield case 301 and 311 are evacuated or sealed with gas, e.g. B. with filled helium.

During operation, the superconducting filter device with the above construction is enclosed in a heat insulating vacuum container and cooled. A signal is input and output through four signal input plugs that pass through and are attached to the wall of the heat-insulating vacuum container and through an antenna output plug. The signal input connector of each channel and a filter input connector and the output connector 309 and an antenna output connector are connected to each other by coaxial lines, such as. B. by semi-rigid cables.

The structure of the connection section between the filter and the distribution unit is described below. On the shield housing 311 facing side of the shield housing 301 four through holes are drilled at regular intervals. Connection connections are press-fit into the through holes 308 appropriate. The four planar circuit filters 303a to 303d are through the four connection ports 308 with the distribution unit 307 connected. 8th FIG. 12 shows a typical view showing one of the four connecting sections when viewed from above, and 9 shows a typical view showing the same section viewed from the side. In the 8th and 9 denotes the reference symbol 323 in the 7 shown planar circuit filter 303a and 303d ,

Like from the 8th and 9 recognizable, the connection connection points 308 an isolator 321 on, by means of an interference fit in the through hole of the shield housing 301 is used, and a connecting conductor 322 , which is inserted into the through hole in the central section by means of an interference fit. The dimension of the connection port 308 is designed based on a signal current carrying capacity so that the characteristic impedance is equal to the line impedance. As in 10 shown, the connecting conductor 322 such a shape that both ends of the cylindrical conductor element are cut to semicircular cross sections and first and second contact surfaces 326 and 328 be formed that are parallel to an axis. The first contact area 326 is perpendicular to the second contact surface 328 , By defining such an angle, the first contact surface comes 326 the connecting conductor 322 in contact with the signal output line 325 of the planar circuit filter 323 , and the second contact surface 328 comes into contact with the input line 327 (Branch line 307a ) of the distribution unit 307 as in the 8th and 9 Darge represents. As a result, the connection loss in the connection section can be reduced.

As described above, the contact electrode comes 324 on the planar circuit filter 323 opposite surface in contact with the cooling plate and is with the shield case 301 connected. A contact electrode is also used accordingly 329 on the area that the distribution unit 307 opposite, with the shield housing 311 connected. In this way the contact areas come 326 and 328 the connecting conductor 322 in contact with the connection lines so that the filter and the distribution unit are connected to each other. As a result, a high current current can flow and reflection loss can be reduced.

If a conductive material, such as. B. a metal, a superconductor or a conductive resin, in the contact portions of the contact surfaces 326 and 328 is filled with the lines, then the contact resistance decreases, so that the heat development is reduced. As a result, the critical current density of the superconducting electrode is hardly reduced. If the connection portions are fixed by soldering or by conductive resins, the mechanical and electrical stability can be improved.

In the example above, the filter electrode does exist from the superconducting thin film material, however it can other conductive too Materials made of a normally conductive metal, such as. B. Cu, Au or Ag as well as made of a superconducting material.

A manufacturing method according to the above example is described below. In this example, the high temperature oxide superconductor material is used as the thin film superconductor material. Lanthanum aluminates (LaAlO ₃ , lattice constant: a-axis 5.365 Å, c-axis 13.11 Å, dielectric constant: about 24) serve as the material for the dielectric substrate. An oxide high-temperature superconductor thin-film material of the thallium 2212 phase (critical temperature ~ 110 K) is formed as a superconducting thin-film electrode material on both surfaces of the dielectric substrate and processed in accordance with the known technology in such a way that a filter electrode or branch line is formed on one of the surfaces. In this way, the planar circuit filter and the distribution unit are manufactured. Another surface is used unchanged as a contact electrode.

The four planar circuit filters manufactured in this way are placed on the shield housing 301 to which the cooling plate and the connection terminal are attached, and are fixed so that the corresponding contact electrodes are in contact with the cooling plate. In this case the first contact surface comes 328 the connecting conductor 322 the connection port 308 in contact with the signal output lines 325 the corresponding planar circuit filter 323 , as in 8th shown.

