JP2009005333A - Dual mode filter and tuning method - Google Patents

Abstract

A dual mode filter having high design freedom and / or high tunability is provided.
A dual mode filter includes a ring resonator (12) and an input feeder (13a) disposed orthogonal to the ring resonator so as to be electromagnetically coupled to the ring resonator. ) And an output feeder (13b), and a dual-mode generation line (15) that is positioned inside the ring resonator and is arranged so as not to overlap the extension lines of the input feeder and the output feeder.
[Selection] Figure 1

Description

  The present invention relates to a high-frequency filter used in the field of wireless communication and the like, and in particular, by using a ring-type resonator and generating an electromagnetic discontinuity in the ring-type resonator, two different resonance modes are provided. The present invention relates to a dual mode filter to be generated and a tuning method thereof.

  In recent years, with the spread and development of mobile phones, high-speed and large-capacity transmission technology has become indispensable. In order to realize high-speed and large-capacity communication, it is necessary to secure a wide frequency band, and the frequency band used for wireless communication is shifted in the direction of high frequency. For this reason, a filter for wireless communication is required to have a filter characteristic that selectively allows only a desired communication frequency to pass through in a high-frequency region and sharply blocks other frequency components. Further, miniaturization and weight reduction are strongly demanded for wireless communication devices using high-frequency circuit elements.

  A ring type resonator is known as a resonator filter including a ring whose circumference is an electric path length of one wavelength or an integral multiple of the wavelength. In order to increase the space efficiency of the ring resonator, a method has been proposed in which two resonance modes (dual mode) are generated by one resonator to obtain a steeper filter characteristic (for example, Patent Documents 1 and 2). reference).

  In the configuration of Patent Document 1, an input line and an output line that are electromagnetically coupled to a ring resonator are arranged so as to be orthogonal to each other, and coupling between two coupling points on the ring resonator, that is, coupling with an input line. A dual mode is generated by providing a stub between the connection point of the point and the output line and using this as an electromagnetic discontinuity. In this method, current concentration occurs in the vicinity of the discontinuous point of the resonator ring, and there is a concern that the power durability deteriorates.

In Patent Document 2, an input line and an output line that are electromagnetically coupled to a ring resonator are arranged so as to be orthogonal to each other, and are positioned symmetrically with respect to a coupling point between the input / output line and the ring resonator. A distributed coupled line is arranged along the outer periphery of the resonator ring. As a result, a dual mode is generated in the ring resonator. According to Patent Document 2, the arrangement position of the distributed coupling line is limited to a symmetrical position viewed from the coupling point, and the degree of freedom of arrangement is low.
Japanese Patent No. 3304724 JP 2000-209002 A

  It is an object of the present invention to provide a dual mode filter that can contribute to downsizing and has improved design freedom and tunability.

In a preferred embodiment, the dual mode filter is
A ring resonator;
An input feeder and an output feeder disposed orthogonal to each other with respect to the ring resonator so as to be electromagnetically coupled to the ring resonator;
A dual-mode generation line located inside the ring resonator and arranged not to overlap with an extension of the input feeder and the output feeder;
Have

  For example, the dual mode generation line includes a first port and a second port that are electromagnetically coupled to the ring resonator, and an arcuate waveguide that connects these ports.

  In a preferred embodiment, the dielectric member is movable in a direction perpendicular to the dual mode generation line and the ring resonator above at least one of the electromagnetic coupling points of the dual mode generation line to the ring resonator. Place. By adjusting the vertical position of the dielectric member, the capacitance between the ring resonator and the dual mode generation line can be changed, and the filter characteristics can be adjusted by changing the dual mode coupling coefficient.

  In a second aspect of the present invention, a multistage filter in which dual mode filters are connected in multiple stages is provided. Each of the multistage filters includes a ring resonator, an input feeder and an output feeder that are arranged orthogonal to the ring resonator so as to be electromagnetically coupled to the ring resonator, Two or more resonators composed of dual-mode generation lines arranged inside the ring resonator so as not to overlap the extension lines of the input feeder and the output feeder are connected in multiple stages, In two or more resonators, two adjacent resonators are arranged to be point-symmetric with each other. A steep frequency cutoff characteristic can be obtained by arranging adjacent dual mode resonators symmetrically.

