JP2015100082A - Tunable filter device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a tunable filter device that can adjust the center frequency of a passband stably in a wide range, while suppressing disturbance of a waveform in filter characteristics.SOLUTION: A tunable filter device according to an embodiment includes a dielectric substrate, a resonator pattern, a characteristic adjustment member, and a drive mechanism. The dielectric substrate has a surface that has been virtually divided into a first area and a second area. The resonator pattern is formed of conductive material in the first area of the surface. The characteristic adjustment member has an opposing surface arranged opposite to the surface and formed of a dielectric substance or a magnetic substance or conductive material. The drive mechanism drives the characteristic adjustment member, so as to define the volume of a space held between the opposing surface and a projection surface obtained by projecting the characteristic adjustment member on the surface, as the spatial volume, and adjust a spatial volume ratio between the spatial volume of the first area and the spatial volume of the second area.

Description

  Embodiments described herein relate generally to a tunable filter device.

  A communication device that performs wireless or wired information communication includes various devices such as an amplifier, a mixer, and a filter (for example, a bandpass filter). The bandpass filter has a characteristic of allowing a frequency within a specific range to pass and blocking (attenuating) a frequency outside the range. The characteristics of the bandpass filter such as the passband width and the center frequency of the passband are designed according to the specifications of the communication system. In a communication system, a bandpass filter having a steep skirt characteristic (frequency cutoff characteristic that divides a passband and other regions) is required from the viewpoint of effective use of frequencies.

  As a band pass filter, there is a planar circuit type filter such as a microphone strip line type filter. In the planar circuit type filter, it is possible to make the skirt characteristic steep by increasing the number of resonant elements. When a normal conductor material is used for the wiring material of the resonant element, if the number of the resonant elements is increased, transmission loss increases, so that it is difficult to increase the number of resonant elements. Even if a good electrical conductor such as copper (Cu) or silver (Ag) is used as the wiring material of the resonant element, it is difficult to provide a large number of resonant elements. On the other hand, since the superconductor has a very small surface resistance in the high frequency region as compared with a normal good electrical conductor, transmission loss is small even if the resonant element formed of the superconductor is multistaged. Accordingly, a bandpass filter having a steep skirt characteristic can be realized by forming the resonant element with a superconductor.

  In addition, in order to construct a communication infrastructure that can flexibly cope with changes in the system, a bandpass filter whose characteristics (for example, the center frequency of the passband) are variable is required. However, if the center frequency of the pass band is changed, the waveform of the filter characteristics may deviate from the ideal shape.

  In the filter device, it is required that the center frequency of the passband can be adjusted stably over a wide range while suppressing the disturbance of the filter characteristic waveform.

JP 2002-057506 A JP 2007-208893 A

Hiroshi Mikami, 4 others, "Improvement of characteristics of superconducting filter by dielectric rod trimming", IEICE Technical Report SCE2003-6, MW2003-6 (2003-4), p29-35

  The problem to be solved by the present invention is to provide a tunable filter device capable of adjusting the center frequency of the passband stably over a wide range while suppressing the disturbance of the filter characteristic waveform.

  A tunable filter device according to an embodiment includes a dielectric substrate, a resonator pattern, a characteristic adjusting member, and a drive mechanism. The dielectric substrate has a surface virtually divided into a first region and a second region. The resonator pattern is formed of a conductive material in the first region of the surface. The characteristic adjusting member has a facing surface facing the surface and is made of a dielectric material, a magnetic material, or a conductive material. The drive mechanism uses a volume of a space sandwiched between the projection surface obtained by projecting the characteristic adjustment member on the surface and the facing surface as a space volume, and a space volume of the first region and a space of the second region The said characteristic adjustment member is driven so that the space volume ratio between space volumes may be adjusted.

1 is a perspective view schematically showing an example of a tunable filter device according to a first embodiment. The top view which shows an example of area division in case one resonator pattern is provided on the dielectric substrate. The figure explaining the frequency characteristic of the filter concerning an embodiment. The perspective view which shows roughly the other example of the tunable filter apparatus which concerns on 1st Embodiment. Sectional drawing of the tunable filter apparatus of FIG. 4 containing an example of the drive mechanism which concerns on 1st Embodiment. The top view which shows an example of area | region division in case the some resonator pattern is provided on the dielectric substrate which concerns on embodiment. The perspective view which shows roughly an example of the tunable filter apparatus which concerns on 2nd Embodiment. The perspective view which shows roughly the other example of the tunable filter apparatus which concerns on 2nd Embodiment. Sectional drawing of the tunable filter apparatus of FIG. 8 containing an example of the drive mechanism which concerns on 2nd Embodiment. Sectional drawing of the tunable filter apparatus of FIG. 8 containing the other example of the drive mechanism which concerns on 2nd Embodiment. (A) And (b) is a figure explaining operation | movement of the rotation unit shown in FIG. The perspective view which shows roughly an example of the tunable filter apparatus which concerns on 3rd Embodiment. The top view which shows a mode that the projection of the characteristic adjustment member shown in FIG. 12 straddles the 1st area | region and 2nd area | region on a dielectric substrate. The perspective view which shows roughly the other example of the tunable filter apparatus which concerns on 3rd Embodiment. FIG. 15 is a cross-sectional view of the tunable filter device of FIG. 14 including an example of a drive mechanism according to a third embodiment. 1 is a perspective view schematically showing a tunable filter device according to an embodiment. The top view which shows the other example of area division in case one resonator pattern is provided on the dielectric substrate which concerns on embodiment. The block diagram which shows roughly the cooling system which concerns on 4th Embodiment. The block diagram which shows an example of the tunable filter apparatus which concerns on 5th Embodiment. The block diagram which shows the other example of the tunable filter apparatus which concerns on 5th Embodiment.

  Hereinafter, embodiments will be described with reference to the drawings. In the following embodiments, the same reference numerals are assigned to the same components, and overlapping descriptions are omitted as appropriate.

