JPH08125405A - Resonator and filter comprising the resonator - Google Patents

Abstract

PURPOSE: To realize the simple resonator with an excellent vibration resistance, an excellent voltage resistance characteristic, a wide setting range of a resonance frequency and an excellent temperature characteristic and to realize the filter comprising the resonator. CONSTITUTION: The resonator is provided with a cylinder 2 comprising a dielectric solid whose lower end is fixed to a lower wall of an outer conductor 1 and whose upper part is opposite to an upper wall of the outer conductor 1 at a proper interval, and a fixed electrode 3 is formed by connecting electrically a lower end of a metallic thin layer adhered to an outer circumferential face of the cylinder 2 to a lower wall of the outer conductor 1 to fit a movingelectrode 4 made of a cylindrical conductor to an upper wall of the outer conductor 1. The moving electrode 4 and the fixed electrode 3 are arranged concentrically, and the axial length of the inner end of the moving electrode 4 inserted to the inside of the fixed electrode 3 is changed, and a parallel resonance circuit is formed by an inductance distributed to the outer conductor 1 and a capacitance of a variable resonance capacitive element comprising the fixed electrode 3 and the moving electrode 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel resonator suitable for removing noise or demultiplexing or synthesizing a signal in a radio communication apparatus or a broadcasting apparatus, and a filter comprising the resonator. is there.

[0002]

2. Description of the Related Art In a relatively low frequency band such as a short-wave band or an ultra-high-frequency band, a resonator composed of a coil and a capacitor, which are lumped constant circuit elements, or a main part shown in FIGS. 41 and 42, for example. Conventionally, a helical resonator having a cross-sectional view is used. 41 is a cross-sectional view taken along the line BB of FIG. 42, and FIG. 42 is a cross-sectional view taken along the line AA of FIG. 41. 1 is an outer conductor, 42 is a helical resonance element, and one end is mechanically electrically connected to the inner wall of the outer conductor 1. to be fixedly connected, wound middle portion coiled at a space, the capacitor forming electrodes 43 attached to the other end is fixed to the inner wall of the outer conductor 1 through an insulator 44 ₁ and 44 _2. 45 is a movable electrode, 46 is a driving screw, and 47 is a lock nut. By rotating the driving screw 46 in the forward or reverse direction to move the movable electrode 45 forward or backward, the electrode 43
It is possible to finely adjust the resonance frequency by changing the capacitance between and. 41 and 42, the illustration of the input / output coupling element and the input / output terminal is omitted.

[0003]

A resonator constituted by a coil and a capacitor, which are lumped constant circuit elements,
It is difficult to manufacture a resonator with a high unloaded Q. In the conventional resonator shown in FIGS. 41 and 42, the helical resonance element 42 is formed by winding a metallic wire rod or a relatively thin round bar-shaped conductor in a coil shape.
Not only the heat dissipation area of itself is small, but also the heat conductivity to the outer conductor 1 is poor, so that the heat generated by the power loss in the helical resonance element 42 is difficult to be effectively radiated from the helical resonance element 42 itself and the outer conductor 1. However, there is a drawback that the resonance frequency fluctuates due to deformation of each component of the resonator due to temperature rise. Both ends of the helical resonance element 42 are directly or indirectly supported and fixed to the inner wall of the outer conductor 1,
Since the intermediate portion is formed so as to maintain a coiled posture by itself without being supported by a support body or the like, it is inferior in earthquake resistance, difficult to manufacture, and high in cost. When the diameter of the wire rod or the round bar forming the helical resonance element 42 is relatively large, the helical resonance element 42 itself is deformed due to the temperature rise of the helical resonance element 42, and the insulator is interposed via the electrode 43.
Mechanical strain is repeatedly applied to 44 ₁ and 44 ₂ and
In some cases, 44 ₁ and 44 ₂ may be damaged. Further, the helical resonator has a disadvantage that the withstand voltage characteristic is inferior since the impedance is high. When a filter is configured using such a helical resonator, the various disadvantages of the helical resonator appear as defects of the filter as they are.

[0004]

SUMMARY OF THE INVENTION According to the present invention, the outer periphery of a cylindrical body made of a solid dielectric is fixed at its lower end to the lower wall of an outer conductor, and its upper end is opposed to the upper wall of the outer conductor with a proper interval. A fixed electrode consisting of a thin metal layer attached to the surface and whose lower end is electrically connected to the lower wall of the outer conductor, and the insertion length into the cylindrical body made of a solid dielectric, which is kept coaxial with the fixed electrode. A resonator provided with a variable resonance capacitance element formed by a movable electrode made of a cylindrical or cylindrical conductor attached to an upper wall of an outer conductor so as to be changeable, and a filter made of the resonator. The realization aims to eliminate the drawbacks of conventional resonators and filters.