In a third aspect, a method for tuning a resonator filter is provided. In this tuning method,
A dual including a first and a second port electromagnetically coupled to the ring resonator and an arcuate waveguide connecting the ports inside a ring resonator formed on a dielectric substrate. A mode generation line is arranged to form a resonator filter,
The characteristic of the resonator filter is adjusted by changing at least one of the electrical length of the dual mode generation line, the line width, and the coupling amount between the dual mode generation line and the ring resonator.

In a preferred embodiment, a dielectric block is disposed above the coupling portion between at least one of the first and second ports and the ring resonator,
The method further includes adjusting the characteristics of the resonator filter by moving the dielectric block in a direction perpendicular to the port and the ring resonator.

  A dual mode filter having a high degree of design freedom and a steep filter characteristic is realized. In addition, the filter characteristics can be adjusted with a simple configuration.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described with reference to the accompanying drawings. FIG. 1 is a schematic configuration diagram of a ring resonator constituting a dual mode resonator filter according to an embodiment of the present invention. As shown in FIG. 1 (a), the resonator filter is arranged so as to be orthogonal to the ring resonator 12 and the ring resonator, and each input is electromagnetically coupled to the ring resonator. It has a feeder 13a and an output feeder 13b, and a dual mode generation line 15 disposed inside the ring resonator 12. The dual mode generation line 15 is arranged so as not to overlap the extension lines X and Y of the input / output feeders 13a and 13b.

  As shown in FIG. 1B, the dual mode generation line 15 has a first port 15a and a second port 15b that are electromagnetically coupled to the ring resonator 12, and an arc shape that connects the two ports. Waveguide 15c. The electrical length Leq of the dual mode generation line 15 can be changed by changing the opening angle of the first port 15a and the second port 15b within a range of less than 90 °. Alternatively, it can be changed by fixing the opening angle of the first port 15a and the second port 15b and changing the curvature of the waveguide 15c. Here, the electrical length Leq is defined as an electromagnetic coupling point C1 between the first port 15a and the ring resonator 12, and an electromagnetic coupling point C2 between the second port 15b and the ring resonator 12. It is the track length between.

  More specifically, the electrical length Leq of the dual mode generation line 15 is set in a range smaller than ¼ of the circumference of the ring resonator 12. For example, it is set to be equal to or longer than the arc length of the ring resonator 12 corresponding to the opening angle between the first port 15 a and the second port 15 b and less than ¼ of the circumference of the ring resonator 12. The opening angle is preferably 36 ° or more and less than 90 °. This is because if the opening angle is smaller than 36 °, it is difficult to obtain electrical coupling between the dual mode generation line and the ring resonator.

  When the coupling position of the first port 15a and the second port 15b is fixed, for example, even when the opening angle is fixed at 45 °, the link resonator 12 uses one wavelength of a signal having a desired frequency as a circumference. When designed, at least one of the electrical length Leq of the dual mode generation line 15 and the width of the dual mode generation line 15 (that is, the width of the waveguide 15c) W1 is changed, thereby resonating with the dual mode generation line 15 and link resonance. Coupling (coupling) with the vessel 12 can be adjusted. By increasing the length of the dual mode generation line 15, the pass frequency bandwidth of the bandpass filter can be increased. The bandwidth can also be changed by narrowing the width W1 of the dual mode generation line 15 (waveguide 15c). Further, as will be described later, adjustment is also possible by changing the coupling capacitance between the dual mode generation line 15 and the link resonator 12.

  The dual mode generating line 15 can be arranged at any position as long as it does not overlap with the extension lines X and Y of the input / output feeders 13a and 13b, but the extension line X of the input feeder 13a is set to 0 °. In this case, it is desirable that the center position be 45 ° ± nπ / 2. Therefore, as shown in FIGS. 2 (a), 2 (b), and 2 (c), 135 ° (45 ° + π / 2), 225 ° (45 ° ± π), and 315 ° (45 ° + 3π). / 2 or 45 ° -π / 2). However, the center line of the dual-mode generation line 15 may be arranged so as to be out of 45 ° ± nπ / 2 because it does not have to overlap the extension lines X and Y of the input / output feeders 13a and 13b.

