JPH11317601A - Group delay time compensation type band-pass filter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a delay time compensation type band-pass filter which compensates a delay time characteristic and reduces amplitude deviation and delay time deviation in a pass band. SOLUTION: In a delay time compensation type band-pass filter, which is formed by cascading a 1st to an N-th (N>=6) dielectric resonators in a U-shape and making main connection between each dielectric resonators with a magnetic coupled circuit, when two dielectric resonators which are located at a U-shaped turning back point are the n-th (n<N) and the (n+1)-th dielectric resonators respectively and sigmoid connection loops (6 and 16) make subconnections between the (n-1)-th dielectric resonator (40c) and the (n+2)-th dielectric resonator (40f), and the (n-2)-th dielectric resonator (40b) and the (n+3)-th dielectric resonator (40g).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a band-pass filter used for broadcasting equipment such as a television method, and more particularly, to a delay time compensation type having a good delay time deviation characteristic and a steep attenuation characteristic within a pass band. Related to a bandpass filter.

[0002]

2. Description of the Related Art Conventionally, in television broadcasting equipment in the VHF band, an elliptic function type using a helical resonator or a coaxial resonator as a resonator in order to remove unnecessary waves such as an IM wave (intermodulation wave). (Bandpass filter; hereinafter, referred to as BPF). FIG. 24 shows an elliptic function type BPF using a conventional coaxial resonator.
FIG. 25, FIG. 26, and FIG.
FIG. 5 is a cross-sectional view of a main part showing a schematic configuration of a BPF shown in FIG. 25 is a cross-sectional view of an essential part taken along line AA 'shown in FIG. 24, FIG. 26 is a cross-sectional view of an essential part taken along line BB' shown in FIG. 25, and FIG. 24 is a sectional view taken along line CC ′ shown in FIG. 24, FIG. 27 (b) is a sectional view taken along line DD ′ shown in FIG. 24, and FIG. FIG. 25 is a cross-sectional view of a main part, which is cut along the line EE ′ shown in 24.

In FIGS. 24 to 27, reference numeral 1 denotes an outer conductor, 2 denotes a partition, 5a and 5b denote capacitive elements forming a sub-coupling circuit, 7 denotes a U-shaped loop element which forms a sub-coupling circuit,
8 is an input (or output) coupling loop, 9a to 9h are rock nights, 11a is an input (or output) terminal, 11b is an output (or input) terminal, 20a to 20h is a coaxial resonator, 21a to 21h is a driving screw, 22a to 22h are resonance frequency adjusting elements, and 23a to 23h are internal conductors.
The elliptic function type BPF using the coaxial resonator shown in FIGS. 24 to 27 has a disadvantage that its shape becomes large due to the use of the λ / 4 coaxial resonator.

FIG. 28 is a cross-sectional view of a principal part showing a schematic configuration of an elliptic function type BPF using a conventional helical resonator. FIG. 29 is a side view showing one of the helical resonators shown in FIG. It is. 28 and 29, 1 is an external conductor, 2 is a partition, 5a and 5b are capacitive elements forming a sub-coupling circuit, 8 is an input (or output) coupling loop, 17 is a loop element forming a sub-coupling circuit, 30a to 30h are helical resonators, 31a to 31h are helical resonance elements, 32a
To 32h are capacitance forming electrodes, 33a to 33h, 34a to 3
4h is an insulator, 35a to 35h are movable electrodes, 36a to
36h is a driving screw, and 37a to 37h are lock nuts. The elliptic function type BPF using the helical resonator shown in FIGS. 28 and 29 has a disadvantage that its shape is complicated and its vibration resistance is poor.

On the other hand, the present inventor has devised a capacitively loaded resonator as an alternative to the conventional λ / 4 coaxial resonator or helical resonator, and has developed an elliptic function type BPF using the capacitively loaded resonator. Was devised. FIG. 30 is a top view showing an upper surface of an elliptic function type BPF using a conventional capacitive loaded resonator. FIGS. 31, 32, and 33 are main portions showing a schematic configuration of the BPF shown in FIG. It is sectional drawing. Note that FIG.
1 is a cross-sectional view of a main part taken along line AA ′ shown in FIG. 30;
32 is a cross-sectional view of a main part taken along line BB ′ shown in FIG. 31, FIG. 33 (a) is a cross-sectional view of a main part cut along line CC ′ shown in FIG. 30, and FIG. Represents DD ′ shown in FIG.
FIG. 33C is a cross-sectional view of a main part taken along line EE ′ shown in FIG. 30.

In FIGS. 30 to 33, reference numeral 1 denotes an external conductor, 2 denotes a partition, 3a to 3h denote fixed electrodes on the lower end, 4a to 4h.
h is a movable electrode, 5a and 5b are capacitive elements forming a sub-coupling circuit, 7 is a U-shaped coupling loop forming a sub-coupling circuit,
8 is an input (or output) coupling loop, 9a to 9h are rock nights, 10a to 10h are capacitance loaded resonators, 11a
Is an input (or output) terminal, and 11b is an output (or input) terminal. The elliptic function type BPF using the capacitively loaded resonator shown in FIGS. 30 to 33 is a capacitively loaded resonator (10a to 10h) mainly coupled by a magnetic coupling circuit.
Are arranged in a U-shape. Then, among the capacitance-loaded resonators arranged in a U-shape, the two capacitance-loaded resonators located at the turning point are replaced with an n-th resonator (a resonator of 10d) and (n + 1) When the (n-1) th resonator (the resonator of 10c) is the (n) -th resonator (the resonator of 10e),
And the (n + 2) -th resonator (resonator of 10f) are sub-coupled by the capacitive element (5a), and the (n-2) -th resonator (resonator of 10b) and (n + 3) A U-shaped coupling loop 7 between the first resonator (10 g resonator)
Are sub-bonded. The elliptic function type BPF using the capacitance-loaded resonator shown in FIGS. 30 to 33 is not so complicated in structure as the elliptic function type BPF using the helical resonator shown in FIGS. 28 and 29. BP of the elliptic function type using the coaxial resonator shown in FIGS.
F has characteristics that it can be miniaturized and has good frequency characteristics.

[0007]

A digital television signal to be started has a large number of segments (13 segments) and a small segment interval (432 KH).
z), many IM waves are generated near the target signal wave.
Depending on the modulation method, a BPF to be used is required to have a small amplitude deviation and delay time (phase) deviation in a pass band and a frequency characteristic having a steep attenuation characteristic. The elliptic function type BPF using the capacitance-loaded resonator shown in FIGS. 30 to 33 is suitable for a BPF that emphasizes the attenuation characteristics of analog television signals and the like. However, the elliptic function type BPF using the capacitance-loaded resonator shown in FIGS. 30 to 33 has a large amplitude deviation and delay time deviation in a pass band, and is required to have the above-mentioned frequency characteristics. However, there is a problem that it is not suitable for the signal BPF.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the prior art, and an object of the present invention is to provide a delay time compensating band-pass filter which compensates for a delay time characteristic and provides a signal within a pass band. An object of the present invention is to provide a technique capable of reducing an amplitude deviation and a delay time (phase) deviation.

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.

[0010]

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, according to the present invention, N (N ≧ 6)
In the delay time compensating band-pass filter in which the first to second dielectric resonators are cascaded and each dielectric resonator is mainly coupled by a magnetic coupling circuit, a U-shaped turning point is formed. , And n (n <n
When the (N) -th and (n + 1) -th dielectric resonators are used,
Between the (n-1) th dielectric resonator and the (n + 2) th dielectric resonator, and between the (n-2) th dielectric resonator and the (n + 3) th dielectric resonator Are sub-coupled by an S-shaped coupling loop.

Further, the present invention is characterized in that an interstage magnetic field coupling adjusting element is provided between the dielectric resonators.

Further, the present invention is characterized in that the interstage magnetic field coupling adjustment element is constituted by two conductive plates arranged at a predetermined interval.

Further, the present invention is characterized in that the inter-step magnetic field coupling adjusting element is constituted by one conductive plate provided with a hole of a predetermined size.

[0015]

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.

[Embodiment 1] FIG. 1 is a top view showing an upper surface of a delay time compensation band-pass filter according to Embodiment 1 of the present invention, and FIGS. 2, 3 and 4 show FIG. BPF shown
FIG. 2 is a sectional view of a main part showing a schematic configuration of FIG. 2 is a cross-sectional view of a main part taken along line AA 'shown in FIG. 1, FIG. 3 is a cross-sectional view of a main part taken along line BB' shown in FIG. 2, and FIG.
FIG. 4 is a sectional view of a main part taken along line CC ′ shown in FIG.
4B is a cross-sectional view of a main part taken along line DD ′ shown in FIG. 1, and FIG. 4C is a cross-sectional view of a main part taken along line EE ′ shown in FIG.

1 to 4, reference numeral 1 denotes an outer conductor;
2 is a partition, 6 and 16 are S-shaped coupling loops constituting a sub-coupling circuit, 7 is a U-shaped coupling loop which is a sub-coupling circuit, 8 is an input (or output) coupling loop, and 40a to 40a.
h is a TM01 delta mode dielectric resonator, 41a-41
h is a dielectric resonance element, 11a is an input (or output) terminal, and 11b is an output (or input) terminal. The input (or output) terminal 11a and the output (or input) terminal 11b are each formed of, for example, a coaxial connector, and connect the outer conductor forming each coaxial connector to the outer conductor 1 forming the resonator. It is. The dielectric resonator element (41) constituting the TM01 delta mode dielectric resonator (40a to 40h)
a to 41h) are made of a dielectric material having a relatively high dielectric constant such as a ceramic, for example.
41h) is a method such as using an appropriate adhesive,
The outer conductor 1 is provided between the upper wall and the lower wall. Note that the delay time compensation type BPF of the present embodiment may be provided with a resonance frequency fine adjustment means for finely adjusting the resonance frequency.

FIGS. 5A and 5B are diagrams for explaining a TM01 delta mode dielectric resonator. FIG. 5A is a diagram showing the internal structure of the dielectric resonator, and FIG. 5B is a plan view. . The TM01 delta mode dielectric resonator R forms a resonance circuit with a dielectric resonance element (RS) forming a capacitive element and an external conductor 1 forming a distributed inductance. In the figure, HD indicates the height of the outer conductor 1, and when the height (HD) of the outer conductor 1 is HD = λo / 4 (λo is the wavelength of the resonance frequency of the dielectric resonator R). , This T
Unloaded Q (Qu) of M01 delta mode dielectric resonator R
Is approximately obtained by the following equation (1).