[0005]

1 (a) is a sectional view showing an embodiment of the present invention [a sectional view taken along line BB of FIG. 1 (b)], and FIG.
In the cross-sectional view taken along the line AA of (a), reference numeral 1 denotes an outer conductor, which is illustrated as a rectangular cube, but it may be formed as a bottomed cylindrical body. Reference numeral 2 denotes a cylindrical body made of a solid dielectric, the lower end of which is fixed to the lower wall of the outer conductor 1 by means such as using an appropriate adhesive, and the upper end of which is spaced apart from the upper wall of the outer conductor 1 by an appropriate distance. They are facing each other. Reference numeral 3 denotes a fixed electrode, which is composed of a thin metal layer of silver or the like attached to the outer peripheral surface of the cylindrical body 2 made of a solid dielectric, the lower end portion of which is electrically connected to the lower wall of the outer conductor 1 by means such as soldering. It is connected. Reference numeral 4 denotes a movable electrode, which is made of a cylindrical or cylindrical conductor (for example, silver) whose outer peripheral surface is threaded, and which is coaxial with the fixed electrode 3 and is screwed into a screw hole provided on the upper wall of the outer conductor 1. , The forward / backward rotation by rotating in the forward or reverse direction makes it possible to change the insertion length into the cylindrical body 2 made of a solid dielectric, and thus also the insertion length into the fixed electrode 3. I am doing it. 5 is a lock nut. Reference numeral 6 is an input (or output) terminal, and 7 is an output (or input) terminal, each of which is, for example, a coaxial plug, and the outer conductor forming each coaxial plug is connected to the outer conductor 1 forming the resonator. is there. 8
Is an input (or output) coupling wire, one end of which is connected to the inner conductor of the coaxial connector 6 and the other end of which is connected to the fixed electrode 3. Reference numeral 9 denotes an output (or input) coupling wire, one end of which is connected to the internal conductor of the coaxial connector 7 and the other end of which is connected to the fixed electrode 3. Reference numeral 10 is a fine adjustment element for the resonance frequency, and is composed of, for example, a metal screw screwed to the wall surface of the outer conductor 1. 11 is a lock nut.

In the resonator of the present invention thus constructed, the distributed inductance in the outer conductor 1 and the capacitance in the variable resonance capacitor formed by the cylindrical body 2 made of a solid dielectric, the fixed electrode 3 and the movable electrode 4 are used. A parallel resonance circuit as shown in the equivalent circuit diagram of FIG. In FIG. 2, R is a resonance circuit, T ₆ is an input (or output) terminal, T ₇ is an output (or input) terminal, M _6R is an input (or output) magnetic field coupling coefficient, and M _R7 is an output (or input) magnetic field. It is the coupling coefficient. For example, when high frequency power is applied to the coaxial connector 6, the electromagnetic field distribution in the resonator of the present invention is as shown in FIG.
As shown in (a) and FIG. 1 (b). A solid line E with an arrow in FIG. 1A represents an electric field vector, a solid line I with an arrow represents a current, and a broken line H in FIG. 1B represents a magnetic field. The resonator of the present invention has a relatively small inductance component and a relatively large capacitance component, so that the resonator has a low impedance type and a good withstand voltage characteristic.
By using a material having a high dielectric constant and a dielectric loss as low as approximately zero as the cylindrical body 2 made of a solid dielectric material forming the variable resonance capacitor, the cylindrical body 2 made of a solid dielectric material, the fixed electrode 3, and Q (Q _d ) of the variable resonance capacitance element composed of the movable electrode 4 can be neglected, and the electromagnetic energy which can be accumulated in the resonator of the present invention corresponds to the volume of the outer conductor 1 to constitute the resonator of the present invention. Since it is possible to make the resistance in the metal part that operates extremely low, a very large unloaded Q can be obtained. The size of the no-load Q (Q _u ) in the case where the outer conductor 1, the fixed electrode 3 and the movable electrode 4 in the resonator of the present invention are made of copper also depends on the ratio of the inductance component and the capacitance component in the resonator of the present invention. Although different, the inventor of the present invention has no load Q (Q
The empirical formula of _u ) was obtained. Q _u ≒ 20f _O ^1/2 · SH (1) In the above formula, f _O : resonance frequency (MHz) SH: height of outer conductor 1 (cm)