  As an example of the arrangement of the dual mode generation line, the center of the dual mode generation line is positioned at a position of 45 ° ± nπ / 2 (n is a natural number) when the extension line of the input feeder is 0 °. However, as long as it does not overlap with the extension lines of the input / output feeders orthogonal to each other, the center may be shifted from the 45 ° position.

  Returning to FIG. 1, in FIG. 1A, the signal (carrier wave) propagated through the input feeder 13 a is electromagnetically coupled to the ring resonator 12, and is clockwise along the ring resonator 12. Propagates counterclockwise evenly. The electric field strength of the carrier wave is greatest at the coupling portion between the input feeder 13a and the ring resonator 12. Considering the clockwise direction, for example, in the output feeder 13b arranged at a position shifted by 3π / 2 phase with respect to the input feeder, the electric field of the electromagnetic wave propagating only through the ring resonator 12 is the smallest and coupled. Pass without. However, since the first port 15a of the dual mode generation line 15 is electromagnetically coupled to the ring resonator 12, a part of the electromagnetic wave propagating through the ring resonator is transferred from the first port to the waveguide 15c. Propagate. This electromagnetic wave is further coupled to the ring resonator 12 at the second port 15b and propagates toward the output feeder 13b. In this sense, the dual mode generation line 15 functions as a feedback path.

  Now, assuming that the electrical length of the dual mode generation line 15 is λ / 8 and the electrical length of the arc portion of the ring resonator 12 facing this is also λ / 8, the phase of the reflected wave appearing at the output feeder 13b is the input feeder. The electric field intensity is the strongest because it is deviated by 2π from the coupling portion with 13a. Therefore, the component reflected by the dual mode generation line 15 is combined with the output feeder 13b and output from the resonator.

  The same thing occurs for the electromagnetic wave propagated counterclockwise, and the component reflected by the dual mode generation line 15 is output to the output feeder 13b. This means that two orthogonal resonance modes occur in the ring resonator 12. The magnitude of the coupling between the two resonance modes is adjusted by at least one of the electrical length Leq of the dual mode generation line 15, the line width W 1, and the coupling capacitance between the dual mode generation line 15 and the ring resonator 12, as will be described later. The

  Since the dual mode generation line 15 is disposed inside the ring resonator 12, it is space efficient and advantageous for downsizing. In addition, since both the ring resonator 12 and the dual mode generation line 15 are formed in an arc, even if some current density is concentrated along the edge, the concentration of such current density is evenly distributed throughout. Thus, local current density concentration can be avoided. Therefore, the power durability is improved.

  FIG. 3 is a schematic diagram showing a dual mode filter packaged as the high frequency filter device 10. As shown in the sectional view of FIG. 3A and the plan view of FIG. 3B, the ring resonator 12, the input / output feeders 13a and 13b, and the dual mode generation line 15 are identical on the dielectric substrate 11. It is formed on a plane. A ground film 14 is formed on the entire back surface of the dielectric substrate 11 and has a so-called microstrip structure. Note that even if a so-called triplate structure in which the input / output feeders 13a and 13b, the ring resonator 12 and the dual mode generation line 15 are sandwiched between upper and lower ground films is adopted, the essence of the invention is not affected. Can be adopted.

The high-frequency filter device 10 is used as, for example, a bandpass filter of 5 GHz band, and the electrical length of the ring resonator 12 is configured to match a desired carrier wavelength in this band. The ring resonator 12 is made of a good conductor or a superconductive material. Superconductive materials are advantageous in that a low-loss, high-Q resonator can be expected because the surface resistance is very small even in a high-frequency region. In that case, as superconducting materials, YBCO (Y-Ba-Cu-O), RBCO (R-Ba-Cu-O; Nd, Gd, Sm, Ho is used instead of Y as R element), BSCCO (Bi-Sr-Ca-Cu -O), PBSCCO (Pb-Bi-Sr-Ca-Cu-O), CBCCO (Cu-Ba p -Ca q -Cu r -O x, 1.5 <p <2.5,2.5 <q <3.5, 3.5 <r <4.5) or the like can be used. The input / output feeders 13a and 13b and the dual mode generation line 15 can also be formed of the same superconducting material as the ring resonator 12 and in the same process.