(First embodiment)
FIG. 1 schematically shows an example of a tunable filter device according to the first embodiment. A tunable filter device 100 shown in FIG. 1 includes a microstrip line type bandpass filter. Specifically, the tunable filter device 100 includes a dielectric substrate 101, and a resonator pattern 102 as a resonant element, a signal input line 103, and a signal output line 104 are superposed on the surface of the dielectric substrate 101. It is made of a conductive material. A ground film is formed of a superconductive material on the entire back surface of the dielectric substrate 101. The ground film can be used as a ground electrode. Alternatively, the ground electrode may be formed by evaporating, for example, an Ag film on the ground film.

  In the example shown in FIG. 1, the resonator pattern 102 is a hairpin type resonator pattern. Note that the resonator pattern 102 is not limited to the hairpin resonator pattern as shown in FIG. 1, and may be, for example, a spiral resonator pattern, an S-shaped resonator pattern, or the like. Furthermore, although one resonator pattern 102 is shown in FIG. 1, the number of resonator patterns 102 may be two or more as in an example described later (for example, an example shown in FIG. 4).

  The dielectric substrate 101 is accommodated in a metal package 106 that shields high frequencies. In FIG. 1, a part of the metal package 106 (specifically, part of the bottom and side walls) is shown, and the other parts are omitted. The metal package 106 is formed in a box shape having a closed space inside. In one example, the metal package 106 includes a rectangular parallelepiped package main body that is open at the top and a lid that closes the opening, and an internal space is formed by the package main body and the lid. The ground electrode provided on the back surface of the dielectric substrate 101 contacts the inner bottom surface of the metal package 106, and the surface of the dielectric substrate 101 is directed to the internal space of the metal package 106.

  The metal package 106 is provided with a coaxial connector (output connector) 108. The signal output line 104 is connected to the central conductor of the coaxial connector 108 via a connection electrode. The signal input line 103 is connected to a center conductor of a coaxial connector (input connector) (not shown) via a connection electrode 107. As a bonding method, wire bonding by ultrasonic thermocompression bonding, tape bonding, solder bonding, or the like can be used. For example, the connection electrode can be formed of a metal such as gold (Au) or silver (Ag) by vapor deposition or sputtering in order to reduce contact resistance. In one example, the connection electrode may be a laminated film including at least one of gold (Au) and silver (Ag).

  In the metal package 106, the characteristic adjusting member 105 is disposed to face the surface of the dielectric substrate 101 with a gap therebetween. More specifically, the characteristic adjusting member 105 is disposed in the thickness direction of the resonator pattern 102 so as to face the resonator pattern 102 and to be spaced from the resonator pattern 102. The characteristic adjusting member 105 may be a member that changes the magnetic field distribution or electric field distribution in the space near the dielectric substrate 101, and is formed of a dielectric (for example, alumina, sapphire) or a magnetic material (for example, ferrite). Alternatively, the characteristic adjusting member 105 may be formed of a conductive material such as metal (for example, copper).

  In the example of FIG. 1, the characteristic adjustment member 105 has a rectangular parallelepiped shape, and the surface of the characteristic adjustment member 105 facing the dielectric substrate 101 (hereinafter referred to as a substrate facing surface) is parallel to the surface of the dielectric substrate 101. It is. The width of the characteristic adjusting member 105 may be matched to the width of the resonator pattern 102. Here, the width represents the dimension of the resonator pattern 102 in the short direction. In the present embodiment, the longitudinal direction and the short direction of the resonator pattern 102 are perpendicular to the thickness direction of the dielectric substrate 101. Note that the shape of the characteristic adjusting member 105 is not limited to an example of a rectangular parallelepiped as shown in FIG. 1, and may be another shape.

  In the planar circuit type filter, the resonance frequency of the resonator pattern 102 may deviate from a desired value due to variations in the thickness and material characteristics of the dielectric substrate 101, deviations in patterning dimensions of the resonator pattern 102, and the like. As a result, desired filter characteristics may not be obtained. Further, if the dielectric constant of the dielectric substrate 101 is increased in order to reduce the size of the filter, the wiring pattern becomes complicated in order to achieve a predetermined wiring impedance. In this case, the thickness and patterning dimension deviation of the dielectric substrate 101 have a great influence on the filter characteristics. In the present embodiment, the resonance frequency of the resonator pattern 102 can be adjusted by using the characteristic adjusting member 105 provided to face the resonator pattern 102, and desired filter characteristics can be obtained.

  The characteristic adjusting member 105 is supported by a driving mechanism (not shown in FIG. 1), and the driving mechanism moves the characteristic adjusting member 105 in parallel to the surface of the dielectric substrate 101. In this case, the distance between the substrate facing surface of the characteristic adjusting member 105 and the surface of the dielectric substrate 101 is kept constant. When the characteristic adjusting member 105 is moved in parallel to the dielectric substrate 101, there is no possibility that the characteristic adjusting member 105 contacts the resonator pattern 102 and damages the resonator pattern 102. More specifically, the drive mechanism moves the characteristic adjustment member 105 in the longitudinal direction of the resonator pattern 102 as indicated by the double-headed arrow in FIG. By moving the characteristic adjusting member 105 in the longitudinal direction of the resonator pattern 102, the resonance frequency of the resonator pattern 102 can be stably adjusted over a wide range.

  In the conventional method of adjusting the resonance frequency of the resonator by moving the dielectric member in the thickness direction of the dielectric substrate, the waveform of the filter characteristics (transmission characteristics and reflection characteristics) may be rapidly collapsed. On the other hand, in the present embodiment in which the characteristic adjusting member 105 is moved in parallel to the dielectric substrate 101, the filter characteristic waveform can be maintained and gradually changed. As described above, in this embodiment, the center frequency of the passband can be adjusted stably over a wide range while suppressing the disturbance of the filter characteristic waveform.

The dielectric substrate 101 is formed of a low-loss material having a small dielectric loss tangent, such as Al ₂ O ₃ (sapphire), MgO, LaAlO ₃ , for example.