FIG. 1 exemplifies the case where the capacitance of the resonator of the present invention is formed by a cylindrical body 2 made of a solid dielectric, a fixed electrode 3 and a movable electrode 4, but a variable capacitance capacitor made of a lumped constant circuit element. May be used. FIG. 1 shows a case in which the input (or output) terminal 6 and the fixed electrode 3 and the output (or input) terminal 7 and the fixed electrode 3 are tap-coupled by coupling lines 8 and 9 as means for coupling in high frequency. As shown in FIG. 3, a means for capacitively coupling the terminal 6 and the fixed electrode 3 through the capacitive element 12 is used, and a capacitance between the terminal 7 and the fixed electrode 3 is provided through the capacitive element 13. A coupling means may be used. As shown in FIG. 4, the probes 14 and 15 are used as the input / output coupling means, or the loop 16 is used as the input / output coupling means as shown in FIG.
And 17 may be used. 3 to 5 are shown in FIG.
Of the side walls of the outer conductor 1 in (b), which corresponds to a cross-sectional view looking upward except the lower side wall (toward the drawing),
Hereinafter, drawings similar to FIGS. 3 to 5, for example, FIG. 6 and the like are also similar cross-sectional views. 3 to 5, reference numerals and configurations not mentioned in the description of the drawings refer to FIG.
Is the same as

FIG. 6 is a sectional view showing another embodiment of the present invention, in which 18 and 19 are inductance elements for compensating transmission characteristics,
Reference numeral 20 denotes a capacitive element for coupling, and other reference numerals and configurations are the same as those in FIG. FIG. 7 is an equivalent circuit diagram of the resonator shown in FIG.
R is a resonance circuit formed by the external conductor 1 and the variable resonance capacitance element, T ₆ and T ₇ are connection terminals to the external circuit, and other reference numerals are the same as those in FIG. In this embodiment, the inductance elements 18 and 19 for transmission characteristic compensation inserted between the connection terminals 6 and 7 to the external circuit, the fixed electrode forming the variable resonance capacitance element and the connection point of the inductance elements 18 and 19 are connected. A low-pass filter circuit is formed by the capacitive element 20 inserted and connected between the resonance frequency f _O and the resonance frequency f _O as shown in FIG. 8 (horizontal axis represents frequency, vertical axis represents attenuation amount). The slope of the attenuation characteristic curve in the low frequency region becomes steep, the slope of the attenuation characteristic curve in the frequency region higher than the resonance frequency f _O becomes gentle, and a transmission stop band is formed in the frequency region including the resonance frequency f _O. In addition, according to the capacitance of the coupling capacitance element 20, the resonance circuit R and the coupling capacitance element
The resonance frequency f _{O of the} circuit composed of 20 changes, and fine adjustment of the resonance frequency can be performed by providing an adjusting element similar to the resonance frequency fine adjusting element 10 shown in FIG. FIG. 9 shows a transmission characteristic compensating inductance element 18 and
19 connection points and fixed electrode 3 forming a variable resonance capacitor
The resonance frequency f _{O of the} circuit including the resonance circuit R and the coupling inductance element 21 changes according to the inductance of the inductance element 21. 6 is different from the embodiment shown in FIG. 6, and other reference numerals, configurations and operations are almost the same as those of the embodiment shown in FIG. Figure 10
In the equivalent circuit diagram of the resonator shown in FIG. 9, the reference numerals other than the inductance element 21 are the same as those in FIG. 7. FIG. 11 (the horizontal axis and the vertical axis are the same as those in FIG. 8) is a diagram showing the transmission characteristics of the resonator shown in FIG. 9, and is almost the same as the characteristics shown in FIG. FIG. 12 is also a cross-sectional view showing another embodiment of the present invention. In this embodiment, the inductance elements 18 and 19 for compensating the transmission characteristics in the embodiment shown in FIG. 6 are replaced with the capacitance elements 22 and 23. The point is different from the embodiment shown in FIG. 6, and other reference numerals and configurations are the same as the embodiment shown in FIG. FIG. 13 is an equivalent circuit diagram of the resonator shown in FIG. 12, and the reference numerals other than the capacitive elements 22 and 23 are the same as those in FIG. 7. FIG. 14 (the horizontal axis and the vertical axis are the same as in FIG. 8)
12 is a diagram showing the transmission characteristics of the resonator shown in FIG. 12, and in the present embodiment, the slope of the attenuation characteristic curve in the frequency region lower than the resonance frequency f _O is gentle and in the frequency region higher than the resonance frequency f _O. The slope of the damping characteristic curve is steep,
A stop band is formed in the frequency region including the resonance frequency f _O. The embodiment shown in FIG. 15 is similar to the embodiment shown in FIG. 12 in that the capacitance elements 22 and 23 are used as the transmission characteristic compensation elements, and the inductance element 21 is used as the coupling element to form tap coupling. The difference is similar to the embodiment shown in FIG. 9, and other reference numerals and configurations are the same as the embodiment shown in FIG. 16 is an equivalent circuit diagram of the resonator shown in FIG. 15, and reference numerals are the same as those in FIG. 13 except the inductance element 21. FIG. 17 (the horizontal axis and the vertical axis are the same as those in FIG. 14) is a diagram showing the transmission characteristics of the resonator shown in FIG. 15, and is almost the same as the characteristics shown in FIG. FIG.
21 to 21 are sectional views showing another embodiment of the present invention, and FIG. 18 is a coupling element 20 in the embodiment shown in FIG.
20 by replacing the coupling element 20 in the embodiment shown in FIG. 6 with a loop 16.
Is a coupling element 20 in the embodiment shown in FIG.
21 is obtained by replacing the coupling element 20 in the embodiment shown in FIG. 12 with the loop 16, and other reference numerals and configurations in each drawing are the same as those in FIG. 6 or 12. .