Then the distribution unit 307 into the shield housing 311 built-in. The shield case 311 is on the shield housing 301 attached so that the input line 327 the distribution unit 307 with the second contact surface 326 the connecting conductor 322 comes into contact. As a result, the shield case block is manufactured. If between the input line 327 and the second contact section 328 a very small space is formed, the signal is completely transmitted by electrostatic coupling. As a result, there is no big problem. However, there is a slight loss of reflection. In In this case, a metal foil is placed in the space or between the contact electrode 329 the distribution unit 307 and the contact area of the shield case 302 used so that the reflection loss and insertion loss characteristics can be improved. More preferably, a mechanism is also provided that measures the relative distance (in the height direction) between the contact surface of the ground electrode 329 of the shield housing 311 and the second contact surface 328 the connecting conductor 322 can adjust.

The dimensions of the shield housing block with the 4-channel superconducting filter manufactured in the above manner are about 110 mm W × 50 mm D × 40 mm H for 1.5 GHz. The shield housing block is on the cooling plate in the heat insulating container with input-output connectors, so that a filter device for low temperature operation will be produced. The filter device for low temperature operation is on a chiller attached and operated at about 70 K. Consequently, higher performance than can be achieved according to the prior art. Compared to the dimensions of the entire filter system including the Chiller is the volume about 1/3 the volume of a dielectric filter device State-of-the-art resonator which has the same functions having. As a result, the size can be considerable be reduced. Furthermore, the insertion loss is less than a few W, to get an output signal of about 10 W per channel. consequently the power consumption is about compared to the prior art reduced by a factor of 10. The power consumption can even then be significantly reduced if a power loss for one amplifier or the like for the entire transmission section of the mobile communication base station system arises.

In the above description, while the thallium 2212 phase high-temperature oxide superconductor thin film material is used as the thin film electrode superconducting material and the lanthanum aluminates are used as the dielectric substrate material, the present invention is not limited to this. Oxide high-temperature superconductor materials of the bismuth system, the yttrium system and the thallium system can be used. In this case, operation can be carried out at the temperature of liquid nitrogen. Furthermore, a low temperature superconductor material, such as. B. Nb, Nb-Ti or Nb ₃ Sn, approximately at the temperature of liquid helium (4.2 K) can be used. In this case, the selection of substrate material is larger than that of the oxide high temperature superconductor thin film material.

11 Fig. 12 is a typical plan view showing a manifold of a filter device for low temperature operation according to a fifth example of the present invention. Output connecting sections 401 . 402 . 403 and 404 a small-format microwave filter (2 GHz), such as. B. a superconducting filter, are arranged in sequence in a straight line at regular intervals of 5 mm at one end of a MgO carrier material with a thickness of 0.5 mm. A first mix point 406 is on the MgO substrate 405 at a distance of λ / 4 from the filter output connection sections 401 and 402 intended. The filter output connection sections 401 and 402 and the first mix point 406 form a first isosceles triangular structure. A second mix point 407 is on the MgO substrate 405 at a distance of λ / 4 from the filter output connection sections 403 and 404 intended. The filter outlet sections 403 and 404 and the second mix point 407 form a second isosceles triangular structure. A third mix point 408 is on the MgO substrate 405 at a distance of λ / 2 from the first and second mixing points 406 and 407 intended. The first and second mix points 406 and 407 and the mix point 408 form a third isosceles triangular structure. λ is a wavelength at the mean resonance frequency of the filter. The dielectric constant of MgO is 10 , Therefore, λ is about 47 mm when the microwave has a frequency of 2 GHz. The filter output connection sections 401 . 402 . 403 and 404 are via branch lines 409 of the same width with the first, second and third mixing points 406 . 407 and 408 connected. If the characteristic impedance of the branch line 409 Is 50 Ω, then the width of the branch line 409 approximately equal to 0.48 mm.

On the MgO substrate 405 two groups of structures are provided, which are formed by the three isosceles triangles. The third mix point 408 is through the branch line 409 connected with a length of λ / 2. All branch lines 409 are formed by a thin film oxide superconductor of the Tl system (critical temperature: 10 K, critical current density: 1.0 × 10 ⁴ A / cm ² ) with a thickness of 2 μm. The distributor and the filter are installed in a shielding housing and inserted in a heat-insulating container. A filter device for low-temperature operation produced in this way is cooled to approximately 80 K by a refrigerator.

It turns out that with incident microwaves with a power of 1 W and a frequency in the 2 GHz band Help a small chiller joint or shared, low-loss transmission can be carried out can.