The circuit pattern (specifically, the pattern of the resonator pattern 102 and the signal input line 103 and the signal output line 104) is, for example, a Y-Ba-Cu-O-based superconducting material (hereinafter referred to as YBCO). The superconductor film formed on the entire surface can be obtained by processing using a photolithography technique. The material of the circuit pattern is not limited to YBCO, but is another oxide superconducting material such as an R—Ba—Cu—O-based material (R is Nb, Ym, Sm, or Ho), Bi. -Sr-Ca-Cu-O-based material, Pb-Bi-Sr-Ca -Cu-O -based _{material, CuBa p Ca q Cu r O} x based material (1.5 <p <2.5,2.5 < q <3.5, 3.5 <r <4.5), or a metal superconducting material such as niobium or niobium tin. The material of the circuit pattern is not limited to the superconducting material but may be a normal conductor material.

  The metal package 106 is formed of, for example, oxygen-free copper having excellent thermal conductivity. Alternatively, the metal package 106 may be formed of pure aluminum, an aluminum alloy, a copper alloy, or the like. The metal package 106 may be formed of a material having a thermal contraction rate close to that of the dielectric substrate 101, such as Kovar, Invar, 42 alloy, or the like.

  Hereinafter, a portion including the dielectric substrate 101, a circuit pattern on the dielectric substrate 101 (including the resonator pattern 102, the signal input line 103, and the signal output line 104), the characteristic adjusting member 105, and the metal package 106 is included. This is called a filter device.

  FIG. 2 is a plan view schematically showing the dielectric substrate 101 shown in FIG. The surface of the dielectric substrate 101 is virtually divided into two regions, that is, a first region 201 and a second region 202, as shown in FIG. The first region 201 is a region including the resonator pattern 102. The second region 202 is a region that does not include the resonator pattern 102, that is, a region other than the first region 201. A projection surface 110 obtained by projecting the characteristic adjustment member 105 onto the dielectric substrate 101 (for example, vertical projection) extends over the first region 201 and the second region 202. If the first region 201 includes the resonator pattern 102 and the second region 202 does not include the resonator pattern 102, the first region 201 and the second region 202 are arbitrarily set. can do.

  When the characteristic adjusting member 105 moves in parallel to the surface of the dielectric substrate 101, the spatial volume ratio between the spatial constant product of the first region 201 and the spatial volume of the second region 202 changes (the spatial volume difference also changes). As well). Here, the space volume is the volume of the space sandwiched between the projection surface 110 and the substrate facing surface of the sex adjusting member 105, that is, a columnar space having the projection surface 110 as the bottom surface and the characteristic facing member 105 as the top surface. Refers to the volume of. Specifically, the columnar space is a space that linearly connects the projection surface 110 and the substrate facing surface of the characteristic adjustment member 105. In the example of FIG. 1, the space has a rectangular parallelepiped shape, and the space volume is obtained by multiplying the distance between the dielectric substrate 101 and the characteristic adjustment member 105 by the area of the projection surface 110.

  The spatial volume of the first region 201 is a space that is defined (sandwiched) between the portion of the projection surface 110 located in the first region 201 and the portion of the substrate facing surface that faces the first region 201. The volume of the second region 202 is defined between the portion of the projection surface 110 located in the second region 202 and the portion of the substrate facing surface facing the second region 202 (sandwiched). Is the volume of the space. The parallel movement of the characteristic adjustment member 105 is an example of a method of driving the characteristic adjustment member 105 so that the spatial volume ratio between the spatial volume of the first region 201 and the spatial volume of the second region 202 changes. .

  FIG. 3 schematically shows how the center frequency of the pass band changes when the characteristic adjusting member 105 is driven. In FIG. 3, the frequency characteristic 300 of the filter when the characteristic adjusting member 105 is at the reference position is shown by a solid line. In the present embodiment and the embodiments described later, when the characteristic adjusting member 105 is driven (for example, moved in the longitudinal direction of the resonator pattern 102), as shown in FIG. 3, the pass bandwidth is hardly changed. The center frequency of the pass band can be changed. The center frequency is shifted to the high frequency side by increasing the spatial volume of the first region 201 as in the characteristic 301. Further, the center frequency is shifted to the low frequency side by reducing the spatial volume in the first region 201 as in the characteristic 302.

4 and 5 are a perspective view and a cross-sectional view schematically showing another example of the tunable filter device according to the present embodiment. In FIG. 4, as in FIG. 1, the metal package 106 is partially omitted.
In the tunable filter device 400 shown in FIG. 4, a plurality of resonator patterns 102 are formed on the surface of the dielectric substrate 101. By combining the plurality of resonator patterns 102, filter characteristics are obtained. In the tunable filter device 400, by providing a plurality of resonator patterns 102, a steep skirt characteristic can be obtained as a filter. As shown in FIG. 5, a ground film 503 is formed on the back surface of the dielectric substrate 101. The dielectric substrate 101 is made of metal so that the ground electrode provided on the back surface of the dielectric substrate 101 is in contact with the inner bottom surface of the metal package 106 and the surface of the dielectric substrate 101 is directed to the internal space 504 of the metal package 106. It is accommodated in the package 106. The metal package 106 includes a package body 501 and a lid 502. An internal space 504 is formed by closing the opening of the package body 501 with a lid 502.

  As shown in FIG. 4, a plurality of characteristic adjusting members 105 are arranged on the surface of the dielectric substrate 101 so as to face each other with a gap. One characteristic adjusting member 105 is provided for each resonator pattern 102, and faces the corresponding resonator pattern 102 with a certain distance in the thickness direction of the dielectric substrate 101.

  A through-hole is provided in the side wall of the metal package 106 (specifically, the package body 501). The characteristic adjusting member 105 extends to the outside of the metal package 106 through the through hole, and is supported by the driving mechanism 510 on the opening side of the corresponding resonator pattern 102. The drive mechanism 510 is provided for each characteristic adjusting member 105. The drive mechanism 510 changes the characteristic adjustment member 105 so that the spatial volume ratio between the spatial volume of the first region including the resonator pattern 102 and the spatial volume of the second region not including the resonator pattern 102 changes. To drive. Specifically, the drive mechanism 510 moves the characteristic adjustment member 105 in the longitudinal direction of the resonator pattern 102.