[0020]

[Formula 1] Qu ≒ 84 × W × (fo) ** (1/2) (1) where W is the width (unit: cm) of the outer conductor 1 and fo
Is the resonance frequency (unit: MHz) of the dielectric resonator R. Further, in the TM01 delta mode dielectric resonator R, when the width (W) of the outer conductor 1 is fixed and the height (HD) of the outer conductor 1 is changed within a range smaller than (λo / 4), resonance occurs. The frequency (fo) does not change (it does not change at all, there is a slight change in frequency),
The no-load Q (Qu) changes in comparison with (HV / HD).
Note that HV represents the height of the outer conductor 1 after the change. When the height (HD) of the outer conductor 1 is kept constant and the width (W) of the outer conductor is changed, the unloaded Q (Qu) becomes (WV
/ W), and the resonance frequency (fo) becomes (WV /
W) ** (1/2). Note that WV represents the width of the outer conductor 1 after the change. When the width (W) and height (HD) of the outer conductor 1 are kept constant and the diameter (D) of the dielectric resonance element (RS) is changed, the resonance frequency (fo) becomes (D / HV). It changes in comparison. Note that DV
Represents the diameter of the changed dielectric resonance element (RS). Further, when the dielectric constant of the dielectric resonance element (RS) is changed from (εr) to (εv), the resonance frequency (fo) becomes (εr
/ Εv) ** (1/2). Note that εr
Represents the dielectric constant of the dielectric resonance element (RS) before the change, and εv represents the dielectric constant of the dielectric resonance element (RS) after the change.

The delay time compensation type BPF of this embodiment is
Dielectric resonators (40a to 14h) are arranged in a U-shape,
The dielectric resonators (40a to 40h) are mainly coupled by a magnetic coupling circuit. Furthermore, in the delay time compensation type BPF of the present embodiment, the number (N) of dielectric resonators is 6 (N ≧
6) It is necessary to be at least, but in the present embodiment, N =
8 will be described.

FIG. 6 is a circuit diagram showing an elliptic function type BPF equalizing circuit using the conventional dielectric resonator shown in FIGS. 30 to 33. FIG. 7 is a circuit diagram showing the equalizing circuit shown in FIG. Is a conversion equalization circuit. The capacitances (Ca to Ch) shown in FIG.
Are the lower fixed electrodes (3a to 3h) and the movable electrodes (4
a to 4h) denote the capacitance of the variable resonant capacitance element formed by the input (or output) coupling loop;
8b shows an output (or input) coupling loop. In the elliptic function type BPFs shown in FIGS. 30 to 33, two of the capacitively-loaded resonators arranged in a U-shape are connected to the n-th resonant resonator at the folding point. (10d resonator) and the (n + 1) th resonator (10
e), the (n−1) th resonator (resonator of 10c) outside its pass band (attenuation band)
And the (n + 2) th resonator (resonator of 10f), the phase difference of the main coupling voltage generated by the main coupling circuit (ΘMc
-f) is represented by the following equation (2).

[0023]

数 Mc-f = −90 ° × ((n + 2) − (n−1)) = − 90 ° × 3 = −270 ° (2) Also, since the (n-1) th resonator and the (n + 2) th resonator are sub-coupled with the capacitive element (5a) smaller than the coupling coefficient of the main coupling circuit, The phase difference of the sub-coupling voltage generated by the sub-coupling circuit between the (n−1) -th resonator and the (n + 2) -th resonator is (90 °). Therefore, the main coupling voltage generated by the main coupling circuit between the (n−1) th resonator and the (n + 2) th resonator,
The phase difference between the sub-coupling voltage generated by the sub-coupling circuit (P
Hc-f) is represented by the following equation (3).

[0024]

PHc-f = −270 ° + 90 ° = −180 ° (3) Further, the (n−2) th resonator (10b) Resonator) and
Between the (n + 3) th resonator (10 g resonator),
Phase difference of main coupling voltage generated by main coupling circuit (ΘMb-g)
Is represented by the following equation (4).

[0025]

４Mb-g = −90 ° × ((n + 3) − (n−2)) = − 90 ° × 5 = −450 ° (4) Since the (n−2) -th resonator and the (n + 3) -th resonator are sub-coupled by the U-shaped coupling loop 7, the (n−2) -th resonance The phase difference of the sub-coupling voltage generated by the sub-coupling circuit between the resonator and the (n + 3) -th resonator is (-90). Therefore, the phase difference (PHb−) between the main coupling voltage generated by the main coupling circuit between the (n−2) th resonator and the (n + 3) th resonator and the sub coupling voltage generated by the sub coupling circuit. g) is represented by the following equation (5).

[0026]

PHb-g = −450 ° −90 ° = −540 ° = −180−360 ° = −180 ° (5) Therefore, The elliptic function form B shown in FIGS.
In the PF, between the (n-1) -th resonator and the (n + 2) -th resonator and between the (n-2) -th resonator and the (n-)
+3) Since the phase difference between the main coupling voltage generated by the main coupling circuit and the sub-coupling voltage generated by the sub-coupling circuit is opposite to that of the third resonator, the main coupling circuit in the attenuation region thereof An attenuation pole is formed at a position where the amplitude of the main coupling voltage attenuated through the sub-coupling circuit becomes equal to the amplitude of the sub-coupling voltage attenuated through the sub-coupling circuit. The BPF in such a state is a general polarized BPF having a pair of attenuation poles, and has a problem that the amplitude deviation characteristic and the delay time (phase) deviation characteristic in the pass band are poor as shown in FIG. There was a point.

FIG. 9 shows a delay time compensation type B according to this embodiment.
FIG. 10 is a circuit diagram showing an equalizing circuit of the PF, and FIG. 10 is a conversion equalizing circuit of the equalizing circuit shown in FIG. The capacitances (CA to CH) shown in FIG. 9 indicate the capacitances formed by the TM01 delta mode dielectric resonance elements (41a to 41h). In the delay time compensation type BPF of the present embodiment, two dielectric resonators located at the turning point among the dielectric resonators arranged in a U-shape are replaced with the n-th resonator (40).
d) and (n + 1) -th resonator (resonator of 40e), the (n−1) -th resonator (resonator of 40c) and the (n + 2) -th resonator (40f) S-shaped coupling loop 1 as a sub-coupling circuit between
Use 6.

By using this S-shaped coupling loop 16, the coupling circuit between the (n-1) -th resonator and the (n + 2) -th resonator can be connected to each other by M61 and M62 shown in FIG. It is represented by an inductance circuit. As can be seen from the circuit diagram of FIG. 10, by using the S-shaped coupling loop 16, the (n-1) th resonator and the (n +)
In the 1) th resonator, the dielectric resonator elements (41c, 41c)
The direction of the current flowing through f) does not change. In the present invention, the S-shaped coupling loop is, as described above,
Between two resonators, a dielectric resonator element (for example, 41 in FIG. 3)
c, 41f, etc.) means a coupling loop that couples so that the direction of the current flowing therethrough does not change.

The (n-1) th resonator and (n +
When a sub-coupling is performed between the (n-1) -th resonator and the (n + 2) -th resonator by sub-coupling with the (2) -th resonator by an S-shaped coupling loop 16, The phase difference of the coupling voltage is (90 °). Therefore, (n-
The phase difference (PHc-f) between the main coupling voltage generated by the main coupling circuit between the 1) th resonator and the (n + 2) th resonator and the sub coupling voltage generated by the sub coupling circuit is as described above. It becomes (−180 °) similarly to the expression (3). Further, in the delay time compensation type BPF of the present embodiment, the (n−2) th resonator (the resonator of 40 b) and the (n + 3) th resonator (the resonator of 40 g) mainly The phase difference (ΘMb-g) of the main coupling voltage generated by the coupling circuit is (−450 °) as shown in the above equation (4). Further, in the delay time compensation type BPF of the present embodiment, S is used as a sub-coupling circuit between the (n−2) -th resonator and the (n + 3) -th resonator.
A letter-shaped coupling loop 6 is used. By using this S-shaped coupling loop 6, the coupling circuit between the (n-2) th resonator and the (n + 3) th resonator is a mutual inductance circuit shown by M63 and M64 in FIG. expressed.
Then, sub-coupling is performed between the (n−2) -th resonator and the (n + 3) -th resonator by the S-shaped coupling loop 6.
The phase difference of the sub-coupling voltage generated by the sub-coupling circuit between the (n−2) -th resonator and the (n + 3) -th resonator is (90 °). Therefore, the phase difference (PHb−) between the main coupling voltage generated by the main coupling circuit between the (n−2) th resonator and the (n + 3) th resonator and the sub coupling voltage generated by the sub coupling circuit. g) is represented by the following equation (6).

[0030]

PHb-g = −450 ° + 90 ° = −360 ° (6) As can be seen from the above equation (6), the present embodiment In the delay time compensation type BPF of the form, the (n−2) th resonator and (n +)
3) The main coupling voltage generated by the coupling in the main coupling circuit and the sub coupling voltage generated by the coupling in the sub coupling circuit have the same phase (the phase difference is -360 °) between the third resonator and the third resonator.

Therefore, at the center frequency of the delay time compensation type BPF of the present embodiment, the S-shaped coupling loop 6
Thus, the resonator (40c) → the resonator (40d) → the resonator (40e) → the resonator (40f) (or the resonator (40
f) → resonator (40e) → resonator (40d) → resonator (40c)), a small amount of shunt loss occurs due to a resistance component in the direction of (resonator (40d) → resonator (40c)), and insertion loss increases. Also,
As the frequency deviates from the center frequency, the phase of the main coupling voltage generated by the main coupling circuit changes to the delay time compensation type B
It is displaced in the direction of ± 90 ° with respect to the phase of the center frequency of the PF. However, since the phase of the sub-coupling voltage generated by the sub-coupling circuit is not displaced, at a frequency displaced from the center frequency of the delay time compensation type BPF, the main coupling voltage generated by the main coupling circuit and the sub-coupling voltage generated by the sub-coupling circuit At the band edge of the pass band of the delay time compensation type BPF, the dB value is about 1 / dB.
The insertion loss is reduced by a factor of 1.4. For this reason, in the delay time compensation type BPF of the present embodiment, an increase in the loss of the center frequency and a decrease in the loss amount near the band edge of the pass band act, and the amplitude deviation in the pass band can be reduced. It is.

