JP2516857B2 - Ring resonator and filter using the ring resonator - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is suitable for the construction of a high-frequency filter which constitutes a broadcaster or a communication device in the short-wave or ultra-high-frequency band, or a high-frequency filter which constitutes a shared antenna device in the above-mentioned band. It relates to a resonator.

[0002]

2. Description of the Related Art Conventionally, a λ / ₄ coaxial resonator (λ is a resonance wavelength), a helical resonator, or a ring resonator as shown in FIGS. 28 and 29 is used as the above high-frequency filter. Has been. FIG. 28 (a) is a plan view showing an example of a main part of a conventional ring resonator, and FIG. 28 (b) is a front view.
In both figures, 40 is a printed circuit board, 41 is a printed circuit board 40.
Inductance forming part of a metal thin film provided on the surface of, 42 in the capacitor forming portion, formed in _^1/2 or an integral multiple thereof resonance wavelength λ a circumferential length of the inductance formation section 41 by an electrical length is there. FIG. 29 (a) is also a plan view showing an example of a main part of a conventional ring resonator, FIG. 29 (b) is a front view, and FIG. 28 is shown except that the shape of the inductance forming portion 43 is rectangular. It has the same structure as the ring resonator. 28 and 29, the illustration of the input coupling element, the output coupling element, the input terminal, the output terminal and the like is omitted.

[0003]

The λ / 4 coaxial resonator is generally large and can be miniaturized by using a TEM dielectric resonant element as a resonant element, but a relatively large amount of solid dielectric is used. As a result, the weight becomes large, and
If the frequency used is low, it is impossible to make it sufficiently compact. The helical resonator has a high impedance in the resonator and thus a high voltage in the resonator, which is inferior in the withstand voltage characteristic, and the surface area of the resonant element is small, which is inferior in the heat radiation effect, resulting in a small power capacity. Further, helical resonator, the resonance element is inferior in vibration resistance because made of linear body wound into a coil, since the shape of the resonant element is complicated, which Invar (R) or Super Invar (registered trademark ) Is difficult to form, and it is extremely difficult to manufacture a resonator having good temperature characteristics of resonance frequency. The ring resonator shown in FIGS. 28 and 29 has inductance forming portions 41 (FIG. 28) and 43 (FIG. 29).
Since the length in the circumferential direction is formed to be 1/2 of the resonance wavelength λ or an integral multiple thereof in terms of electrical length, the size becomes large when the resonance frequency is relatively low. Further, in any of the ring resonators shown in FIGS. 28 and 29, the printed circuit board 40
Is thin, the Q of the resonator cannot be increased to a certain extent or more due to the loss in the printed circuit board 40, and the total area is small because both the inductance forming portions 41 and 43 are made of a thin metal thin film. Since it is thin, it is not suitable as a resonator for high power.

[0004]

SUMMARY OF THE INVENTION According to the present invention, an inductance forming portion is formed by bending a metal plate having one end fixed to a wall surface of a shield case, and the other end facing the wall surface. It is intended to eliminate the conventional drawback by realizing a ring resonator having a resonant element including the other end and a capacitance forming portion between the other end and the wall surface facing the other end.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 (a) is a sectional view showing a main part of an embodiment of the present invention (a sectional view taken along the line CC of FIG. 1 (b)), FIG. 1 (b).
1A is a cross-sectional view taken along the line AA of FIG. 1A, and FIG.
(A) BB cross-sectional views, in each figure, 1 is a shield case, 2 is an inductance forming portion of a resonance element, and a metal plate of an appropriate width is bent into a substantially U-shape or U-shape to form a shield case 1. The wall portion is fixed to, for example, a lower wall, and the other end is bent so as to be parallel to the lower wall to form a bent portion 3. As shown in the drawing, the bending direction of the bending portion 3 is such that the bending portion 3 is bent toward the outside of the space surrounded by the inductance forming portion 2 of the resonant element and a part of the lower wall of the shield case 1, or in the opposite direction. You may fold it. The bent portion 3 at the other end of the inductance forming portion 2 of the resonant element is fixed to the lower wall of the shield case 1 via the solid dielectric 4. Instead of interposing the solid dielectric 4 between the bent portion 3 at the other end of the inductance forming portion 2 of the resonant element and the lower wall of the shield case 1, between the bent portion 3 and the lower wall of the shield case 1, The bent portion 3 may be fixed to the lower wall of the shield case 1 by interposing an appropriate number of small spacers made of an insulating material. Further, an electrode plate may be attached to the other end of the inductance forming portion 2 of the resonant element in a T shape and fixed to the lower wall of the shield case 1 via a solid dielectric or an insulating spacer. The bending portion 3 or the electrode plate attached in a T shape and the lower wall of the shield case 1 facing the bending portion 3 constitute a capacitance forming portion of the resonance element. Inductance forming part 2
A capacitive element such as a fixed capacitance ceramic capacitor or a butterfly variable capacitance capacitor may be interposed between the other end of the above and the lower wall of the shield case 1.
In FIG. 1A, a solid line with an arrow indicates a current flowing through the resonance element including the inductance forming portion 2, the bent portion 3, the solid dielectric 4, and a part of the lower wall of the shield case 1. The broken line with an arrow in (c) represents a magnetic field.