  In one example, the drive mechanism 510 includes a spring member 511, a pressing plate member 512, and a piezoelectric element 513. The piezoelectric element 513 is an example of a drive source (actuator) that drives the characteristic adjustment member 105. The drive mechanism 510 may use a magnetostrictive element as a drive source. The pressing plate member 512 is disposed to face the wall surface of the metal package 106, and the base of the characteristic adjusting member 105 is fixed. The spring member 511 is disposed between the metal package 106 and the pressing plate member 512. The pressing plate member 512 transmits the pressing force of the spring member 511 to the piezoelectric element 513 and applies a preload to the piezoelectric element 513.

  The piezoelectric element 513 is disposed between the metal package 106 and the pressing plate member 512. Specifically, one end of the piezoelectric element 513 is fixed to the metal package 106 and the other end is fixed to the pressing plate member 512. A lead wire (not shown) for applying a voltage is connected to the piezoelectric element 513. The piezoelectric element 513 expands and contracts by applying a voltage. The expansion and contraction of the piezoelectric element 513 is controlled by the applied voltage. The expansion / contraction direction of the piezoelectric element 513 substantially coincides with the longitudinal direction of the resonator pattern 102. The characteristic adjusting member 105 moves due to expansion and contraction of the piezoelectric element 513. By adjusting the amount of movement of each of the characteristic adjustment members 105, the resonance frequency of the resonator pattern 102 can be changed uniformly. As a result, the center frequency of the pass band can be adjusted without disturbing the waveform of the filter characteristics (for example, the pass characteristics and the reflection characteristics).

  FIG. 6 shows an example of region division when a plurality of resonator patterns 102 are provided on the dielectric substrate 101. As shown in FIG. 6, a plurality of first regions 201 and a plurality of second regions 202 are set based on the position of the resonator pattern 102. Each characteristic adjusting member 105 is virtually projected onto the dielectric substrate 101 so as to straddle the first region 201 and the second region 202. If the first region 201 includes the resonator pattern 102 and the second region 202 does not include the resonator pattern 102, the first region 201 and the second region 202 are arbitrarily set. can do.

  In the example shown in FIG. 5, the substrate facing surface of the characteristic adjusting member 105 is not a uniform plane but has a surface inclined with respect to the surface of the dielectric substrate 101. Specifically, the substrate facing surface on the base side of the characteristic adjusting member 105 is parallel to the surface of the dielectric substrate 101, but the substrate facing surface on the distal end side is inclined with respect to the surface of the dielectric substrate 101. At the tip, the distance between the characteristic adjustment member 105 and the dielectric substrate 101 increases as it goes toward the tip. Thereby, compared with the case where the board | substrate opposing surface of the characteristic adjustment member 105 is a uniform plane, the variation | change_quantity of the space volume of the 1st area | region 201 with respect to the movement amount of the characteristic adjustment member 105 increases. As a result, a desired center frequency change amount can be obtained with a smaller movement amount of the characteristic adjusting member 105. Furthermore, since the range in which the spatial volume in the first region 201 can be changed is increased, the center frequency of the passband can be adjusted in a wider range. Note that at least a part of the substrate facing surface of the characteristic adjusting member 105 may be a curved surface.

  As described above, in the tunable filter device according to this embodiment, the resonance frequency of the resonator pattern is accurately and easily moved by moving the characteristic adjusting member in the longitudinal direction of the resonator pattern with respect to each resonator pattern. Can be adjusted. As a result, it is possible to adjust the center frequency of the pass band while preventing disturbance of the filter characteristic waveform.

(Second Embodiment)
In the first embodiment, the characteristic adjusting member is moved in parallel to the surface of the dielectric substrate (specifically, in the longitudinal direction of the resonator pattern). In the second embodiment, the characteristic adjusting member is rotated around an axis parallel to the lateral direction of the resonator pattern 102.

  FIG. 7 schematically shows an example of a tunable filter device according to the second embodiment. In FIG. 7, the metal package 106 is partially omitted as in FIG. In the tunable filter device 700 shown in FIG. 7, the characteristic adjustment member 105 is supported so as to be rotatable about an axis substantially parallel to the short direction of the resonator pattern 102. Also in the tunable filter device 700, the first region 201 and the second region 202 can be set on the surface of the dielectric substrate 101 in the same manner as in the example shown in FIG. A drive mechanism (not shown in FIG. 7) is arranged around the axis so that the spatial volume ratio between the spatial volume of the first region 201 and the spatial volume of the second region 202 changes. The characteristic adjusting member 105 is rotated. In the present embodiment, the resonance frequency of the resonator pattern 102 is adjusted by adjusting the rotation amount of the characteristic adjusting member 105. Thereby, the center frequency of the pass band can be adjusted while preventing the disturbance of the filter characteristic waveform.

  8 and 9 are a perspective view and a cross-sectional view schematically showing another example of the tunable filter device according to the second embodiment. In FIG. 8, like FIG. 1, the metal package 106 is partially omitted.

  In the tunable filter device 800 shown in FIG. 8, a plurality of resonator patterns 102 are provided on the surface of the dielectric substrate 101. A plurality of characteristic adjusting members 105 are arranged facing the surface of the dielectric substrate 101 with a gap therebetween. One characteristic adjusting member 105 is provided for each resonator pattern 102 and faces the corresponding resonator pattern 102 in the thickness direction of the dielectric substrate 101. The width of the characteristic adjusting member 105 may be matched to the width of the resonator pattern 102. In the tunable filter device 800, the first region 201 and the second region 202 can be set on the surface of the dielectric substrate 101 in the same manner as in the example shown in FIG.