As for the phase characteristics in the pass band,
A sub-combination wave generated by the sub-coupling circuit including the S-shaped coupling loop 6 acts, so that the phase of the combined coupling wave approaches the phase of the sub-coupling wave generated by the sub-coupling circuit, and the phase change approaches a straight line. As a result, the amount of change in the delay time is compensated to be small, so that the delay time deviation in the pass band can be reduced and the delay time characteristics can be improved.

If the amount of delay time compensation by the sub-coupling circuit composed of the S-shaped coupling loop 6 is smaller than the optimum value,
The amount of compensation is small and the delay time characteristic is close to a pan-bottom type. FIG. 11 shows the delay time characteristics in this state. When the compensation amount of the delay time by the sub-coupling circuit including the S-shaped coupling loop 6 is the optimum amount, the flat portion of the delay time characteristic becomes the widest. FIG. 12 shows the delay time characteristics in this state. If the compensation amount of the delay time by the sub-coupling circuit including the S-shaped coupling loop 6 is larger than the optimum amount, the compensation amount becomes overcompensated. FIG. 13 shows the delay time characteristics in this state. If a certain allowable ripple-like delay time characteristic can be tolerated in the pass band, the delay time characteristic of the overcompensation type delay time compensation type BPF becomes the widest.

The delay time compensation type BP according to the present embodiment
In F, the sub-coupling circuit composed of the S-shaped loop 6 is in-phase coupled, and the sub-coupling circuit composed of the S-shaped loop 6 has a disadvantage in that the attenuation outside the pass band is reduced. Next, a configuration for improving this defect and obtaining a large attenuation will be described. In the delay time compensation type BPF of the present embodiment, the (n-3) th resonator (4
0a resonator) and the (n + 4) th resonator (4
0h resonator), the phase difference (ΘMa-h) of the coupling voltage generated by the path of the resonator (40a) → the resonator (40b) → the resonator (40g) → the resonator (40h) is as follows: It is expressed by equation (7).

[0035]

ΘMa-h = −90 ° + 90 ° −90 ° = −90 ° (7) Also, the (n-3) th And the (n + 4) -th resonator are sub-coupled by a U-shaped coupling loop 7, so that the (n-3) -th resonator and the (n + 4) -th resonator are Thus, the phase difference of the sub-coupling voltage generated by the sub-coupling circuit is (−90 °). Therefore, between the (n−3) -th resonator and the (n + 4) -th resonator, the resonator (40a) → the resonator (40b) → the resonator (40g) → the resonator (40h) The phase difference between the generated coupling voltage and the sub-coupling voltage generated by the sub-coupling circuit (PHa-f
) Is represented by the following equation (8).

[0036]

(8) PHa-f = −90 ° −90 ° = −180 ° (8) As can be seen from the above equation (8), the present embodiment In the delay time compensation type BPF of the form (1), the resonator (40a) is connected between the (n-1) -th resonator and the (n + 4) -th resonator.
Resonator (40b) → Resonator (40g) → Resonator (40
The coupling voltage generated by the path h) and the sub-coupling voltage generated by the sub-coupling circuit have opposite phases (the phase difference is −180 °).

Therefore, in the delay time compensation type BPF of the present embodiment, the resonator (40a)
→ resonator (40b) → resonator (40g) → resonator (40
h), an attenuation pole is formed at a frequency where the amplitude of the coupling voltage attenuated through the sub-coupling circuit is equal to the amplitude of the sub-coupling voltage attenuated through the sub-coupling circuit. Can be improved.

FIGS. 14 to 17 are graphs showing frequency characteristics of an example of the delay time compensation type BPF of the present embodiment. 14 to 17 show a U-shaped coupling loop between the (n−3) th resonator and the (n + 4) th resonator in the delay time compensation type BPF of the present embodiment. BPF sub-coupled by a sub-coupling circuit consisting of 7
It is.

FIG. 14 is a graph showing attenuation characteristics.
The horizontal axis is frequency (MHz) and the memory interval is 20 MHz, and the vertical axis is the attenuation (dB) and the memory interval is 5 dB. The center frequency of the delay time compensation type BPF is 551 MHz.
In FIG. 14, the frequency is 574.544.
The attenuation amount at MHz (point a in FIG. 14) is −26.6.
92 dB, and the frequency is 554.456 MHz (FIG. 1).
The attenuation amount at the time point b at point 4) is -26.746 dB. FIG. 15 is a graph showing the graph shown in FIG. 14 in an enlarged manner, and the memory interval on the vertical axis is 1 dB. This figure 1
As can be seen from the graph of FIG.
The attenuation is within 2 dB between (point a in FIG. 15) and 554 MHz (point b in FIG. 15), and the delay time compensation type BPF shown in FIG. 14 has a small amplitude deviation in its pass band. I have.

FIG. 16 is a graph showing phase characteristics.
The horizontal axis is frequency (MHz) and the memory interval is 20 MHz, and the vertical axis is angle and the memory interval is 90 °. In FIG. 16, when the frequency is 548 MHz (point a in FIG. 15), the phase is −44.36 °, and the frequency is 554 MHz.
The phase at (point b in FIG. 15) is −49.704 °. FIG. 17 is a graph showing the delay time characteristic. The horizontal axis represents the frequency (MHz) and the memory interval is 20 MHz, and the vertical axis is the delay amount (ns) and the memory interval is 100 ns. In FIG. 17, the frequency is 548 MHz (a in FIG. 15).
The delay amount at the time of (point) is 280.52 ns, and the delay amount at the frequency of 554 MHz (point b in FIG. 15) is
274.11 ns. As can be seen from the graph of FIG. 17, the delay time compensation type BPF shown in FIG. 14 has a delay amount between 548 MHz and 554 MHz of 2 MHz.
This is within 75 ns, and the delay time deviation within the pass band is small.

The delay time compensation type BP according to the present embodiment
In F, when the U-shaped coupling loop 7 is not used as a sub-coupling circuit between the (n−3) -th resonator and the (n + 4) -th resonator, in the attenuation characteristic shown in FIG. Although the amount of attenuation outside the pass band decreases, the amplitude deviation and the delay time deviation within the pass band can be reduced even in this case.

[Second Embodiment] FIG. 18 shows a BP constituted by cascade-connected dielectric resonators in a magnetic coupling circuit in multiple stages.
18A and 18B are diagrams for explaining magnetic coupling of the dielectric resonator in F, and FIG. 18A shows a multistage-connected dielectric resonator (FIG. 18 shows only adjacent Rn and Rn + 1 dielectric resonators); (B) is a plan view, and FIG. (C) is a side view. Generally, the height (HD) of the outer conductor 1 is HD ≒ λo / 4 (λo is the wavelength of the center frequency of the BPF), and the width (W) of the outer conductor 1 is W = λc / 2 (λc is the wavelength of the cutoff frequency of the BPF). Therefore, the dielectric resonator (R
n) and the magnetic loss (LM) between the dielectric resonator (Rn + 1) can be obtained by the following equation (9).

[0043]

LM = (54.6 × LC) / 2W (dB) (9) where LC is a dielectric resonance constituting the dielectric resonator (Rn, Rn + 1). Shows the spacing between elements. According to the magnetic loss (LM) obtained by the above equation (9), the magnetic coupling coefficient (Mm) between the dielectric resonator (Rn) and the dielectric resonator (Rn + 1) is expressed by the following (10). You can ask.

[0044]

Mm = 10 ** (-2 × LM / 20) (10) Here, when the load Q (QL) is high, LC> W, and the BPF is It may be large. In such a case, the BPF can be reduced in size by interposing an interstage magnetic field coupling adjustment element between the adjacent dielectric resonators (Rn, Rn + 1).

FIG. 19 is a cross-sectional view of a main part showing a schematic configuration of a delay time compensating band-pass filter according to a second embodiment of the present invention. FIG. is there. The delay time compensating BPF according to the present embodiment includes a dielectric resonator (4a) in a dielectric resonator (40a to 40h).
0a to 40h) are arranged at predetermined intervals as appropriate, and the interstage magnetic field coupling adjustment element 51 is arranged between adjacent dielectric resonators (40a to 40h) (or dielectric resonance elements (40a to 40h)).
Is a band-pass filter that obtains required electrical characteristics.

FIG. 20 is a diagram showing an example of the interstage magnetic field coupling adjusting element 51 shown in FIG. The inter-stage magnetic field coupling adjusting element 51 shown in FIG.
(54) are provided and arranged on the two conductor plates (52, 5).
3). The short sides of the two conductor plates (52, 53) are electrically and mechanically connected to the upper and lower walls of the outer conductor 1, and one of the two conductor plates (52, 53) The long side is electrically and mechanically connected to the partition 2 or the side wall of the external conductor 1. When the interstage magnetic field coupling adjusting element 51 shown in FIG. 20 is provided, the dielectric resonator (R
n) and the magnetic coupling coefficient (Mmi) between the dielectric resonator (Rn + 1) can be obtained by the following (11).

[0047]

Mmi = Mm × (Iw / W) (11) where Iw is the width of the predetermined interval (54 in FIG. 20). As can be seen from the equation (11), when the interstage magnetic field coupling adjusting element 51 shown in FIG. 20 is provided, the magnetic coupling between the dielectric resonator (Rn) and the dielectric resonator (Rn + 1) is provided. The coefficient is determined by the predetermined interval (54 in FIG. 20) width (I
w) can be adjusted as appropriate.

FIG. 21 is a diagram showing another example of the inter-stage magnetic field coupling adjusting element 51 shown in FIG. The inter-stage magnetic field coupling adjusting element 51 shown in FIG. 21 is composed of one conductor plate 55 provided with a predetermined hole (56 in FIG. 21) in the upper central part.
The upper side and the lower side of this one conductor plate 55 are
Are electrically and mechanically connected to the upper wall and the lower wall, and the side of one conductor plate 55 is electrically and mechanically connected to the side wall of the partition wall 2 or the outer conductor 1. When the inter-stage magnetic field coupling adjusting element 51 shown in FIG.
The magnetic coupling coefficient (Mmi) between the dielectric resonator (Rn) and the dielectric resonator (Rn + 1) can be obtained by the following (12).