FIG. 2A is an equivalent circuit diagram of the ring resonator of the present invention. L ₁ to L ₃ are from the inductance forming portion 2 of the resonance element shown in FIG. The inductance component C _A in the portion is formed by the bent portion 3 shown in FIG. 1A, the lower wall of the shield case 1 facing the bent portion 3, and the solid dielectric 4 interposed therebetween. It is the capacity of the capacity forming portion. 2B is an equivalent circuit diagram in which the inductance components L ₁ to L ₃ in FIG. 2A are collectively represented as L, and other reference numerals are the same as those in FIG. 2A. 1 and 2, the input coupling element, the output coupling element, the input terminal, the output terminal, the resonance frequency fine adjustment element, and the like are not shown.

In the ring resonator of the present invention constructed as described above, the larger the shield case 1 is formed, that is, as shown in FIG. The larger the length dimensions X, Y and Z, the greater the amount of electromagnetic energy that can be stored. In other words,
The larger the shield case 1 is, the more unloaded Q (Q _U )
Can be higher. As a result of actual measurement of the prototype by the present inventor, when the width of the inductance forming portion 2 is y and the length of the facing gap between the portion to and the portion of the inductance forming portion 2 is x,
When X≈Y≈Z, X / x≈2, and Y / y≈2, and the distance between the top of the inductance forming portion 2 and the upper wall of the shield case 1 is chosen to be approximately x / 2. , It was confirmed that the electromagnetic energy can be stored most efficiently. Therefore, when the dimensions of each part are selected as described above, the no-load Q (Q _U ) can be maximized. When the dimensions of the respective parts are selected as described above, no load is applied to the bent portion 3, the lower wall of the shield case 1 facing the bent portion 3, and the solid dielectric 4 interposed between the folded portion 3 and the solid dielectric 4. When Q (no-load Q determined by the dielectric loss in the capacitance forming portion) is much higher than the no-load Q of the metal portion when the shield case 1 and the inductance forming portion 2 are formed of copper, that is, the capacitance The unloaded Q (Q _U ) of the ring resonator of the present invention when the dielectric loss in the formed portion is negligible can be approximately calculated by the following equation.

[Equation 1] In the above equation, each unit of X and Y is cm, and the unit of frequency f is
MHz.

In the ring resonator of the present invention, FIG.
The current shown by the solid line with an arrow in (a), that is, the current flowing in the resonance element formed by the inductance forming portion 2, the bent portion 3, the solid dielectric 4, and a part of the lower wall of the shield case 1 Since the distribution is uniform, the width of the inductance forming portion 2 is relatively wide, and the length in the longitudinal direction is relatively short, the impedance of the resonant element is low. Since the impedance of the resonant element is low, the current flowing through the resonant element is relatively large, but the width of the inductance forming portion 2 is relatively wide, so the current density is relatively small, and this current causes the inductance forming portion 2 to generate heat. Even so, since the surface area of the inductance forming portion 2 is large, the heat dissipation effect is good and the temperature rise can be suppressed to a low level. As a result of the low temperature rise in the resonant element, when the loss power is the same as that of the conventional resonator, the power capacity of the ring resonator of the present invention is larger than that of the conventional resonator. Since the impedance of the resonant element is low as described above, the voltage generated in the resonant element is also low,
Therefore, the breakdown voltage characteristics are good.

Since the shield case 1 in the ring resonator of the present invention is made of a box-shaped body, it can be provided with sufficient mechanical strength by being formed of a metal plate having an appropriate thickness according to the resonance wavelength, and the inductance can be reduced. By forming the forming portion 2 also from a metal plate having an appropriate thickness according to the resonance wavelength, the mechanical strength of the inductance forming portion 2 itself can be increased, and the bent portion 3, the solid dielectric 4 and the shield are formed. The capacitance forming part formed of a part of the lower wall of the case 1 can also be formed so as to have sufficient mechanical strength, and one end of the inductance forming part 2 is fixed to the lower wall of the shield case 1 and the other end. Is fixed to the lower wall of the shield case 1 via the capacitance forming portion, so that the entire resonant element, and thus the entire resonator, is configured to have sufficient mechanical strength. It is possible. Since Ingukutansu forming portion 2 of the present invention the ring resonator is formed by simply bending a metal plate, it is easy to work even in the case of using the Invar (R) or Super Invar (registered trademark) material, such as . Inductance forming part 2
As described above, it is possible to provide sufficient mechanical strength by forming a metal plate with an appropriate thickness according to the resonance wavelength. As described above, for example, the resonance wavelength is relatively long such as in the shortwave band. In this case, a plate having a thickness corresponding to the resonance wavelength cannot be used as the metal plate forming the inductance forming portion 2, and a metal plate thinner than a required value may be used. In such a case, the mechanical strength can be increased by bending the edge of the metal plate.

FIG. 3A is a cross-sectional view showing an example of the configuration of the input coupling element, the output coupling element, the input terminal and the output terminal (hereinafter collectively referred to as input / output element) in the ring resonator of the present invention. Fig. {A-A sectional view of Fig. 3 (b)},
FIG. 3 (b) is a front view, and in both figures, 5 is an input (or output) terminal, which is, for example, a coaxial plug. Reference numeral 6 denotes an input (or output) coupling capacitance element, which is made of a metal plate having an appropriate width and length, has one end connected to the internal conductor of the input (or output) coaxial connector 5, and the plate surface of the inductance forming portion 2. Among them, a part of the vertical portion in the upper part of the bent portion 3 is opposed to the bent portion 3 with an appropriate interval. 7 is output (or input)
Terminals 8 are output (or input) coupling capacitance elements, and these have the same configuration as the input (or output) terminal 5 and the input (or output) coupling capacitance element 6. FIG. 3C shows FIG.
And an equivalent circuit diagram of the resonator of the present invention shown in FIG.
T _I is an input terminal, C _I is an input coupling capacitance, R is a resonant circuit formed by the shield case 1 and a resonant element, C _O is an output coupling capacitance, and T _O is an output terminal. Instead of configuring the input (or output) coupling capacitance element 6 and the output (or input) coupling capacitance element 8 as described above, between the input (or output) terminal 5 and the bent portion 3 and the output (or input) terminal. A capacitance element such as a butterfly type variable capacitance capacitor or a fixed capacitance ceramic capacitor may be interposed between 7 and the bent portion 3.