  As a specific manufacturing example, a YBCO superconducting thin film having a thickness of 100 nm is formed by PLD on both surfaces of a 0.5 mm thick MgO dielectric substrate 11 on which a (100) crystal plane appears, and one surface is a grant surface. 14, the ring resonator 12, the input / output feeders 13a and 13b, and the dual mode generation line 15 are formed on the other surface by photolithography and wet etching.

  The dielectric substrate 11 on which such a resonator pattern is formed is accommodated in the package body 30a and sealed by the upper lid 30b. The package 30 is, for example, a gold-plated copper shield case. The ground surface 14 on the back surface of the dielectric substrate 11 is in contact with the bottom surface of the package body 30a. The input / output feeders 13a and 13b are connected to the input / output connectors 35a and 35b of the package main body 30a through, for example, gold (Au) wire bonding via connection electrodes (not shown). Coaxial cables (not shown) extend from the input / output connectors 35a and 35b. When the ring resonator 12 or the like is formed of a superconductive material, the high frequency filter is held in the vacuum cooling chamber together with the package 30.

  FIG. 4A is a graph showing changes in filter characteristics when the waveguide length of the dual mode generation line 15 is changed in the ring resonator 12 having the configuration shown in FIG. 1, and FIG. 4B is surrounded by a circle in FIG. 4A. It is an enlarged graph of the part A.

  The positions of the first port 15a and the second port 15b of the dual mode generation line 15 are fixed at an opening angle of 45 ° as shown in FIG. 1A, and rotated by 45 ° from the extension line X of the input feeder 13a. The center of the dual-mode generation line 15 is arranged at the position, and the length of the waveguide 15c is 2.61 mm (0.115λ), 3.47 mm (0.153λ), 4.11 mm (0.182λ). ) And changed the simulation. These waveguide lengths are both in the vicinity of λ / 8 and in a range smaller than λ / 4. The radius of the ring resonator 12 formed of YBCO is set to 3.5 mm and the line width is set to 0.5 mm. From FIG. 4A, it can be seen that a steep frequency cut-off characteristic can be obtained by generating the dual mode and the attenuation pole at any length.

  Further, as can be seen from the enlarged graph of FIG. 4B, it can be seen that the center frequency and the bandwidth can be adjusted by adjusting the length of the waveguide 15c. More specifically, in the dual mode, the peak position on the high frequency f2 side does not change, but the peak position on the low frequency f1 side shifts to the lower frequency side.

  FIG. 5 shows filter characteristics when the opening angle of the first port and the second port of the dual mode generation line 15 is set to 90 °, that is, the electrical length Leq is set to λ / 4 as a comparative example. Unlike the characteristics of FIGS. 4A and 4B, it can be seen that no attenuation pole is seen and unnecessary resonance appears on the high frequency side. Therefore, in order to effectively pass only a desired frequency, it is desirable to set the electrical length of the dual mode generation line 15 in a range smaller than λ / 4. However, if Leq is too small, the ring resonator 12 and the dual mode generation line 15 are too close to each other, and parasitic capacitance is generated and may resonate with each other. Therefore, λ / 10 or more and less than λ / 4. Is desirable.

FIG. 6 is a graph showing changes in the coupling coefficient k when the waveguide length is changed. When two different resonance frequencies at the time of dual mode generation are f1 and f2 (f1 <f2), the inter-resonance coupling coefficient k is
k = (f2 ² −f1 ² ) / (f2 ² + f1 ² )
It is represented by

  As the length of the waveguide 15c is increased, the coupling coefficient k increases, that is, the coupling between the two orthogonal modes increases, the interval between the resonance modes increases, and the passband increases (low frequency side). Shifts to a lower frequency). Therefore, a desired filter characteristic can be achieved by controlling the electrical length of the dual mode generation line 15 by design.