FIG. 22 is a cross-sectional view (cross-sectional view taken along the line BB of FIG. 23) showing a filter constructed by using the resonator of the present invention shown in FIG. 1, and FIG. 23 is a cross-sectional view taken along the line A-A of FIG. In both figures, 1C is a common outer conductor, 3 ₁ to 3 ₄ are fixed electrodes similar to those described in FIG. 1, and 4 ₁ to 4 ₄ are also shown in FIG.
The movable electrode is the same as that described in, and the fixed electrode 3 ₁
Through 3 ₄ form a variable resonance element. 5 ₁ to
5 ₄ is a lock nut, 6 is an input (or output) terminal, 7 is an output (or input) terminal, 8 is an input (or output) coupling wire, 9
Is an output (or input) coupling wire, 10 ₁ to 10 ₄ are fine adjustment elements for resonance frequency, 11 ₁ to 11 ₄ are lock nuts, and these are also lock nuts 5 and input (or output) terminals shown in FIG. 6, output (or input) terminal 7, tap coupling wire 8
9 and 9, the resonance frequency fine adjustment element 10, and the lock nut 11. FIG. 24 is an equivalent circuit diagram of the filter of the present invention shown in FIGS. 22 and 23. R ₁ to R ₄ are resonance circuits, T ₆ is an input (or output) terminal, and T ₇ is an output (or input).
Terminals, M ₆₁ is an input (or output) magnetic field coupling coefficient, M ₄₇ is an output (or input) magnetic field coupling coefficient, and M ₁₂ to M ₃₄ are interstage magnetic field coupling coefficients. 25 is a conversion equivalent circuit diagram of the equivalent circuit diagram shown in FIG. 24, and reference numerals are the same as those in FIG. 22 to 25 exemplify the case where the input / output coupling element is formed by the tap coupling lines 8 and 9, but from the capacitors 12 and 13 or the probes 14 and 15 shown in FIGS. The present invention can also be implemented by using a capacitive coupling element or a magnetic field coupling element composed of the loops 16 and 17.

Also in designing the bandpass filter of the present invention shown in FIGS. 22 to 25, the element value of the standardized low-pass filter is obtained, and the circuit constant is determined from this value to obtain the required transmission characteristic. What is obtained is the same as the conventional design method, and the process shown in FIG.
Fig. 27 (horizontal axis is the standardized frequency, vertical axis is the attenuation, f _C is the standardized cutoff frequency) is a curve diagram of the transmission characteristics. Based on the element values g ₁ to g _n of the filter, a case will be described in which a band-pass filter having a Tie-Visiev characteristic in the pass band and a Wagner characteristic in the attenuation band is designed. Voltage standing wave ratio (VSWR) in the passband allowed by the design of the bandpass filter
Let S be S, the allowable ripple L _r in the pass band is expressed by the following equation.

[Equation 1] Together determine the allowable ripple L _r from the above equation, we obtain the element values g ₁ from Equation (3) defines a circuit order n, to no element values g ₂ from equation (4) determining the g _n.

[Equation 2] k = 2, 3, ---, n In formulas (3) and (4),

(Equation 3) In FIG. 26, R _L is a load resistance, and when the circuit order n is an odd number, R _L = 1 ... (9) When the circuit order n is an even number,

[Equation 4] From the element values g ₁ to g _n obtained from the equations (3) and (4), the required center frequency f _O of the band-pass filter, and the pass bandwidth Bwr, the input-output magnetic field coupling coefficient and the inter-step magnetic field coupling coefficient are calculated. Expression (1
1) and Equation (12). When the input / output magnetic field coupling coefficient is represented by M ₀₁ and M _{n, n + 1} ,

(Equation 5) M ₁₂ = M _{n−1, n} , M ₂₃ = M
_{n-2, n-1} and ------ and these are collectively referred to as M
_{k, k + 1} (k = 1, 2, -----, n-1)

(Equation 6) 28 and the inter-stage magnetic field coupling coefficient M _{k, k + 1} obtained by the equation (12).
And can be used to find the center distance between the adjacent resonant capacitors. FIG. 28 shows an example of the relationship between the inter-stage magnetic field coupling coefficient and the center interval of the adjacent resonance capacitive elements, which is obtained as a result of repeated experiments on the prototype by the present inventor. -0.3C) / W where: d: center distance between adjacent variable resonance capacitors (Fig. 22) C: outer diameter of fixed electrode forming the variable resonance capacitors (Fig. 2)
2) W: Width of common outer conductor (FIG. 23) Further, the vertical axis represents the inter-stage magnetic field coupling coefficient M _{k, k + 1} .

The transmission characteristic L of the band pass filter of the present invention shown in FIGS. 22 to 25 is expressed by the following equation.

(Equation 7) In the above equation, L: Transmission loss T _n (x) is a Chebyshev polynomial, and when x <1, T _n (x) = cos (n cos ⁻¹ x) When x> 1, T _n (x) = Cosh (n cosh ^-1 x) x: normalized frequency,

(Equation 8) f ₀ : Center frequency in pass band of BPF f: Arbitrary transmission frequency Bwr: Allowable pass frequency bandwidth S: Allowable voltage standing wave ratio (VSWR) in pass band FIG. 29 is shown in FIG. 22 to FIG. 25. It is a figure which shows an example of the transmission characteristic of the filter of this invention, a horizontal axis is a frequency and a vertical axis is an attenuation amount.

[0012] Figure 30 is a sectional view showing the present invention the band-pass device which constitutes the interstage coupling with electric field coupling (cross-sectional view similar portion as FIG 22), 1C common outer conductor, to 3 ₁ 3 ₄ is a fixed electrode, 4 ₁ to 4 ₄ are movable electrodes, 5 ₁ to 5 ₄ are lock nuts, 6 is an input (or output) terminal, 7 is an output (or input) terminal, 24 ₆₁ is an input (or output) coupling Capacitance element, 24 ₁₂
To 24 ₃₄ are inter-stage coupling capacitance elements, and 24 ₄₇ are output (or input) coupling capacitance elements. 31 is an equivalent circuit diagram of the band-pass filter of the present invention shown in FIG. 30, where T ₆ is an input (or output) terminal, R ₁ to R ₄ are resonant circuits, and 24 ₆₁ is an input (or output) coupling. Capacitances, 24 ₁₂ to 24 ₃₄ are interstage coupling capacitors, 24 ₄₇ are output (or input) coupling capacitors, and T ₇ is an output (or input) terminal. 32 is a conversion equivalent circuit diagram of the equivalent circuit shown in FIG. 31, and reference numerals are the same as those in FIG. Although FIG. 30 exemplifies a case where the input / output coupling element is formed of a capacitive element, a high frequency coupling means such as a tap coupling line, a probe or a loop may be used. FIG. 33 is a diagram showing an example of the transmission characteristics of the bandpass filter of the present invention shown in FIG. 30, in which the horizontal axis represents frequency and the vertical axis represents attenuation amount.

FIG. 34 is a sectional view showing a filter constituted by using the resonator of the present invention shown in FIG. 6 [AA sectional view of FIG. 35], and FIG. 35 is a right side view of FIG. , In both figures,
1C is a common outer conductor, 1S ₁ to 1S ₃ are partition walls made of conductor plates, 3 ₁ to 3 ₄ are fixed electrodes, 4 ₁ to 4 ₄ are movable electrodes,
5 ₄ is a lock nut, 6 and 7 are terminals for connecting to an external circuit,
18 ₁ , 19 ₁ to 18 ₄ and 19 ₄ are inductance elements for compensating transmission characteristics, and 20 ₁ to 20 ₄ are coupling capacitance elements.
36 is an equivalent circuit diagram of the filter shown in FIG. 34, wherein R ₁ to R ₄ are fixed electrodes 3 ₁ to 3 ₄ and movable electrodes 4 ₁ to 4 ₄
A resonant circuit formed by a variable resonance capacitor element and a common outer conductor 1C, T ₆ and T ₇ are connection terminals with the external circuit, and 18 ₁ , 198 ₁ to 198 ₃ and 19 ₄ are inductances for transmission characteristic compensation. in element 198 ₁ is combined inductance element of the inductance elements 19 ₁ and 18 ₂ in FIG. 34, 198 ₂
The combined inductance element of the inductance elements 19 ₂ and 18 _3, 198 ₃ combined inductance element of the inductance elements 19 ₃ and 18 _4, 20 ₁ to 20 ₄ are coupling capacitance element. The transmission characteristics of the filter shown in FIG. 34 are those obtained by superimposing and combining the transmission characteristics of the resonators at the respective stages constituting this filter, that is, the transmission characteristics almost the same as those shown in FIG. , If the resonance frequencies (f _O in FIG. 8) of the circuit composed of the resonators of each stage and the coupling capacitance element are f _O1 to f _O4 , these resonance frequencies are appropriately adjusted, for example, by bringing them close to each other, It is possible to provide a blocking region with a large amount of attenuation, and it is possible to provide a blocking region with a wide frequency range by adjusting the resonance frequencies f _O1 to f _O4 of the respective stages to values that are appropriately separated. Figure 37 is an equivalent circuit diagram of a and braze filter constructed using the resonator shown in FIG. 9, 21 ₁
Numerals 2 to 21 ₄ are inductance elements for tap coupling, and other reference numerals are the same as those in FIG. The transmission characteristic of the filter of the present invention represented by the equivalent circuit diagram shown in FIG. 37 is almost the same as the transmission characteristic of the resonators at each stage constituting the filter, that is, the transmission characteristic shown in FIG. The transmission characteristics of (1) are superposed and combined, and by appropriately adjusting the resonance frequency of each stage, it is possible to appropriately adjust the attenuation amount and frequency range of the combined blocking region. Figure 38 is a sectional view showing the present invention duplexer braze constructed using the resonator shown in FIG. 15, to 22 _1, 23 ₁
22 ₄ and 23 ₄ are capacitive elements for compensating transmission characteristics, 21 ₁ to 21
Reference numeral ₄ denotes an inductance element for tap coupling, and other symbols and configurations are the same as those in FIG. FIG. 39 is an equivalent circuit diagram of the filter shown in FIG. 38, in which R ₁ to R ₄ are resonant circuits and T ₆
And T ₇ are terminals for connecting to an external circuit, 22 ₁ , 232 ₁ to 232 ₃
And 23 ₄ are capacitance elements for compensating transmission characteristics, and 2 32 ₁ is a capacitance element in FIG.
, The combined capacitive element of the capacitive elements 23 ₁ and 22 ₂ , 232 ₂ is the combined capacitive element of the capacitive elements 23 ₂ and 22 ₃ , and 232 ₃ is the capacitive element 23 ₃
And 22 ₄ are combined capacitive elements, and 21 ₁ to 21 ₄ are inductance elements for tap coupling. The transmission characteristic of the filter of the present invention shown in FIG. 38 is obtained by superposing and combining the transmission characteristics of the resonators at the respective stages constituting this filter, that is, the transmission characteristic almost the same as the transmission characteristic shown in FIG. By appropriately adjusting the resonance frequency of each stage, the attenuation amount and frequency range of the combined block region can be adjusted appropriately. Figure 40
It is an equivalent circuit diagram of a configuration to braze duplexer using the resonator shown in FIG. 12, the 20 ₁ to 20 ₄ with coupling capacitance element, and other reference numerals are the same as in FIG. 39. The transmission characteristic of the filter of the present invention represented by the equivalent circuit diagram shown in FIG. 40 is almost the same as the transmission characteristic of the resonators at the respective stages constituting this filter, that is, the transmission characteristic shown in FIG. The transmission characteristics of (1) are superposed and combined, and by appropriately adjusting the resonance frequency of each stage, it is possible to appropriately adjust the attenuation amount and frequency range of the combined blocking region. The filter of the present invention described with reference to the drawings after FIG. 22 is a case where four variable resonance capacitance elements are provided, that is, the circuit order n is 4. However, the circuit order can be increased or decreased as appropriate. The invention may be implemented. Further, although the filter of the present invention described with reference to the drawings after FIG. 22 is a combline type filter, the present invention can also be applied to an interdigital type filter.

[0014]

In the resonator of the present invention, since the resonance capacitance element is formed in a variable capacitance type, the resonance frequency can be set over a wide range, and the heat radiation area of the variable resonance capacitance element is relatively wide. Since the variable resonant capacitance element and the external conductor have good thermal conductivity, the resonant capacitance element and the external conductor effectively radiate heat, and the temperature rise of each part of the resonator is suppressed to a low level.
The fluctuation of the resonance frequency due to the deformation of each part due to the temperature rise becomes extremely small. In addition, the structure is extremely simple and mechanically robust, so it has excellent seismic resistance, and the resonator impedance
It has features such as low dance and good withstand voltage characteristics, and the filter comprising the resonator of the present invention also has the same features as described above.

[Brief description of drawings]

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

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

FIG. 3 is a sectional view showing another embodiment of the present invention.

FIG. 4 is a sectional view showing another embodiment of the present invention.

FIG. 5 is a cross-sectional view showing another embodiment of the present invention.

FIG. 6 is a sectional view showing another embodiment of the present invention.

FIG. 7 is an equivalent circuit diagram of the resonator of the present invention.

FIG. 8 is a diagram showing transmission characteristics of the resonator of the present invention.

FIG. 9 is a cross-sectional view showing another embodiment of the present invention.

FIG. 10 is an equivalent circuit diagram of the resonator of the present invention.

FIG. 11 is a diagram showing transmission characteristics of the resonator of the present invention.

FIG. 12 is a sectional view showing another embodiment of the present invention.

FIG. 13 is an equivalent circuit diagram of the resonator of the present invention.

FIG. 14 is a diagram showing transmission characteristics of the resonator of the present invention.

FIG. 15 is a sectional view showing another embodiment of the present invention.

FIG. 16 is an equivalent circuit diagram of the resonator of the present invention.

FIG. 17 is a diagram showing transmission characteristics of the resonator of the present invention.

FIG. 18 is a sectional view showing another embodiment of the present invention.

FIG. 19 is a sectional view showing another embodiment of the present invention.

FIG. 20 is a sectional view showing another embodiment of the present invention.

FIG. 21 is a sectional view showing another embodiment of the present invention.

FIG. 22 is a sectional view showing the filter of the present invention.

FIG. 23 is a cross-sectional view showing the filter of the present invention.

FIG. 24 is an equivalent circuit diagram of the filter of the present invention.

FIG. 25 is an equivalent circuit diagram of the filter of the present invention.

FIG. 26 is a diagram for explaining a designing method of the filter of the present invention.

FIG. 27 is a diagram for explaining a designing method of the filter of the present invention.

FIG. 28 is a diagram for explaining a designing method of the filter of the present invention.

FIG. 29 is a diagram showing transmission characteristics of the filter of the present invention.

FIG. 30 is a sectional view showing the filter of the present invention.

FIG. 31 is an equivalent circuit diagram of the filter of the present invention.

FIG. 32 is an equivalent circuit diagram of the filter of the present invention.

FIG. 33 is a diagram showing transmission characteristics of the filter of the present invention.

FIG. 34 is a sectional view showing the filter of the present invention.

FIG. 35 is a side view showing the filter of the present invention.

FIG. 36 is an equivalent circuit diagram of the filter of the present invention.

FIG. 37 is an equivalent circuit diagram of the filter of the present invention.

FIG. 38 is a sectional view showing the filter of the present invention.

FIG. 39 is an equivalent circuit diagram of the filter of the present invention.

FIG. 40 is an equivalent circuit diagram of the filter of the present invention.

FIG. 41 is a sectional view showing a conventional helical resonator.

FIG. 42 is a sectional view showing a conventional helical resonator.

[Explanation of symbols]

1 outer conductor 2 cylindrical body made of solid dielectric 3 fixed electrode 4 movable electrode 5 lock nut 6, 7 input / output terminal 8, 9 input / output coupling line 10 resonance frequency fine adjustment element 11 locknut 12, 13 capacitive element 14, 15 Probes 16 and 17 Loops 18 and 19 Transmission characteristic compensation inductance element 20 Coupling capacitance element 21 Coupling inductance element 22 and 23 Transmission characteristic compensation capacitance element 1C Common outer conductor 3 _{1 to} 3 ₄ Fixed electrode 4 ₁ to 4 ₄ Movable electrode 5 _{1 to} 5 ₄ Lock nut 10 _{1 to} 11 ₄ Resonance frequency fine adjustment element 11 _{1 to} 11 ₄ Lock nut 24 ₆₁ , 24 _{47 I} / O coupling capacitance element 24 ₁₂ 〜 24 ₃₄ Inter-stage coupling capacitance element 18 ₁ to 18 ₄ Transmission characteristic compensation inductance element 19 _{1 to} 19 ₄ Transmission characteristic compensation inductance element 20 _{1 to} 20 ₄ Coupling capacitance element 1S _{1 to} 1S ₃ Partition wall 22 _{1 to} 22 ₄ Transmission characteristic compensation capacitance element 23 ₁ to 23 ₄ transmission characteristic compensating capacitance element 21 ₁ to 21 ₄ coupling Inn Reactance element 42 a helical resonance element 43 electrodes 44 _1, 44 ₂ insulator 45 movable electrode 46 driving screw 47 Lock nut

Claims (7)

[Claims] 1. A lower end portion of an outer conductor is fixed to a lower wall of the outer conductor, and an upper end portion of the outer conductor is attached to an outer peripheral surface of a solid dielectric body facing the upper wall of the outer conductor at an appropriate interval. A fixed electrode made of a thin metal layer electrically connected to the lower wall of the outer conductor; and a fixed electrode that is kept coaxial with the fixed electrode and can change the insertion length into the cylindrical body made of the solid dielectric. A resonator comprising a variable resonance capacitor element formed by a movable electrode made of a cylindrical or cylindrical conductor attached to the upper wall of the outer conductor. 2. A lower end of an outer conductor is fixed to a lower wall of the outer conductor, and an upper end of the outer conductor is attached to an outer circumferential surface of a solid dielectric body facing the upper wall of the outer conductor at an appropriate interval. A fixed electrode made of a thin metal layer electrically connected to the lower wall of the outer conductor and coaxial with the fixed electrode, and the insertion length into the cylindrical body made of the solid dielectric can be changed. A variable resonance capacitance element formed by a movable electrode made of a cylindrical or cylindrical conductor attached to the upper wall of the outer conductor, and a fixed element forming the input (or output) terminal and the variable resonance capacitance element. A resonator comprising means for coupling an electrode with a high frequency, and means for coupling an output (or input) terminal and a fixed electrode forming the variable resonance capacitor element with a high frequency. 3. A lower end of an outer conductor is fixed to a lower wall of the outer conductor, and an upper end of the outer conductor is attached to an outer peripheral surface of a solid dielectric body facing the upper wall of the outer conductor at an appropriate interval. A fixed electrode made of a thin metal layer electrically connected to the lower wall of the outer conductor and coaxial with the fixed electrode, and the insertion length into the cylindrical body made of the solid dielectric can be changed. The variable resonance capacitor formed by a movable electrode made of a cylindrical or cylindrical conductor attached to the upper wall of the outer conductor, and is inserted between two terminals for interrupt connection to an external circuit. In addition, a series circuit of two transmission characteristic compensation inductance elements or capacitance elements, a connection point between the two transmission characteristic compensation inductance elements or capacitance elements, and a fixed electrode forming the variable resonance capacitance element Target Resonator, comprising the means for coupling. 4. A lower end of a common outer conductor is fixed to the lower wall of the common outer conductor, and an upper end of the outer conductor is attached to an outer peripheral surface of a solid dielectric body facing the upper wall of the outer conductor at an appropriate interval.
A fixed electrode composed of a thin metal layer whose lower end is electrically connected to the lower wall of the common outer conductor, and an insertion length which is kept coaxial with the fixed electrode and is inserted into the cylindrical body made of the solid dielectric. A plurality of variable resonance capacitors, which are formed by a movable electrode made of a cylindrical or columnar conductor and attached to the upper wall of the common outer conductor so as to be variable, and are arranged at appropriate intervals. An element, a series circuit of a plurality of transmission characteristic compensating inductance elements or capacitance elements inserted between two terminals for interrupt connection to an external circuit, and the plurality of transmission characteristic compensating inductance elements or capacitors A filter comprising, at each connection point between the elements, means for separately coupling a fixed electrode forming each of the plurality of variable resonance capacitors in terms of high frequency. 5. A lower end of a common outer conductor is fixed to a lower wall of the common outer conductor, and an upper end of the outer conductor is attached to an outer peripheral surface of a solid dielectric body facing the upper wall of the outer conductor with an appropriate interval.
A fixed electrode composed of a thin metal layer whose lower end is electrically connected to the lower wall of the common outer conductor, and an insertion length which is kept coaxial with the fixed electrode and is inserted into the cylindrical body made of the solid dielectric. It is formed by a movable electrode made of a cylindrical or columnar conductor attached to the upper wall of the common outer conductor so as to be changeable, and is arranged at an appropriate interval from each other, and it is also subjected to high-frequency heating. A plurality of variable resonance capacitance elements connected in series, and a fixed electrode forming a variable resonance capacitance element of the first stage (or the last stage) of the plurality of variable resonance capacitance elements is applied to the input (or output) terminal at high frequency. And a means for coupling a fixed electrode forming a final stage (or initial stage) variable resonant capacitance element among the plurality of variable resonant capacitance elements to an output (or input) terminal in a high frequency manner. Characterized by that Vessel. 6. The filter according to claim 5, wherein the plurality of variable resonance capacitors are connected in series by magnetic field coupling. 7. The filter according to claim 5, wherein the cascade connection of the plurality of variable resonance capacitance elements is electric field coupling.