FIG. 4A is a sectional view showing another example of the structure of the input / output element {AA sectional view of FIG. 4B}, FIG. 4B.
Is a rear view, in both figures, 10 is a conductor for tap coupling,
Output (or input) terminal 7 and inductance forming portion 2
Among them, the lower case of the shield case 1 is connected to an appropriate portion of the vertical portion in the upper part of the end fixedly grounded. A tap coupling conductor 9 is also provided between the input (or output) terminal 5 and an appropriate portion of the vertical portion above the end of the inductance forming portion 2 which is fixedly grounded to the lower wall of the shield case 1. Is not shown in the figure.

FIG. 5A is a sectional view showing another example of the structure of the input / output element {AA sectional view of FIG. 5B}, FIG. 5B.
Is a rear view, and in both figures, 11 and 12 are coupling elements made of metal plates of appropriate width and length, respectively, and the coupling element 11 is
A coupling element is provided between the input (or output) terminal 5 and an appropriate portion of a vertical portion of the inductance forming portion 2 above the end fixedly grounded to the lower wall of the shield case 1.
Reference numeral 12 is provided between the output (or input) terminal 7 and an appropriate portion of a vertical portion of the inductance forming portion 2 above the end fixedly grounded to the lower wall of the shield case 1. In this configuration example, the plate surfaces of the coupling elements 11 and 12 and the inductance forming portion 2 are coupled by magnetic field coupling, so that tap coupling and magnetic field coupling are combined. FIG. 5 (c) is an equivalent circuit diagram of the resonator shown in FIGS. 5 (a) and 5 (b), in which M _I and M _O are magnetic field coupling coefficients, and other symbols are as in FIG. 3 (c). It is the same.

FIG. 6A is a sectional view showing another example of the structure of the input / output element {AA sectional view of FIG. 6B}, FIG. 6B.
Is a rear view, and in both figures, 13 and 14 are strip-shaped metal plates, which are provided in parallel with each other at appropriate intervals, and the shield case 1 of the inductance forming portion 2 is provided.
It is provided at a proper interval from the vertical portion above the end portion which is fixedly grounded to the lower wall of the lower wall, and both ends are provided with terminals 5 and 7, respectively.
The strip case is connected to the lower wall of the shield case 1 by the vertical portion of the inductance forming portion 2 and the strip-shaped metal plates 13 and 14, respectively. FIG.
6A is a cross-sectional view similar to FIG. 6A and the reference numerals are also the same, but in FIGS. 6A and 6B, the end portions of the strip-shaped metal plates 13 and 14 on the side opposite to the ground side are formed. Providing terminals 5 and 7,
While the input / output connection is configured to be positive connection,
In the configuration example shown in FIG. 7, strip-shaped metal plates 13 and 14 are used.
Terminals 5 and 7 (terminal 5 is not shown in the figure) are provided at the ground side end of (the metal plate 13 is not shown in the figure) so that the input / output coupling is performed by the reverse coupling. It is composed.

FIG. 8 (a) is a sectional view showing another example of the structure of the input / output element {sectional view taken along the line BB of FIG. 8 (b)}, FIG. 8 (b).
8A is a sectional view taken along the line AA in FIG. 8A. In both figures, reference numerals 15 and 16 are coupling loops, and a strip-shaped metal plate having an appropriate width is formed into a substantially U-shaped shape similar to that of the inductance forming portion 2. It is bent into a U-shape or U-shape, one end is fixedly grounded to the lower wall of the shield case 1, the other end is opposed to the lower wall of the shield case 1 at an appropriate interval, and the other end is It is connected to terminals 5 and 7. FIG. 8C is an equivalent circuit diagram of the resonator shown in FIGS. 8A and 8B, and the reference numerals are the same as those in FIG. 3C. FIG. 8 exemplifies a case in which the bending directions of the coupling loops 15 and 16 are the same as the bending direction of the inductance forming portion 2 and the input / output coupling is performed by the positive coupling. The bending directions of the coupling loops 15 and 16 may be opposite to the bending direction of the inductance forming portion 2, and the input / output coupling may be performed by the reverse coupling.

