JP3146911B2 - Dielectric filter - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dielectric filter using a blocked dielectric and acting as a band rejection filter.

[0002]

2. Description of the Related Art FIG. 17 shows the configuration of a conventional dielectric filter which is provided as a band-stop filter by providing a resonator with a plurality of stages in a dielectric block. In FIG. 17, the dielectric block 1 has a rectangular parallelepiped shape, has three through holes 2 formed therein, and has outer conductors 3 formed at predetermined locations on the outer surface. An inner conductor 4 is formed on the inner surface of the through hole 2. Also, the outer conductor 3 is not formed except for a part of the right front surface of the dielectric block 1 in the drawing, and the coupling conductors 5 extending from the inner conductor 4 and capacitively coupled to these coupling conductors 5. Three coupling conductors 6 are formed, and a transmission path conductor 7 is provided between each coupling conductor 6.
Is formed. Outer conductors 3 are formed on the other five surfaces of the dielectric block 1 except the right front surface in the drawing. FIG.
FIG. 18 shows an equivalent circuit of the dielectric filter shown in FIG. Here Z _T resonator configured in a dielectric block, C _T is the trap capacity comprised between the coupling conductor 5-6 shown in FIG. 17.

In this manner, a band-stop type dielectric filter is formed by coupling adjacent resonators with a phase difference of π / 2 (rad) using the transmission line conductor. The characteristics of the dielectric filter shown in FIGS. 17 and 18 are as shown in FIG. Here, fo is the operating frequency, and this dielectric filter blocks the lower side of fo.

[0004]

In the conventional dielectric filter having the band rejection characteristic shown in FIG. 17, an integrated dielectric filter is formed using a dielectric block having a relatively simple structure. However, the length of the transmission line conductor 7 for coupling adjacent resonators with a phase difference of π / 2 (rad) becomes very long (this transmission line has a half surface made of a dielectric material and the other half surface made of a dielectric material). Since this is a strip line using air as the air, its electrical length is longer than the resonator length of the dielectric resonator.) Therefore, there is a problem that the size of the resonator in the arrangement direction becomes large. Further, as shown in FIG. 19, the out-of-band attenuation characteristics were poor, and particularly, 2fo and 3fo attenuation could not be expected. For this reason, there is a possibility that the operating frequency fo may be adversely affected by spurious circuits in the subsequent stage of the dielectric filter.

SUMMARY OF THE INVENTION It is an object of the present invention to reduce the size of resonators in the arrangement direction without using the transmission line conductor for coupling adjacent resonators with a predetermined phase difference. It is an object of the present invention to provide an improved dielectric filter.

Another object of the present invention is to provide a dielectric filter having an improved attenuation characteristic outside the band used (for example, 2fo, 3fo).

[0007]

A dielectric filter according to the present invention is provided for coupling adjacent resonators with a phase difference of π / 2 (rad) without using a conductor for a transmission line. as described, comprising a dielectric block a plurality of voids arranged formed therein, an outer conductor is formed on a predetermined portion of the outer surface of the dielectric block, the dielectric filter forms the inner conductor to the air gap, respectively Short one opening
Multiple end, by the first and second voids formed two rows, dielectric and the outer conductor of the conductor and the dielectric block among formed in the gap of the first column to the open end and the other opening stage of
With constituting the co exciter, the adjacent resonators, their by capacitive coupling with the coupling conductor formed on the outer surface of the dielectric block is an end of the resonator, the band pass filter section comprising a plurality of stages of resonators constitute, together with a resonator of multiple stages by the dielectric and the outer conductor of the conductor and the dielectric block among formed in the gap of the second column, the resonator and the resonator of the band-pass filter section Are combined at each stage.