  FIG. 7 is a graph showing changes in filter characteristics depending on the position of the dual mode generation line 15 inside the ring resonator 12. 4A and 4B, the simulation was performed by changing the center position of the dual mode generation line 15 to 45 °, 135 °, 225 °, and 315 ° under the same conditions as in the simulation. A curve a indicated by a solid line is a filter characteristic arranged at a position of 45 °, a curve c indicated by a dashed line is a filter characteristic arranged at a position of 225 ° (45 ° + π), and a curve b of a dotted line is 135 ° or 315 The filter characteristics are arranged at the position of °. In either case, the input / output feeders 13a and 13b are arranged so as not to overlap the extension lines X and Y.

  As can be seen from the graph of FIG. 7, the degree of freedom of the arrangement position of the dual mode generation line 15 is extremely high. However, when strict conditions are required for removing unnecessary frequencies in the vicinity of the desired frequency, it is desirable to arrange them at 45 ° or 225 ° positions, that is, 45 ° ± nπ (n is a natural number).

  FIG. 8 is a diagram showing changes in filter characteristics when the line width W1 of the dual mode generation line 15 is changed. In FIG. 8A, the length of the dual mode generation line 15 arranged inside the ring resonator 12 is set to 6.00 mm, and the width W1 is 0.25 mm, 0.50 mm, 0.75 mm, When it is increased to 1.00 mm, the transmission characteristics change in the direction of increasing the bandwidth as shown in FIG.

  FIG. 9 is a diagram illustrating a change in filter characteristics when the coupling amount between the dual mode generation line 15 and the ring resonator 12 is changed by changing the coupling width W2 of the dual mode generation line 15. In FIG. 9A, the coupling width W 2 is the width of the coupling portion where the port 15 a (or the port 15 b) faces the ring resonator 12. The line length at this time is 6.00 mm, and the gap between the port 15 and the ring resonator 12 is 75 μm. When the coupling width W2 is changed to 1.0 mm, 1.5 mm, and 2.0 mm, the change in characteristics on the high frequency side is slight, but the characteristic on the low frequency side shifts to the lower side. The width becomes wider.

  In this way, by changing at least one of the electrical length Leq of the dual mode generation line 15, the line width W 1, and the coupling amount (for example, the coupling width W 2) between the dual mode generation line 15 and the ring resonator 12. The filter characteristic can be set to a desired value at the design stage.

  FIG. 10 shows a configuration example of a multistage filter when the resonator of FIG. 1 is multistaged. In this example, two ring resonators 12A and 12B are used, and these resonators are electromagnetically coupled via a coupling line 13c. When the ring resonator 2A, the dual mode generation line 15A, and the input feeder 13a are the first resonator, the ring resonator 2B, the dual mode generation line 15B, the output feeder 13b, and the second resonator, the first resonator The resonator and the second resonator are arranged point-symmetrically with respect to the center of the coupled line 13c.

  The coupling line 13c is an output feeder when viewed from the ring type resonator 12A, and the coupling line 13c is an input feeder when viewed from the ring type resonator 12B. Therefore, the basic configuration is the same as that of FIG. As a result, space efficiency is improved. In addition, by arranging the first resonator and the second resonator symmetrically, a very steep attenuation pole can be obtained on both sides of the pass band, and a filter having excellent frequency cutoff characteristics is realized. . Similarly, when a multistage filter having three or more stages is used, a steep filter characteristic having a dual mode can be realized by connecting two adjacent resonators so as to be point-symmetric with each other. Since the dual mode generation line 15 is formed inside each ring resonator 12, space efficiency is improved as the number of stages increases, which is advantageous for downsizing.

  FIG. 11 is a schematic diagram of a dual mode filter constituting the high frequency filter device of the second embodiment of the present invention. In the embodiment described above, the filter characteristics are adjusted at the design stage by changing at least one of the waveguide length, the line width W1, and the coupling amount (coupling width W2) of the dual mode generation line 15. However, even if the dual-mode generation line 15 is designed in accordance with a desired signal wavelength (frequency), when actually manufactured as a product, due to patterning accuracy errors and variations in the substrate thickness of the dielectric substrate 11. There may be variations between products. In such a case, fine adjustment is required for each product in order to align characteristics between products after patterning.