  As shown in FIG. 9, a through hole is provided in the side wall of the metal package 106. The characteristic adjusting member 105 extends to the outside of the metal package 106 through the through hole, and is supported by the driving mechanism 910 on the opening side of the corresponding resonator pattern 102. The drive mechanism 910 is provided for each characteristic adjustment member 105. The drive mechanism 910 drives the characteristic adjustment member 105 so that the spatial volume ratio between the spatial volume of the first region 201 and the spatial volume of the second region 202 changes. Specifically, the drive mechanism 910 rotates the characteristic adjustment member 105 around a support shaft 913 provided on the characteristic adjustment member 105.

  In one example, the drive mechanism 910 includes a spring member 911 and a piezoelectric element 912. In the example shown in FIG. 9, the package body 501 includes a protrusion 901 protruding in the longitudinal direction of the resonator pattern 102, and the lid 502 includes a protrusion 902 protruding in the longitudinal direction of the resonator pattern 102. The spring member 911 is disposed between the protruding portion 902 of the metal package 106 and the characteristic adjusting member 105. The pressing force of the spring member 911 is applied as a preload to the piezoelectric element 912 via the characteristic adjusting member 105.

  The piezoelectric element 912 is disposed between the protruding portion 901 of the metal package 106 and the characteristic adjusting member 105. Specifically, one end of the piezoelectric element 912 is fixed to the protruding portion 901 of the metal package 106 and the other end is fixed to the characteristic adjusting member 105. A lead wire (not shown) for applying a voltage is connected to the piezoelectric element 912. The piezoelectric element 912 expands and contracts in the thickness direction of the dielectric substrate 101 by applying a voltage. Expansion and contraction of the piezoelectric element 912 is converted into rotation by the support shaft 913. The characteristic adjusting member 105 rotates around the support shaft 913 by the expansion and contraction of the piezoelectric element 912, and the posture of the characteristic adjusting member 105 changes. When the piezoelectric element 912 expands, the characteristic adjustment member 105 approaches the resonator pattern 102. In this case, the spatial volume in the first region 201 becomes small. When the piezoelectric element 912 contracts, the characteristic adjusting member 105 moves away from the resonator pattern 102. In this case, the spatial volume in the first region 201 is increased. By adjusting the rotation amount of each of the characteristic adjustment members 105, the resonance frequency of the resonator pattern 102 can be changed uniformly. As a result, the center frequency of the pass band can be adjusted without disturbing the waveform of the filter characteristics.

  FIG. 10 schematically shows another example of the drive mechanism according to the second embodiment. In the example shown in FIG. 10, the drive mechanism is a rotation unit 1002 that rotationally drives a rotation shaft 1001 provided on the characteristic adjustment member 105. A plurality of characteristic adjusting members 105 may be connected to one rotating shaft 1001. In this case, these characteristic adjustment members 105 are simultaneously rotated by the rotation unit 1002.

  FIGS. 11A and 11B schematically show a structural example of the rotation unit 1002. As shown in FIG. 11A, the rotating unit 1002 includes a piezoelectric element 1101, a spring member 1102, and a rotating member 1103. The rotating member 1103 is attached to the rotating shaft 1001 and supported by the piezoelectric element 1101 and the spring member 1102 so as to rotate about the rotating shaft 1001. The rotating member 1103 transmits the pressing force of the spring member 1102 to the piezoelectric element 1101 and applies a preload to the piezoelectric element 1101. A lead wire (not shown) for applying a voltage is connected to the piezoelectric element 1101. The piezoelectric element 1101 expands and contracts by applying a voltage. As shown in FIG. 11B, the characteristic adjusting member 105 mechanically connected to the rotating member 1103 is rotated by the extension of the piezoelectric element 1101. When the piezoelectric element 1101 contracts, the characteristic adjusting member 105 rotates in the opposite direction to the case where the piezoelectric element 1101 extends. By adjusting the rotation amount of each of the characteristic adjustment members 105, the resonance frequency of the resonator pattern 102 can be changed uniformly. As a result, the center frequency of the pass band can be adjusted without disturbing the waveform of the filter characteristics.

  The rotating unit 1002 may be an actuator that can directly generate a rotational driving force such as an ultrasonic motor.

  As described above, in the tunable filter device according to the present embodiment, the resonance of the resonator pattern is achieved by rotating the characteristic adjustment member around the axis perpendicular to the short direction of the resonator pattern with respect to each resonator pattern. The frequency can be adjusted accurately and easily. As a result, it is possible to adjust the center frequency of the pass band while preventing disturbance of the filter characteristic waveform.

(Third embodiment)
In the third embodiment, the characteristic adjusting member is rotated around an axis parallel to the thickness direction of the dielectric substrate.
FIG. 12 schematically shows an example of a tunable filter device according to the third embodiment. In FIG. 12, like FIG. 1, the metal package 106 is partially omitted. In the tunable filter device 1200 shown in FIG. 12, the characteristic adjusting member 105 is disposed in the metal package 106 so as to face the surface of the dielectric substrate 101 with a gap. More specifically, the characteristic adjusting member 105 is disposed in the thickness direction of the resonator pattern 102 so as to face the resonator pattern 102 and to be spaced from the resonator pattern 102.

  The characteristic adjusting member 105 is supported so as to be rotatable around an axis substantially parallel to the thickness direction of the dielectric substrate 101. This axis passes through the characteristic adjusting member 105. In the example shown in FIG. 12, the substrate facing surface of the characteristic adjusting member 105 is inclined with respect to the surface of the dielectric substrate 101, and the planar shape of the characteristic adjusting member 105 viewed from the dielectric substrate 101 side is circular. .

  FIG. 13 is a plan view schematically showing the dielectric substrate 101 shown in FIG. The surface of the dielectric substrate 101 is virtually divided into a first region 201 and a second region 202, as shown in FIG. A resonator pattern 102 is formed in the first region 201. The second region 202 is a region that does not include the resonator pattern 102. A projection surface 1210 obtained by projecting the characteristic adjustment member 105 onto the dielectric substrate 101 (for example, vertical projection) extends over the first region 201 and the second region 202.