FIG. 9 is a cross-sectional view showing an example of the structure of a fine adjustment element for the resonance frequency in the ring resonator of the present invention {FIG. 1
In the sectional view corresponding to (a)}, 17 is a fixed electrode plate, one end of which is fixed to the end of the inductance forming portion 2 on the bent portion 3 side. 18 is a movable electrode plate, 19 is a drive screw, 20 is a lock nut, and the fixed electrode plate 17 and the movable electrode plate
The capacity formed between the drive screw 19 is inserted in parallel with the capacity formed between the bent portion 3 and the lower wall of the shield case 1, and the drive screw 19 is rotated in the forward or reverse direction. The movable electrode plate 18 is moved forward or backward to move the fixed electrode plate 17
The resonance frequency can be finely adjusted by changing the capacitance formed between the two. In addition, the bent portion 3 and the sheet
The center frequency of the resonance frequency can be changed and set relatively large by changing the capacity formed between the lower case 1 and the lower wall relatively. Fixed electrode plate
Instead of providing the movable electrode plate 17 and the movable electrode plate 18, a variable capacitance capacitor is connected in parallel between the bent portion 3 and the lower wall of the shield case 1, and the drive shaft of the movable element in the variable capacitance capacitor is shielded. Alternatively, the resonance frequency may be finely adjusted by deriving the variable capacitor from the outside of the case 1 and changing the capacitance of the variable capacitor by an external operation.

FIG. 10 is also a cross-sectional view (cross-sectional view corresponding to FIG. 1A) showing an example of the structure of the fine adjustment element of the resonance frequency in the ring resonator of the present invention, in which 21 is a tuning screw, and
It is inserted from the lower wall of the case 1 into the space surrounded by the inductance forming portion 2. 22 is a lock nut. 11A is a sectional view taken along the line BB of FIG. 11B, and FIG. 11B is a sectional view taken along the line AA of FIG.
In this configuration example, the tuning screw 21 is attached to the shield case 1
Is inserted into the space surrounded by the inductance forming portion 2 from the side wall. 22 is a lock nut. FIG.
0 and FIG. 11, the tuning screw 21 is rotated in the forward direction or the reverse direction to change the insertion length into the shield case 1 to change the self-inductance and resonate. The frequency can be finely adjusted.
In each of the configuration examples shown in FIGS. 10 and 11, the tuning screw 21 is inserted in the space surrounded by the inductance forming portion 2, but the inductance forming portion 2 and the shield case are shown. You may make it insert in the space between 1. Other reference numerals in FIGS. 3 to 11 are the same as those in FIG.

FIG. 12 (a) is a sectional view showing a main part of a bandpass filter constituted by cascade-connecting a plurality of ring resonators of the present invention {a sectional view taken along line BB of FIG. 12 (b)}, Figure 12 (b)
Is a sectional view taken along the line AA of FIG.
Is a common shield case, 2 ₁ to 2 ₄ are inductance forming parts, 3 ₁ to 3 ₄ are bent parts, 4 ₁ to 4 ₄ are solid dielectrics, inductance forming parts 2 ₁ to 2 ₄ and bent parts 3 ₁ to 3 ₄ and solid dielectrics 4 ₁ to 4 ₄ have the same structure as the inductance forming portion 2, the bent portion 3 and the solid dielectric 4 shown in FIG. A resonance element is formed with a part of the lower wall. FIG.
Although not shown in FIG. 3, any input / output element among the input / output elements shown in FIGS. 3 to 8 is selected to set the input (or output) terminal and the input (or output) coupling element as the first-stage resonant element. 9 and the output (or input) terminal and the output (or input) coupling element are coupled to the final stage resonant element.
To the resonance frequency fine adjustment element shown in FIG.
Any fine tuning element is selected and coupled to each resonant element. FIG. 12 illustrates the case where four resonant elements are connected in cascade, but it goes without saying that the band pass filter can be configured by appropriately increasing or decreasing the number. FIG. 12C is a schematic diagram of FIG.
Sectional drawing for demonstrating the interstage coupling of the band pass filter shown to (b), ie, the sectional view which shows the resonant element part of the first step and the next step among CC sectional views of FIG. 12 (a). In the figure, the broken line with an arrow indicates the magnetic field, S _C is the center interval of the resonance element, and other reference numerals are the same as those in FIGS. 12A and 12B. Figure 12 inductance forming part 2 ₁ (c) In
And 2 ₂ and the width y, select the relation between the distance x of the vertical portion of the inductance forming part 2 ₁ and 2 ₂ to x = y, the common - Rudoke - width X of the scan 31 and the inductance forming part 2 ₁ and
The relationship between the 2 ₂ spacing x of the vertical portion with choosing the X = 2x, the common inductance forming part 2 ₁ and 2 ₂ of the top sheet - Rudoke - approximately the distance between the upper wall of the scan 31 x / Choose 2,
FIG. 13 shows the results of actual measurement of changes in the magnetic field coupling coefficient M _m between steps when the center spacing S _C of the resonant element is changed. FIG.
In 3, the horizontal axis is a regular interval scale,

[Equation 2] And the vertical axis is a logarithmic scale, which is the magnetic field coupling coefficient M _m . In designing the band-pass filter, the inter-stage magnetic field coupling coefficient M _m is obtained by the circuit design of the same method as the conventional one, and the center spacing S _C of the resonance element is calculated from the magnetic field coupling characteristic curve shown in FIG. Ask.