  Therefore, in the second embodiment, a dielectric block is disposed above at least one of the electromagnetic coupling points C1 and C2 (see FIG. 1B) to the ring resonator 12 of the dual mode generation line 15. The filter characteristics after patterning can be finely adjusted by holding the dual mode generation line 15 and the ring resonator 12 so as to be vertically movable.

  In the example of FIG. 11, between the first port 15a of the dual mode generation line 15 and the ring resonator 12, and between the second port 15b and the ring resonator 12, the dielectric portion blocks are respectively located above these patterns. 51a and 51b are arranged. In this example, a rectangular parallelepiped block is used as the dielectric block 51, but any shape can be used as long as it can cover the coupling portion between the port and the ring resonator 12 such as a cylindrical block or an elliptical cylindrical block. Can be used. As a material of the dielectric block 51, MgO, SrTiO3, TiO2, Al2O3, or the like is used.

  As in the first embodiment, the dual mode generation line 15 and the ring resonator 12 are formed by forming an epitaxial YBCO film on both surfaces of the dielectric substrate 11 by sputtering or PLD, and photolithography and wet etching only on one surface. It is formed by patterning. Here, as an example of manufacturing a 5 GHz band filter, a resonator having a ring radius of 3.5 mm and a line width of 0.5 mm is formed on a MgO substrate 11 having a thickness of 0.5 mm.

  FIG. 12A is a B-B ′ cross-sectional view of FIG. 11. The dielectric block 51 is held so as to be movable in the vertical direction with respect to the dual mode generation line 15 and the ring resonator 12 formed on the dielectric substrate 11. The capacitance between the port 15 a (or 15 b) and the ring resonator 12 is changed by changing the height position of the dielectric block 51 at the joint between the dual mode generation line 15 and the ring resonator 12. Thus, only the coupling coefficient can be changed.

  As shown in FIG. 12B, the height position of the dielectric block 51 can be adjusted by, for example, a screw trimmer 55 attached to the upper lid 60b of the package 60. In this case, the dielectric block 51 is held in the package 60 by the support rod 53 connected to the trimmer 55. The rest of the package configuration is the same as that of the first embodiment except that a trimmer 55 as a driving means for the dielectric block 51 is provided on the upper lid 60a of the package 60. The driving means for adjusting the height position of the dielectric block 51 is not limited to the screw type trimmer 55, and an actuator may be used.

  FIG. 13 is a diagram showing filter characteristics when the dielectric block 51 is arranged. As shown in FIG. 13A, a cylindrical MgO having a diameter of 0.5 mm and a height of 1 mm is formed on the gap between the ports 15a and 15b of the dual mode generation line 15 having the configuration shown in FIG. The single crystal dielectric blocks 51a and 51b are arranged, and the filter positions are simulated by changing their height positions. As a comparative example, the filter characteristics when the dielectric blocks 51a and 51b are not arranged are also simulated.

  As shown in FIG. 13B, the filter characteristics are changed by changing the height position of the dielectric block 51 with respect to the resonator 12 and the dual mode generation line 15 within a range of 0.1 to 0.5 mm. Can do. Compared with the case where the dielectric block 51 is not disposed (solid line in the graph), the dielectric block 51 is moved from the position of 0.5 mm in height to the position of 0.1 mm with respect to the resonator 12 and the dual mode generation line 15. As the distance approaches, the coupling coefficient changes, and the characteristics on the low frequency side shift to the lower side.

  The configuration in which the dielectric block 51 is disposed above the electromagnetic coupling point between the dual mode generation line 15 and the ring resonator 12 as shown in FIG. 13 is also applicable to the multistage filter of FIG. . In this case, it is also possible to obtain the effect of aligning the filter characteristics between a plurality of resonators assembled in multiple stages.

  As described above, according to the present invention, a dual mode filter having steep filter characteristics and high design freedom and / or tunability is realized. In addition, the filter characteristics can be finely adjusted with a simple configuration after the resonator pattern is formed.