  The drive mechanism (not shown in FIG. 12) causes the characteristic adjusting member 105 to change the spatial volume ratio between the spatial volume of the first region 201 and the spatial volume of the second region 202. To drive. Specifically, the drive mechanism rotates the characteristic adjusting member 105 around an axis substantially parallel to the thickness direction of the dielectric substrate 101. In this case, the distance between the characteristic adjusting member 105 and the dielectric substrate 101 is kept constant. When the characteristic adjustment member 105 is rotated around an axis parallel to the thickness direction of the dielectric substrate 101, there is no possibility that the characteristic adjustment member 105 contacts the resonator pattern 102 and damages the resonator pattern 102. In the present embodiment, the resonance frequency of the resonator pattern 102 is adjusted by adjusting the rotation amount of the characteristic adjusting member 105. Thereby, the center frequency of the pass band can be adjusted while preventing the disturbance of the filter characteristic waveform.

  The characteristic adjusting member 105 is not limited to the example shown in FIG. 12 and may have any shape. However, it is desirable to have a shape as shown in FIG. 12 so that a desired center frequency change amount can be obtained with a small amount of rotation.

  14 and 15 are a perspective view and a cross-sectional view schematically showing another example of the tunable filter device according to the third embodiment. In FIG. 14, the metal package 106 is partially omitted as in FIG.

  In the tunable filter device 1400 shown in FIG. 14, a plurality of resonator patterns 102 are provided on the surface of the dielectric substrate 101. A plurality of characteristic adjusting members 105 are arranged facing the surface of the dielectric substrate 101 with a gap therebetween. One characteristic adjusting member 105 is provided for each resonator pattern 102, and faces the corresponding resonator pattern 102 with a certain distance in the thickness direction of the dielectric substrate 101. The width of the characteristic adjusting member 105 may be matched to the width of the resonator pattern 102. In the tunable filter device 1400, the first region 201 and the second region 202 can be set on the surface of the dielectric substrate 101 in the same manner as in the example shown in FIG.

  As shown in FIG. 15, a through hole is provided in the upper part (specifically, the lid 502) of the metal package 106. The characteristic adjustment member 105 extends to the outside of the metal package 106 through the through hole, and is supported by a rotation unit 1510 as a drive mechanism. The rotation unit 1510 is provided for each characteristic adjustment member 105. The rotation unit 1510 drives the characteristic adjustment member 105 so that the spatial volume ratio between the spatial volume of the first region 201 and the spatial volume of the second region 202 changes. Specifically, the rotation unit 1510 rotates the characteristic adjustment member 105 with an axis passing through the characteristic adjustment member 105 and parallel to the thickness direction of the dielectric substrate 101 as a rotation axis 1511.

  The rotation unit 1510 can have the same structure as the rotation unit 1002 described with reference to FIG. For this reason, the specific description about the rotation unit 1510 is omitted. The rotation unit 1510 may be an actuator that can directly generate a rotational driving force such as an ultrasonic motor. By adjusting the rotation amount of each of the characteristic adjustment members 105, the resonance frequency of the resonator pattern 102 can be changed uniformly. As a result, the center frequency of the pass band can be adjusted without disturbing the waveform of the filter characteristics.

  As described above, in the tunable filter device according to this embodiment, the resonance frequency of the resonator pattern is obtained by rotating the characteristic adjusting member around the axis perpendicular to the thickness direction of the dielectric substrate with respect to each resonator pattern. Can be adjusted accurately and easily. As a result, it is possible to adjust the center frequency of the pass band while preventing disturbance of the filter characteristic waveform.

  It should be noted that two or more of the driving methods for the characteristic adjusting member according to the first to third embodiments described above may be combined. FIG. 16 schematically shows an example of a combination of the first to third embodiments. In the tunable filter device 1600 shown in FIG. 16, the characteristic adjusting member 105 is movable in the longitudinal direction of the resonator pattern 102, is rotatable around an axis parallel to the short direction of the resonator pattern 102, and is a dielectric. It can rotate around an axis parallel to the thickness direction of the substrate 101. As described above, by combining the driving methods of the characteristic adjusting members according to the first to third embodiments, the degree of freedom in adjusting the center frequency of the pass band is increased.

  FIG. 17 shows another example of region division when one resonator pattern is provided on a dielectric substrate. As shown in FIG. 17, the surface of the dielectric substrate 101 can be virtually divided into a first region 1701 that includes the resonator pattern 102 and a second region 1702 that does not include the resonator pattern 102.

(Fourth embodiment)
When the conductor part (resonator pattern or the like) of the filter device is formed of an existing superconducting material, the conductor part is maintained in a superconducting state by cooling the entire filter device. In the fourth embodiment, a cooling system for cooling the filter device will be described.

  FIG. 18 schematically shows a cooling system according to the fourth embodiment. In the cooling system shown in FIG. 18, a filter device 1806 is enclosed in an adiabatic vacuum vessel 1801. The filter device 1806 may be any of the filter devices according to the above-described embodiments. The vacuum pump 1802 evacuates the inside of the heat insulating vacuum vessel 1801.

  The heat insulating vacuum container 1801 includes a lower container having an opening above and an upper container having an opening below. The sealed space is defined by joining the lower container and the upper container with the openings facing each other. By interposing an O-ring between the lower container and the upper container, the degree of vacuum inside the heat insulating vacuum container 1801 is maintained.

  The filter device 1806 is held on the cold plate 1805 in the heat insulating vacuum vessel 1801. The cold plate 1805 is thermally coupled to the refrigerator cold head 1804 of the refrigerator 1803. The filter device 1806 is cooled by the refrigerator 1803 under vacuum to a temperature at which the conductor portion of the filter device 1806 becomes superconductive. Since the superconducting properties can be improved as the temperature is lowered, it is desirable to set the temperature to a lower temperature. The refrigerator 1803 only needs to be cooled, and any type of refrigerator 1803 may be used. For example, the refrigerator 1803 may be a pulse tube refrigerator, a Stirling refrigerator, or a GM (Gifford-McMahon) refrigerator.