[0008]

The dielectric filter according to the present invention includes a dielectric block in which a plurality of voids are formed and arranged therein, an outer conductor is formed at a predetermined position on an outer surface of the dielectric block, and an inner conductor is formed in the void. In the formed dielectric filter, two gaps in the first and second rows are formed, and one of the gaps in the first row is a short-circuited end and the other is an open end. inner conductors formed on, as well as constitute a plurality of resonators that resonate at respective quarter-wave by a dielectric block, and the outer conductor, the other opening, the outer guide
From the inner conductor, causing capacitance only between itself and the body
By forming a continuous coupling conductor and inductively coupling the adjacent resonators of the plurality of resonators by the capacitance , a band-pass filter unit including a plurality of resonators is formed. With one opening of each gap in the second row as a short-circuited end and the other opening as an open end, the inner conductor, the dielectric block, and the outer conductor formed in the gap in the second row are each 1 /. A plurality of resonators that resonate at four wavelengths are formed, and these resonators are respectively coupled to resonators at each stage of the bandpass filter unit.

The dielectric filter according to the present invention further includes a dielectric block having a plurality of voids arranged therein, an outer conductor being formed at a predetermined position on an outer surface of the dielectric block, and an inner conductor being placed in the void. In the formed dielectric filter, first and second gaps are formed in two rows, and the inner conductor formed in each gap in the first row, with both openings of the gaps in the first row being open ends,
1 each by the dielectric block and the outer conductor
And a plurality of resonators that resonate at a half wavelength
In the opening, causing a capacitance only between the outer conductor
Forming a continuous coupling conductor from the inner conductor,
A plurality of resonators adjacent to each other of the plurality of resonators are inductively coupled to each other by the capacitance to form a band-pass filter unit including a plurality of resonators. A plurality of resonators, each of which is an open end or a short-circuited end, and which resonates at a half wavelength by the inner conductor, the dielectric block, and the outer conductor formed in the gaps in the second row, are formed. , Each of which is coupled to a resonator at each stage of the band-pass filter.

[0011]

According to the dielectric filter of the present invention , the resonator length formed by the inner conductor formed in the gaps of the first row, the dielectric of the dielectric block, and the outer conductor formed on the outer surface of the dielectric block is λ. / 4 resonators are capacitively coupled with adjacent resonators by coupling conductors formed on the outer surface of a dielectric block which is an end face of the resonators, and a band pass composed of a plurality of resonators is provided. Acts as a filter. The inner conductor formed in each gap in the second row, the dielectric of the dielectric block and the outer conductor formed on the outer surface of the dielectric block act as resonators having a resonator length of λ / 4, respectively . and the resonator and the band-pass filter section
Each resonator is coupled at each stage. A plurality of resonators constituting the band-pass filter unit are coupled with adjacent resonators with a phase difference of π / 2 (rad). Are coupled with a phase difference of π / 2 (rad) by the air gap, thereby acting as a band rejection filter.

[0012]

In the dielectric filter according to the second aspect, the first filter
A plurality of resonators each having a resonator length of λ / 4, which are formed by the inner conductor formed in the gap of the row, the dielectric of the dielectric block, and the outer conductor formed on the outer surface of the dielectric block, are connected to adjacent resonators. The devices are inductively coupled (combline coupled) and act as a band-pass filter section including a plurality of resonators. The inner conductor formed in each gap in the second row, the dielectric of the dielectric block and the outer conductor formed on the outer surface of the dielectric block act as resonators having a resonator length of λ / 4, respectively. In addition, the resonator and each resonator of the band-pass filter unit are coupled at each stage. A plurality of resonators constituting the band-pass filter section are coupled with each other with a phase difference of π / 2 (rad) between the adjacent resonators. Are coupled by a phase difference of π / 2 (rad), thereby acting as a band rejection filter.

In the dielectric filter according to the third aspect, the first filter
The inner conductor, dielectric block and outer conductor of each gap in the row
Λ / 2 length resonators are connected by inductive coupling
To form a band-pass filter unit. Since both openings of each gap in the second row are open ends or short-circuit ends, they also become λ / 2 length resonators, respectively.
In addition, the resonator and the bandpass filter unit are coupled at each stage. A plurality of resonators constituting the band-pass filter section are coupled with each other with a phase difference of π / 2 (rad) between the adjacent resonators. Between multiple resonators due to the air gap of π
/ (Rad) and acts as a band rejection filter.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The structure of a dielectric filter according to a first embodiment of the present invention will be described with reference to FIGS.

