JPH0818304A - Band pass filter consisting of double mode dielectric resonator - Google Patents

Abstract

PURPOSE:To realize the band pass filter which has the temperature characteristic improved and stabilized and is superior in quake-proof property. CONSTITUTION:A resonance element main body 2R consisting of a part which has a relatively large diameter, a supporting part consisting of a part 2S which has a relatively small diameter, and a flange part 2F are collected into one body by the same solid state dielectric material to form a double mode dielectric resonance element 2. The flange part 2F of the double mode dielectric resonance element 2 is attached to an end wall 14 and a partition of an outer conductor. Resonance frequency fine adjustment elements 5 and 6 of the H mode and the V mode, an inter-mode coupling adjustment element 7 and an input/output coupling element 3 are attached to a cylindrical partition 11 of the outer conductor.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to the ultra high frequency band (UHF).
Also, the present invention relates to a bandpass filter constituted by using a double mode dielectric resonator, which is suitable as a constituent element of various communication devices such as a wireless communication device or a broadcasting device in the centimeter wave band (SHF).

[0002]

2. Description of the Related Art FIG. 23 (a) is a sectional view showing a conventional band-pass filter made of a double mode dielectric resonator [FIG.
23B is a cross-sectional view taken along line CC of FIG. 23B.
23A is an end view taken along line AA of FIG. 23A, and FIG.
Cylindrical side wall of the in B-B end view, 1 ₁ and 1 ₂ is the external conductor,
1 ₃ and 1 ₄ is external conductor of the end wall, 12 ₁ and 12 ₂ are dual mode - de dielectric resonance element, 13 ₁ to 13 ₄ in support of the boat, such as polytetrafluoroethylene (so-called Teflon) or It is made of a solid dielectric having a low dielectric constant such as polystyrene. Between the outer conductor cylindrical side wall 1 ₁ of the support 13 ₁ and 13 _2, between the cylindrical side wall 1 ₂ of the outer conductor and the support 13 _3, and 13 _4,
It is fixed with an appropriate adhesive. 5 ₁ , 5 ₂ and 5 ₃ , 5 ₄ are H-mode resonance frequency fine adjustment elements, 6 ₁ , 6 ₂ and 6 ₃ , 6 ₄ are V-mode resonance frequency fine adjustment elements, 7 ₁ , 7 ₂ and 7 ₃ , 7 ₄ are inter-mode coupling adjusting elements, the common axis of the elements 5 ₁ and 5 _{2 and} the common axis of the elements 6 ₁ and 6 ₂ are orthogonal to each other, and the elements 5 ₃ and 5 ₄ The common axis and the common axis of the elements 6 ₃ and 6 ₄ are orthogonal to each other, the common axis of the elements 7 ₁ and 7 _{2 and} the common axis of the elements 7 ₃ and 7 ₄ are orthogonal to each other, and the element 5 ₁ and The common axis of 5 _{2 and} the common axis of the elements 7 ₁ and 7 ₂ are mounted so as to intersect each other with an angle difference of 45 °. 8 _V is an input (or output) coupling loop, 4 _V is an input (or output) terminal, _{82 V} is an output (or input) coupling loop
, _{42 V} is an output (or input) terminal, ₁₅ is a partition wall, and 9 is an inter-stage coupling hole. FIG. 24 is a diagram showing a conventional duplexer,
Each of F ₁ and F ₂ is a conventional bandpass filter, and the respective pass center frequencies are appropriately different from each other. L ₁ and L ₂ connect the input / output terminals of the band pass filter F ₁ and F ₂ to the T-type connector TC
CA is a cable connected to a common antenna or the like.

[0003]

In the conventional band-pass filter composed of the double-mode dielectric resonator shown in FIG. 23, the supports 13 ₁ to 13 composed of a solid dielectric having a low dielectric constant are used. _The dual mode dielectric resonant elements 12 ₁ and 12
₂ is configured to be supported at a required location, but in general, a solid dielectric with a low dielectric constant has a large coefficient of linear expansion with respect to temperature changes, and is inferior in temperature characteristics of the dielectric constant. It is extremely difficult to make the temperature characteristics of a bandpass filter formed by using a conventional resonator configured to support a resonant element by a dielectric material good and stable. or,
When a duplexer is constructed using the above-mentioned conventional resonator, it is extremely difficult to stabilize the temperature characteristics well, and the input / output coupling filter of the band pass filter F ₁ shown in FIG. −
The length from the ground end of the loop to the branch point of the T-type connector TC via the input / output coupling loop and the connecting line L ₁ is the electrical length and corresponds to the pass center frequency of the band pass filter F _2. and forming a _^1/4 or an odd multiple thereof of wavelengths, the band-pass unit F ₂ of the input and output coupling Le - flop input and output coupling Le from ground end - T type via the flop and the connection line L ₂ the reaching the branch point of the connector TC length in electrical length, it is necessary to form a _^1/4 or an odd multiple thereof of a wavelength corresponding to the passing center frequency of the band-pass device F _1. That is, in the conventional duplexer, external connecting lines L ₁ and L ₂ having different lengths from each other are required, so that it is inevitable that the whole becomes complicated and large.