According to the distribution structure in the present example, the filter output connection sections are 401 . 402 . 403 and 404 arranged in a straight line at regular intervals. As a result, the filter output connection section lies 401 , the first mix point 406 and the third mix point 408 on the same straight line. The filter output connection section lies accordingly 404 , the second mixing point 407 and the third mix point 408 on the same straight line. Accordingly, the occurrence of radiation loss due to bending of the branch lines may occur 409 at the first and second mixing points 406 and 407 be prevented.

Because the distributor according to the present example has a structure that rests on three isosceles triangles based, it can be trained on the same level. By Using such a structure it is possible to shape the manifold a thin layer to produce, which is applied to the same carrier material. As a result, easily connects to a thin film type microwave filter produce. Moreover can be a transmission line stronger be reduced in size than in the prior art, so that a low loss Distributor can be realized.

In the present example, the filter output connection sections are indeed 401 . 402 . 403 and 404 at regular intervals on one end of the MgO carrier material 405 and the branch line is λ / 4 in a first stage and λ / 2 in a second stage, but the present invention is not limited to this. For example, the three isosceles triangular structures described above can also be used if the branch line has a length of (2n + 1) λ / 4 in the first stage and a length of (m + 1) λ / 2 in the second stage and the filter outlet connection sections are not arranged at regular intervals, so that the distributor can be realized in the form of the thin layer which is applied to the same carrier material, and a distributor with similar characteristics can be achieved, where n and m are 0 or natural numbers , A structure in which n and m are not equal to 0 is effective in the case where microwaves with a high frequency of 2 GHz or above are used or a carrier material with a high dielectric constant is used, so that the length of a transmission line for the Manufacture of the distributor is too short.

In the present example, although two structures each having four filter output connection sections are arranged, the present invention is not limited to this. For example, three filter output connection sections can be used. If three structures are arranged, the third mixing point can 408 by a transmission line with a length of (1 + 1) λ / 2, where 1 is 0 or a natural number.

12 Fig. 14 shows a typical plan view illustrating a manifold of a filter device for cryogenic operation according to a sixth example of the present invention. The distributor according to the present example differs from the above example in that filter output connection sections 422 arcuate with a radius of λ / 4 around mixing points 421 are arranged around.

Four filter output connection sections 422 are on the MgO carrier material 405 at regular intervals of 5 mm in an arc around the mixing points 421 arranged. Each filter output connection section 422 is through a branch line 423 with a width of about 0.48 mm with the mixing point 421 connected so that a fan-shaped structure is formed.

On the MgO substrate 405 Two fan-shaped structures are formed and connected to each other by a branch line, which has the same width as that of the branch line 423 and has a length of λ / 2. Other conditions, such as B. the material of the branch line 423 , the microwave frequency and the like are the same as in the above examples.

The carrier material 405 of the present example has an arcuate contour for the connection of the filter output connection sections 422 on how in 12 shown, but the external shape is not limited to this. In view of the functions, it is sufficient if the signal connection can be realized so that at the filter output connection sections 402 no extreme change in impedance is caused. For example, the backing material 405 cut out in a plane at the filter output connection section 422 almost perpendicular to the branch line 423 stands. According to such a shape, the end face of the ground electrode of the terminal end of the filter output line, which is at the filter output connection portion 422 to the branch line 423 connected, take the form of a level. As a result, the manufacture is easy to carry out.

The filter output connection section 422 is by a gold foil or a copper foil or by wire bonding, such as. B. a gold line or Al-Si line connected to the filter output line. The connection from the ground electrodes of the distributor to the filter should be carried out by bonding the gold foil or the copper foil to the electrodes using a silver paste or the like. A shield housing can be connected, in which the distributor and the filter are embedded.

In the same way as in the above Example is a filter device for low temperature operation under Use of the distributor according to the present Example made and using a small chiller cooled to about 80 K. Then you leave microwaves with a power of 2 W and a frequency in the 2 GHz band. The result shows that a joint or shared low-loss transmission can be carried out can.

As for the structure of the manifold formed on the basis of the fan-shaped structures according to the present example, the manifold can be formed on the same plane so that it is similar in shape to the first example a thin layer can be formed on the same carrier material. Since the node branches fan-shaped towards the filter, the number of filter output connection sections can be 422 can easily be enlarged. Consequently, the merging of the filter output connection sections 422 to a mix point 421 executed who. In this way it is possible to obtain a compact distributor with a very low loss.