[0049]

Mmi = Mm × (AW / (W × HD)) (12) where Aw is the area of the predetermined hole (56 in FIG. 21). As can be seen from the above equation (12), when the interstage magnetic field coupling adjusting element 51 shown in FIG. 21 is provided, the magnetic coupling between the dielectric resonator (Rn) and the dielectric resonator (Rn + 1) is provided. The coefficient can be appropriately adjusted according to the area (Aw) of the predetermined hole (56 in FIG. 21).

FIG. 22 is a diagram showing another example of the inter-stage magnetic field coupling adjusting element 51 shown in FIG. The interstage magnetic field coupling adjustment element 51 shown in FIG.
This conductor 57 is electrically and mechanically connected to the upper and lower walls of outer conductor 1. The size of the conductor 57 is appropriately adjusted, or an adjacent dielectric resonator (R
By appropriately increasing or decreasing the number of conductors 57 arranged between n) and the dielectric resonator (Rn + 1), the magnetic coupling coefficient can be adjusted to a required value.

FIG. 23 is a diagram showing another example of the inter-stage magnetic field coupling adjusting element 51 shown in FIG. The inter-stage magnetic field coupling adjusting element 51 shown in FIG. 23 includes a round bar-shaped or square bar-shaped conductor 58, which is electrically and mechanically connected to the upper and lower walls of the outer conductor 1. . By appropriately adjusting the size of the conductor 58, or by appropriately increasing or decreasing the number of conductors 58 arranged between the adjacent dielectric resonators (Rn) and (Rn + 1).
The magnetic coupling coefficient can be adjusted to a required value.

As described above, the invention made by the present inventor
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.

[0053]

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

According to the present invention, in a band-pass filter using a capacitance-loaded resonator, it is possible to reduce the amplitude deviation and the delay time deviation in the pass band and obtain a steep attenuation characteristic. .

[Brief description of the drawings]

FIG. 1 is a top view illustrating a top surface of a delay time compensation bandpass filter 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 delay time compensation band-pass filter according to the first embodiment of the present invention.

FIG. 3 is a fragmentary cross-sectional view showing a schematic configuration of a delay time compensation band-pass filter according to Embodiment 1 of the present invention.

FIG. 4 is a cross-sectional view of a main part showing a schematic configuration of a delay time compensation band-pass filter according to the first embodiment of the present invention.

FIG. 5 is a diagram for explaining a TM01 delta mode dielectric resonator.

FIG. 6 is a circuit diagram showing an equalizer circuit of an elliptic function band-pass filter using the conventional capacitance-loaded resonator shown in FIGS. 30 to 33.

FIG. 7 is a conversion equalization circuit of the equalization circuit shown in FIG. 6;

FIG. 8 shows amplitude deviation characteristics and delay times (phases) in a pass band in the band pass filters shown in FIGS. 30 to 33.
It is a graph which shows a deviation characteristic.

FIG. 9 is a circuit diagram showing an equalization circuit of the delay time compensation band-pass filter according to the first embodiment.

FIG. 10 is a conversion equalization circuit of the equalization circuit shown in FIG. 9;

FIG. 11 is a diagram illustrating a delay time in the pass band when the compensation amount of the delay time by the sub-coupling circuit including the S-shaped coupling loop is smaller than the optimum value in the delay time compensation band-pass filter according to the first embodiment; 9 is a graph showing a (phase) deviation characteristic.

FIG. 12 is a diagram illustrating a delay time in the pass band when the compensation amount of the delay time by the sub-coupling circuit including the S-shaped coupling loop is the optimum value in the delay time compensation band-pass filter according to the first embodiment; 9 is a graph showing a (phase) deviation characteristic.

FIG. 13 is a diagram illustrating a delay time in the pass band when the compensation amount of the delay time by the sub-coupling circuit including the S-shaped coupling loop is larger than the optimum value in the delay time compensation band-pass filter according to the first embodiment; 9 is a graph showing a (phase) deviation characteristic.

FIG. 14 is a graph showing an attenuation characteristic of an example of the delay time compensation band-pass filter according to the first embodiment.

FIG. 15 is a graph showing the graph of FIG. 14 in an enlarged manner.

FIG. 16 is a graph showing a phase characteristic of an example of the delay time compensation band-pass filter according to the first embodiment.

FIG. 17 is a graph showing a delay time characteristic of an example of the delay time compensation band-pass filter according to the first embodiment.

FIG. 18 is a diagram for explaining magnetic coupling of the dielectric resonator in the BPF configured by cascade-connecting the dielectric resonator in the magnetic coupling circuit.

FIG. 19 is a fragmentary cross-sectional view showing a schematic configuration of a delay time compensation band-pass filter according to Embodiment 2 of the present invention.

20 is a diagram showing an example of the inter-stage magnetic field coupling adjusting element shown in FIG. 19;

21 is a diagram showing another example of the interstage magnetic field coupling adjustment element shown in FIG. 19;

FIG. 22 is a diagram showing another example of the interstage magnetic field coupling adjustment element shown in FIG. 19;

23 is a diagram showing another example of the interstage magnetic field coupling adjustment element shown in FIG. 19;

FIG. 24 is a plan view showing an upper surface of an elliptic function band-pass filter using a conventional coaxial resonator.

25 is a fragmentary cross-sectional view showing a schematic configuration of the bandpass filter shown in FIG. 24.

26 is a cross-sectional view of a main part showing a schematic configuration of the bandpass filter shown in FIG.

FIG. 27 is a cross-sectional view of a principal part showing a schematic configuration of the bandpass filter shown in FIG.

FIG. 28 is a cross-sectional view of a main part showing a schematic configuration of an elliptic function band-pass filter using a conventional helical resonator.

FIG. 29 is a side view showing one of the helical resonators shown in FIG.

FIG. 30 is a top view showing the upper surface of a conventional elliptic function band-pass filter using a capacitance-loaded resonator.

31 is a fragmentary cross-sectional view showing a schematic configuration of the bandpass filter shown in FIG. 30.

32 is a fragmentary cross-sectional view showing a schematic configuration of the bandpass filter shown in FIG. 30.

33 is a fragmentary cross-sectional view showing a schematic configuration of the bandpass filter shown in FIG. 30.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... External conductor, 2 ... Partition, 3a-3h ... Lower fixed electrode 4a-4h, 35a-35h ... Movable electrode, 5,5
a, 5b, 15: Capacitance elements forming a sub-coupling circuit,
16 ... S-shaped loop element forming a sub-coupling circuit, 7 ...
U-shaped loop elements constituting a sub-coupling circuit, 8, 8a,
8b: Input (or output) coupling loop, 9a to 9h, 3
7a to 37h: lock nut, 11a: input (or output) terminal, 11b: output (or input) terminal, 13a to
13h: Lower end cylindrical body made of a fixed dielectric; 17: Loop element forming a sub-coupling circuit; 20a to 20h: Coaxial resonator; 21a to 21h; 36a to 36h: Drive screw;
2a to 22h: resonance frequency adjusting elements, 23a to 23h
... Inner conductor, 30a-30h ... Helical resonator, 31a
To 31h: helical resonance element, 32a to 32h: capacitance forming electrode, 33a to 33h, 34a to 34h: insulator
40a-40h, R, Rn, Rn + 1 ... TM01 delta
Mode dielectric resonators, 41a to 41h, RS: dielectric resonance element, 51: interstage magnetic field coupling adjustment element, 52, 53, 5
5 ... conductor plate, 54 ... interval, 55 ... hole, 57, 58 ... conductor.

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[Procedure amendment]

[Submission date] June 2, 1998

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0039

[Correction method] Change

[Correction contents]

FIG. 14 is a graph showing attenuation characteristics.
The horizontal axis is frequency (MHz) and the memory interval is 2 MHz, and the vertical axis is the attenuation (dB) and the memory interval is 5 dB. Also,
The center frequency of the delay time compensation type BPF is 551 MHz, and the frequency is 574.544 MH in FIG.
The attenuation at z (point a in FIG. 14) is −26.692.
When the frequency is 554.456 MHz (point b in FIG. 14), the attenuation is −30.431 dB.
FIG. 15 is a graph showing the graph shown in FIG. 14 in an enlarged manner, and the memory interval on the vertical axis is 1 dB. As can be seen from the graph of FIG. 15, the frequency is 548 MHz (FIG. 1).
The attenuation is within 2 dB between point 5 (point a) and 554 MHz (point b in FIG. 15), and the delay deviation compensation type BPF shown in FIG. 14 has a small amplitude deviation in the pass band.

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0040

[Correction method] Change

[Correction contents]

FIG. 16 is a graph showing phase characteristics.
The horizontal axis is the frequency (MHz) and the memory interval is 2 MHz, and the vertical axis is the angle and the memory interval is 90 °. In FIG. 16, when the frequency is 548 MHz (point a in FIG. 16 ), the phase is −44.36 °, and the frequency is 554 MHz.
The phase at (point b in FIG. 16 ) is −49.704 °. FIG. 17 is a graph showing the delay time characteristic. The horizontal axis represents the frequency (MHz) and the memory interval is 2 MHz, and the vertical axis represents the delay amount (ns) and the memory interval is 100 ns. In FIG. 17, the frequency is 548 MHz (a in FIG. 17 ) .
The delay amount at the time of (point) is 280.52 ns, and the delay amount at the frequency of 554 MHz (point b in FIG. 17 ) is
274.11 ns. As can be seen from the graph of FIG. 17, the delay time compensation type BPF shown in FIG. 14 has a delay amount between 548 MHz and 554 MHz of 2 MHz.
This is within 75 ns, and the delay time deviation within the pass band is small.

[Procedure amendment 3]

[Document name to be amended] Statement

[Correction target item name] 0044

[Correction method] Change

[Correction contents]

[0044]

Mm = 10 ** ( -LM / 20) (10) Here, when the load Q (QL) is high, LC> W, and the BPF becomes large. May be. In such a case, the BPF can be reduced in size by interposing an interstage magnetic field coupling adjustment element between the adjacent dielectric resonators (Rn, Rn + 1).

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0045

[Correction method] Change

[Correction contents]

FIG. 19 is a cross-sectional view of a main part showing a schematic configuration of a delay time compensating band-pass filter according to a second embodiment of the present invention. FIG. is there. Delay compensated BPF in this embodiment, by disposing the dielectric resonator (40a-40h) at appropriate regular intervals, the adjacent dielectric resonators (40a-40h) (or dielectric resonator element) This is a band-pass filter in which a required electric characteristic is obtained by interposing an inter-stage magnetic field coupling adjusting element 51 therebetween.