  Connectors 1807, 1808, and 1809 are attached to the side wall of the heat insulating vacuum container 1801. The input connector 1810 of the filter device 1806 is connected to the frequency signal detection device 1818 via a coaxial cable 1811 in the heat insulation vacuum vessel 1801, a connector 1807, and a coaxial cable 1812 outside the heat insulation vacuum vessel 1801. The frequency signal detection device 1818 may be a network analyzer, for example. The output connector 1813 of the filter device 1806 is connected to the frequency signal detection device 1818 via a coaxial cable 1814 in the heat insulating vacuum vessel 1801, a connector 1808, and a coaxial cable 1815 outside the heat insulating vacuum vessel 1801. An actuator (not shown) of the drive mechanism is connected to a driver 1819 via a wiring cable 1816 in the heat insulating vacuum vessel 1801, a connector 1809, and a wiring cable 1817 outside the heat insulating vacuum vessel 1801. The driver 1819 generates a drive signal (voltage signal) for driving the actuator.

  In the cooling system shown in FIG. 18, the vibration of the refrigerator 1803 mainly acts on the filter device 1806 in the vertical direction. Typically, the filter device 1806 is placed on the cold plate 1805 so that the thickness direction of the dielectric substrate coincides with the vertical direction. In this case, in the conventional method of moving the characteristic adjusting member in the thickness direction of the dielectric substrate, the driving direction of the characteristic adjusting member and the vibration direction 1820 of the refrigerator 1803 are the same direction, and the positioning accuracy of the characteristic adjusting member is reduced. There is. On the other hand, when the filter device 1806 is the filter device according to the first embodiment, the driving direction of the characteristic adjusting member is the horizontal direction. Since the driving direction of the characteristic adjusting member and the vibration direction 1820 of the refrigerator 1803 are different, it is possible to prevent the positioning accuracy of the characteristic adjusting member from being lowered. Similarly, when the filter device 1806 is a filter device according to the third embodiment, since the driving direction of the characteristic adjusting member and the vibration direction 1820 are different, a decrease in positioning accuracy of the characteristic adjusting member can be prevented.

(Fifth embodiment)
In the fifth embodiment, a control system for a tunable filter device will be described.
FIG. 19 schematically shows an example of a tunable filter device according to the fifth embodiment. In the tunable filter apparatus 1900 shown in FIG. 19, the input signal (Sig. 1) is given to the filter device 1913 via the input connector 1914. The input signal is also provided to the frequency signal detector 1916. The filter device 1913 may be any of the filter devices according to the above-described embodiments.

  The filter device 1913 filters the input signal to generate an output signal (Sig. 2). An output signal from the filter device 1913 is sent to the frequency signal detection device 1916 through the output connector 1915. The frequency signal detection device 1916 obtains a spectrum waveform (for example, a center frequency, a pass characteristic, and a reflection characteristic) of the output signal. This spectrum waveform is sent to the control device 1910 as a sensor signal.

  The actuator movement amount detection sensor 1917 detects the movement amount of an actuator (for example, a piezoelectric element) 1912 included in the drive mechanism and generates a sensor signal. The sensor signal is sent to the control device 1910.

  The control device 1910 compares the spectrum waveform with the target reference spectrum waveform and compares the sensor signal from the actuator movement amount detection sensor 1917 with the target actuator movement amount so that the spectrum waveform approaches the reference spectrum waveform. Then, a control signal is transmitted to the driver 1911. The driver 1911 drives the actuator 1912 based on a control signal from the control device 1910. By repeating this feedback control, a desired stable filter characteristic can be obtained. As the actuator 1912, for example, a piezoelectric element, a magnetostrictive element, or the like can be used.

Next, a series of operations in which the control device 1910 controls the filter characteristics of the filter device 1913 according to the work command 1901 will be described.
First, a work command 1901 related to a series of operations of the actuator 1912 is input to the operation command generation unit 1902. The work instruction 1901 may be in the form of a program. Further, the operator may input a work command 1901 displayed on the panel to the control device 1910. The input device for inputting the work command 1901 may be integrated with the actuator 1912 or the control device 1910, or may be capable of communicating with the actuator 1912 or the control device 1910 by wire or wireless.

  The operation command generation unit 1902 decomposes the input work command 1901 into operation procedures necessary for each work process, and expands the operation procedure into an operation command level instruction sequence for the actuator 1912. The target command value generation unit 1903 calculates each target trajectory and target value for the actuator 1912 according to each generated operation command, and outputs a target command value related to driving of the actuator 1912. The actuator drive control unit 1904 controls the driver 1911 so that the actuator 1912 performs an operation according to work according to the target command value from the target command value generation unit 1903.

  In the control device 1910, sensor signals from the frequency signal detection device 1916 and the actuator movement amount detection sensor 1917 are given to the signal processing circuit unit 1905. The signal processing circuit unit 1905 includes an analog-digital converter and the like, and performs various signal processes on the sensor signal. The determination unit 1906 receives the sensor signal after the signal processing from the signal processing circuit unit 1905. The determination unit 1906 performs various determination processes according to the amount of deviation of the spectrum waveform from the reference spectrum waveform. The determination unit 1906 performs arithmetic processing so that desired filter characteristics can be obtained by observing the spectrum waveform by the frequency signal detection device 1916 and adjusting the spatial volume ratio by the actuator 1912. A portion including the signal processing circuit unit 1905 and the determination unit 1906 is referred to as a spatial volume control unit 1909.

  The operation command generation unit 1902 sends operation mode information corresponding to operation commands that are sequentially output and executed to the operation mode information unit 1907 together with information on execution work. The operation mode information unit 1907 stores a spectrum waveform correction command of the filter device 1913 defined for each operation mode included in various work commands. In addition, in the determination unit 1906, for each command information 1908 in each operation mode, the content of the determination unit output such as a drive stop for the actuator drive control unit 1904 or a return value command for the operation command generation unit 1902 is set. Depending on the operation mode, different processing is defined according to each operation mode, such as driving stop of the actuator 1912 or return value command generation.