FIG. 14 is a diagram for explaining an example of a method of manufacturing the above bandpass filter. FIG. 14A is a part which constitutes an inductance forming portion in a cascade-connected resonant element, and 32 is a strip-shaped member. common fixed portion, the 2 ₁ to 2 ₄ in the common fixed portion 32 inductance forming part which projects perpendicularly from the side edge of the strip, they are integrally formed by means such as punching a metal plate. In FIG. 14 (b) component of the capacitive formation portion in the resonator element, 33 is a strip-shaped dielectric plate, depositing a metal thin film on the back surface of the entire part of the surface, i.e., from 2 ₁ inductance forming portion 2 _A metal thin film is attached to the portions 33 ₁ to 334 corresponding to the bent portions (portions corresponding to 3 ₁ to 3 ₄ in FIG. 12) of the outer end portions of ₄ . From 2 ₁ inductance forming portion shown in FIG. 14 (a) folding each base of 2 ₄ so that the strip-shaped common fixed portion 32 and a right angle, further, the inductance forming portion
2 ₁ to folding the 2 ₄ substantially U-shaped or U-shaped as shown in FIG. 14 (c), a strip-shaped common lower surface common sheet fixed portion 32 - Rudoke - the lower wall of the scan 31 by soldering or the like 14B, the strip-shaped dielectric plate 33 shown in FIG. 14B is arranged in parallel with the strip-shaped common fixing portion 32 with a required space therebetween, and a shield film common to the metal thin film provided on the lower surface thereof. The lower walls of the space 31 are fixed by soldering or the like, and the bent portions 3 ₁ at the outer ends of the inductance forming portions 2 ₁ to 2 ₄
To 3 ₄ {in FIG. 14 (c), the inductance forming portion 2 ₂
Through 2 ₄ and the bent portions 3 ₂ through 3 ₄ are not exposed}, the lower surfaces of the band pass filter are fixed to the metal thin film portions 33 ₁ through 33 ₄ attached to the surface of the strip-shaped dielectric plate 33, respectively. The wave device can be easily manufactured.

[0019] Figure 12, the plate surface of each vertical portion of the inductance formation section 2 ₁ to 2 _4, a common - Rudoke - scan 31
Although the case where the elements are arranged in parallel with the longitudinal direction of and the orientations of the respective resonance elements are the same, it may be arranged so that the orientations of some of the resonance elements are opposite. or,
15 (a) and 15 (b) are cross-sectional views of the main part {FIG.
(A) Figure 15 B-B sectional view of (b), FIG. 15 (b) to indicate the A-A sectional view of FIG. 15 (a)}, each vertical inductance forming part 2 ₁ to 2 ₄ The plate surface of the part may be arranged so as to be at right angles to the longitudinal direction of the common shield case 31, and in this case also, the directions of the respective resonance elements are all the same or a part thereof are reversed. A bandpass filter can be constructed. FIG. 15C is a cross-sectional view corresponding to FIG. 12C, and the broken line with an arrow indicates the magnetic field. Also in the bandpass filter shown in FIG. 15, the center interval of the resonant elements can be obtained by the same method as in the case of the bandpass filter shown in FIG. Other symbols in FIG. 15 are
It is similar to FIG.

In the band-pass filter shown in FIGS. 12 and 15, when it is desired to change the degree of interstage coupling in order to obtain the required electrical characteristics, it is necessary to change the center interval of the resonant elements. Therefore, it is disadvantageous in design and production. FIG.
FIG. 1A is a cross-sectional view showing an example of the configuration of means for changing the degree of coupling between stages without changing the center interval of the resonant element {FIG.
6 (b) is a cross-sectional view taken along line BB in FIG. 6 (b), and FIG.
(A) AA sectional view, in both figures, 23 is a metal rod for preventing inter-stage coupling, which is provided between the upper and lower walls of the common shield case 31 between adjacent resonant elements. It is provided. By providing the metal rod 23 for preventing inter-stage coupling, the inter-stage coupling can be made sparser as compared with the case where this is not provided. In providing the inter-stage coupling preventing metal rod 23, when the inter-stage coupling inhibiting metal rod 23 is provided at the center of the line connecting the centers of the adjacent resonance elements, the coupling can be made the most sparse, and the inter-stage coupling inhibiting metal rod 23
The larger the diameter, the larger the number of metal rods 23 for preventing inter-stage coupling can be. In FIG.
Shows only the first stage and the next stage of the resonator portion composed of the inductance formation section 2 ₁ and 2 _2, of course be provided interstage coupling blocking metal rod also between each resonator element following stages, the following description The same applies to each configuration example.

FIG. 17A is a sectional view taken along the line BB of FIG. 17B, and FIG. 17B is a sectional view taken along the line AA of FIG. 17A. A metal plate 24 having an appropriate width is used to replace the metal rod 23 for preventing inter-stage coupling, and the plate surface of the metal plate 24 for inhibiting inter-stage coupling is common at the center of the line connecting the centers of the adjacent resonance elements. -When it is provided so as to be perpendicular to the longitudinal direction of the space 31, the connection can be made the most sparse, and the wider the width of the metal plate 24 for preventing inter-stage coupling is, the thicker it is installed. As the number increases, the interstage coupling can be made looser.

FIG. 18 (a) is a sectional view taken along line BB of FIG. 18 (b), and FIG. 18 (b) is a sectional view taken along line AA of FIG. 18 (a). A metal plate for preventing coupling, which is inserted into a common shield case 31 from a hole formed in, for example, an upper wall of a common shield case 31 between adjacent resonance elements, and changes its insertion length. In addition, the plate surface is provided so as to be at a right angle or substantially a right angle with the longitudinal direction of the common shield case 31. 26 and 27 are holders, which are common seals.
Insertion area of the metal plate 25 for preventing interstage coupling into the common shield case 31 by pressure bonding to the front and back surfaces of the metal plate 25 for inhibiting interstage coupling which is led out of the case 31. Is held at the required value. For this reason, for example, either one of the holders 26 and 27 is fixed to the outer wall of the common shield case 31, and each length is appropriately made larger than the width of the metal plate 25 for preventing inter-stage coupling. Screws on both ends of 26 and 27 (not shown)
By mounting and loosening the screw, the insertion area of the metal plate 25 for preventing interstage coupling between the common shield case 31 can be changed, and by tightening the screw, the metal plate 25 for inhibiting interstage coupling can be fixed. It is formed so that it can be held at the required position. In this configuration example, the degree of inter-step coupling can be changed by changing the insertion area of the metal plate 25 for inter-step coupling prevention into the common shield case 31.