[Procedure amendment 5]

[Document name to be amended] Drawing

[Correction target item name] FIG.

[Correction method] Change

[Correction contents]

FIG. 14

[Procedure amendment 6]

[Document name to be amended] Drawing

[Correction target item name] FIG.

[Correction method] Change

[Correction contents]

FIG.

[Procedure amendment 7]

[Document name to be amended] Drawing

[Correction target item name] FIG.

[Correction method] Change

[Correction contents]

FIG. 16

[Procedure amendment 8]

[Document name to be amended] Drawing

[Correction target item name] FIG.

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[Correction contents]

FIG. ────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] March 12, 1999

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Full text

[Correction method] Change

[Correction contents]

[Document Name] Statement

[Title of Invention] group delay compensated bandpass filter

[Claims]

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a television method and the like relates to the bandpass filter used in a broadcast facility, in particular, a good group delay time deviation characteristic in the pass band,
About steep group delay compensated bandpass filter attenuation characteristics.

[0002]

2. Description of the Related Art Conventionally, in television broadcasting equipment in the VHF band, an elliptic function type using a helical resonator or a coaxial resonator as a resonator in order to remove unnecessary waves such as an IM wave (intermodulation wave). (Bandpass filter; hereinafter, referred to as BPF). FIG. 24 shows an elliptic function type BPF using a conventional coaxial resonator.
FIG. 25, FIG. 26, and FIG.
FIG. 5 is a cross-sectional view of a main part showing a schematic configuration of a BPF shown in FIG. 25 is a cross-sectional view of an essential part taken along line AA 'shown in FIG. 24, FIG. 26 is a cross-sectional view of an essential part taken along line BB' shown in FIG. 25, and FIG. 24 is a sectional view taken along line CC ′ shown in FIG. 24, FIG. 27 (b) is a sectional view taken along line DD ′ shown in FIG. 24, and FIG. FIG. 25 is a cross-sectional view of a main part, taken along line EE ′ shown in FIG. 24 to 27, 1 is an external conductor, 2 is a partition,
5a and 5b are capacitive elements forming a sub-coupling circuit, 7 is a U-shaped loop element forming a sub-coupling circuit, 8 is an input (or output) coupling loop, 9a to 9h are rock nights, 11
a is an input (or output) terminal, 11b is an output (or input) terminal, 20a to 20h are coaxial resonators, 21a to 21
h is a driving screw, 22a to 22h are resonance frequency adjusting elements, and 23a to 23h are internal conductors. Elliptic function type BPF using the coaxial resonator shown in FIGS.
Has a drawback that its shape becomes large due to the use of a λ / 4 coaxial resonator.

FIG. 28 is a cross-sectional view of a principal part showing a schematic configuration of an elliptic function type BPF using a conventional helical resonator. FIG. 29 is a side view showing one of the helical resonators shown in FIG. It is. 28 and 29, 1 is an external conductor, 2 is a partition, 5a and 5b are capacitive elements forming a sub-coupling circuit, 8 is an input (or output) coupling loop, 17 is a loop element forming a sub-coupling circuit, 30a to 30h are helical resonators, 31a to 31h are helical resonance elements, 32a
To 32h are capacitance forming electrodes, 33a to 33h, 34a to 3
4h is an insulator, 35a to 35h are movable electrodes, 36a to
36h is a driving screw, and 37a to 37h are lock nuts. The elliptic function type BPF using the helical resonator shown in FIGS. 28 and 29 has a disadvantage that its shape is complicated and its vibration resistance is poor.

On the other hand, the present inventor has devised a capacitive loaded resonator as an alternative to the conventional λ / 4 coaxial resonator or helical resonator, and has an elliptic function type BPF using the capacitive loaded resonator. Was devised. FIG. 30 is a top view showing an upper surface of an elliptic function type BPF using a conventional capacitive loaded resonator. FIGS. 31, 32, and 33 are main portions showing a schematic configuration of the BPF shown in FIG. It is sectional drawing. Note that FIG.
1 is a cross-sectional view of a main part taken along line AA ′ shown in FIG. 30;
32 is a cross-sectional view of a main part taken along line BB ′ shown in FIG. 31, FIG. 33 (a) is a cross-sectional view of a main part cut along line CC ′ shown in FIG. 30, and FIG. Represents DD ′ shown in FIG.
FIG. 33C is a cross-sectional view of a main part taken along line EE ′ shown in FIG. 30. 30 to 33, 1 is an external conductor, 2 is a partition, 3a to 3
h is a lower fixed electrode, 4a to 4h are movable electrodes, 5a, 5
b is a capacitive element forming a sub-coupling circuit, 7 is a U-shaped coupling loop forming a sub-coupling circuit, 8 is an input (or output)
Coupling loop, 9a-9h is rock knight, 10a-10
h is a capacitive loaded resonator, 11a is an input (or output) terminal, and 11b is an output (or input) terminal. This figure 3
In the elliptic function type BPF using the capacitance-loaded resonators shown in FIGS. 0 to 33, the capacitance-loaded resonators (10a to 10h) mainly coupled by the magnetic coupling circuit are arranged in a U-shape. Then, in the capacitance-loaded resonator arranged in a U-shape,
When the two capacitive loaded resonators located at the turning point are an n-th resonator (a resonator of 10d) and an (n + 1) -th resonator (a resonator of 10e), (n-1) The sub-coupling between the (n + 2) -th resonator (10f resonator) and the (n + 2) -th resonator (10f resonator) is performed by a capacitive element (5a). The (10b resonator) and the (n + 3) th resonator (10g resonator) are sub-coupled by a U-shaped coupling loop 7.
The elliptic function type BPF using the capacitance-loaded resonator shown in FIGS. 30 to 33 is not so complicated in structure as the elliptic function type BPF using the helical resonator shown in FIGS. 28 and 29. Also, it is characterized in that it can be made smaller and has better frequency characteristics than the elliptic function type BPF using the coaxial resonator shown in FIGS.

[0005]

A digital television signal to be started has a large number of segments (13 segments) and a small segment interval (432 KH).
z), many IM waves are generated near the target signal wave.
Further, depending on the modulation method, a BPF to be used is required to have a small amplitude deviation and a group delay time deviation in a pass band and a frequency characteristic having a steep attenuation characteristic. The elliptic function type BPF using the capacitance-loaded resonator shown in FIGS. 30 to 33 is suitable for a BPF that emphasizes the attenuation characteristics of analog television signals and the like. However, FIG. 30 to BPF of elliptic function form using capacitance-loaded type resonator shown in FIG. 33, a digital amplitude deviation in the pass band, the group delay time deviation is large, the frequency characteristics as described above are required There is a problem that it is not suitable for a BPF for television signals. The present invention, wherein has been made to the prior art solving the problems of technology, object of the present invention, the group delay time compensated bandpass filter, compensates for the group delay time characteristic, the amplitude in the pass band It is an object of the present invention to provide a technique capable of reducing the deviation and the group delay time deviation . 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.

[0006]

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, in the present invention, N (N
The dielectric resonators up to ≧ 6) are successively connected in a U-shape, and the respective dielectric resonators are mainly coupled by a magnetic coupling circuit.
In the group delay time compensated bandpass filter, the two dielectric resonators located on the shape of the turning point of the co, respectively n (n <N) th, when an (n + 1) th dielectric resonators, (N-1) th dielectric resonator and (n + 2)
Th between the dielectric resonators, and (n-2) th dielectric resonators (n + 3) th volume between the dielectric resonators
It is characterized by being sub-coupled by a quantitative coupling loop.
Further, the invention is characterized in that an interstage magnetic field coupling adjusting element is provided between the dielectric resonators. Further, the present invention is characterized in that the interstage magnetic field coupling adjustment element is constituted by two conductive plates arranged at a predetermined interval. Further, the present invention is characterized in that the inter-step magnetic field coupling adjusting element is constituted by a single conductive plate provided with a hole of a predetermined size.

[0007]

Embodiments of the present invention will be described below in detail with reference to the drawings. In all the drawings for describing the embodiments, components having the same functions are denoted by the same reference numerals, and repeated description thereof will be omitted. [Embodiment 1] Fig. 1 is a top view showing an upper surface of a group delay time compensating band-pass filter according to Embodiment 1 of the present invention, and Figs. FIG. 2 is a sectional view of a main part showing a schematic configuration of a BPF shown in FIG. 1. Note that FIG.
FIG. 3 is a cross-sectional view of a main part taken along line -A ′, and FIG.
FIG. 4A is a cross-sectional view of a main part taken along line CC ′ shown in FIG. 1, and FIG.
FIG. 4 is a sectional view of an essential part taken along line DD ′ shown in FIG.
FIG. 2C is a cross-sectional view of a principal part taken along line EE ′ shown in FIG. 1. 1 to 4, 1 is an outer conductor, 2 is a partition, 6, 16 are S-shaped coupling loops forming a sub-coupling circuit, 7 is a U-shaped coupling loop forming a sub-coupling circuit,
8 is an input (or output) coupling loop, 40a to 40h are TM01 delta mode dielectric resonators, 41a to 41h are dielectric resonance elements, 11a is an input (or output) terminal, 1
1b is an output (or input) terminal. Input (or output) terminal 11a and output (or input) terminal 11b
Are made of, for example, coaxial connectors, and the outer conductors forming the respective coaxial connectors are connected to the outer conductor 1 constituting the resonator. TM01 delta mode dielectric resonator (4
0a to 40h) (41a to 4h)
1h) is made of, for example, a dielectric material having a relatively high dielectric constant such as ceramic, and the dielectric resonance elements (41a to 41a)
h) is installed between the upper wall and the lower wall of the outer conductor 1 by a method such as using an appropriate adhesive. Incidentally, in the group delay time compensating BPF of this embodiment may be provided a resonance frequency fine adjustment means for finely adjusting the resonance frequency.