Finally, the following notes are disclosed regarding the above description.
(Appendix 1)
A ring resonator;
An input feeder and an output feeder disposed orthogonal to each other with respect to the ring resonator so as to be electromagnetically coupled to the ring resonator;
A dual-mode generation line located inside the ring resonator and arranged not to overlap with an extension of the input feeder and the output feeder;
A dual mode filter characterized by comprising:
(Appendix 2)
2. The dual mode according to claim 1, wherein the dual mode generation line is arranged at a position of 45 ° ± nπ / 2 (n is a natural number) with the center of the extension line of the input feeder being 0 °. filter.
(Appendix 3)
The dual mode generation line includes a first port and a second port that are electromagnetically coupled to the ring resonator, and an arcuate waveguide that connects between the ports. The dual mode filter according to supplementary note 1 or 2.
(Appendix 4)
Appendix 1 characterized in that the length between the two electromagnetic coupling points of the dual mode generation line to the ring resonator is smaller than ¼ of the circumference of the ring resonator. The dual mode filter described.
(Appendix 5)
The dual mode filter according to appendix 3, wherein an opening angle of the first port and the second port is not less than 36 ° and less than 90 °.
(Appendix 6)
The ring resonator, the dual mode generation line, the input feeder, and the output feeder are formed on a first surface of a dielectric substrate, and a ground layer is formed on a second surface opposite to the first surface. The dual mode filter according to any one of appendices 1 to 5, characterized in that:
(Appendix 7)
A dielectric member positioned above an electromagnetic coupling point of the dual mode generation line to the ring resonator and movably disposed in a direction perpendicular to the dual mode generation line and the ring resonator ,
The dual mode filter according to appendix 1, further comprising:
(Appendix 8)
Located between at least one of the first port and the ring resonator and between the second port and the ring resonator, the dual mode generation line and the ring resonator A dielectric member arranged to be movable in the vertical direction;
The dual mode filter according to supplementary note 3, further comprising:
(Appendix 9)
Driving means for driving the dielectric member in the vertical direction;
The dual mode filter according to claim 7, further comprising:
(Appendix 10)
A ring resonator;
An input feeder and an output feeder disposed orthogonal to each other with respect to the ring resonator so as to be electromagnetically coupled to the ring resonator;
A dual mode generating line disposed inside the ring resonator so as not to overlap with the respective extension lines of the input feeder and the output feeder;
A multi-stage filter in which two or more resonators constituted by
In the two or more resonators, two adjacent resonators are arranged so as to be point-symmetric with each other.
(Appendix 11)
11. The multistage filter according to appendix 10, wherein the dual mode generation line is arranged at a position of 45 ° ± nπ / 2 (n is a natural number) with the center of the dual mode generation line being 0 ° as an extension line of the input feeder.
(Appendix 12)
Supplementary note 10 characterized in that the length between two electrical connection points of the dual mode generation line 15 to the ring resonator 12 is less than ¼ of the circumference of the corresponding ring resonator. Or the multistage filter of 11.
(Appendix 13)
A dual including a first and second ports electromagnetically coupled to the ring resonator and an arcuate waveguide connecting between the ports inside the ring resonator formed on the dielectric substrate A mode generation line is arranged to form a resonator filter,
The characteristics of the resonator filter are adjusted by changing at least one of the electrical length of the dual mode generation line, the line width, and the coupling amount between the dual mode generation line and the ring resonator. Tuning method.
(Appendix 14)
A dielectric block is disposed above the coupling portion between at least one of the first and second ports and the ring resonator,
14. The tuning method according to appendix 13, wherein the dielectric block is moved in a direction perpendicular to the port and the ring resonator to adjust characteristics of the resonator filter.