The distributor according to the present example exhibits the fan-shaped structure on so that between there is enough clearance left in the filter outlet connection sections can. The filter can easily be placed on the same substrate as the distributor be formed. In this case, one by one thin shaped small format filter used such. B. a superconducting Filter.

The distributor according to the present example has a length the branch lines of λ / 4 or λ / 2 on but is not limited to this. For example, one Branch line with a length from (2n + 1) λ / 4 or (m + 1) λ / 2 be used in the same way as in the examples above, where n and m are natural Numbers are.

The distributor according to the present example has a structure in which two fan-shaped structures together are connected. The number of fan-shaped structures can also be three or more.

In the above examples and the present example, a superconductor of the Ti system is used in the branch line distributor, but metals such as Au, Pt, Cu, Ag and the like can also be used. If the oxide superconductor is used as a branch line, other superconductors than the superconductor of the Tl system can be used, e.g. B. the superconductors of the bi- and the y-system. In particular, Bi ₂ Sr ₂ Ca ₂ Cr ₃ O _{10 + x is} hardly toxic and has a critical temperature higher than 100 K, so that the refrigerator does not have to be enlarged. If a layer product of a superconductor and a metal is used as the branch line, the transmission through the metal can be ensured even if the superconductor loses its superconductivity due to failure of the refrigerator or the like. As a result, the functions are not completely damaged, so that the stability of the distributor can be improved.

The material used as the carrier material of the distributor is not limited to MgO. For example, LaAlO ₃ , SrTiO ₃ , LaGaO ₃ , NdGaO ₃ or the like can be used. When using LaAlO ₃ , the crystal properties of the branch line (the oxide superconductor) can be improved, since the mismatch of the lattice constant to the branch line consisting of the oxide superconductor is small. As a result, the critical temperature and the critical current density can be improved, so that the performance of the refrigerator can be reduced. High power microwaves can also be used. The same effects can also be achieved when using SrTiO ₃ , La-GaO ₃ and NdGaO ₃ . Particularly when using SrTiO ₃ , the size of the distributor can be reduced even further because of the high dielectric constant of 310.

Claims (12)