  Therefore, when spectral waveform correction is performed by the determination unit 1906, a command for stopping actuator driving is sent from the determination unit 1906 to the actuator drive control unit 1904 in accordance with a countermeasure control method for the actuator 1912 corresponding to the defined operation mode. In some cases, a return value command for correcting the target value is sent to the operation command generator 1902. Thus, an actuator 1912 that performs a corresponding processing operation suitable for the current operation for spectrum waveform correction and ensures the reliability and certainty of the spectrum waveform variable function (center frequency variable function while maintaining the bandwidth). Can be controlled.

  FIG. 20 schematically shows another example of the tunable filter device according to the fifth embodiment. The tunable filter device shown in FIG. 20 drives and controls the actuator 1312 by feedforward control based on the table data 2001. The table data 2001 stores actuator drive information acquired in advance in comparison with the resonance frequency change. The target command value generation unit 1903 of the control device 2010 calculates each target trajectory and target value for the actuator 1912 with reference to the table data 2001, and outputs a target command value related to driving of the actuator 1912. The actuator drive control unit 1904 controls the driver 1911 so that the actuator 1912 performs an operation according to work according to the target command value from the target command value generation unit 1903.

  In addition, although the example which uses a piezoelectric element as a drive source which drives a characteristic adjustment member was demonstrated, the drive method of a characteristic adjustment member is not limited to the demonstrated example. You may employ | adopt the system which adjusts advancing / retreating amount by a manual drive by using a characteristic adjustment member as a screw-type rod member, or the system using an electric motor, an air cylinder, a hydraulic cylinder, etc. However, when it is desired to arbitrarily change the stop position, it is necessary to provide an actuator that can adjust the advance / retreat amount.

  Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

  DESCRIPTION OF SYMBOLS 100 ... Tunable filter apparatus, 101 ... Dielectric substrate, 102 ... Resonator pattern, 103 ... Signal input line, 104 ... Signal output line, 105 ... Characteristic adjustment member, 106 ... Metal package, 107 ... Connection electrode, 108 ... Coaxial Connector: 110 ... Projection plane, 201 ... First area, 202 ... Second area, 400 ... Tunable filter device, 501 ... Package body, 502 ... Cover, 503 ... Ground film, 504 ... Internal space, 510 ... Drive Mechanism, 511 ... Spring member, 512 ... Pressing plate member, 513 ... Piezoelectric element, 700 ... Tunable filter device, 800 ... Tunable filter device, 901 ... Projection, 902 ... Projection, 910 ... Drive mechanism, 911 ... Spring 912 ... piezoelectric element, 913 ... support shaft, 1001 ... rotation shaft, 1002 ... rotation unit, 1101 Piezoelectric element, 1102 ... Spring member, 1103 ... Rotating member, 1200 ... Tunable filter device, 1210 ... Projection surface, 1312 ... Actuator, 1400 ... Tunable filter device, 1510 ... Rotating unit, 1511 ... Rotating shaft, 1600 ... Tunable Filter device, 1701 ... 1st area | region, 1702 ... 2nd area | region, 1801 ... Heat insulation vacuum container, 1802 ... Vacuum pump, 1803 ... Refrigerator, 1804 ... Refrigerator cold head, 1805 ... Cold plate, 1806 ... Filter device, 1807 ... Connector, 1808 ... Connector, 1809 ... Connector, 1810 ... Input connector, 1811 ... Coaxial cable, 1812 ... Coaxial cable, 1813 ... Output connector, 1814 ... Coaxial cable, 1815 ... Coaxial cable, 1816 ... Wiring cable , 1817 ... wiring cable, 1818 ... frequency signal detection device, 1819 ... driver, 1820 ... vibration direction, 1900 ... tunable filter device, 1901 ... work command, 1902 ... operation command generation unit, 1903 ... target command value generation unit, 1904 ... actuator drive control unit, 1905 ... signal processing circuit unit, 1906 ... determination unit, 1907 ... operation mode information unit, 1908 ... command information, 1909 ... space volume control unit, 1910 ... control device, 1911 ... driver, 1912 ... actuator, 1913 ... Filter device, 1914 ... Filter device, 1914 ... Input connector, 1915 ... Output connector, 1916 ... Frequency signal detection device, 1917 ... Actuator movement amount detection sensor, 2001 ... Table data, 2010 ... Control device.

Claims (9)

A dielectric substrate having a surface virtually divided into a first region and a second region;
A resonator pattern formed of a conductive material in the first region of the surface;
A characteristic adjusting member having a facing surface facing the surface and formed of a dielectric, magnetic material or conductive material;
A volume of a space sandwiched between the projection surface obtained by projecting the characteristic adjusting member on the surface and the facing surface is defined as a space volume, and a space volume of the first region and a space volume of the second region A drive mechanism for driving the characteristic adjusting member so as to adjust the space volume ratio between
A tunable filter device comprising:   The tunable filter device according to claim 1, wherein the conductive material is a superconductive material.   The tunable filter device according to claim 1, wherein the drive mechanism includes a voltage element or a magnetostrictive element as a drive source.   The tunable filter device according to claim 1, wherein the drive mechanism moves the characteristic adjusting member in a direction parallel to the surface.   The tunable filter device according to claim 1, wherein the drive mechanism rotates the characteristic adjusting member around an axis parallel to the surface.   The tunable filter device according to claim 1, wherein the drive mechanism rotates the characteristic adjusting member around an axis perpendicular to the surface.   The tunable filter device according to claim 1, wherein a plurality of the resonator patterns are provided, and one characteristic adjusting member is provided for each of the plurality of resonator patterns.   The tunable filter device according to claim 1, wherein the facing surface has a surface inclined with respect to the surface.   The tunable filter device according to claim 1, further comprising a control unit that controls the drive mechanism so that a spectrum waveform of a signal output from the resonator pattern approaches a target reference spectrum waveform.

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