It is a schematic block diagram of the dual mode filter which concerns on one Embodiment of this invention. It is a figure which shows the modification of the dual mode filter of FIG. It is the schematic which shows the state which packaged the dual mode filter of FIG. It is a graph which shows the filter characteristic when changing the waveguide length of a dual mode generating line. It is the graph which expanded the circle part A of the graph of FIG. 4A. As a comparative example, it is a graph which shows the filter characteristic when the electrical length of the dual mode generation line is set to λ / 4. It is a graph which shows the change of the coupling coefficient k when changing the waveguide length of a dual mode generating line. It is a graph which shows the filter characteristic when the arrangement position of the dual mode generating line arranged inside a ring type resonator is changed. It is a figure which shows the filter characteristic when the width W1 of a dual mode generation line is changed. It is a figure which shows the filter characteristic when changing the coupling amount between a dual mode generating line and a ring type resonator. It is a figure which shows the structural example of a multistage filter. It is a schematic top view of the dual mode filter which concerns on 2nd Embodiment of this invention. FIG. 10 is a cross-sectional configuration diagram of the dual mode filter of FIG. 9. It is a measurement graph of filter characteristics when a dielectric block is arranged above the coupling point (electrical connection point) between the dual mode generation line and the ring resonator and the position is adjusted.

Explanation of symbols

10 Dual mode filter (High frequency filter device)
11 Dielectric substrates 12, 12A, 12B Ring resonators 13a, 13b Input feeder and output feeder 13c Coupling line 14 Ground layers 15, 15A, 15B Dual mode generation line 15a First port 15b Second port 15c Waveguides 30, 60 Package 51 Dielectric Block (Dielectric Material)
55 Trimmer (drive means)
53 Support Rod Leq Dual Mode Generation Line Electrical Length W1 Waveguide Width W2 Coupling Width

Claims (11)

A ring resonator;
An input feeder and an output feeder disposed orthogonal to each other with respect to the ring resonator so as to be electromagnetically coupled to the ring resonator;
A dual-mode generation line located inside the ring resonator and arranged not to overlap with an extension of the input feeder and the output feeder;
A dual mode filter characterized by comprising:   2. The dual according to claim 1, wherein a center of the dual mode generation line is disposed at a position of 45 ° ± nπ / 2 (n is a natural number) with an extension line of the input feeder being 0 °. Mode filter.   The dual mode generation line includes a first port and a second port that are electromagnetically coupled to the ring resonator, and an arcuate waveguide that connects between the ports. The dual mode filter according to claim 1 or 2.   2. The length between two electromagnetic coupling points of the dual mode generation line to the ring resonator is smaller than 1/4 of the circumference of the ring resonator. Dual mode filter described in 1.   4. The dual mode filter according to claim 3, wherein an opening angle of the first port and the second port is 36 ° or more and less than 90 °. 5. A dielectric member positioned above an electromagnetic coupling point of the dual mode generation line to the ring resonator and movably disposed in a direction perpendicular to the dual mode generation line and the ring resonator ,
The dual mode filter according to claim 1, further comprising: Located between at least one of the first port and the ring resonator and between the second port and the ring resonator, the dual mode generation line and the ring resonator A dielectric member arranged to be movable in the vertical direction;
The dual mode filter according to claim 3, further comprising: Driving means for driving the dielectric member in the vertical direction;
The dual mode filter according to claim 6, further comprising: A ring resonator;
An input feeder and an output feeder disposed orthogonal to each other with respect to the ring resonator so as to be electromagnetically coupled to the ring resonator;
A dual mode generating line disposed inside the ring resonator so as not to overlap with the respective extension lines of the input feeder and the output feeder;
A multi-stage filter in which two or more resonators constituted by
In the two or more resonators, two adjacent resonators are arranged so as to be point-symmetric with each other. A dual including a first and second ports electromagnetically coupled to the ring resonator and an arcuate waveguide connecting between the ports inside the ring resonator formed on the dielectric substrate A mode generation line is arranged to form a resonator filter,
The characteristics of the resonator filter are adjusted by changing at least one of the electrical length of the dual mode generation line, the line width, and the coupling amount between the dual mode generation line and the ring resonator. Tuning method. A dielectric block is disposed above the coupling portion between at least one of the first and second ports and the ring resonator;
11. The tuning method according to claim 10, wherein the dielectric block is moved in a direction perpendicular to the port and the ring resonator to adjust characteristics of the resonator filter.

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