19A is a sectional view taken along line BB of FIG. 19B, and FIG. 19B is a sectional view taken along line AA of FIG. 19A. In both figures, 28 is a step. With a coupling loop, a metal plate having an appropriate width is bent into a U-shape or a U-shape, and both ends are fixedly grounded to, for example, the lower wall of a common shield case 31 between adjacent resonance elements. Shield case with a common surface
It is provided so as to be parallel to the longitudinal direction of 31, that is, the plate surface of the vertical portion of the interstage coupling loop 28 is perpendicular to the longitudinal direction of the common shield case 31. In this configuration example, by providing the inter-stage coupling loop 28 contrary to the above-mentioned respective configuration examples, the inter-stage coupling can be made denser as compared with the case where it is not provided. The larger the loop area of the loop 28 and the larger the width of the metal plate forming the interstage coupling loop 28, the denser the interstage coupling can be made. When the loop surface of the interstage coupling loop 28 is provided so as to be parallel to the longitudinal direction of the common shield case 31, the interstage coupling can be made most dense and the common sheath can be formed. By changing the angle of the loop surface with respect to the longitudinal direction of the case 31,
It is possible to change the degree of inter-stage coupling by changing the number of magnetic field lines passing through the loop. To form the interstage coupling loop 28 rotatably, for example, a part of the lower wall of the common shield case 31 between the adjacent resonance elements is formed as a wall that is rotatable in the lower wall. However, the purpose can be achieved by fixing both ends of the interstage coupling loop 28 to the inner surface of the rotating wall surface. Or a common sheet - Rudoke - out of the wall of the scan 31, the inductance forming portion to form a resonant element 2 ₁
And 2 ₂ of interstage coupling le the lower wall which is grounded secure each end - flop 28
The case has been described where both ends grounded fixed inductance forming portion 2 ₁ and 2 between stages wall on each end of the ₂ faces the lower wall grounded fixedly coupled Le - ground fixing both end portions of the flops 28 You may.

The example of the configuration of the means for coupling the stages by magnetic field coupling has been described above, but the means for coupling the stages by capacitance will be described below. FIG. 20 (a) is shown in FIG.
20 (b) is a sectional view taken along line BB of FIG.
In A-A sectional view of (a), in both figures, the fixed electrodes 29 and 30, fixed to each other in the portion 3 ₁ and 3 ₂ fold each outer end, face each other with an appropriate spacing of each inner end I am allowed. Reference numeral 34 denotes a movable electrode, the contour of which is formed in a rectangular shape, and the inner end of the rotary drive shaft 35 is fixed to the center thereof. 36 is a lock nut. When forming in this way, the fixed electrode 29 and the movable electrode
Inter-stage coupling is performed through the capacitance between 34 and the capacitance between the movable electrode 34 and the fixed electrode 30, and the rotary drive shaft 35 is operated to move the movable electrode.
When 34 is rotated, the facing area between the fixed electrode 29 and the movable electrode 34 and the facing area between the movable electrode 34 and the fixed electrode 30 are changed, and the inter-stage coupling degree is changed. When the rotary drive shaft 35 is formed of a feed screw, when the feed screw is rotated in the forward direction or the reverse direction, the movable electrode 34 rotates and moves forward or backward to move the fixed electrode 29.
As the facing area with 30 and 30 changes, the facing gap also changes to change the degree of interstage coupling. When the contour of the movable electrode 34 is formed in a circular shape and the inner end of the feed screw is fixed to the center of the contour, the movable electrode 34 moves forward or backward when the feed screw is rotated in the forward or reverse direction. The degree of interstage coupling will be changed.

FIG. 21 (a) is a sectional view taken along line BB of FIG. 21 (b), and FIG. 21 (b) is a sectional view taken along line AA of FIG. 21 (a). in capacitance forming electrodes, and fixed to each other in the portion 3 ₁ and 3 ₂ fold each outer end, each inner end are opposed to each other over the appropriate area, interstage coupling is carried out by capacitance generated therebetween. FIG. 22A shows B of FIG. 22B.
22B and FIG. 22B are sectional views taken along the line AA of FIG. 22A. In this configuration example, the capacitance forming electrodes 37 and 38 are formed.
Solid dielectric plate 39 composed of a ceramic plate or the like between the facing gaps
The outer end of the common shield case 31 through a hole formed in the side wall of the common shield case 31 to the outside of the common shield case 31 to form a capacitance at the inner end of the solid dielectric plate 39. Electrodes 37 and 38
It is possible to change the degree of inter-stage coupling by changing the insertion length into the gap between the two facing each other. The interstage capacitive coupling means, in addition to the above, during the bending portion 3 ₁ and 3 _2, for example, capacitive elements, such as a ceramic capacitor or a butterfly variable capacitor of a fixed capacity may be interposed.