FIGS. 5A and 5B are diagrams for explaining a TM01 delta mode dielectric resonator. FIG. 5A is a diagram showing the internal configuration of the dielectric resonator, and FIG. 5B is a plan view. . The TM01 delta mode dielectric resonator R forms a resonance circuit with a dielectric resonance element (RS) forming a capacitive element and an external conductor 1 forming a distributed inductance. In the figure, HD indicates the height of the outer conductor 1, and when the height (HD) of the outer conductor 1 is HD = λo / 4 (λo is the wavelength of the resonance frequency of the dielectric resonator R). , This TM
01 Unloaded Q (Qu) of the delta mode dielectric resonator R
Is approximately obtained by the following equation (1).

[0009]

[Formula 1] Qu ≒ 84 × W × (fo) ** (1/2) (1) where W is the width (unit: cm) of the outer conductor 1 and fo
Is the resonance frequency (unit: MHz) of the dielectric resonator R. Further, in the TM01 delta mode dielectric resonator R, when the width (W) of the outer conductor 1 is fixed and the height (HD) of the outer conductor 1 is changed within a range smaller than (λo / 4), resonance occurs. The frequency (fo) does not change (it does not change at all, there is a slight change in frequency),
The no-load Q (Qu) changes in comparison with (HV / HD).
Note that HV represents the height of the outer conductor 1 after the change. When the height (HD) of the outer conductor 1 is kept constant and the width (W) of the outer conductor is changed, the unloaded Q (Qu) becomes (WV
/ W), and the resonance frequency (fo) becomes (WV /
W) ** (1/2). Note that WV represents the width of the outer conductor 1 after the change. When the width (W) and height (HD) of the outer conductor 1 are kept constant and the diameter (D) of the dielectric resonance element (RS) is changed, the resonance frequency (fo) becomes (D / HV). It changes in comparison. Note that DV
Represents the diameter of the changed dielectric resonance element (RS). Further, when the dielectric constant of the dielectric resonance element (RS) is changed from (εr) to (εv), the resonance frequency (fo) becomes (εr
/ Εv) ** (1/2). Note that εr
Represents the dielectric constant of the dielectric resonance element (RS) before the change, and εv represents the dielectric constant of the dielectric resonance element (RS) after the change.

[0010] The group delay time of the present embodiment compensated BPF
In this example, the dielectric resonators (40a to 14h) are arranged in a U-shape, and the respective dielectric resonators (40a to 40h) are mainly coupled by a magnetic coupling circuit. Furthermore, in the group delay time compensating BPF of this embodiment, the number of dielectric resonators (N) 6
(N ≧ 6) is required, but in the present embodiment, a case where N = 8 will be described. FIG. 6 is a circuit diagram showing an equalizer circuit of an elliptic function type BPF using the conventional capacitance-loaded resonator shown in FIGS. 30 to 33.
Is a conversion equalization circuit of the equalization circuit shown in FIG. In addition,
The capacitances (Ca to Ch) shown in FIG.
a to 3h) and the capacitance of the variable resonance capacitor formed by the movable electrodes (4a to 4h), 8a denotes an input (or output) coupling loop, and 8b denotes an output (or input) coupling loop. In the elliptic function type BPFs shown in FIGS. 30 to 33, two of the capacitively-loaded resonators arranged in a U-shape are connected to the n-th resonant resonator at the folding point. Vessel (10d resonator);
When the (n + 1) -th resonator (the resonator of 10e) is used, the (n-1) -th resonator (the resonator of 10c) and the (n + 2) -th resonance outside the pass band (attenuation band). The phase difference (ΘMc-f) of the main coupling voltage generated by the main coupling circuit with the device (resonator of 10f) is expressed by the following equation (2).

[0011]

数 Mc-f = −90 ° × ((n + 2) − (n−1)) = − 90 ° × 3 = −270 ° (2) Also, since the (n-1) th resonator and the (n + 2) th resonator are sub-coupled with the capacitive element (5a) smaller than the coupling coefficient of the main coupling circuit, The phase difference of the sub-coupling voltage generated by the sub-coupling circuit between the (n−1) -th resonator and the (n + 2) -th resonator is (90 °). Therefore, the main coupling voltage generated by the main coupling circuit between the (n−1) th resonator and the (n + 2) th resonator,
The phase difference between the sub-coupling voltage generated by the sub-coupling circuit (P
Hc-f) is represented by the following equation (3).

[0012]

PHc-f = −270 ° + 90 ° = −180 ° (3) Further, the (n−2) th resonator (10b) Resonator) and
Between the (n + 3) th resonator (10 g resonator),
Phase difference of main coupling voltage generated by main coupling circuit (ΘMb-g)
Is represented by the following equation (4).

[0013]

４Mb-g = −90 ° × ((n + 3) − (n−2)) = − 90 ° × 5 = −450 ° (4) Since the (n−2) -th resonator and the (n + 3) -th resonator are sub-coupled by the U-shaped coupling loop 7, the (n−2) -th resonance The phase difference of the sub-coupling voltage generated by the sub-coupling circuit between the resonator and the (n + 3) -th resonator is (-90). Therefore, the phase difference (PHb−) between the main coupling voltage generated by the main coupling circuit between the (n−2) th resonator and the (n + 3) th resonator and the sub coupling voltage generated by the sub coupling circuit. g) is represented by the following equation (5).

[0014]

PHb-g = −450 ° −90 ° = −540 ° = −180−360 ° = −180 ° (5) Therefore, The elliptic function form B shown in FIGS.
In the PF, between the (n-1) -th resonator and the (n + 2) -th resonator and between the (n-2) -th resonator and the (n-)
+3) Since the phase difference between the main coupling voltage generated by the main coupling circuit and the sub-coupling voltage generated by the sub-coupling circuit is opposite to that of the third resonator, the main coupling circuit in the attenuation region thereof An attenuation pole is formed at a position where the amplitude of the main coupling voltage attenuated through the sub-coupling circuit becomes equal to the amplitude of the sub-coupling voltage attenuated through the sub-coupling circuit. this
As described above, the elliptic function type BPF shown in FIGS.
FIG. 8 shows an example of characteristics when a pair of attenuation poles are provided.
Thus, both the amplitude characteristic and the group delay time characteristic
There was a disadvantage that the difference was large.

[0015] Figure 9 is a circuit diagram showing an equivalent circuit of the group delay time compensating BPF of this embodiment, FIG. 10, FIG. 9
Is a conversion equalization circuit of the equalization circuit shown in FIG. The capacitances (CA to CH) shown in FIG. 9 indicate the capacitances formed by the TM01 delta mode dielectric resonance elements (41a to 41h). Group delay time compensating BPF in this embodiment, among the disposed U-shaped dielectric resonators, the two dielectric resonators located on the folding point, n-th resonator (40d
) And the (n + 1) th resonator (the resonator of 40e), the (n−1) th resonator (the resonator of 40c) and the (n + 2) th resonator (of the 40f) Resonator)
As a sub-coupling circuit between and, instead of the capacitive element 5a,
S-shaped loop element (capacitive loop element of the present invention)
16, the (n-2) th resonator (40b
Resonator) and the (n + 3) th resonator (40g resonance)
U-shaped loop as a sub-coupling circuit between
Instead of the element 7, an S-shaped loop element (the content of the present invention)
Using the quantitative loop element 6), and the (n−3) th
Resonator (resonator of 10a) and (n + 4) th resonator
(10h resonator) as a sub-coupling circuit,
Use normal U-shaped loop element 7 instead of child 5b
In this regard, the elliptic function form shown in FIGS.
Different from BPF. Use an S-shaped coupling loop 6
Thus, the (n−2) th resonator and the (n + 3) th resonator
The coupling circuit with the resonator is shown in M63 and M64 in FIG.
It is represented by a mutual inductance circuit.

Each mutual inductor shown in FIGS. 7 and 10
In the sense circuit (M41, M42, M63, M64)
Loop element side that constitutes the circuit (skip multiple circuit elements
Side where the mutual inductance circuits are directly connected)
Are the secondary coils, and the remaining coils are the primary coils.
You. In this case, the mutual inductance circuit shown in FIG.
(M63, M64) is one of the mutual inductance circuits M64.
The secondary coupling voltage induced in the secondary coil and the mutual coupling shown in FIG.
Mutual inductor by the conductance circuit (M41, M42)
And the sub-coupling voltage induced in the primary coil of the
By comparison, it is easy to see that
You. That is, as shown in FIG. 10, the (n-2) th resonance
And the (n + 3) th resonator as a sub-coupling circuit
When the S-shaped loop 6 is used, the (n + 3)
The sub-coupling voltage induced in the eye resonator is as shown in FIG.
And the (n-2) th resonator and the (n + 3) th resonator
U-shaped loop 7 is used as a sub-coupling circuit with the container
In this case, the secondary coupling induced in the (n + 3) th resonator
The phase differs by 180 ° compared to the combined voltage. I
Therefore, the (n−2) th resonator and the (n + 3) th resonator
Between the cavity and the resonator, a sub-loop generated by the S-shaped coupling loop 6 is formed.
The phase difference of the coupling voltage is (90 °) . In the present invention, the S-shaped loop (6, 16) is the same as FIG.
As shown in FIG.
Of which the both ends are electrically and mechanically connected to the partition 2
Means a loop element .

Similarly, the (n-1) th resonator and (n)
+2) S-shaped as a sub-coupling circuit between the resonator
, The phase difference of the sub-coupling voltage generated by the sub-coupling circuit between the (n−1) -th resonator and the (n + 2) -th resonator becomes (90 °).
Therefore, the phase difference (PHc−) between the main coupling voltage generated by the main coupling circuit between the (n−1) th resonator and the (n + 2) th resonator and the sub coupling voltage generated by the sub coupling circuit. f) is (-180 °) similarly to the above equation (3).
Becomes (N-2) th resonator, and (n + 3)
The phase difference (ΘMb-g) of the main coupling voltage generated by the main coupling circuit between the resonator and the third resonator is (−450 °) as shown in the above equation (4). Further, as described above, (n
Between the (-2) th resonator and the (n + 3) th resonator
Using an S-shaped loop 6 as a sub-coupling circuit
Accordingly, the phase difference of the sub-coupling voltage generated by the sub-coupling circuit between the (n−2) -th resonator and the (n + 3) -th resonator becomes (90 °). Therefore, the phase difference (PHb−) between the main coupling voltage generated by the main coupling circuit between the (n−2) th resonator and the (n + 3) th resonator and the sub coupling voltage generated by the sub coupling circuit. g) is represented by the following equation (6).

[0018]

PHb-g = −450 ° + 90 ° = −360 ° (6) As can be seen from the above equation (6), the present embodiment form the group delay time compensating the BPF, and (n-2) -th resonators (n
The main coupling voltage generated by the coupling in the main coupling circuit and the sub-coupling voltage generated by the coupling in the sub-coupling circuit have the same phase (having a phase difference of -360 °) with the (+3) th resonator. Accordingly, the group delay time of the embodiment compensated BPF
At the center frequency of the resonator (40c) → the resonator (40d) → the resonator (4
0e) → resonator (40f) (or resonator (40f) →
Resonator (40e) → Resonator (40d) → Resonator (40
The shunt caused by the resistance component in the direction c)) causes a small amount of shunt loss, which increases the insertion loss. The frequency is, as displaced from the center frequency, the phase of the main coupling voltage caused by the main binding circuit, the group delay time compensating BPF
Is displaced in the direction of ± 90 ° with respect to the phase of the center frequency.

[0019] However, since the phase of the sub-coupling voltage caused by the sub-coupling circuit is not displaced, the group delay time compensating B
At a frequency displaced from the center frequency of the PF, the combined voltage of the main coupling voltage generated by the main coupling circuit and the sub-coupling voltage generated by the sub-coupling circuit acts in a decreasing direction, and the pass band of the group delay time compensating BPF is reduced. DB at band edge
The insertion loss is reduced to about 1 / 1.4 times the value. For this reason,
In the group delay time compensating BPF of this embodiment, the loss increase of the center frequency, and reduction in loss in the vicinity of the band edge of the pass band is applied, it is possible to reduce the amplitude deviation in the pass-band . With respect to the phase characteristic in the pass band, the sub-coupled wave generated by the sub-coupled circuit including the S-shaped coupling loop 6 acts to change the phase of the combined coupled wave to:
The phase of the sub-coupling wave generated by the sub-coupling circuit approaches, and the phase change approaches a straight line. That is, in the passband
Generated in the (n + 3) th resonator by the main coupling circuit
With the electromagnetic field and the sub-coupling circuit consisting of the S-shaped loop 6
The electromagnetic field generated in the (n + 3) th resonator is the center frequency
In the vicinity of the numbers, they cancel each other out and the pass band
Near the edge, they tend to join each other and pass
The deviation of the amplitude characteristic in the region becomes smaller . Due to this,
Since the amount of change in delay time is compensated to be small,
Reduced group delay time deviation in over-band, group delay time characteristics
Can be improved . Accordingly, since it is compensated to the amount of change in the group delay time is small, in the pass-band
To reduce the group delay time deviation, it is possible to improve the group delay time characteristics.

[0020] compensation amount of the group delay time by sub-coupling circuit consisting of coupling loops 6 S-shaped is smaller than the size of the optimum, the group delay time characteristic similar to the compensation amount is small pan bottom shape. FIG. 11 shows the group delay time characteristics in this state. When the compensation amount is optimal size of the group delay time due to side coupling circuit consisting of coupling loops 6 of S-shaped, wider flat part of the group delay time characteristic is the most. Figure 1 group delay time characteristic of the state
It is shown in FIG. Is larger than the optimum size compensation amount of the group delay time by sub-coupling circuit consisting of coupling loops 6 S-shaped,
The compensation amount becomes overcompensated. Shows a group delay time characteristic of the state in FIG. 13. Within the passband, can tolerate some degree of ripple specific group delay time characteristic, if possible, most group delay time characteristic group delay time compensating BPF of overcompensation shaped becomes wider. Group delay time compensation type of this embodiment
In the BPF , between the (n−3) th resonator (resonator of 40a) and the (n + 4) th resonator (resonator of 40h), the resonator (40a) → the resonator ( 40b) →
The phase difference (ΘMa-h) of the coupling voltage generated by the path from the resonator (40g) to the resonator (40h) is expressed by the following equation (7).

[0021]

ΘMa-h = −90 ° + 90 ° −90 ° = −90 ° (7) Also, the (n-3) th And the (n + 4) -th resonator are sub-coupled by a U-shaped coupling loop 7, so that the (n-3) -th resonator and the (n + 4) -th resonator are Thus, the phase difference of the sub-coupling voltage generated by the sub-coupling circuit is (−90 °). Therefore, between the (n−3) -th resonator and the (n + 4) -th resonator, the resonator (40a) → the resonator (40b) → the resonator (40g) → the resonator (40h) The phase difference between the generated coupling voltage and the sub-coupling voltage generated by the sub-coupling circuit (PHa-f
) Is represented by the following equation (8).

[0022]

(8) PHa-f = −90 ° −90 ° = −180 ° (8) As can be seen from the above equation (8), the present embodiment of the group delay time compensating BPF form, between the (n-1) -th resonator (n + 4) th resonator, the resonator (40a) →
Resonator (40b) → Resonator (40g) → Resonator (40
The coupling voltage generated by the path h) and the sub-coupling voltage generated by the sub-coupling circuit have opposite phases (the phase difference is −180 °). Accordingly, the group delay time of the embodiment compensated B
In the PF, in the attenuation range, the resonator (40a) → the resonator (40b) → the resonator (40g) → the resonator (40h)
The attenuation pole is formed at a frequency where the amplitude of the coupling voltage attenuated via the sub-coupling circuit and the amplitude of the sub-coupling voltage attenuated through the sub-coupling circuit are the same. The characteristics can be improved. Immediately
In the group delay time compensation type BPF of the present embodiment, (n
Between the -2) th resonator and the (n + 3) th resonator
Are connected by a sub-coupling circuit including an S-shaped coupling loop 6.
Phase-coupled sub-coupling consisting of this S-shaped loop 6
The circuit reduces the amount of attenuation outside the passband, but (n
Between the -3) th resonator and the (n + 4) th resonator
Are connected by a sub-coupling circuit composed of a U-shaped coupling loop 7.
To generate a pair of attenuation poles outside the passband
To improve the attenuation characteristics outside the pass band.
Can be . As described above, the group delay time compensation according to the present embodiment is performed.
In the compensation type BPF, the attenuation pole is limited to two pairs or less.
Is the deviation of the amplitude characteristic and group delay time characteristic in the passband.
The difference can be improved together. In addition, U-shaped loop
7 is provided to improve the attenuation characteristics outside the pass band.
Therefore, the group delay time compensation type BPF of the present embodiment is
And the attenuation outside the pass band satisfies the specified conditions
Then, the U-shaped loop 7 is not provided, and the S-shaped loop
By providing only the sub-coupling circuit consisting of (6, 16)
Is also good.

[0023] FIGS. 14 to 17 is a graph showing an example of the frequency characteristic of the group <br/> delay compensating BPF of this embodiment. Graph shown in FIG. 14 to FIG. 17, in the group delay time compensating BPF of this embodiment, (n-
Between the 3) th resonator and the (n + 4) th resonator,
The BPF is sub-coupled by a sub-coupling circuit including a U-shaped coupling loop 7. FIG. 14 is a graph showing the attenuation characteristics. The horizontal axis represents the frequency (MHz), the memory interval is 2 MHz,
The vertical axis represents the attenuation (dB), and the memory interval is 5 dB. The center frequency of the group delay time compensated BPF is 551MH
14, and the frequency is 547.54 in FIG.
The attenuation at 4 MHz (point a in FIG. 14) is −26.
It is 692 dB, and the attenuation when the frequency is 554.456 MHz (point b in FIG. 14) is −30.431 dB. FIG. 15 is a graph showing the graph shown in FIG. 14 in an enlarged manner, and the memory interval on the vertical axis is 1 dB. As can be seen from the graph of FIG.
Its attenuation between 554MHz from (a point in FIG. 15) (b point in Fig. 15) is within 2 dB, the group late <br/> length of time compensated BPF shown in FIG. 14, in the pass band The amplitude deviation is reduced.

FIG. 16 is a graph showing phase characteristics.
The horizontal axis is the frequency (MHz) and the memory interval is 2 MHz, and the vertical axis is the angle and the memory interval is 90 °. In FIG. 16, when the frequency is 548 MHz (point a in FIG. 16), the phase is −44.36 °, and the frequency is 554 MHz.
The phase at (point b in FIG. 16) is −49.704 °. Figure 17 is a graph showing the group delay time characteristic,
The horizontal axis represents the frequency (MHz) and the memory interval is 2 MHz, and the vertical axis represents the delay amount (ns) and the memory interval is 100 ns. In FIG. 17, the frequency is 548 MHz (a in FIG. 17).
The delay amount at the time of (point) is 280.52 ns, and the delay amount at the frequency of 554 MHz (point b in FIG. 17) is
274.11 ns. As can be seen from the graph of FIG. 17, the group delay time compensated BPF shown in FIG. 14, the delay amount between the frequency of 554MHz from 548MHz is
Is within 275 ns, the group delay time deviation in the passband is reduced. Incidentally, in the group delay time compensating BPF of this embodiment, when not using the coupling loop 7 of U-shaped as a by-coupling circuit between the (n-3) -th resonator (n + 4) th resonator the, in the attenuation characteristics shown in FIG. 14, although the attenuation amount outside the pass band is reduced, even in this case, it is possible to reduce the amplitude deviation and the group delay time deviation in the passband.

[Embodiment 2] FIG. 18 shows a BP formed by connecting dielectric resonators in a magnetic coupling circuit in multiple stages.
18A and 18B are diagrams for explaining magnetic coupling of the dielectric resonator in F, and FIG. 18A shows a multistage-connected dielectric resonator (FIG. 18 shows only adjacent Rn and Rn + 1 dielectric resonators); (B) is a plan view, and FIG. (C) is a side view. Generally, the height (HD) of the outer conductor 1 is HD ≒ λo / 4 (λo is the wavelength of the center frequency of the BPF), and the width (W) of the outer conductor 1 is W = λc / 2 (λc is the wavelength of the cutoff frequency of the BPF). Therefore, the dielectric resonator (R
The magnetic loss (LM) between n) and the dielectric resonator (Rn + 1) can be obtained by the following equation (9).

[0026]

LM = (54.6 × LC) / 2W (dB) (9) where LC is a dielectric resonance constituting the dielectric resonator (Rn, Rn + 1). Shows the spacing between elements. Based on the magnetic loss (LM) determined by the above equation (9), the magnetic coupling coefficient (Mm) between the dielectric resonator (Rn) and the dielectric resonator (Rn + 1) is expressed by the following (10). You can ask.