FIG. 1 is a perspective view of the appearance of a dielectric filter, and FIG. 1B is a view as viewed obliquely from above and behind FIG.
In FIG. 1, the dielectric block 1 has a rectangular parallelepiped shape, and has a total of six through holes 2 and 8 penetrating therethrough in the same axial direction. An outer conductor 3 is formed at a predetermined position on the outer surface of the dielectric block 1, and inner conductors 4 and 9 are formed on the inner surfaces of the through holes 2 and 8. An outer conductor 3 continuous from the inner conductor 4 is formed on the front right surface in FIG. 1A, and this portion is a short-circuit end. As shown in FIG. 1B, the surface of the inner conductor 4 facing the short-circuit end is an open end. In addition, an outer conductor 3 that is continuous from the inner conductor 9 is formed on the front right surface in FIG. 1B, and this portion is a short-circuit end. A coupling conductor 10 that is continuous from the inner conductor 9 is formed on a surface (the surface in FIG. 1A) facing the short-circuit end. These coupling conductors 10 form capacitance between adjacent coupling conductors. The coupling conductor 10 is provided on the upper surface in the figure.
, A continuous input / output conductor 11 is formed. When mounting this dielectric filter on a circuit board, the upper surface in FIG. 1 is surface-mounted with the upper surface facing the circuit board. that time,
The outer conductor 3 on the upper surface in FIG. 1 is electrically connected to a ground electrode or the like on the circuit board, and the input / output conductor 11
Are electrically connected to the conductor pattern on the circuit board.

FIG. 2 is an equivalent circuit diagram of the dielectric filter shown in FIG. Here, Z _P is a resonator of a band-pass filter portion formed by the inner conductor 9 formed in the through hole 8 shown in FIG. 1, the dielectric of the dielectric block 1 and the outer conductor 3,
_CP is the capacitance formed by the coupling conductor 10. Further, Z _T is a resonator constituted by the inner conductor 4 formed on the inner surface of the through hole 2 shown in FIG. 1, the dielectric of the dielectric block 1 and the outer conductor 3, and Z _K is the resonator Z _T the mutual impedance between the dielectric resonator Z _P constituting the band pass filter section. Thus, the resonator Z _T
There bonded via a resonator Z _P of the mutual impedance Z _K and the band pass filter section.

FIG. 3 is a characteristic diagram of the dielectric filter shown in FIG. (A) shows the characteristics of only the band-pass filter section, and (B) shows the overall characteristics. The characteristics of the entire dielectric filter are obtained by superimposing the characteristics of the band rejection filter on the characteristics of the band pass filter. In this way, the used band f
o, and attenuates the low-frequency side, and 2f
The high-frequency side such as o and 3fo is also attenuated by the characteristics of the band-pass filter unit.

Next, the structure of a dielectric filter according to a second embodiment of the present invention is shown in FIG. Unlike the example shown in FIG. 1, in this case, a coupling blocking hole 12 is formed between the three through holes 2. The outer conductor 3 is provided on the inner surface of the coupling block hole 12.
And a continuous conductor is provided. Therefore, the three resonators formed by the through holes 2 hardly couple.
Thereby, the attenuation pole of the band rejection filter and the resonance frequency have a one-to-one correspondence, and the characteristic adjustment becomes easy.

Next, the structure of a dielectric filter according to a third embodiment of the present invention will be described with reference to FIG. The external perspective view of the dielectric filter according to the third embodiment is the same as that shown in FIG. FIG. 5 shows the three through holes 8 shown in FIG.
FIG. 3 is a cross-sectional view of the central portion of FIG. 1 cut along a plane corresponding to a plane passing in the axial direction. Thus, the through hole 8 has a step structure in which the inside diameter is small on the short-circuit end side and large on the open end side. With this configuration, the resonator impedance on the open end side becomes smaller than the resonator impedance on the short-circuit end side, and the overall resonator length is shortened, so that the axial size of the through hole can be reduced.

Next, the structure of a dielectric filter according to a fourth embodiment is shown in FIG. FIG. 6 is a front view as viewed from one opening surface of the through hole. The overall configuration is similar to the example shown in FIG. By making the cross-sectional shape of each through hole elliptical in this way, the height dimension of the dielectric filter can be reduced.

Next, the structure of a dielectric filter according to a fifth embodiment is shown in FIG.

FIG. 7 is a perspective view of the appearance of the dielectric filter, and FIG. 7B is a diagram viewed from obliquely rearward above FIG.
In FIG. 7, the dielectric block 1 has a rectangular parallelepiped shape, and has a total of six through holes 2, 8 penetrating therethrough in the same axial direction. An outer conductor 3 is formed at a predetermined position on the outer surface of the dielectric block 1, and inner conductors 4 and 9 are formed on the inner surfaces of the through holes 2 and 8. A coupling conductor 5 continuing from the inner conductor 4 and a coupling conductor 10 continuing from the inner conductor 9 are formed on the front right surface in FIG. With this structure, capacitance is formed between the coupling conductor 5 and the coupling conductor 10 at each stage, and simultaneously, capacitance is formed between the adjacent coupling conductors 10-10. In addition, on the upper surface in the figure, the input / output conductor 1 continuous from the coupling conductor 10 is provided.
1 are formed. Further, an outer conductor 3 continuous from the inner conductors 4 and 9 is formed on the front right surface in FIG. 7B, and this portion is used as a short-circuit end.

FIG. 8 is an equivalent circuit diagram of the dielectric filter shown in FIG. Here, Z _P is a resonator constituted by the inner conductor 9 formed in the through hole 8 shown in FIG. 7, the dielectric of the dielectric block 1 and the outer conductor 3, and _CP is the coupling conductor 1
The capacitance constituted by 0, _CT is the coupling conductor 5-1.
This is the capacitance formed between zero. Z _T is a resonator constituted by the inner conductor 4 formed on the inner surface of the through hole 2 shown in FIG. 1, the dielectric of the dielectric block 1 and the outer conductor 3. Thus, the three resonators Z _T are three resonators Z
Π / 2 (ra) through a band-pass filter unit composed of _P
A dielectric filter that acts as a band rejection filter by coupling with the phase difference of d) is obtained. The characteristics of this filter are shown in FIG.
This is substantially the same as that shown in FIG.

Next, the structure of a dielectric filter according to a sixth embodiment of the present invention is shown in FIG.

FIG. 9 is a perspective view of the appearance of the dielectric filter, and FIG. 9B is a diagram viewed from obliquely above the rear of FIG.
In FIG. 9, the dielectric block 1 has a rectangular parallelepiped shape, and has a total of six through holes 2 and 8 penetrating therethrough in the same axial direction. An outer conductor 3 is formed at a predetermined position on the outer surface of the dielectric block 1, and inner conductors 4 and 9 are formed on inner surfaces of the through holes 2 and 8. The outer conductor 3 continuous from the inner conductor 4 is formed on the front right surface in FIG. 9A, and this portion is a short-circuit end. As shown in FIG. 9B, the surface of the inner conductor 4 facing the short-circuit end is an open end. 9A, a coupling conductor 10 that is continuous from the inner conductor 9 is formed on the front right surface of FIG. 9A. An outer conductor 3 continuous from the inner conductor 9 is formed on a surface facing this surface, and this portion is a short-circuit end. The coupling conductor 10 is provided on the upper surface in the figure.
, A continuous input / output conductor 11 is formed. With this structure, a tip capacitance is generated between the coupling conductor 10 and the outer conductor 3 that are continuous from the inner conductor 9 in the through hole 8, and the three resonators are comb-line-coupled by the tip capacitance.