Filter device for low-temperature operation, comprising: a shield housing block ( 1 ; 301 . 311 ) with signal input and output sections ( 2a . 2 B ; 309 ) and a closed room ( 10 ) in which a between the signal input and output sections ( 2a . 2 B ; 309 ) connected filter element ( 11 ) is housed, a heat-insulating container ( 4 ) in which the shield housing block ( 1 ) is housed, a cooling plate ( 3 ; 306 ) in the heat-insulating container ( 4 ) is provided in which the shield housing block ( 1 ; 301 . 311 ) in the thermal contact state on the cooling plate ( 3 ; 306 ) is fixed, characterized in that the filter element ( 11 ) has: several filter coupling line blocks ( 106a to 106d ), each consisting of a filter electrode ( 101 to 101d ; 303a to 303d . 302 ), consisting of a superconducting thin film and a thin film coupling line ( 103a to 103d ; 305a to 305d ), the respective thin-film coupling line having a length of (2m + 1) λ / 4, where m is zero or a natural number and λ is a signal wavelength, the respective thin-film coupling line ( 103 ) is connected to the output end of the corresponding filter electrode, the input end of each filter electrode being connected to the corresponding input section ( 2a ) connected is; and at least one output coupling line ( 109a . 109c ; 307a ) with the same characteristic impedance as that of the corresponding thin-film coupling line ( 103a to 103d ; 305a to 305d ) with one end of the corresponding thin-film coupling line ( 103a to 103d ; 305a to 305d ) is connected on the opposite side of the corresponding filter electrode, the other ends of the output coupling lines ( 109a . 109c ; 307a ) with the corresponding output sections ( 2 B ) are connected so that the number of output coupling lines ( 109a . 109c ; 307a ) less than the number of thin-film coupling lines ( 103a to 103d ; 305a to 305d ) is. Filter device for low-temperature operation according to claim 1, wherein the filter coupling line blocks ( 106a to 106d ) on are laminated to one another, a first conductive connector is arranged such that it extends in the lamination direction and one end of the respective thin-film coupling line ( 103 ) on an opposite side of the corresponding filter electrode ( 101 ) connects to a first coupling section ( 108 ) to build; the at least one output coupling line ( 109 ) several first output coupling lines ( 109a . 109c ), each with a length of nλ / 2, where n is a natural number and λ is a signal wavelength, the respective first output coupling line with the first coupling section ( 108 ) connected is; a second conductive connector is arranged so that it extends in the lamination direction and ends of the respective first output coupling lines on an opposite side of the first coupling section ( 108 ) connects to a second coupling section ( 118 ) to build; and a respective second output coupling line ( 120 ) with the second coupling section ( 118 ) is connected, the second output coupling line ( 120 ) the same characteristic impedance as the first output coupling line ( 109a . 109c ) having. Filter device for low-temperature operation according to claim 1 or 2, wherein the corresponding filter electrode ( 101 ) and the respective thin-film coupling line ( 103 ) in each of the filter coupling line blocks ( 106a to 106d ) are on a common level (AA). Filter device for low-temperature operation according to one of claims 1 to 3, wherein the thin-film coupling line ( 103 ) consists of an oxide superconductor layer. Filter device for low-temperature operation according to one of claims 1 to 3, wherein the thin-film coupling line ( 103 ) consists of a metal layer. Filter device for low-temperature operation according to one of claims 1 to 3, wherein the thin-film coupling line ( 103 ) is a laminate of an oxide superconductor layer and a metal layer. Filter device for low-temperature operation according to claim 1, wherein the filter element has a structure in which a filter unit from a plurality of planar filter electrodes ( 303a to 303d ) is composed and a distributor ( 307 ) consists of branch lines, to which the thin-film coupling lines and each of the output coupling lines provided on a substrate belong, the filter electrodes in each case via a plurality of connection connections ( 308 ) are connected to the branch lines of the distributor; the distributor ( 307 ) is arranged so that a plane enclosing the distributor has a corresponding area of each planar filter electrode ( 303a to 303d ) cuts; and each of the connection ports ( 308 ) a connecting conductor ( 322 ) which, at a first end, corresponds to a corresponding surface of the planar filter electrode ( 303 ) parallel first contact surface ( 326 ) and at a second end one to a corresponding surface of the distributor ( 307 ) parallel second contact surface ( 328 ) having. The low temperature operation filter device according to claim 7, wherein the first ( 326 ) and the second contact surface ( 328 ) each connection connector ( 322 ) on a longitudinal axis of the connection ( 308 ) are perpendicular to each other. Filter device for low-temperature operation according to claim 7 or 8, wherein the respective first contact surface ( 326 ) in contact with the corresponding filter electrode of each of the planar filter electrodes ( 303a to 303d ) and the respective second contact surface ( 328 ) in contact with the corresponding branch line of the distributor ( 307 ) is. Filter device for low-temperature operation according to one of claims 7 to 9, wherein between the respective first contact surface ( 326 ) and the corresponding filter electrode of each of the planar filter electrodes ( 303a to 303d ) a conductive material is provided. Filter device for low-temperature operation according to one of claims 7 to 10, wherein the conductive material between the respective second contact surface ( 328 ) and the corresponding branch line of the distributor ( 307 ) is provided. The low temperature operation filter device according to claim 1, wherein a part of the filter element between the output ends of the filter electrodes and an output section of the corresponding output coupling line consists of a distributor, the distributor including at least one structure comprising: first, second, third and fourth filter output connection sections ( 401 to 404 ), each corresponding to one of four output ends of the filter electrodes; a first mixing point ( 406 ) which is at a distance of (2n + 1) λ / 4 from both the first and the second filter output connection section ( 401 . 402 ) is provided, where λ is a wavelength of an average resonance frequency of a filter element and n is 0 or a natural number; a second mixing point ( 407 ) which is at a distance of (2n + 1) λ / 4 from both the third and fourth filter output connection sections ( 403 . 404 ) is provided and lies on a plane which connects the first and second filter output connection sections ( 401 . 402 ) and the first mix Point ( 406 ) includes; and a third mix point ( 408 ), which is at a distance of (m + 1) λ / 2 from both the first and the second mixing point ( 406 . 407 ) is provided, where m is 0 or a natural number, and which lies on the plane that the first and second filter output connection sections ( 401 . 402 ) and the first mixing point ( 406 ) includes; and straight branch lines ( 409 ) in the form of a thin layer which is applied to a carrier material and has the same characteristic impedance as the corresponding thin-film coupling line and at least three of the first, second, third and fourth filter output connection sections ( 401 to 404 ) with the first, second and third mixing points ( 406 to 408 ) connects.