[0004]

SUMMARY OF THE INVENTION According to the present invention, a resonance element body having a relatively large diameter portion, a support portion having a relatively small diameter portion, and a resonance element body via the support portion are provided. A double-layer structure that is integrally formed of the same solid dielectric material with a flange portion that is provided on the opposite side and that is attached to the end wall of the bottomed cylindrical outer conductor or the partition wall that is provided at the intermediate portion in the axial direction of the outer conductor. Dual mode with mode dielectric resonator
The purpose of the present invention is to eliminate the above-mentioned drawbacks of conventional bandpass filters by realizing a bandpass filter composed of a dielectric resonator.

[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 A-A end view of (a), ₁₁ is a cylindrical side wall of the outer conductor,
1 ₃ and 1 ₄ is external conductor of the end walls, 2 double mode - in de dielectric resonant element, as shown in FIG. 1 (c), a cylindrical resonator body 2R, become smaller in diameter than the body 2R Support part 2S and flange part
2F, which are integrally formed of the same solid dielectric material, and the product D × H of the diameter D and the axial length H of the main body 2R integrally forms the main body 2R, the support portion 2S and the flange portion 2F. It is determined according to the material of the solid dielectric, the relative permittivity, the mode used, the resonance frequency, and the like. That is, by appropriately selecting the product D × H of diameter D and axial length H of the body 2R, EH _{11 delta} shown an electromagnetic field distribution in FIG. 2 mode - de dielectric resonance element, or the electromagnetic 3 it is possible to form the de-dielectric resonance element - HE _{11 delta} mode as shown the field distribution. 2 and 3, a solid line with an arrow shows an electric field distribution, and a broken line with an arrow shows a magnetic field distribution. 2 (a) and 3 (a)
Is a side view of only the 2R part of the resonant element body.
FIGS. 3B and 3B are views of the resonant element body 2R viewed from the front, that is, the left side of FIG. 1C.
The diameter d of the supporting portion 2S shown in FIG. 1 (c) is λ / (2ε ^1/2 ).
When it is determined that> d, the supporting portion 2S serves as a blocking area, and there is almost no possibility that the supporting portion 2S affects the resonance action. In addition to the above conditions, the diameter d of the supporting portion 2S is determined in consideration of having sufficient mechanical strength to support the resonant element body 2R. An appropriate number of through holes for a set screw are formed in the peripheral portion of the flange 2F, and as shown in FIG. 1 (a), the flange 2F is fixed to the end wall 1 ₄ (or 1 ₃ ) of the outer conductor by the set screw. Then, the resonance element 2 is supported at a required position. Next, 3 _H is an input (or output) coupling capacitance element, and 3 _V is an output (or input) coupling capacitance element.
It consists of 4 _H is an input (or output) terminal, and 4 _V is an output (or input) terminal, each of which is, for example, a coaxial plug. 5 ₂
The H mode - de of the resonance frequency fine-tuning element, 6 ₂ V mode - de of the resonance frequency fine-tuning element, is 7 ₁ and 7 ₂ mode - a coupling adjustment element between de. Element 3 _H and element 5 ₂ common axis and element 3 _V and element
The common axis of 6 ₂ is orthogonal to each other, and the elements 7 ₁ and 7 ₂
A common axis of the common axis and the element 3 _H and the element 5 ₂ are provided so as to intersect at an angle difference of 45 °. Elements 5 ₂ , 6 ₂ , 7 ₁ and
7 ₂ etc., the insertion length into the outer conductor (hereinafter referred to as the pipe insertion length) can be freely and finely adjusted, and can be fixed at the required pipe insertion length, for example, screwed onto the cylindrical side wall of the outer conductor. It consists of a metal screw and a lock nut. This point is
The same applies to the resonance frequency fine adjustment element and the inter-mode coupling adjustment element in each embodiment described in detail below.