FIG. 23 is a diagram showing an example of an equivalent circuit of a magnetic field coupling type bandpass filter constituted by using the ring resonator of the present invention, in which T _I is an input terminal, T _O is an output terminal, and R ₁ to R ₁ . R ₄ is a resonance circuit, M _I1 is an input coupling magnetic field coefficient, M 4 _O is an output coupling magnetic field coefficient, and M ₁₂ , M ₂₃ and M ₃₄ are interstage coupling magnetic field coefficients.
Figure 24 is a diagram showing an example of an equivalent circuit of the capacitive coupling type bandpass wave filter constructed by using the present invention the ring resonator, C _I1
Is the input coupling capacitance, C _4O is the output coupling capacitance, C ₁₂ , C ₂₃ and
C ₃₄ is an inter-stage coupling capacitance, and other symbols are the same as those in FIG. 23. FIG. 25 is a diagram showing an example of the transmission characteristics of a bandpass filter constituted by using the ring resonator of the present invention, where the horizontal axis is the transmission frequency f (MHz) and the vertical axis is the attenuation amount ATT (dB), f. _O is the center frequency.

The case where the band pass filter is constructed by using the ring resonator of the present invention has been described above. However, only one ring resonator of the present invention is used and the input / output elements shown in FIGS. It is possible to operate as a band-stop filter by omitting any one of the sets and using the remaining set of terminals and coupling elements as input and output terminals and input and output coupling elements. As shown in FIG. 12 or 15, the common sheet - Rudoke - while disposing a plurality of resonant elements in the scan 31, as shown in the equivalent circuit in FIG. 26, the input terminal T _I and the output terminal T _{Between O} , for example, the inductance of the inductance element consisting of lumped constant circuit elements L _I1 , L
_12, L _23, L _34, and _{L. 4O} was inserted and connected in series, between the connection point and each resonance element of each inductance element, the capacitance C _{R 1} of the capacitive element for example made of lumped circuit elements, C _R2, C
_A low pass filter can be constructed by inserting and connecting _R3 and C _R4 . In addition, as shown in the equivalent circuit of FIG. 27, the capacitances C _I1 , C ₁₂ , C _{23 of} the capacitive elements composed of, for example, lumped constant circuit elements are provided between the input terminal T _I and the output terminal T _O.
C ₃₄ and C 4 _O are inserted and connected in series, and the inductance L _R1 , L _R2 , L _R3, and L _R4 of the inductance element composed of, for example, a lumped constant circuit element are connected in series between the connection point of each capacitive element and each resonant element. A high pass filter can be constructed by inserting and connecting.

[0028]

As is apparent from the above detailed description, the ring resonator of the present invention is small and lightweight, easy to manufacture, has good temperature characteristics of resonance frequency, is highly reliable, and has a high power capacity. A large-sized filter constituted by using the ring resonator of the present invention also has the above-mentioned characteristics, and since it is easy to mass-produce, it is a high-frequency filter or a high-frequency filter which constitutes a broadcasting device or a communication device in the short-wave or ultra-high-frequency band. Is suitable for the configuration of a high-frequency filter or the like that constitutes an antenna shared device in the above band.

[Brief description of drawings]

FIG. 1 is a sectional view showing a main part of an embodiment of the present invention.

FIG. 2 is an equivalent circuit diagram of the ring resonator of the present invention.

FIG. 3 is a diagram illustrating a configuration example of input and output coupling elements of the ring resonator of the present invention.

FIG. 4 is a diagram illustrating a configuration example of input and output coupling elements of the ring resonator of the present invention.

FIG. 5 is a diagram illustrating a configuration example of input and output coupling elements of the ring resonator of the present invention.

FIG. 6 is a diagram illustrating a configuration example of input and output coupling elements of the ring resonator of the present invention.

FIG. 7 is a sectional view showing a configuration example of input and output coupling elements of the ring resonator of the present invention.

FIG. 8 is a diagram illustrating a configuration example of input and output coupling elements of the ring resonator of the present invention.

FIG. 9 is a cross-sectional view showing a configuration example of a resonance frequency fine adjustment element of the ring resonator of the present invention.

FIG. 10 is a cross-sectional view showing a configuration example of a resonance frequency fine adjustment element of the ring resonator of the present invention.

FIG. 11 is a diagram illustrating a configuration example of a resonance frequency fine adjustment element of the ring resonator of the present invention.

FIG. 12 is a diagram illustrating a configuration example of a filter using the ring resonator of the present invention.

FIG. 13 is a diagram showing the relationship between the center spacing of resonant elements and the inter-stage coupling coefficient in a filter using the ring resonator of the present invention.

FIG. 14 is a diagram illustrating an example of a method for manufacturing a filter using the ring resonator of the present invention.

FIG. 15 is a diagram illustrating a configuration example of a filter using the ring resonator of the present invention.

FIG. 16 is a cross-sectional view showing a configuration example of an inter-stage coupling element of a filter using the ring resonator of the present invention.

FIG. 17 is a cross-sectional view showing a configuration example of an interstage coupling element of a filter using the ring resonator of the present invention.

FIG. 18 is a cross-sectional view showing a configuration example of an inter-stage coupling element of a filter using the ring resonator of the present invention.

FIG. 19 is a sectional view showing a configuration example of an interstage coupling element of a filter using the ring resonator of the present invention.

FIG. 20 is a cross-sectional view showing a configuration example of an interstage coupling element of a filter using the ring resonator of the present invention.