FIG. 10 is an equivalent circuit diagram of the dielectric filter shown in FIG. Here, Z _P is a resonator constituted by the inner conductor 9 formed in the through hole 8 shown in FIG. 9, the dielectric of the dielectric block 1 and the outer conductor 3. FIG. 9 shows Z _T
A resonator formed by the conductor 4 within which is formed on the inner surface of the through hole 2 and the dielectric and the outer conductor 3 of the dielectric block 1 shown in, Z _K dielectric resonator constituting the band pass filter section Mutual impedance between Z _P and dielectric resonator Z _T. In this way, the resonator Z _T is bonded through the resonator Z _P of the mutual impedance Z _K and the band pass filter section. Thus three resonators Z _T via a bandpass filter unit consisting of three resonators Z _P [pi / 2
A dielectric filter that acts as a band rejection filter by combining with a (rad) phase difference is obtained.

Next, the structure of a dielectric filter according to a seventh embodiment is shown in FIG.

FIG. 11 is an external perspective view of the dielectric filter, and FIG. 11 (B) is a view as viewed obliquely from above and behind (A).
In FIG. 11, the dielectric block 1 has a rectangular parallelepiped shape,
A total of six through holes 2, 8 penetrating in the same axial direction are formed inside. An outer conductor 3 is formed at a predetermined position on the outer surface of the dielectric block 1, and inner conductors 4 and 9 are formed on the inner surfaces of the through holes 2 and 8. A coupling conductor 5 continuing from the inner conductor 4 and a coupling conductor 10 continuing from the inner conductor 9 are formed on the front right surface in FIG. With this structure, capacitance is formed between the coupling conductor 5 and the coupling conductor 10 at each stage. In addition, an input / output conductor 11 continuous from the coupling conductor 10 is formed on the upper surface in the drawing. Further, an outer conductor 3 continuous from the inner conductors 4 and 9 is formed on the front right surface in FIG. 11B, and this portion is a short-circuit end.

FIG. 12 is an equivalent circuit diagram of the dielectric filter shown in FIG. Here Z _P resonator constituted by an inner conductor 9 formed in the through hole 8 and the dielectric and the outer conductor 3 of the dielectric block 1 shown in FIG. 11, C _T is between coupling conductor 5-10 The capacitance is configured as follows. Also Z _T
Is a resonator formed by the inner conductor 4 formed on the inner surface of the through hole 2 shown in FIG. 11, the dielectric of the dielectric block 1, and the outer conductor 3. Thus, three resonators Z _T
Π / via a bandpass filter consisting of two resonators Z _P
A dielectric filter that combines with a phase difference of 2 (rad) and acts as a band rejection filter is obtained.

Next, the structure of a dielectric filter according to an eighth embodiment is shown in FIG.

FIG. 13 is an external perspective view of the dielectric filter, and FIG. 13B is a diagram viewed from obliquely above the rear of FIG.
In FIG. 13, the dielectric block 1 has a rectangular parallelepiped shape,
A total of six through holes 2, 8 penetrating in the same axial direction are formed inside. An outer conductor 3 is formed at a predetermined position on the outer surface of the dielectric block 1, and inner conductors 4 and 9 are formed on the inner surfaces of the through holes 2 and 8. As shown in FIGS. 13A and 13B, both ends of the inner conductor 4 are short-circuited. In addition, a coupling conductor 10 that is continuous from the inner conductor 9 is formed on the front right surface in FIG. 13A, and the surface facing this surface is an open end. The coupling conductor 1 is provided on the upper surface in the figure.
The input / output conductors 11 continuing from 0 are formed. With this structure, a tip capacitance is generated between the coupling conductor 10 and the outer conductor 3, and the three resonators are comb-line coupled by the tip capacitance.

FIG. 14 is an equivalent circuit diagram of the dielectric filter shown in FIG. Here, Z _P is a resonator having a resonator length λ / 2 constituted by the inner conductor 9 formed in the through hole 8 shown in FIG. 13, the dielectric of the dielectric block 1 and the outer conductor 3, and Z _T is This is a resonator having an electrical length of λ / 2 constituted by the inner conductor 4 formed on the inner surface of the through hole 2 shown in FIG. 13, the dielectric of the dielectric block 1 and the outer conductor 3. Thus three resonators Z _T via a bandpass filter consisting of three resonators Z _P binds with a phase difference of π / 2 (rad), to obtain a dielectric filter acting as a band stop filter.

Next, the structure of a dielectric filter according to a ninth embodiment is shown in FIG.

FIG. 15 is an external perspective view of the dielectric filter, and FIG. 15B is a view seen from obliquely above the rear of FIG.
In FIG. 15, the dielectric block 1 has a rectangular parallelepiped shape,
A total of six through holes 2, 8 penetrating in the same axial direction are formed inside. An outer conductor 3 is formed at a predetermined position on the outer surface of the dielectric block 1, and inner conductors 4 and 9 are formed on the inner surfaces of the through holes 2 and 8. As shown in FIGS. 15A and 15B, both ends of the inner conductors 4 and 9 are both open ends.
In addition, a coupling conductor 10 that is continuous from the inner conductor 9 is formed on the right front surface of FIG. Also, on the upper surface in the figure, the input / output conductor 11
Is formed. With this structure, a tip capacitance is generated between the coupling conductor 10 and the outer conductor 3, and the tip capacitance is
Two resonators are comb-line coupled.

FIG. 16 is an equivalent circuit diagram of the dielectric filter shown in FIG. Here, Z _P is a resonator having a resonator length λ / 2 constituted by the inner conductor 9 formed in the through hole 8 shown in FIG. 15, the dielectric of the dielectric block 1 and the outer conductor 3, and Z _T is This is a resonator having an electrical length of λ / 2 constituted by the inner conductor 4 formed on the inner surface of the through hole 2 shown in FIG. 15, the dielectric of the dielectric block 1 and the outer conductor 3. Thus three resonators Z _T via a bandpass filter consisting of three resonators Z _P binds with a phase difference of π / 2 (rad), to obtain a dielectric filter acting as a band stop filter.

In each of the embodiments, an example is shown in which a single dielectric block is provided with a void formed of a through hole. However, by stacking a plurality of dielectric plates having grooves formed therein, a plurality of dielectric plates are internally formed. A dielectric block having voids may be configured.

[0038]

According to the dielectric filter of the present invention, a plurality of resonators are formed together with a band-pass filter section composed of a plurality of resonators in which adjacent resonators are coupled to each other. Since the filter unit and the filter unit are coupled at each stage to act as a band-stop filter as a whole, a conventional transmission line conductor for coupling adjacent resonators with a predetermined phase difference is unnecessary, The size of the resonator in the array direction is reduced. Further, since the band other than the stop band excluding the used band is attenuated by the characteristics of the band-pass filter section, the adverse effect due to the spurious of the circuit at the subsequent stage of the dielectric filter is sufficiently suppressed. In addition, outside the dielectric block which is the end face of the resonator
A coupling conductor formed on the surface provides coupling between adjacent resonators.
The coupling amount, etc., depending on the coupling conductor pattern.
Adjustment (setting) becomes easy.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a configuration of a dielectric filter according to a first embodiment.

FIG. 2 is an equivalent circuit diagram of the dielectric filter according to the first embodiment.

FIG. 3 is a characteristic diagram of the dielectric filter according to the first embodiment.

FIG. 4 is a diagram illustrating a configuration of a dielectric filter according to a second embodiment.

FIG. 5 is a diagram illustrating a configuration of a dielectric filter according to a third embodiment.

FIG. 6 is a diagram illustrating a configuration of a dielectric filter according to a fourth embodiment.

FIG. 7 is a diagram illustrating a configuration of a dielectric filter according to a fifth embodiment.

FIG. 8 is an equivalent circuit diagram of a dielectric filter according to a fifth embodiment.

FIG. 9 is a diagram illustrating a configuration of a dielectric filter according to a sixth embodiment.

FIG. 10 is an equivalent circuit diagram of a dielectric filter according to a sixth embodiment.

FIG. 11 is a diagram illustrating a configuration of a dielectric filter according to a seventh embodiment.

FIG. 12 is an equivalent circuit diagram of a dielectric filter according to a seventh embodiment.

FIG. 13 is a diagram illustrating a configuration of a dielectric filter according to an eighth embodiment.

FIG. 14 is an equivalent circuit diagram of a dielectric filter according to an eighth embodiment.

FIG. 15 is a diagram illustrating a configuration of a dielectric filter according to a ninth embodiment.

FIG. 16 is an equivalent circuit diagram of a dielectric filter according to a ninth embodiment.

FIG. 17 is a diagram showing a configuration of a conventional dielectric filter.

18 is an equivalent circuit diagram of the dielectric filter shown in FIG.

19 is a characteristic diagram of the dielectric filter shown in FIG.

[Explanation of symbols]

 1-dielectric block 2-through hole (gap) 3-outer conductor 4-inner conductor 5-coupling conductor 6-coupling conductor 7-transmission path conductor 8-through hole (gap) 9-inner conductor 10-coupling Conductor 11-input / output conductor 12-coupling hole

──────────────────────────────────────────────────続 き Continued on the front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) H01P 1/205

Claims (3)

(57) [Claims] 1. A dielectric filter comprising: a dielectric block in which a plurality of voids are arranged and formed therein; an outer conductor is formed at a predetermined position on an outer surface of the dielectric block; and an inner conductor is formed in the void. First and second two rows of gaps are formed, and one opening of the first row of gaps is a short-circuited end and the other opening is an open end.
The inner conductor, the dielectric block, and the outer conductor formed in each gap of the row constitute a plurality of resonators each of which resonates at a quarter wavelength, and a coupling conductor is formed at the open end. A band-pass filter section composed of a plurality of resonators is formed by capacitively coupling adjacent resonators to each other, one opening of each gap in the second row is short-circuited, and the other opening is formed. Each having an open end, the inner conductor, the dielectric block, and the outer conductor formed in the gaps in the second row each have 1/4
A dielectric filter comprising a plurality of resonators that resonate at wavelengths, and coupling these resonators to resonators at each stage of the bandpass filter unit. 2. A dielectric filter comprising: a dielectric block in which a plurality of voids are arranged and formed therein; an outer conductor formed at a predetermined location on an outer surface of the dielectric block; and an inner conductor formed in the void. First and second two rows of gaps are formed, and one opening of the first row of gaps is a short-circuited end and the other opening is an open end.
The inner conductor, the dielectric block, and the outer conductor formed in each space of the row constitute a plurality of resonators that resonate at a quarter wavelength, and the other opening has
From the inner conductor that causes capacitance only between the conductor and
By forming a continuous coupling conductor and inductively coupling the adjacent resonators of the plurality of resonators by the capacitance , a band-pass filter unit including a plurality of resonators is formed. With one opening of each gap in the second row as a short-circuited end and the other opening as an open end, the inner conductor, the dielectric block, and the outer conductor formed in the gap in the second row each form 1 / 4
A dielectric filter comprising a plurality of resonators that resonate at wavelengths, and coupling these resonators to resonators at each stage of the bandpass filter unit. 3. A dielectric filter comprising: a dielectric block in which a plurality of voids are formed and formed therein; an outer conductor formed at a predetermined position on an outer surface of the dielectric block; and an inner conductor formed in the void. The first and second two rows of gaps are formed, and the inner conductor, the dielectric block, and the outer conductor formed in each of the first row of gaps are open ends with both openings of the first row of gaps as open ends. A plurality of resonators that resonate at a half wavelength, and a capacitance is generated in the opening only between itself and an outer conductor.
Forming a continuous coupling conductor from the inner conductor,
The capacitance constitutes a band-pass filter section composed of a plurality of resonators, in which resonators adjacent to each other of the plurality of resonators are inductively coupled to each other. Open ends or short-circuit ends, each of which is formed by an inner conductor, a dielectric block, and the outer conductor formed in the second row of gaps.
A dielectric filter comprising a plurality of resonators that resonate at wavelengths, and coupling these resonators to resonators at each stage of the bandpass filter unit.