In the band pass filter of the present invention comprising a resonator having a double mode dielectric resonance element as described with reference to FIG. 1C, for example, a terminal 4 _H and a capacitive element 3 _H are used. the addition of input Te, the electromagnetic field shown in FIG. 4 (a) (H mode - de) is generated, mode - when properly adjust the tube insertion length of the coupling adjusting elements ₇₁ and beauty 7 ₂ between de, 4 The electromagnetic field shown in FIG. 4B is generated, and the electromagnetic field (V mode) shown in FIG. 4C is excited by this electromagnetic field. Thus, H mode - by suitably adjusting each tube insertion length of the resonance frequency fine-tuning element 6 ₂ de, - de of the resonance frequency fine-tuning element 5 ₂ and V mode
Double mode resonance occurs. The electromagnetic field shown in FIG. 4C is coupled with the capacitive element 3 _V and output from the terminal 4 _V. A solid line with an arrow in FIG. 4 indicates an electric field, and a broken line with an arrow indicates a magnetic field. FIG. 5 is an equivalent circuit diagram of the bandpass filter, where C ₁ and C ₂ are the size of the resonant element 2, the relative permittivity, and the size of the entire resonator formed together with the outer conductor.
Equivalent capacitance determined by the size of the resonance frequency fine adjustment elements 5 ₂ and 6 ₂ , etc., L ₁ and L ₂ are equivalent inductances determined by the size of the resonance element 2, the relative permittivity, the size of the entire resonator, C ₁₂ the motor - interstage coupling capacitance formed by the de linkage adjustment element ₇₁ and 7 _2, C _T1 is input that is formed by the capacitor 3 _H (or output) binding capacity, C _2T capacitor element 3 _V
Is the output (or input) coupling capacitance formed by

FIG. 6 (a) is a sectional view showing another embodiment of the present invention [a sectional view taken along the line BB of FIG. 6 (b)], and FIG. 6 (b) is
In A-A end view in FIG. 6 (a), the present embodiment, the input (or output) coupling element, provided on the end wall 1 ₃ outer conductor coupling Le -
And forming at flop 8 _H, the capacitor 3 _H in FIG. 1 H mode - which was replaced by de resonance frequency fine-tuning element 5 _1, other numerals and configurations are the same as FIG. It should be noted that the set screw for mechanical coupling of the flange portion of the outer conductor in each of FIGS. 6 and below is omitted from illustration. In the present embodiment, for example, binding Le - flows the input current to the flop 8 _H, bond Le - electromagnetic field generated around the flop 8 _H is shown in FIG. 4 (a) and magnetically coupled with the resonator element 2 An electromagnetic field (H mode) is generated, and thereafter, the electromagnetic field shown in FIG. 4 (b) is generated in the same manner as in the previous embodiment, and the electromagnetic field (V) shown in FIG. 4 (c) is generated by this electromagnetic field.
Mode) is excited, and double mode resonance is performed.
The electromagnetic field shown in (c) is coupled to the capacitive element 3 _V and output from the terminal 4 _V. FIG. 7 is an equivalent circuit diagram of the bandpass filter of the present invention shown in FIG. 6, where M _T1 is an input (or output) magnetic coupling coefficient, and other symbols are the same as those in FIG.

FIG. 8 (a) is also a sectional view showing another embodiment of the present invention [a sectional view taken along the line DD of FIG. 8 (b)], FIG. 8 (b).
8A is an end view of FIG. 8A, and FIG.
In B-B end view of (a), respectively, 2 ₁ and 2 ₂ Figure 1
(C) the same dual mode resonant element shown - in de dielectric resonance element, the flange portion of the resonant element 2 _1, the conductor plate is interposed between the cylindrical side wall 1 ₁ and 1 ₂ of the outer conductor Attached to the partition wall ₁₅ of the resonance element 2 _{2 and} the flange portion of the resonance element 2 ₂ is an end wall 1 _{4 of the} outer conductor.
Figure 9 attached with, substantially at the center of the partition wall 1 ₅ in FIG. 8
C-C end view of (a)], a cross-shaped coupling hole 9 is formed. 5 ₃ and 5 ₄ are resonance mode fine adjustment elements for H mode, 6 ₄ are resonance frequency fine adjustment elements for V mode, 7 ₃ and
7 ₄ is an inter-mode coupling adjusting element, 32 _V is an output (or input) coupling capacitive element, and is composed of, for example, a probe. _{42 V} is an output (or input) terminal, and is composed of, for example, a coaxial plug. Element 5 ₃
And 5 _{4 and} the common axis of the capacitive element 3 _2V and the element 6 ₄ are orthogonal to each other, and the common axis of the elements 7 ₃ and 7 _{4 and} the common axis of the elements 5 ₃ and 5 ₄ are 45 While intersecting at an angle difference of °, the common axes of the elements 7 ₃ and 7 ₄ are orthogonal to the common axes of the elements 7 ₁ and 7 ₂ , and the common axes of the elements 5 ₃ and 5 ₄ and the elements 5 ₁ and 5 It is formed so that the common axis of ₂ is parallel. Other reference numerals and configurations are the same as those in FIGS. 1 and 6.