FIG. 21 is a cross-sectional view showing a configuration example of an inter-stage coupling element of a filter using the ring resonator of the present invention.

FIG. 22 is a cross-sectional view showing a configuration example of an interstage coupling element of a filter using the ring resonator of the present invention.

FIG. 23 is an equivalent circuit diagram of a filter using the ring resonator of the present invention.

FIG. 24 is an equivalent circuit diagram of a filter using the ring resonator of the present invention.

FIG. 25 is a diagram showing an example of transmission characteristics of a filter using the ring resonator of the present invention.

FIG. 26 is an equivalent circuit diagram of a filter using the ring resonator of the present invention.

FIG. 27 is an equivalent circuit diagram of a filter using the ring resonator of the present invention.

FIG. 28 is a diagram showing a conventional ring resonator.

FIG. 29 is a diagram showing a conventional ring resonator.

[Explanation of symbols]

1 sheet - Rudoke - scan second inductance forming part 3 bent portion 4 solid dielectric L ₁ inductance L ₂ the inductance L ₃ inductance L Inductance C _A capacitance 5 input (or output) terminal 6 Input (or output) coupling element 7 output (or Input) terminal 8 Output (or input) coupling element T _I Input terminal T _O Output terminal C _I Input coupling capacitance C _O Output coupling capacitance R Resonance circuit 10 Tap coupling conductor 11 Coupling element 12 Coupling element M _I Magnetic field coupling coefficient M _O Magnetic field coupling coefficient 13 Band-shaped metal plate 14 Band-shaped metal plate 15 Coupling loop 16 Coupling loop 17 Fixed electrode plate 18 Movable electrode plate 19 Drive screw 20 Lock nut 21 Tuning screw 22 Lock nut 31 Common sheath Rudoke - scan 2 ₁ inductance forming part 2 ₂ inductance forming part 2 ₃ inductance forming part 2 ₄ inductance forming part 3 ₁ bent portion 3 ₂ folded portions 3 ₃ Ri bending portion 3 ₄ bent portion 4 ₁ solid dielectric 4 ₂ solid dielectric 4 ₃ solid dielectric 4 ₄ solid dielectric 32 strip-shaped common fixed portion 33 belt-shaped dielectric plate 33 _first metal thin film deposition section 33 _second metal thin film deposition Part 33 ₃ Metal thin film adhering part 33 ₄ Metal thin film adhering part 23 Inter-stage coupling preventing metal rod 24 Inter-stage coupling inhibiting metal plate 25 Inter-stage coupling inhibiting metal plate 26 Holding device 27 Holding device 28 Inter-stage coupling loop 29 Fixed electrode 30 Fixed electrode 34 Movable electrode 35 Rotation drive shaft 36 Lock nut 37 Capacitance forming electrode 38 Capacitance forming electrode 39 Solid dielectric plate R ₁ Resonance circuit R ₂ Resonance circuit R ₃ Resonance circuit R ₄ Resonance circuit M _I1 Input coupling magnetic field Coefficient M _4O Coupling magnetic field coefficient M ₁₂ Coupling magnetic field coefficient between stages M ₂₃ Coupling magnetic field coefficient between stages M ₃₄ Coupling magnetic field coefficient between stages C _I1 Input coupling capacitance C _4O Output coupling capacitance C ₁₂ Coupling capacitance between stages C ₂₃ Coupling capacitance between stages C ₃₄ interstage coupling capacitance L _I1 coupling inductance L ₁₂ coupling inductance L ₂₃ bond in Inductance L ₃₄ coupling inductance _{L. 4O} coupling inductance C _R1 coupling capacitance C _R2 coupling capacitor C _R3 coupling capacitance C _R4 coupling capacitance C _I1 coupling capacitor C ₁₂ coupling capacitor C ₂₃ coupling capacitor C ₃₄ coupling capacitance _{C. 4O} coupling capacitance L _R1 coupling inductance L _R2 coupling inductance L _R3 coupling inductance L _R4 coupling inductance 40 Printed circuit board 41 Inductance forming part 42 Capacitance forming part 43 Inductance forming part

Claims (4)

(57) [Claims] 1. A one bending a metal plate fixed to the lower wall of the shield case to a U-shaped or U-shaped, the sea and the other end
A resonance element including an inductance forming portion facing the lower wall of the shield case, and a capacitance forming portion between the other end of the inductance forming portion and the lower wall of the shield case facing the other end. A ring resonator characterized by. 2. The width of the inductance forming portion is formed to be approximately 1/2 of the width of the wall surface of the shield case facing the plate surface of the vertical portion of the inductance forming portion, and the vertical portions of the inductance forming portion face each other. The length of the gap is formed to be approximately 1/2 of the width of the wall surface of the shield case parallel to the length direction of the facing gap.
The ring resonator according to 1. 3. One end is fixed to a lower wall of a common shield case.
Bend the metal plate into a U-shape or U-shape.
The inder made to face the lower wall of the common shield case.
Other than the inductance forming part and the inductance forming part.
Of the common shield case facing the end and the other end
A resonant element consisting of a capacitance forming part between the lower wall and
Filtering characterized by being configured by appropriately arranging several cascades
vessel. 4. Each of the inductance forming portions has a contour shape.
Band-shaped common fixed part in the metal plate formed in the shape of comb teeth
To the bottom wall of the common shield case,
Bend the metal piece protruding from the side edge of the through-fixing part.
The filter according to claim 3, which comprises: