JP3072282B2 - Bandpass 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 resonator and a band-pass filter, and more particularly, to a dielectric resonator having a small electric loss, a group delay time deviation characteristic within a pass band, and an attenuation characteristic. The present invention relates to a steep group delay time compensating band-pass filter and a band-pass filter having a larger attenuation than conventional ones.

[0002]

2. Description of the Related Art FIG. 26 is a perspective view showing a schematic configuration of a band-pass filter (hereinafter, referred to as a BPF) using a conventional dielectric resonator, and FIG.
It is sectional drawing which shows the cross section cut | disconnected by A 'cutting line. FIG.
6, 27, outer conductor 1 is made of TE ₁₁ cutoff waveguide, 2 a to 2 c is the partition wall, the input (or output) terminal 3, the output (or input) terminal 4, 5a to 5d is V mode Frequency adjusting screws, 6a to 6d are H mode frequency adjusting screws, 7a to 7d are coupling adjusting screws, 8 is an input (or output) coupling loop, 9 is an output (or input) coupling loop, and 10a to 10d are dual mode dielectrics. Resonator, 1
1a~11d the support of each dielectric resonator (10a~10d), 12a~12 e is capacitive coupling window that is formed in the partition wall (2 a to 2 c).

FIG. 28 shows a V mode frequency adjusting screw (5a to 5d) and an H mode frequency adjusting screw (6a) shown in FIG.
FIGS. 28A to 26D) and the relationship between the coupling adjustment screws (7a to 7d), FIG. 28A being a cut line BB ′ shown in FIG. 27, and FIG. 28 (c) is the DD ′ cutting line shown in FIG. 27, and FIG.
FIG. 28 (e) is a cross-sectional view showing a cross section taken along a line EE ′ shown in FIG. As shown in FIG. 28, the V mode frequency adjusting screws (5a to 5d) and the H mode frequency adjusting screws (6a to 6d) are provided such that their axial directions have an angle difference of 90 °. Coupling adjustment screw (7
a to 7d) are V mode frequency adjustment screws (5a to 5d)
Are provided so as to have an angle difference of ± 45 ° with respect to the axial direction.

FIG. 29 shows a conventional B shown in FIGS. 26 and 27.
It is a circuit diagram showing an equivalent circuit of PF. In FIG.
S1 is a V mode resonance circuit of the dielectric resonator 10a, RS
2 is an H mode resonance circuit of the dielectric resonator 10a,
Similarly, RS3 is an H mode resonance circuit of the dielectric resonator 10b, RS4 is a V mode resonance circuit of the dielectric resonator 10b, RS5 is a V mode resonance circuit of the dielectric resonator 10c, and RS6 is a dielectric The H mode resonance circuit of the resonator 10c, RS7 is the H mode resonance circuit of the dielectric resonator 10d, and RS8 is the V mode resonance circuit of the dielectric resonator 10d. L _{1V to} L _4V and L _{1H to} L _4H are the inductance components constituting each resonance circuit (RS1 to RS8),
C _{1V to} C _4V and C _{1H to} C _4H correspond to each resonance circuit (RS1
To RS8). M ₀₁ is a magnetic coupling circuit that magnetically couples the input (or output) coupling loop 8 with the V-mode resonance circuit (RS1) of the dielectric resonator 10a, M ₀₂ is an output (or input) coupling loop 9, This is a magnetic coupling circuit that magnetically couples the dielectric resonator 10d with the V-mode resonance circuit (RS8). C ₁₂ is a capacitive coupling circuit that capacitively couples the V-mode resonance circuit (RS1) and the H-mode resonance circuit (RS2) of the dielectric resonator 10a.
₃₄ denotes an H mode resonance circuit (RS) of the dielectric resonator 10b.
3) and V-mode resonant circuit (RS4) and capacitive coupling circuit capacitively coupling the, C ₅₆ is the capacitance of capacitive coupling between V mode resonance circuit of the dielectric resonator 10c (RS5) and H-mode resonant circuit (RS6) The coupling circuit, _C78, is a dielectric resonator 10d
H mode resonance circuit (RS7) and V mode resonance circuit (R
S8) is a capacitive coupling circuit. The amount of coupling by this capacitive coupling circuit (C ₁₂ , C ₃₄ , C ₅₆ , C ₇₈ )
It can be adjusted with the coupling adjustment screws (7a to 7d).

In the conventional BPF shown in FIGS. 26 and 27, a first capacitive coupling window 1 provided in a first partition 2a is provided.
2a capacitively couples the H-mode resonance circuit (RS2) of the first dielectric resonator 10a and the H-mode resonance circuit (RS3) of the second dielectric resonator 10b.
a is provided between the V-mode resonance circuit (RS1) of the first dielectric resonator 10a and the second capacitive coupling window 12b.
Is capacitively coupled to the V-mode resonance circuit (RS4) of the dielectric resonator 10b. The third capacitive coupling window 12c provided in the second partition 2b includes a V-mode resonance circuit (RS4) of the second dielectric resonator 10b and a V-mode resonance circuit (RS) of the third dielectric resonator 10c. RS5). The fourth capacitive coupling window 12d provided in the third partition 2c is an H-mode resonance circuit (RS6) of the third dielectric resonator 10c.
And the H-mode resonance circuit (RS) of the fourth dielectric resonator 10 d
7), and similarly, the fifth capacitive coupling window 12e provided in the third partition 2c is connected to the V-mode resonance circuit (RS5) of the third dielectric resonator 10c and the fourth capacitive coupling window 12e. The V-mode resonance circuit (RS8) of the dielectric resonator 10d is capacitively coupled.

In FIG. 29, C ₂₃ denotes a first partition 2a.
First capacitive coupling circuit due to capacitive coupling windows 12a, C ₁₄ provided is a capacitive coupling circuit according to a second capacitive coupling window 12b provided on the first partition wall 2a. Similarly, C
_67, the fourth capacitive coupling circuit due to capacitive coupling windows 12d of which is provided in the third partition wall 2c, C ₅₈ is the fifth capacitive coupling window 12e due to capacitive coupling circuit provided in the third partition wall 2c And C ₄₅ is a capacitive coupling circuit formed by the third capacitive coupling window 12c provided in the second partition 2b. Binding amount by the capacitive coupling circuit _{(C 14, C 23, C} 45, C 58, C 67) is adjusted by the size of the partition wall (2 a to 2 c) the provided capacitive coupling window (12a to 12e) be able to.

Now, each V-mode frequency adjusting screw (5a-5d) and H-mode frequency adjusting screw (6a-6) are adjusted so that each resonator (RS1-RS8) tunes to a predetermined frequency.
6d), this conventional BPF
The operation of will be briefly described. In the conventional BPF, the high-frequency power input from the input (or output) terminal 4, by the magnetic coupling circuit M _01, is magnetically coupled with the V-mode resonant circuit of the dielectric resonator 10a (RS1), thereby, the resonance The circuit (RS1) is excited. In addition, the resonance circuit (RS
Part of the resonance electric field 1) is capacitively coupled to the H-mode resonance circuit (RS2) of the dielectric resonator 10a by the coupling adjustment screw 7a, and the resonance circuit (RS2) is excited. A part of the resonance electric field of the resonance circuit (RS2) is capacitively coupled to the H-mode resonance circuit (RS3) of the dielectric resonator 10b by the capacitive coupling window 12a provided in the partition wall 2a.
S3) is excited.

A part of the resonance electric field of the resonance circuit (RS3) is
The coupling adjustment screw 7b is capacitively coupled to the V-mode resonance circuit (RS4) of the dielectric resonator 10b, and the resonance circuit (RS
4) is excited. At this time, the connection adjustment screws (7a, 7
The installation position of b) is selected such that the directions of the resonance electric field vector generated in the resonance circuit (RS1) and the resonance electric field vector generated in the resonance circuit (RS4) are different by 180 °, and the resonance circuit (RS1) and the resonance circuit ( RS4) is capacitively coupled with the capacitive coupling window 12b provided in the partition wall 2a.

Thus, the resonance circuit (RS1) → the capacitance coupling circuit (C ₁₂ ) → the resonance circuit (RS2) → the capacitance coupling circuit (C ₂₃ ) → the resonance circuit (RS3) → the capacitance coupling circuit (C ₃₄ )
→ A resonance circuit (RS4)
An electromagnetic field occurring in 4) can be a resonant circuit (RS1) → capacitive coupling circuit (C ₁₄₎ → electromagnetic field and the opposite phase generated in the resonant circuit (RS4) a path consisting of the resonant circuit (RS4). Therefore, outside the passband (attenuation region), an attenuation pole (attenuation pole) is generated at a pair of frequencies at which the amplitudes of both electromagnetic fields are equal to each other. Similarly, the resonance circuit (RS5) → capacitive coupling circuit (C ₅₆ ) → resonance circuit (RS
6) → a capacitive coupling circuit (C ₆₇ ) → a resonance circuit (RS 7) → a capacitive coupling circuit (C ₇₈ ) → an electromagnetic field generated in the resonance circuit (RS 8) through a path consisting of the resonance circuit (RS 8) and the resonance circuit (R
S5) → Capacitive coupling circuit (C ₅₈ ) → Resonant circuit (RS8) In the path, the electromagnetic field generated in the resonant circuit (RS8) can be out of phase. An attenuation pole (attenuation pole) is generated at a pair of frequencies at which the amplitudes of the two electromagnetic fields are equal to each other. Thus, the conventional BPF has a capacitive coupling circuit (C ₁₂ ,
By adjusting the values of C ₂₃ , C ₃₄ , C ₁₄ , C ₅₆ , C ₆₇ , C ₇₈ , and C ₅₈ ), a two-pole polarized Chebyshev type band-pass filter is obtained.

[0010]

In the BPF using the conventional dielectric resonator shown in FIGS. 26 to 29, four dielectric resonators (10a to 10d) are cascade-connected in series. Since the length in the major axis direction is large, there is a problem that a container for installing and storing the BPF vertically or horizontally becomes large. Also, in the conventional BPF using the dielectric resonator shown in FIGS. 26 to 29, the attenuation can be increased by providing three pairs of attenuation poles. In a BPF using a dielectric resonator, there is a problem that a 3-pair polarized Chebyshev bandpass filter cannot be formed due to its structure. On the other hand, the digital television signal to be started now has the number of segments (13 segments).
And segment interval is narrow (432KHz)
Therefore, many IM waves are generated near the target signal wave. Depending on the modulation method, the BPF to be used is required to have a small amplitude deviation and a group delay time deviation within a pass band and a frequency characteristic having a steep attenuation characteristic. However,
The BPF using the conventional dielectric resonator shown in FIGS. 26 to 29 is a two-pole polar Chebyshev type band-pass filter, and the BPF which emphasizes the attenuation characteristics of analog television signals and the like.
Although suitable for a PF, there is a problem that the amplitude deviation and the group delay time deviation in the pass band are large, and thus the BPF is not suitable for a digital television signal BPF requiring the above-mentioned frequency characteristics.

As shown in FIG. 27, each of the dielectric resonators (10a to 10d) includes a dielectric resonator (10a to 10d).
d) It is fixed to the outer conductor 1 by supports (11a to 11d) made of a dielectric material having a lower dielectric constant.
Therefore, as shown in FIG. 30, the capacitance (C ₁₁ ) due to the dielectric material constituting the support 11 and the resistance (R ₁₁ ) due to the dielectric loss of the dielectric material constituting the support 11 are different from each other. This will occur at the corner of the resonator 10. The capacitance (C ₁₁ ) and the resistance (R ₁₁ ) cause a reduction in the no-load Q of the dielectric resonator 10, and as a result, the electrical characteristics of the BPF deteriorate. Thus, in the BPF using the conventional dielectric resonator, each dielectric resonator (1
The support (11a to 11d) that supports 0a to 10d) causes unnecessary capacitance (C ₁₁ ) and resistance (R ₁₁ ), thereby deteriorating the electrical characteristics of the BPF. .

[0012] The present invention has been made to solve the problems of the prior art, an object of the present invention, the passband
Amplitude deviation and group delay time deviation
To provide a bandpass filter using a dielectric resonator
To provide. Another object of the present invention is to provide a band-pass filter using a dielectric resonator that can reduce an installation space for installing the band-pass filter.

[0013]

The above and other objects and novel features of the present invention will become apparent from the description of the present specification and the accompanying drawings.

[0015]

SUMMARY OF THE INVENTION Among the inventions disclosed in the present application, the outline of a representative one will be briefly described.
It is as follows.

That is, the present invention relates to a band-pass filter in which four dual-mode dielectric resonators are arranged in a straight line, wherein a second dual-mode dielectric resonator and a third dual-mode dielectric resonator are arranged.
A third mode in which the first mode resonance circuit of the second dual mode dielectric resonator and the first mode resonance circuit of the third dual mode dielectric resonator are capacitively coupled to the first dual mode dielectric resonator. A second partition wall on which a capacitive coupling window is formed, and the respective dual mode dielectric resonators
Provided for each, to adjust the installation position of the first to fourth coupling adjusting screw for adjusting the coupling capacitance between the first mode resonance circuit and the second mode resonant circuit of each dual mode dielectric resonator, Further , the size of a fourth capacitive coupling window formed in a third partition provided between the third dual-mode dielectric resonator and the fourth dual-mode dielectric resonator is adjusted, It is characterized in that the amplitude deviation and the group delay time deviation in the pass band are reduced.

Further, the present invention is a bandpass filter comprising four dual-mode dielectric resonators arranged in a U-shape, wherein the second dual-mode dielectric resonator and the third dual-mode dielectric resonator are arranged in a U-shape. Capacitively coupled to the dielectric resonator by a capacitive element, and each of the dual mode dielectric resonators
And the first of each of the dual mode dielectric resonators
The installation positions of the first to fourth coupling adjustment screws for adjusting the coupling capacitance between the mode resonance circuit and the second mode resonance circuit are adjusted, and further, the first dual mode dielectric resonator and the second between the dual mode dielectric resonator, and the third dual-mode dielectric third capacitive coupling window that is formed in the partition wall provided between the resonator and the fourth dual mode dielectric resonator The size is adjusted to reduce the amplitude deviation and the group delay time deviation in the pass band.

Further, the present invention provides a first dual mode induction.
The electric resonator and the fourth dual-mode dielectric resonator by U
It is characterized in that it is magnetically coupled by a loop element in the shape of a letter .

[0019]

[0020]

[0021]

Embodiments of the present invention will be described below in detail with reference to the drawings.

In all the drawings for describing the embodiments, those having the same functions are denoted by the same reference numerals, and their repeated description will be omitted.

[First Embodiment] FIGS. 1 and 2 show a schematic configuration of a group delay time compensating band-pass filter (hereinafter referred to as a BPF) using a dielectric resonator according to a first embodiment of the present invention. It is principal part sectional drawing which shows. FIG. 1 is similar to FIG.
FIG. 2A is a cross-sectional view of the same portion as FIG.
2B is a cut line, FIG. 2B is a CC ′ cut line shown in FIG. 1, FIG. 2C is a DD ′ cut line shown in FIG.
FIG. 2E is a cross-sectional view illustrating a cross section cut along a line EE ′ illustrated in FIG. 1.

1 and 2, reference numeral 14 denotes an input / output coupling probe, reference numerals 20a to 20d denote dielectric resonators, and other symbols are the same as those in FIGS. 26, 27, and 28.
FIG. 3 is a cross-sectional view of a principal part for describing the dielectric resonator 20 of the present embodiment. As shown in FIG. 3, the dielectric resonator 20 of the present embodiment is a dielectric resonator element. 21 and a support column 22 and a support 23 which are integrally formed of the same material as the dielectric resonator element 21. This support column 2
2 (D1) and the axial length (L1) of the support column 22
Is a value that satisfies the following equation (1).

[0025]

D1 <2 × D / 3 L1 <L / 3 (1) where D is the diameter of the dielectric resonator element 21, L is the axial length of the dielectric resonator element 21. The dimensions of the support column 22
By setting the value to satisfy the above expression (1), the support pillar portion 22 can be cut at a wavelength of the cutoff frequency (cutoff wavelength; λ
_C ) Since the following dimensions are obtained, the electromagnetic field in the dielectric resonator element 21 does not enter the support column 22. As a result, the support column part 22 is
Therefore, the supporting column 22 is a simple supporting column.

FIGS. 4A and 4B are diagrams for explaining an electromagnetic field in the dielectric resonator element 21. FIG. 4A is a cross-sectional view of a main part of the dielectric resonator element 21, and FIG. FIG. 3 is a cross-sectional view showing a cross section cut along a line FF ′ shown in FIG. In FIG. 4, the solid line represents the electric field (E), and the broken line represents the magnetic field (H). As can be understood from FIG. 4, the support column 22 is provided so as to be perpendicular to the electric field (E) and the magnetic field (H), so that the electric loss can be reduced. Also, the dielectric resonator element 2
1. Since the support portion 23 and the support column portion 22 can be integrally formed of the same material, the reliability of the BPF can be improved. Further, unlike the conventional BPF, a support (11a to 11d) for supporting the dielectric resonators (10a to 10d) is not required, so that not only the number of parts can be reduced, but also assembly such as bonding. Since the number of steps can be reduced, the cost of the BPF can be reduced. In the dielectric resonator 20 of the present embodiment, the dielectric resonator element 21 and the support pillar 22 are attached to the partition 2 by fixing the support 23 to the partition 2 with screws or the like. As described above, by using the dielectric resonator 20 of the present embodiment, it is possible to configure a BPF with small electric loss and high reliability.

Group Delay Time Compensated BPF of the Present Embodiment
Is different from the conventional BPF shown in FIG. 27 in the size of the capacitive coupling window 12e provided in the partition wall 2c and the installation position of the coupling adjusting screw 7d. As described above, FIG.
BPF using the conventional dielectric resonator shown in FIGS.
A bandpass filter having two pairs of polarized Chebyshev type bandpass filters having two pairs of attenuation poles has a large attenuation as shown in FIG. 31, but has a passband as shown in FIG. 33 is large, and at the same time, FIG.
As shown in (1), there is a disadvantage that the group delay time deviation of the group delay time (τ) in the pass band is large. On the contrary,
In the group delay time compensation type BPF of the present embodiment, the partition 2c
The size of the capacitive coupling window 12e provided in the V-mode frequency adjusting screw 5d is large.
Is provided so as to have an angle difference of -45 ° with respect to the axial direction of FIG. 5 shows the group delay time compensation type B of this embodiment.
FIG. 3 is a circuit diagram showing an equivalent circuit of a PF, in which FIG.
_{Reference numeral 01} denotes a capacitive coupling circuit that capacitively couples the input / output coupling probe 14 and the V-mode resonance circuit (RS1) of the dielectric resonator 10a. The equalizer shown in FIG. 5 and the equalizer shown in FIG. 29 have the same basic circuit configuration. However, in the group delay time compensation type BPF of the present embodiment, since the coupling adjustment screw 7d and the coupling adjustment screw 7c have the same axial direction, the resonance electric field vector generated in the resonance circuit (RS5) and the resonance circuit (RS8) ) Is in phase with the resonance electric field vector.

[0028] Thus, the resonant circuit (RS5) → capacitive coupling circuit (C ₅₆₎ → resonant circuit (RS6) → capacitive coupling circuit (C ₆₇₎ → resonant circuit (RS7) → capacitive coupling circuit (C ₇₈₎
→ A resonance circuit (RS8)
An electromagnetic field occurring in the 8), and an electromagnetic field generated in the resonant circuit (RS8) in the route from the resonance circuit (RS5) → capacitive coupling circuit (C ₅₈₎ → resonant circuit (RS8), it may be in phase. On the other hand, in the pass band, the resonance circuit (RS5)
→ capacitive coupling circuit (C ₅₆₎ → resonant circuit (RS6) → capacitive coupling circuit (C ₆₇₎ → resonant circuit (RS7) → capacitive coupling circuit (C ₇₈₎ → resonant circuit path consisting of the resonant circuit (RS8) (RS8 ) and the electromagnetic field generated, and the electromagnetic field generated in the resonant circuit (RS5) → capacitive coupling circuit (C ₅₈₎ → resonant circuit path consisting of the resonant circuit (RS8) (RS8), in the vicinity of the center frequency, with each other The bands tend to cancel each other around the band edge of the pass band, and the deviation of the amplitude characteristic in the pass band becomes small. Similarly, the deviation of the group delay time (τ) within the pass band also decreases. That is, the group delay time compensation type BPF of the present embodiment
As shown in FIG. 6, in the amplitude characteristic, the attenuation pole is limited to a pair, and the amount of attenuation is small.
As shown in FIG. 8, it is possible to reduce the amplitude deviation in the pass band and, at the same time, to reduce the group delay time deviation in the pass band as shown in FIG.

[0029] In this case, the compensation amount of the group delay time can be adjusted by the value of the capacitive coupling circuit C _58, the capacitive coupling circuit C
_{If the} amount of compensation of the group delay time according to ₅₈ is smaller than the optimum value, the amount of compensation is small and the group delay time characteristic is almost a pan-bottom shape. FIG. 9 shows the group delay time characteristics in this state. When the compensation amount is optimal size of the group delay time due to the capacitive coupling circuit C ₅₈ is a flat portion of the group delay time characteristic is widened top. FIG. 10 shows the group delay time characteristics in this state. Capacitive coupling circuit C
_{If the} amount of compensation for the group delay time according to ₅₈ is greater than the optimal amount, the amount of compensation will be overcompensated. The graph shown in FIG. 8 shows the group delay time characteristics in this state. If a certain allowable ripple-like group delay time characteristic can be allowed in the pass band of the BPF, the group delay time characteristic of the overcompensation type group delay time compensation type BPF becomes the widest.

As described above, according to the group delay time compensation type BPF of the present embodiment, the amplitude deviation in the pass band is small,
The group delay time deviation in the pass band can be reduced. In the group delay time compensating BPF of the present embodiment, the conventional dielectric resonator 10 can be used as long as the deterioration of the electrical characteristics due to the support 11 is within an allowable range. Also, the group delay time compensation type B of the present embodiment
In the PF, the coupling adjustment screws (7a, 7a,
7b), and the size of the capacitive coupling window 12b provided in the partition wall 2a may be adjusted.

[Second Embodiment] FIG. 11 shows a group delay time compensation type BP using a dielectric resonator according to a second embodiment of the present invention.
FIG. 12 is a front view showing the front of F, and FIG.
It is sectional drawing which shows the cross section cut | disconnected by G 'cutting line. FIG.
1, in FIG. 12, 30 is the first capacitive element, 31 is U
The letter-shaped coupling loop element 32 is a partition, and the other reference numerals are the same as those in FIGS.

Group delay time compensation type BPF of this embodiment
Disposes four dielectric resonators (20a to 20d) in a vertical U-shape by arranging the dielectric resonators (20a, 20b) on the dielectric resonators (20c, 20d). And a dielectric resonator 20b and a dielectric resonator 20b.
c is capacitively coupled by a first capacitive element 30 composed of a capacitive coupling plate.
and d are magnetically coupled by a U-shaped coupling loop element 31. Although not shown, the coupling adjustment screw 7d is also used in the group delay time compensating BPF of the present embodiment.
Is-with respect to the axial direction of the V mode frequency adjusting screw 5d.
It is provided to have an angle difference of 45 °.

FIG. 13 is a circuit diagram showing an equivalent circuit of the group delay time compensation type BPF of the present embodiment. In the group delay time compensation BPF of this embodiment, the capacitive coupling window 33a provided in the partition wall 32 includes a dielectric resonator 20 b H mode H mode resonance circuit of the dielectric resonator 20 a (RS2) The resonance circuit (RS3) is capacitively coupled, and similarly, the partition 3
The capacitive coupling window 33b provided in the dielectric resonator 2
0 a V mode resonance circuit (RS1) and the dielectric resonator 20
b is capacitively coupled to the V-mode resonance circuit (RS4). Capacitive coupling window 33c provided in the partition wall 32 includes a dielectric resonator H mode resonance circuit of the dielectric resonator 20 c (RS6)
Capacitively coupled with a 20 d H-mode resonance circuit (RS7),
Capacitive coupling window 33d provided in the partition wall 32, V-mode resonant circuit of the dielectric resonator 20 c (RS5) and dielectric resonator 20 d V mode resonance circuit (RS8) and capacitively coupling the. Here, the group delay time compensating BPF of the above embodiment
Similarly to the above, the size of the capacitive coupling window 33d provided in the partition 32 is increased.

Further, the first capacitor 30 includes a dielectric resonator V mode resonance circuit of the dielectric resonator 20 b (RS4)
The Vc mode resonance circuit (RS5) of 20c is capacitively coupled. Furthermore, coupling loop element 31 of the U-shape, magnetically coupled V mode resonance circuit of the dielectric resonator 20 a and (RS1) V mode resonance circuit of the dielectric resonator 20 d and (RS8).

[0035] In FIG. 13, C _'23, the capacitive coupling circuit according provided in the partition wall 32 capacitive coupling window 33a, C'
_14, the capacitive coupling circuit due to capacitive coupling window 33b provided in the partition wall 32, C _'67, the capacitive coupling circuit due to capacitive coupling windows 33c provided in the partition wall 32, C' ₅₈ is the partition wall 32
Is a capacitive coupling circuit formed by the capacitive coupling window 33d provided in the first embodiment. C ′ ₄₅ is a capacitive coupling circuit using the first capacitive element 30. Further, M ₁₈ and M ₈₁ are magnetic coupling circuits formed by a U-shaped coupling loop element 31.

The equalizing circuit shown in FIG. 13 and the equalizing circuit shown in FIG. 5 have the same basic circuit configuration. Even in the group delay time compensating BPF of this embodiment, the resonance circuit (RS5 ) → Capacitive coupling circuit (C ₅₆ ) → Resonant circuit (RS
6) → Capacitive coupling circuit (C _'67 ) → Resonant circuit (RS7) →
Capacitive coupling circuits (C ₇₈₎ → the electromagnetic field generated in the resonant circuit in the route from the resonance circuit (RS8) (RS8), the resonant circuit (RS5) → capacitive coupling circuit (C _'58) → resonant circuit (RS
The electromagnetic field generated in the resonance circuit (RS8) in the path consisting of 8) can be in phase. Thus, also in the group delay time compensation type BPF of the present embodiment, the amplitude deviation in the pass band and the group delay time deviation can be reduced as in the first embodiment.

In addition, in the group delay time compensation type BPF of this embodiment, the V-mode resonance circuit (RS1) of the dielectric resonator 10a and the V-mode resonance circuit (RS8) of the dielectric resonator 10d are are magnetically coupled by the magnetic coupling circuit (M _18, M ₈₁₎ by coupling loop element 31 of the U-shape,
Resonant circuit (RS1) → capacitive coupling circuit (C ₁₂₎ → resonant circuit (RS2) → capacitive coupling circuit (C _'23) → resonant circuit (RS
3) → Capacitive coupling circuit (C ₃₄ ) → Resonant circuit (RS4) → Capacitive coupling circuit (C ′ ₄₅ ) → Resonant circuit (RS5) → Capacitive coupling circuit (C ₅₆ ) → Resonant circuit (RS6) → Capacitive coupling circuit ( C _'67) → resonant circuit (RS7) → capacitive coupling circuit (C ₇₈₎ → the electromagnetic field generated in the resonant circuit in the route from the resonance circuit (RS8) (RS8), the resonant circuit (RS1) → the magnetic coupling circuit (M ₁₈ , M ₈₁ ) → The electromagnetic field generated in the resonance circuit (RS8) can be in an opposite phase on the path formed by the resonance circuit (RS8). Thus, outside the pass band (attenuation region), an attenuation pole (attenuation pole) can be generated at a pair of frequencies at which the amplitudes of both electromagnetic fields are equal to each other. Therefore, as shown in FIG. 14, in the group delay time compensation type BPF of the present embodiment, two pairs of attenuation poles can be generated. As can be understood from the graph of FIG. 14, the group delay time compensation type BPF of the present embodiment is
Can increase the attenuation outside the pass band by about 10 dB as compared with the group delay time compensation type BPF of the first embodiment.

FIGS. 15 to 18 are graphs showing frequency characteristics of an example of the group delay time compensation type BPF of the present embodiment. FIG. 15 is a graph showing the attenuation characteristics, in which the horizontal axis represents the frequency (MHz) and the memory interval is 2 MHz, and the vertical axis represents the attenuation (dB) and the memory interval is 10 dB. The center frequency of the group delay time compensation type BPF is 482 MHz, and in FIG. 15, the frequency is 478.544 MHz.
The attenuation at z (point A in FIG. 15) is −31.07 d.
B, and the frequency is 485.456 MHz (B in FIG. 15).
The attenuation at the time of (point) is -30.077 dB. FIG. 16 is a graph showing the graph shown in FIG. 15 in an enlarged manner, in which the memory interval on the horizontal axis is 1 MHz and the memory interval on the vertical axis is 0.5 dB. As can be seen from the graph of FIG. 16, the frequency is changed from 479.2 MHz (point A in FIG. 16) to 4
The attenuation is within 0.1 dB between 84.8 MHz (point B in FIG. 16), and the group delay time compensation type BPF shown in FIG. 15 has a small amplitude deviation in the pass band.

FIG. 17 is a graph showing phase characteristics.
The horizontal axis is the frequency (MHz) and the memory interval is 1 MHz, and the vertical axis is the angle and the memory interval is 90 °. In FIG. 17, when the frequency is 479.2 MHz (point A in FIG. 17), the phase is 43.327 °, and the frequency is 484.8.
The phase at MHz (point B in FIG. 17) is 115.78.
°. FIG. 18 is a graph showing the group delay time characteristic, where the horizontal axis is frequency (MHz), the memory interval is 1 MHz,
The vertical axis indicates the delay amount (ns) and the memory interval is 100 ns. It should be noted that this delay amount (ns) indicates that the frequency is 480.5.
This represents a relative delay amount when the delay amount at 6 MHz (point C in FIG. 18) is set to 0. In FIG. 18, when the frequency is 47 9 . Delay amount at 2 MHz (point A in FIG. 18) (difference from delay amount when frequency is 480.56 MHz)
Is 213.101 ns and the frequency is 484.8M
Hz (point B in FIG. 18) (the frequency is 48
The difference with the amount of delay at 0.56 MHz) is 205.68.
1 ns.

The group delay time compensation type B according to the present embodiment
In the PF, instead of the input / output coupling loop (8, 9),
As shown in FIG. 19, the input / output coupling probe (14, 1
5) may be provided. In the group delay time compensation type BPF of the present embodiment, the input / output coupling probe (1
FIG. 20 shows an equivalent circuit provided with (4, 15). In FIG. 20, C ₀₁ is the input / output coupling probe 14.
Capacitive coupling circuit, C ₀₂ to V-mode resonant circuit of the dielectric resonator 10a and (RS1) capacitively coupled with the dielectric resonator 1
This is a capacitive coupling circuit that capacitively couples the 0d V-mode resonance circuit (RS8) and the input / output coupling probe 15. As described above, in the group delay time compensating BPF of the present embodiment, the four dielectric resonators (20a to 20d) are arranged in a U-shape, so that the BPF is arranged. The space can be reduced, which allows BP
It is possible to reduce the size of the storage container for storing F. In the group delay time compensating BPF of the present embodiment, the U-shaped coupling loop element 31 magnetically couples between the dielectric resonator 20a and the dielectric resonator 20d. As in the first embodiment, the amplitude deviation and the group delay time deviation in the pass band can be reduced, and the attenuation outside the pass band can be reduced as compared with the group delay time compensation type BPF of the first embodiment. Can be bigger. In the group delay time compensating BPF of the present embodiment, the U-shaped coupling loop element 31 for coupling between the dielectric resonator 20a and the dielectric resonator 20d can be omitted. In this case, similarly to the first embodiment, the amplitude deviation and the group delay time deviation in the pass band can be reduced, and the storage container for storing the BPF can be downsized.

[Third Embodiment] FIG. 21 is a cross-sectional view of a principal part showing a schematic configuration of a BPF using a dielectric resonator according to a third embodiment of the present invention. is there. In FIG. 21, reference numeral 30 denotes a first capacitance element, 35 denotes a second capacitance element, 31 denotes a U-shaped coupling loop element, 32 denotes a partition, and the other symbols are the same as those in FIGS.
Same as 7. The BPF according to the present embodiment includes a dielectric resonator (20a, 2d) on a dielectric resonator (20c, 20d).
0b), four dielectric resonators (2
0a to 20d) are vertically arranged in a U-shape.
The first between the dielectric resonator 20b and the dielectric resonator 20c
And the dielectric resonator 20a
And a dielectric resonator 20d connected by a second capacitive element 35. Although illustration is omitted, in the BPF of the present embodiment, the coupling adjustment screw 7d is disposed in the axial direction of the V-mode frequency adjustment screw 5d, similarly to the conventional BPF shown in FIGS. , 45 °, and the size of the capacitive coupling window 33d provided in the partition 32 is the same as that of the conventional BPF. FIG. 22 is a circuit diagram showing an equivalent circuit of the BPF of the present embodiment. In the BPF of the present embodiment, the second capacitive element 35 capacitively couples the V-mode resonance circuit (RS1) of the dielectric resonator 10a and the V-mode resonance circuit (RS8) of the dielectric resonator 10d. In FIG.
C ′ ₁₈ is a capacitive coupling circuit formed by the second capacitive element 35. The other reference numerals are the same as those in FIG. The equalizer shown in FIG. 22 and the equalizer shown in FIG. 29 have the same basic circuit configuration. BPF of this embodiment
Also, since the coupling adjustment screw 7d has an angle difference of 45 ° with respect to the axial direction of the V-mode frequency adjustment screw 5d, the resonance electric field vector generated in the resonance circuit (RS5) and the resonance circuit (RS8 ) Is opposite in phase to the resonance electric field vector. Therefore, outside the pass band (attenuation region), an attenuation pole (attenuation pole) can be generated at a pair of frequencies where the amplitudes of both electromagnetic fields are equal to each other.

[0042] Further, the V-mode resonant circuit of the dielectric resonator 10a (RS1), and V-mode resonant circuit of the dielectric resonator 10d (RS8), but are capacitively coupled by a capacitive coupling circuit C _'18 by capacitive element 31 And the resonance circuit (RS
1) → Capacitive coupling circuit (C ₁₂ ) → Resonant circuit (RS2) → Capacitive coupling circuit (C ′ ₂₃ ) → Resonant circuit (RS3) → Capacitive coupling circuit (C ₃₄ ) → Resonant circuit (RS4) → Capacitive coupling circuit ( C ′ ₄₅ ) → Resonant circuit (RS5) → Capacitive coupling circuit (C ₅₆ ) → Resonant circuit (RS6) → Capacitive coupling circuit (C ′ ₆₇ ) → Resonant circuit (RS7) → Capacitive coupling circuit (C ₇₈ ) → Resonant circuit The electromagnetic field generated in the resonance circuit (RS8) on the path consisting of (RS8) and the electromagnetic field generated in the resonance circuit (RS8) on the path consisting of the resonance circuit (RS1) → the capacitive coupling circuit (C ′ ₁₈ ) → the resonance circuit (RS8) The field and the field can be in opposite phase. Thus, outside the pass band (attenuation region), an attenuation pole (attenuation pole) can be generated at a pair of frequencies where the amplitudes of both electromagnetic fields are equal to each other. Therefore, as shown in FIG. 23, in the BPF of the present embodiment, three pairs of attenuation poles can be generated. As a result, in the BPF of the present embodiment, the conventional BPF shown in FIGS. About 10dB compared to BPF
The more the attenuation, the greater the amount of attenuation. However, the BPF of the present embodiment has a large amplitude deviation in the pass band and a large group delay time deviation in the pass band, similarly to the conventional BPF shown in FIGS.

In the BPF of this embodiment,
Instead of the input / output coupling loops (8, 9), input / output coupling probes (14, 15) may be provided as shown in FIG. FIG. 25 shows an equivalent circuit in the case where input / output coupling probes (14, 15) are provided in the BPF of the present embodiment. In FIG. 25, C ₀₁ is a capacitive coupling circuit that capacitively couples the input / output coupling probe 14 and the V-mode resonance circuit (RS1) of the dielectric resonator 10a.
₀₂ is a V-mode resonance circuit (RS
8) and a capacitive coupling circuit that capacitively couples the input / output coupling probe 15. As described above, in the BPF of the present embodiment, the amount of attenuation can be increased as compared with the conventional BPF.

As described above, the invention made by the present inventor is:
Although a specific description has been given based on the above-described embodiment, the present invention is not limited to the above-described embodiment, and it is needless to say that various modifications can be made without departing from the gist of the invention.

[0045]

The effects obtained by typical ones of the inventions disclosed in the present application will be briefly described as follows.

(1) According to the present invention, a dielectric resonator is used.
Of the amplitude deviation in the pass band
Difference and group delay time deviation can be reduced.
You. (2) According to the present invention, band pass using a dielectric resonator
In the filter, the amplitude deviation in the pass band and the group delay
Reduce delay time deviation and increase attenuation
It is possible to do. (3) According to the present invention, band pass using a dielectric resonator
Filter for placing a bandpass filter
The installation space can be reduced.

[Brief description of the drawings]

FIG. 1 is a sectional view of a main part showing a schematic configuration of a group delay time compensating band-pass filter using a dielectric resonator according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view of a main part showing a schematic configuration of a group delay time compensation band-pass filter using the dielectric resonator according to the first embodiment of the present invention.

FIG. 3 is a fragmentary cross-sectional view for explaining the dielectric resonator according to the first embodiment of the present invention.

FIG. 4 is a diagram for explaining an electromagnetic field in the dielectric resonator element according to the first embodiment of the present invention.

FIG. 5 is a circuit diagram showing an equivalent circuit of the group delay time compensation type bandpass filter according to the first embodiment of the present invention.

FIG. 6 is a graph showing an attenuation characteristic of the group delay time compensation type bandpass filter according to the first embodiment of the present invention.

FIG. 7 is an enlarged graph showing the graph shown in FIG. 6;

FIG. 8 is a graph showing group delay time characteristics of the group delay time compensation type bandpass filter according to the first embodiment of the present invention.

FIG. 9 is a graph showing group delay time characteristics when the amount of group delay time compensation is smaller than an optimal amount in the group delay time compensation type bandpass filter according to the first embodiment of the present invention.

FIG. 10 is a graph showing group delay time characteristics when the amount of group delay time compensation is optimal in the group delay time compensation type bandpass filter according to the first embodiment of the present invention.

FIG. 11 is a front view showing the front of a group delay time compensation type bandpass filter using a dielectric resonator according to a second embodiment of the present invention.

FIG. 12 is a cross-sectional view of a main part showing a schematic configuration of a group delay time compensating band-pass filter using a dielectric resonator according to a second embodiment of the present invention.

FIG. 13 is a circuit diagram showing an equivalent circuit of a group delay time compensation band-pass filter according to a second embodiment of the present invention.

FIG. 14 is a graph showing an attenuation characteristic of the group delay time compensation type bandpass filter according to the second embodiment of the present invention.

FIG. 15 is a graph showing an attenuation characteristic of an example of a group delay time compensation band-pass filter according to the second embodiment of the present invention.

16 is a graph showing the graph shown in FIG. 15 in an enlarged manner.

FIG. 17 is a graph showing a phase characteristic of an example of a group delay time compensation type bandpass filter according to the second embodiment of the present invention.

FIG. 18 is a graph showing a group delay time characteristic of an example of a group delay time compensation type bandpass filter according to the second embodiment of the present invention.

FIG. 19 is a fragmentary cross-sectional view showing a schematic configuration of a modification of the group delay time compensation type bandpass filter using the dielectric resonator according to the second embodiment of the present invention.

20 is a circuit diagram showing an equivalent circuit of the group delay time compensation type band pass filter shown in FIG.

FIG. 21 is a fragmentary cross-sectional view showing a schematic configuration of a band-pass filter using the dielectric resonator according to the third embodiment of the present invention.

FIG. 22 is a circuit diagram showing an equivalent circuit of the bandpass filter according to the third embodiment of the present invention.

FIG. 23 is a graph showing attenuation characteristics of the bandpass filter according to the third embodiment of the present invention.

FIG. 24 is a fragmentary cross-sectional view showing a schematic configuration of a modification of the bandpass filter using the dielectric resonator according to the third embodiment of the present invention.

FIG. 25 is a circuit diagram showing an equivalent circuit of the bandpass filter shown in FIG.

FIG. 26 is a perspective view showing a schematic configuration of a band-pass filter using a conventional dielectric resonator.

FIG. 27 is a cross-sectional view of a main part showing a schematic configuration of a band-pass filter using a conventional dielectric resonator.

28 is a diagram showing a relationship among a V mode frequency adjustment screw, an H mode frequency adjustment screw, and a coupling adjustment screw shown in FIG. 26.

FIG. 29 is a circuit diagram showing an equivalent circuit of the conventional bandpass filter shown in FIGS. 26 and 27.

FIG. 30 is a view for explaining a problem in a conventional method of supporting a dielectric resonator.

FIG. 31 is a graph showing an attenuation characteristic of the bandpass filter using the conventional dielectric resonator shown in FIGS. 26 and 27.

FIG. 32 is a graph showing the graph shown in FIG. 31 in an enlarged manner.

FIG. 33 is a graph showing a group delay time characteristic of the bandpass filter using the conventional dielectric resonator shown in FIGS. 26 and 27.

[Explanation of symbols]

1 ... TE ₁₁ outer conductor made of cut-off waveguide,. 2a-
2c, 32 ... partition, 3 ... input (or output) terminal, 4 ...
Output (or input) terminals, 5a to 5d: V mode frequency adjusting screw, 6a to 6d: H mode frequency adjusting screw, 7a
7d: coupling adjustment screw, 8: input (or output) coupling loop, 9: output (or input) coupling loop, 10, 10
a to 10d, 20, 20a to 20d: dual mode dielectric resonator; 11, 11a to 11d: support, 12a to
12e, 33a to 33d ... capacitive coupling windows, 14, 15 ...
Input / output coupling probe, 21 ... dielectric resonator element, 22 ...
Support pillar part, 23 ... Support part, 30, 35 ... Capacitance element, 31
... U-shaped coupling loop element.

Continuation of the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H01P 7/10 H01P 1/20 H01P 1/208 H01P 1/205

Claims (4)

(57) [Claims] 1. Four dual-mode dielectric resonators arranged in a straight line, a cylindrical outer conductor in which the four dual-mode dielectric resonators are provided, and each of the outer conductors A first to a fourth mode provided for each dual mode dielectric resonator to adjust a coupling capacitance between a first mode resonance circuit and a second mode resonance circuit of each of the dual mode dielectric resonators. A coupling adjusting screw; a first partition provided between the first dual-mode dielectric resonator and the second dual-mode dielectric resonator, wherein the first dual-mode dielectric resonator is provided. A first capacitive coupling window that capacitively couples the first mode resonance circuit of the first dual mode dielectric resonator with the first mode resonance circuit of the second dual mode dielectric resonator; and a second capacitive coupling window of the first dual mode dielectric resonator. Mode resonance circuit and the second A first partition wall formed with a second capacitive coupling window for capacitively coupling the second mode resonance circuit of the dual mode dielectric resonator of the first embodiment, the second dual mode dielectric resonator and the third A second partition provided between the first dual mode dielectric resonator and the second dual mode dielectric resonator, and a second partition between the first dual mode dielectric resonator and the third dual mode dielectric resonator. A second partition in which a third capacitive coupling window for capacitively coupling the one-mode resonance circuit is formed; and between the third dual-mode dielectric resonator and the fourth dual-mode dielectric resonator A third partition provided in the third dual mode dielectric resonator, the first mode resonance circuit of the third dual mode dielectric resonator being capacitively coupled to the first mode resonance circuit of the fourth dual mode dielectric resonator. 4 capacitive coupling windows; A fifth capacitive coupling window formed with a fifth capacitive coupling window for capacitively coupling the second mode resonance circuit of the third dual mode dielectric resonator and the second mode resonance circuit of the fourth dual mode dielectric resonator. a band-pass filter and a third partition wall, and an axial front Symbol third coupling adjusting screw and fourth coupling adjustment screw to the same, and a fourth that is formed before Symbol third partition wall A band-pass filter wherein a size of a capacitive coupling window is adjusted to reduce an amplitude deviation and a group delay time deviation in a pass band. 2. A dual-mode dielectric resonator arranged in a U-shape, a cylindrical outer conductor in which the four dual-mode dielectric resonators are provided, and A first to a second mode that are provided for each of the dual mode dielectric resonators and adjust a coupling capacitance between a first mode resonance circuit and a second mode resonance circuit of each of the dual mode dielectric resonators. 4, the coupling adjustment screw, between the first dual mode dielectric resonator and the second dual mode dielectric resonator, and between the third dual mode dielectric resonator and the fourth dual mode A partition provided between the first dual-mode dielectric resonator and the first dual-mode dielectric resonator; Capacitively coupled first A capacitive coupling window, a second capacitive coupling window coupling a second mode resonance circuit of the first dual mode dielectric resonator and a second mode resonance circuit of the second dual mode dielectric resonator, A third capacitive coupling window that capacitively couples a first mode resonance circuit of the third dual mode dielectric resonator and a first mode resonance circuit of the fourth dual mode dielectric resonator; and A partition wall having a fourth capacitive coupling window for capacitively coupling the second mode resonance circuit of the dual mode dielectric resonator and the second mode resonance circuit of the fourth dual mode dielectric resonator; A first mode resonance circuit of the second dual mode dielectric resonator and a first mode resonance circuit of the third dual mode dielectric resonator;
A band-pass filter having a capacitive element for capacitively coupling a mode resonance circuit, wherein the third coupling adjustment screw and the fourth coupling adjustment screw have the same axial direction, and a third capacitive coupling window. Wherein the amplitude deviation and the group delay time deviation in the pass band are reduced. 3. A U-shaped loop element for magnetically coupling a first mode resonance circuit of the first dual mode dielectric resonator and a first mode resonance circuit of the fourth dual mode dielectric resonator. The band-pass filter according to claim 2, further comprising: 4. The dual mode dielectric resonator according to claim 1,
The columnar dielectric resonator, the columnar support column, and the columnar support are integrally formed on the same axis in the order of the dielectric resonator, the support column, and the support. Wherein the diameter of the dielectric resonator element is (D) and the axial length of the dielectric resonator element is (L).
4. The method according to claim 1, wherein 1) satisfies D1 <2 × D / 3, and the axial length (L1) of the support column satisfies L1 <L / 3. A bandpass filter as described.