[0009] For example, via the terminals 4 _V, and the capacitor 3 _V adding input, 10 an electromagnetic field shown in (a) (V mode - de) occurs, mode - de linkage adjustment element 7 ₁ and 7 ₂ the electromagnetic field shown in FIG. 10 (b) generated by the tube insertion length of the adjustment, the electromagnetic field shown in FIG. 10 (c) by an electromagnetic field (H mode - de) are excited, the resonance frequency fine-tuning element 5 ₁ , dual mode by adjusting the 5 ₂ and the tube insertion length of 6 ₂ - resonance of de is performed. Electromagnetic field shown in FIG. 10 (c), to excite the bound pores 9 bored in the partition wall 1 _5, Figure in the resonator having a resonant element 2 ₂ 10
The electromagnetic field shown in (d) is generated. Mode - the electromagnetic field is generated that shown in FIG. 10 (e) by the coupling adjusting element 7 ₃ and 7 ₄ of tube insertion length adjustment between de, 10 by the electromagnetic field (f)
The electromagnetic field shown in is excited, and the resonance frequency fine adjustment elements 5 ₃ , 5 ₄
And double by each tube insertion length adjustments 6 ₄ mode - resonance of de is performed. Electromagnetic field shown in FIG. 10 (f) binds to the capacitive coupling element 3 _2V, output from the terminal 4 _2V. A solid line with an arrow in FIG. 10 indicates an electric field, and a broken line with an arrow indicates a magnetic field. Field shown in the electromagnetic field and Figure 10 (f) of FIG. 10 (a), and subcombinations in opposite phases to each other through a horizontal short pores in binding pores 9 bored in the partition wall 1 _5, Yes Form a polar bandpass filter. The electrical characteristics of the pass band are determined according to the length and width of the vertical long pores in the coupled pores 9, and the frequency of the attenuation pole in the polar bandpass filter is determined according to the length and width of the short horizontal pores. The position is set. By forming the contour shape of the coupling pore 9 into, for example, a rectangle only in the vertical direction or an elongated elliptical shape in the vertical direction, the electromagnetic field shown in FIG.
An apolar band-pass filter can be formed without coupling with the electromagnetic field shown in (f), and even when the coupling pore 9 is formed in a cross shape, the length of the pore in the vertical direction is By appropriately setting the ratio of the lengths of the pores in the horizontal direction, an apolar bandpass filter can be formed.

[0010] Figure 11 is an equivalent circuit diagram in the case of forming the present invention the band-pass device shown in FIG. 8 Attenuation Poles, C ₁
And C ₂ the size of the resonant elements 2 ₁ on the side of the resonators interior resonance element 2 ₁ 8, the dielectric constant, resonant element 2 ₁ interior was side resonators overall size, the resonance frequency fine Equivalent capacitance determined by the size of adjusting elements 5 ₁ , 5 ₂ and 6 ₂ , etc., C ₃
And C ₄ is the magnitude of the resonance element 2 ₂ on the side of the resonators interior resonance element 2 ₂ 8, the dielectric constant, the resonance element 2 ₂ interior was side resonators overall size, the resonance frequency fine Equivalent capacitance determined by the size of adjusting elements 5 ₃ , 5 ₄ and 6 ₄ , etc., L ₁
And L ₂ resonant element 2 ₁ size, dielectric constant, equivalent inductance determined by the size of the entire resonator side who furnished the resonant element 2 _1, L ₃ and L ₄ of the resonant element 2 ₂ size , dielectric constant, equivalent inductance determined by the size of the entire resonator side who furnished the resonant element 2 _2, C ₂₃ is interstage formed by a long pores of the vertical direction in the coupling pores 9 bored in the partition wall 1 ₅ Coupling capacitance, C ₃₄ is inter-mode coupling adjustment element 7 ₃
And 7 ₄ is an inter-stage coupling capacitance, C _4T is an output (or input) coupling capacitance formed by the capacitive element 3 _2V ,
C ₁₄ and C ₄₁ is a sub-coupling capacitance formed by the horizontal short pores in binding pores 9 bored in the partition wall 1 _5, other reference numerals are the same as FIG.

[0011] Incidentally, when the dielectric constant of the solid dielectric material to form a resonant element 2 ₁ is relatively high, the flange portion of the resonant element 2 _1, when attached directly to the partition wall 1 _5, bored in the partition wall 1 ₅ Further, one surface of the bonding pore 9 comes into contact with the solid dielectric material having a relatively high dielectric constant, and the other surface of the bonding pore 9 comes into contact with air, so that the difference in relative dielectric constant between both surfaces of the bonding pore 9 becomes large. Disturbances may occur in the electromagnetic field in the vicinity of the coupling pores 9, which may adversely affect the inter-stage coupling. In such a case, FIG. 12 [a cross-sectional view similar to FIG. 8A] is used. shown way, space between the flange portion and the partition wall 1 ₅ of the resonant element 2 ₁ -
The support 10 is interposed, the space - the support, by forming a dielectric plate having a lower dielectric constant than the dielectric constant of the resonant element 2 _1, both sides of the binding pores 9 bored in the partition wall 1 ₅ It is possible to suppress the disturbance of the electromagnetic field by reducing the difference in relative permittivity in. Further, by appropriately selecting the thickness of the spacer 10, it is possible to suppress the generation of unnecessary modes. Ten
₁ space is interposed between the flange portion of the resonator element 2 ₂ and the end wall 1 ₄ - in service, by defining its thickness suitably, unnecessary mode - it is possible to suppress the occurrence of de. Space - from Sa 10 ₁ is only to utilize the thickness, the material, no problem either solid dielectric or metal body. 13, space is interposed between the flange portion and the partition wall 1 ₅ of the resonant element 2 ₁ - Sa 10 ₂ bond pores inside diameter provided in the partition wall 1 ₅ 9
Suitably with large consisting of contour size, solid dielectric or metal body than made ring-shaped space - in service, this space - by providing the service, both the air on both sides of the binding pores 9 bored in the partition wall 1 ₅ Since it exists, the disturbance of the electromagnetic field can be prevented, and the generation of the unnecessary mode can be suppressed by appropriately setting the thickness. Resonant element 2 ₂
The flange portion and the end wall 1 ₄ space is interposed between the - Sa 10 ₂
A flange portion and space is interposed between the partition wall 1 ₅ of the resonant element 2 ₁ - in service, unwanted mode by defining its thickness suitably - - same space as the support 10 ₂ to suppress the occurrence of de You can Space respectively interposed around the screws between the resonant element 2 ₁ of the flange portion and the partition wall 1 around the screws ₅ between and the resonance element 2 _{and second} flange portion and the end wall 1 ₄ 14 - Sa 10 Reference numeral ₃ denotes a seat made of a metal body or a solid dielectric, respectively, and has the same effect as the spacer shown in FIG. 12 to 14
Other reference numerals and configurations not mentioned in the description of are the same as those in FIG.

FIG. 15 (a) is also a sectional view showing another embodiment of the present invention [a sectional view taken along the line CC of FIG. 15 (b)], FIG.
15B is an AA end view of FIG. 15A, FIG.
It is a B-B end view of FIG. 15 (a), in the present embodiment, the dual mode - the flange portions of de dielectric resonant element 2 ₁ and 2 ₂ are both attached to the partition wall 1 _5. 8 _V is input (or output)
Coupling Le - flop, 8 _2V is output (or input) coupled Le - flop, 6 ₁ and 6 ₃ V mode - in de resonance frequency fine-tuning element, the other code and configuration is the same as FIG. Coupling Le in this embodiment - binding relation flop 8 _V and the resonant element 2 _1, interstage coupling relationship and the resonant element 2 ₂ and the coupling Le - When showing the coupling relationship between flop 8 _2V in electromagnetic field distribution, 10 Is exactly the same as. In this embodiment, between the flange portion and the partition wall 1 ₅ of the resonator element 2 _1, the resonant element 2 ₂
Between the flange portion and the partition wall 1 _5, space is interposed between the flange portion and the partition wall 1 ₅ of the resonator element 2 ₁ in FIGS. 12 through 14 - the same space as the support 10, 10 ₂ or 10 ₃ - by providing the support, disturbance and unnecessary mode electromagnetic field in the vicinity of the binding pores 9 provided in the partition wall 1 ₅ - it is possible to suppress the occurrence of soil. 16 is an equivalent circuit diagram in the case where the bandpass filter shown in FIG. 15 is configured to have a polar shape, M _4T is an output (or input) magnetic coupling coefficient, and other symbols are those in FIGS. The same as 11.

The band-pass filter of the present invention is formed into a polar type,
The transmission characteristic when the passband is configured to have the Chebyshev characteristic can be obtained by the following equation.

[Equation 1] f _p : Frequency of band edge that gives the allowable voltage standing wave ratio In the above equation, _Re is the real part and I _m is the imaginary part. FIG. 17 is a diagram showing the transmission characteristics of the above-described polarized band-pass filter of the present invention, in which the horizontal axis represents frequency and the vertical axis represents attenuation.

The transmission characteristic in the case where the band-pass filter of the present invention is formed in a non-polar shape and the pass band thereof has a Chebyshev characteristic can be obtained by the following equation.

[Equation 2] ATT: Transmission loss T _n (x): Chebyshev polynomial, in the case of x <1, T _n (x) = cos (n cos ^-1 x) In the case of x> 1, T _n (x) = cosh (n cosh ^-1 x) x: Normalized frequency,

(Equation 3) f ₀ : Center frequency in the pass band of the band pass filter f: Arbitrary transmission frequency B _Wr : Allowable pass frequency bandwidth of the band pass filter S: Allowable voltage standing wave ratio (VSWR) diagram in the pass band 18 is a diagram showing the transmission characteristics of the non-polar type bandpass filter of the present invention, and the horizontal and vertical axes are the same as those in FIG. FIG.
15 and FIG. 15, the case where the order n of the band-pass filter is 4 has been described. However, the order n can be appropriately increased to implement the present invention, and the number n is 2 or an integer multiple thereof. A polarized band-pass filter can be constructed by sub-coupling the resonant circuits separated by one another.

In the embodiment shown in FIGS. 8 and 15, when the load Q of each resonant circuit is relatively high, that is, when the interstage coupling of the bandpass filter is relatively sparse, FIG.
The electromagnetic field coupling and the double mode resonance are performed as described above, and as shown in FIGS. 17 and 18, the characteristic curves in the low frequency region and the high frequency region with respect to the center frequency are symmetrical. However, as a result of repeated experiments on the prototype by the present inventor, the following facts could be clarified. That is, in the embodiment shown in FIGS. 8 and 15, when the load Q of each resonant circuit is relatively low, that is, when the interstage coupling of the bandpass filter is relatively dense, FIG.
As shown in (the horizontal axis and the vertical axis are the same as those in FIG. 17), the characteristic curves in the low frequency region and the high frequency region are asymmetric with respect to the center frequency, and the characteristic curves become lower as the load Q of each resonant circuit decreases. It was recognized that the degree of asymmetry of the was remarkable. The present inventors have results which take various improvements, was rotated relative to the cylindrical side wall 1 ₁ and 1 ₂ of the outer conductor about a common cylinder axis, the asymmetry of the characteristic curve at a certain rotation angle We were able to confirm that it was corrected to obtain the ideal characteristics. In the present invention,
Based on the fact that it was possible to correct the asymmetry of the characteristic curve by the relative rotation of the cylindrical side wall 1 ₁ and 1 _2,
As shown in FIG. 20, the insertion hole of the set screws provided in the flange portion which projects at each end of the cylindrical side wall 1 ₁ and 1 ₂ of the outer conductor, i.e., between the cylindrical side wall 1 ₁ and 1 ₂ the contour shape of the insertion hole 11 of the coupling screws between the peripheral portion of the partition wall 1 ₅ of interposing, formed in curved oval circumferentially extending flange portion of the cylindrical side wall 1 _1, the peripheral portion of the partition wall 1 ₅ and by loosening the screws coupling the flange portion of the cylindrical side wall 1 _2, is formed so that the cylindrical side wall 1 ₁ and 1 ₂ capable of relative rotation about a common cylindrical axis. As shown in FIG. 15, the outer conductor of the end wall 1 ₃ and 1 ₄ in the input-output coupling Le - when such mounting a flop 8 _V and 8 _2V are input and output coupling Le - flop 8 _V (or 8
To match the direction of an electric field to bind the binding pores 9 provided in the direction of the electric field and the partition wall 1 ₅ of the electromagnetic field induced by the current flowing through the _2V) to the required angle difference, coupled pores bored in the partition wall 1 ₅ 9
Direction of electric field excited by and input / output coupling loop 8 _2V
(Or 8 _V) of the electric field direction that bind to match the required angle difference, the end wall 1 ₃ and a cylindrical side wall 1 ₁ and is rotatable relative, also the end wall 1 ₄ and a cylindrical side wall 1 ₂ It is also desirable to make it relatively rotatable, for this purpose, the cylindrical side walls ₁₁ and
Of 1 _second flange portion, the end wall 1 ₃ and 1 ₄ profile of the insertion hole of the screws which are bored in the flange portion coupled with even 2
It is formed in a curved elliptical shape extending in the circumferential direction as indicated by 0.

FIG. 21 is a sectional view showing an example of a demultiplexer constructed by using the bandpass filter of the present invention [a sectional view similar to FIG. 15 (a)], and BPF ₁ and BPF ₂ are shown in FIG. In a band pass filter similar to the band pass filter of the present invention shown in FIG. 3, the respective pass center frequencies are different from each other. 1 ₆ is a partition wall interposed between the outer conductors of the band pass filters BPF ₁ and BPF ₂ ,
8 _2V1 is an input (or output) coupling _loop on the side of bandpass filter BPF ₁ , and 8 _2V2 is an input (or output) on the side of bandpass filter BPF ₂
The coupling loop, T _C, is a common input (or output) terminal, and comprises, for example, a coaxial plug. T ₁ is an output (or input) terminal of the bandpass filter BPF ₁ , and T ₂ is an output (or input) terminal of the bandpass filter BPF ₂ . Input of the band-pass device BPF ₁ side (or output) coupled Le - length of flop 8 _2V1, i.e., Le - from the ground terminal of the flop to the connection point to the extension of the inner conductor of the coaxial connector T _C a length, corresponding to the pass center frequency of the band-pass device BPF ₂ is formed on the _^1/4 wavelength, the input of the band-pass unit BPF ₂ side (or output) coupled Le - length of flop 8 _2V2 , i.e., Le - coaxial connector T _C of a length of up to connection point to the extension of the inner conductor, _^1/4 of a wavelength corresponding to the passing center frequency of the band pass wave filter BPF ₁ from the ground terminal of the flop It formed in the input of the band-pass unit BPF ₁ to the passage center frequency of the band-pass unit BPF ₂ Inpi - dancing is very high, bandwidth to pass center frequency of the band pass wave filter BPF ₁ It is formed so that the input impedance of the pass filter BPF ₂ is extremely high. FIG. 22 is a cross-sectional view showing a duplexer formed so that common input (or output) coupling is performed by capacitance, 3 _TC is a coupling capacitance forming electrode, and each of band pass filters BPF ₁ and BPF ₂ An input (or output) coupling capacitance is formed between the first-stage (or last-stage) resonator and the resonance element forming the resonator. The capacitance formed between the coupling capacitance forming electrode 3 _TC and the resonance element on the side of the band pass filter BPF ₁ and the coupling capacitance forming electrode 3 _TC and the resonance element on the side of the band pass filter BPF ₂ are by varying the capacity proper to be formed between, but it is possible to prevent interference between the band-pass unit BPF ₁ and BPF ₂ mutually among the coupling capacitor forming electrode 3 _TC as required band Connect an inductance element (not shown) between the partition located on the side of the pass filter BPF ₁ and the partition wall ₁₆ ,
An inductance element (not shown) is connected between the portion of the coupling capacitance forming electrode 3 _TC located on the side of the band pass filter BPF ₂ and the partition ₁₆ and the inductance of each inductance element is appropriately adjusted. Select and pass bandpass filter
BPF ₂ input of the central pass band pass wave filter BPF ₁ with respect to the frequency Inpi - dancing is very high, the band-pass device BPF ₂ input Inpi to the passage center frequency of the band pass wave filter BPF ₁ - The dance may be formed to be extremely high. 21 and 22 exemplify the case where the band-pass filter shown in FIG. 15 is used, but the band-pass filter shown in FIG. 8 may be used, and in any case. The duplexer can be configured by appropriately increasing or decreasing the number of resonant elements that configure each bandpass filter.

[0017]

According to the present invention, as a double-mode dielectric resonant element, a resonant element body having a relatively large diameter portion, a support portion having a relatively small diameter, and a flange portion are made of the same solid dielectric material. Since the double-mode dielectric resonance element integrally formed of the material is provided, the support for the resonance element is not particularly required unlike the conventional case, and the resonance element itself allows the end wall of the outer conductor to be formed. Alternatively, since it can be mounted on a partition wall, there is no fear of deterioration of the temperature characteristics caused by the conventional support, and the temperature characteristics are extremely good, and a bandpass filter with excellent earthquake resistance is realized. be able to. The conventional duplexer shown in FIG. 24 requires external connection lines L ₁ and L ₂ for connecting the two bandpass filters to the T-type connector TC, so that the entire configuration is In contrast to the relatively complicated and large size, in the demultiplexer including the bandpass filter of the present invention, two bandpass filters are installed in a substantially common outer conductor, and common connection terminals T _C corresponding to T-connector TC in a conventional duplexer shown, by mounting the cylindrical sidewall of the substantially common outer conductor, in a conventional duplexer shown in FIG. 24 External connection line
L ₁ and L ₂ to be able to form the whole structure in a relatively brief small omitted, also similar to the temperature characteristics and the present invention the band-pass device is good, implement the duplexer with excellent earthquake resistance can do.

[Brief description of drawings]

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

FIG. 2 is a diagram showing an electromagnetic field distribution of a resonance element used in the present invention.

FIG. 3 is a diagram showing an electromagnetic field distribution of a resonance element used in the present invention.

FIG. 4 is an electromagnetic field distribution diagram for explaining the operation of the bandpass filter of the present invention.

FIG. 5 is an equivalent circuit diagram of the bandpass filter of the present invention.

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

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

FIG. 8 is a diagram showing another embodiment of the present invention.

FIG. 9 is a diagram showing interstage coupling pores in the bandpass filter of the present invention.

FIG. 10 is an electromagnetic field distribution diagram for explaining the operation of the bandpass filter of the present invention.

FIG. 11 is an equivalent circuit diagram of the bandpass filter of the present invention.

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

FIG. 13 is a diagram showing another embodiment of the present invention.

FIG. 14 is a diagram showing another embodiment of the present invention.

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

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

FIG. 17 is a curve diagram showing the transmission characteristics of the bandpass filter of the present invention.

FIG. 18 is a curve diagram showing the transmission characteristics of the bandpass filter of the present invention.

FIG. 19 is a curve diagram for explaining the transmission characteristics of the bandpass filter of the present invention.

FIG. 20 is a diagram showing a main part of another embodiment of the present invention.

FIG. 21 is a diagram showing a demultiplexer using the bandpass filter of the present invention.

FIG. 22 is a diagram showing a demultiplexer using the bandpass filter of the present invention.

FIG. 23 is a diagram showing a conventional bandpass filter.

FIG. 24 is a diagram showing a conventional duplexer.

[Explanation of symbols]

1 ₁ , 1 ₂ Outer conductor cylindrical side wall 1 ₃ , 1 ₄ Outer conductor end wall 1 ₅ , 1 ₆ Outer conductor partition 2, 2 ₁ , 2 ₂ Resonance element 2R Resonance element body 2S Resonance element support 2F Resonant element flange 3 _H , 3 _V , _{32 V} Input / output coupling capacitance element 4 _H , 4 _V , _{42 V} Input / output terminal 5 _{1 to} 5 ₄ H mode resonance frequency fine adjustment element 6 _{1 to} 6 ₆ V Mode resonance frequency fine adjustment element 7 _{1 to} 7 ₄ Mode inter-coupling adjustment element 8 _H , 8 _V , _{82 V} Input / output coupling loop 9 Inter-stage coupling hole 10, 10 ₁ @ 10 ₃ Spacer 11 _Set screw insertion hole BPF ₁ , BPF ₂ Inventive band-pass filter 8 _2V1 , 8 _{2V2 I} / O coupling _loop T _C , T ₁ , T _{2 I} / O terminal 3 _{TC I} / O coupling capacitance forming electrode 12 ₁ , 12 ₂ Resonance element 13 ₁ ~ 13 ₄ Support F ₁ , F ₂ Band pass filter L ₁ , L ₂ Connection line TCT type connector CA cable

Claims (5)

[Claims] 1. A resonance element body having a relatively large diameter portion, a support portion having a relatively small diameter portion, and a support portion provided on the opposite side of the resonance element body through the support portion. Double mode dielectric resonance in which an end wall of a cylindrical outer conductor or a flange portion attached to a partition wall provided at an axially intermediate portion of the outer conductor is integrally formed of the same solid dielectric material. Dual mode characterized by having an element
Bandpass filter consisting of a dielectric resonator. 2. A double-mode dielectric resonator element is provided with a double-layer structure between a flange portion and a partition wall provided in an axially intermediate portion of a bottomed cylindrical outer conductor having an interstage coupling hole. The dual mode according to claim 1, wherein a spacer made of a solid dielectric plate having a relative dielectric constant lower than that of the solid dielectric material forming the mode dielectric resonant element is interposed. A bandpass filter consisting of a dielectric resonator. 3. A flange portion of a double-mode dielectric resonator element and a partition wall provided in an axially intermediate portion of a bottomed cylindrical outer conductor having an inter-stage coupling hole formed therein are mechanically coupled to each other. The double-mode washer according to claim 1, further comprising a washer provided for each set screw and interposed between the flange of the double-mode dielectric resonance element and the partition wall having the interstage coupling hole. A bandpass filter consisting of a dielectric resonator. 4. A partition wall having an interstage coupling hole formed therein, which is interposed in the axially intermediate portion of the cylindrical side wall of the bottomed cylindrical outer conductor, and at the end of the cylindrical side wall of the bottomed cylindrical outer conductor. In order to connect the flange part with the set screw with a set screw, the set screw insertion hole bored in the flange part provided at the end of the cylindrical side wall of the bottomed cylindrical outer conductor has a curved elliptical shape extending in the circumferential direction. A band pass filter comprising the double mode dielectric resonator according to claim 1 formed in. 5. A bottomed cylindrical outer conductor for connecting an end wall of the bottomed cylindrical outer conductor and a flange portion provided at an end of a cylindrical side wall of the bottomed cylindrical outer conductor with a set screw. The double-mode dielectric resonator according to claim 1, wherein a through hole for a set screw formed in a flange portion provided at an end of the cylindrical side wall is formed in a curved elliptical shape extending in a circumferential direction. Bandpass filter.