[0027]

Mm = 10 ** (LM / 20) (10) Here, when the load Q (QL) is high, LC> W, and the BPF becomes large. There are cases. In such a case, the BPF can be reduced in size by interposing an interstage magnetic field coupling adjustment element between the adjacent dielectric resonators (Rn, Rn + 1). Figure 19 is a fragmentary cross-sectional view showing a schematic configuration of the group delay time compensated bandpass filter of the second embodiment of the present invention, FIG. 19 is a fragmentary cross-sectional view of the same portion as FIG. 3. Group delay time compensating BPF in this embodiment, the dielectric resonators arranged in (40a-40h) appropriate regular intervals, the adjacent dielectric resonators (40A～40
h ) is a band-pass filter in which a required electric characteristic is obtained by interposing an inter-stage magnetic field coupling adjustment element 51 during h ) .

FIG. 20 is a diagram showing an example of the interstage magnetic field coupling adjusting element 51 shown in FIG. The inter-stage magnetic field coupling adjusting element 51 shown in FIG.
(54) are provided and arranged on the two conductor plates (52, 5).
3). The short sides of the two conductor plates (52, 53) are electrically and mechanically connected to the upper and lower walls of the outer conductor 1, and one of the two conductor plates (52, 53) The long side is electrically and mechanically connected to the partition 2 or the side wall of the external conductor 1. When the interstage magnetic field coupling adjusting element 51 shown in FIG. 20 is provided, the dielectric resonator (R
n) and the magnetic coupling coefficient (Mmi) between the dielectric resonator (Rn + 1) can be obtained by the following (11).

[0029]

Mmi = Mm × (Iw / W) (11) where Iw is the width of the predetermined interval (54 in FIG. 20). As can be seen from the equation (11), when the interstage magnetic field coupling adjusting element 51 shown in FIG. 20 is provided, the magnetic coupling between the dielectric resonator (Rn) and the dielectric resonator (Rn + 1) is provided. The coefficient is determined by the predetermined interval (54 in FIG. 20) width (I
w) can be adjusted as appropriate. FIG. 21 is a diagram showing another example of the inter-stage magnetic field coupling adjustment element 51 shown in FIG. Interstage magnetic field coupling adjusting element 51 shown in FIG.
Is provided with a predetermined hole (56 in FIG. 21) in the upper central portion.
It is composed of a single conductor plate 55. The upper side and the lower side of the single conductor plate 55 are electrically and mechanically connected to the upper and lower walls of the external conductor 1, and the side of the single conductor plate 55 is connected to the partition wall 2 or the external conductor 1. One side wall is electrically and mechanically connected. The magnetic coupling coefficient (M) between the dielectric resonator (Rn) and the dielectric resonator (Rn + 1) when the interstage magnetic field coupling adjusting element 51 shown in FIG. 21 is provided.
mi) can be obtained by the following (12).

[0030]

Mmi = Mm × (AW / (W × HD)) (12) where Aw is the area of the predetermined hole (56 in FIG. 21). As can be seen from the above equation (12), when the interstage magnetic field coupling adjusting element 51 shown in FIG. 21 is provided, the magnetic coupling between the dielectric resonator (Rn) and the dielectric resonator (Rn + 1) is provided. The coefficient can be appropriately adjusted according to the area (Aw) of the predetermined hole (56 in FIG. 21). FIG.
20 is a diagram showing another example of the inter-stage magnetic field coupling adjusting element 51 shown in FIG. The inter-stage magnetic field coupling adjusting element 51 shown in FIG. 22 includes a strip-shaped conductor 57, which is electrically and mechanically connected to the upper and lower walls of the outer conductor 1. By appropriately adjusting the size of the conductor 57, or by appropriately increasing or decreasing the number of conductors 57 disposed between the adjacent dielectric resonators (Rn) and (Rn + 1), The coupling coefficient can be adjusted to the required value. FIG. 23 is a diagram showing another example of the interstage magnetic field coupling adjustment element 51 shown in FIG. The inter-stage magnetic field coupling adjusting element 51 shown in FIG. 23 includes a round bar-shaped or square bar-shaped conductor 58, which is electrically and mechanically connected to the upper and lower walls of the outer conductor 1. . By appropriately adjusting the size of the conductor 58 or by appropriately increasing or decreasing the number of conductors 58 disposed between the adjacent dielectric resonators (Rn) and (Rn + 1). The coupling coefficient can be adjusted to the required value. As described above, the invention made by the inventor has been specifically described based on the embodiment. However, the present invention is not limited to the embodiment, and can be variously modified without departing from the gist of the invention. Of course, it is.

[0031]

The effects obtained by typical ones of the inventions disclosed in the present application will be briefly described as follows. According to the present invention, the bandpass filter using dielectric resonators, reduced amplitude deviation in the pass band, and the group delay time deviation, also, it is possible to obtain a steep attenuation characteristic.

[Brief description of the drawings]

1 is a top view of the top surface of the group delay time compensated bandpass filter of the first embodiment of the present invention.

Figure 2 is a fragmentary cross-sectional view showing a schematic configuration of the group delay time compensated bandpass filter of the first embodiment of the present invention.

3 is a fragmentary cross-sectional view showing a schematic configuration of the group delay time compensated bandpass filter of the first embodiment of the present invention.

4 is a fragmentary cross-sectional view showing a schematic configuration of the group delay time compensated bandpass filter of the first embodiment of the present invention.

FIG. 5 is a diagram for explaining a TM01 delta mode dielectric resonator.

FIG. 6 is a circuit diagram showing an equalizer circuit of an elliptic function band-pass filter using the conventional capacitance-loaded resonator shown in FIGS. 30 to 33.

FIG. 7 is a conversion equalization circuit of the equalization circuit shown in FIG. 6;

8 is a graph showing amplitude deviation characteristics and group delay time deviation characteristics in a pass band in the band pass filters shown in FIGS. 30 to 33. FIG.

9 is a circuit diagram showing an equivalent circuit of the group delay time of the embodiment 1 compensated bandpass filter.

FIG. 10 is a conversion equalization circuit of the equalization circuit shown in FIG. 9;

[11] In the group delay time compensated bandpass filter of the first embodiment, the group in the passband when the compensation amount of the group delay time by sub-coupling circuit consisting of the coupling loop S-shaped is smaller than the size of the optimal 5 is a graph showing a delay time deviation characteristic.

[12] In the group delay time compensated bandpass filter of the first embodiment, the group in the passband when the compensation amount is optimal size of the group delay time due to side coupling circuit comprising a coupling loop S-shaped 5 is a graph showing a delay time deviation characteristic.

[13] In the group delay time compensated bandpass filter of the first embodiment, the group in the passband when the compensation amount of the group delay time by sub-coupling circuit consisting of the coupling loop S-shaped is greater than the size of the optimal 5 is a graph showing a delay time deviation characteristic.

14 is a graph showing the attenuation characteristics of an example of the group delay time compensated bandpass filter of the first embodiment.

FIG. 15 is a graph showing the graph of FIG. 14 in an enlarged manner.

16 is a graph showing an example of the phase characteristic of the group delay time compensated bandpass filter of the first embodiment.

17 is a graph showing the group delay time characteristic of one example of the present group delay compensated bandpass filter of the first embodiment.

FIG. 18 is a diagram for explaining magnetic coupling of the dielectric resonator in the BPF configured by cascade-connecting the dielectric resonator in the magnetic coupling circuit.

19 is a fragmentary cross-sectional view showing a schematic configuration of the group delay time compensated bandpass filter of the second embodiment of the present invention.

20 is a diagram showing an example of the inter-stage magnetic field coupling adjusting element shown in FIG. 19;

21 is a diagram showing another example of the interstage magnetic field coupling adjustment element shown in FIG. 19;

FIG. 22 is a diagram showing another example of the interstage magnetic field coupling adjustment element shown in FIG. 19;

23 is a diagram showing another example of the interstage magnetic field coupling adjustment element shown in FIG. 19;

FIG. 24 is a plan view showing an upper surface of an elliptic function band-pass filter using a conventional coaxial resonator.

25 is a fragmentary cross-sectional view showing a schematic configuration of the bandpass filter shown in FIG. 24.

26 is a cross-sectional view of a main part showing a schematic configuration of the bandpass filter shown in FIG.

FIG. 27 is a cross-sectional view of a principal part showing a schematic configuration of the bandpass filter shown in FIG.

FIG. 28 is a cross-sectional view of a main part showing a schematic configuration of an elliptic function band-pass filter using a conventional helical resonator.

FIG. 29 is a side view showing one of the helical resonators shown in FIG.

FIG. 30 is a top view showing the upper surface of a conventional elliptic function band-pass filter using a capacitance-loaded resonator.

31 is a fragmentary cross-sectional view showing a schematic configuration of the bandpass filter shown in FIG. 30.

32 is a fragmentary cross-sectional view showing a schematic configuration of the bandpass filter shown in FIG. 30.

33 is a fragmentary cross-sectional view showing a schematic configuration of the bandpass filter shown in FIG. 30.

[Description of Signs] 1 ... external conductor, 2 ... partition, 3a to 3h ... lower end side fixed electrode, 4a to 4h, 35a to 35h ... movable electrode, 5, 5
a, 5b, 15: Capacitance elements forming a sub-coupling circuit,
16 ... S-shaped loop element forming a sub-coupling circuit, 7 ...
U-shaped loop elements constituting a sub-coupling circuit, 8, 8a,
8b: Input (or output) coupling loop, 9a to 9h, 3
7a to 37h: lock nut, 11a: input (or output) terminal, 11b: output (or input) terminal, 13a to
13h: Lower end cylindrical body made of a fixed dielectric; 17: Loop element forming a sub-coupling circuit; 20a to 20h: Coaxial resonator; 21a to 21h; 36a to 36h: Drive screw;
2a to 22h: resonance frequency adjusting elements, 23a to 23h
... Inner conductor, 30a-30h ... Helical resonator, 31a
To 31h: helical resonance element, 32a to 32h: capacitance forming electrode, 33a to 33h, 34a to 34h: insulator
40a-40h, R, Rn, Rn + 1 ... TM01 delta
Mode dielectric resonators, 41a to 41h, RS: dielectric resonance element, 51: interstage magnetic field coupling adjustment element, 52, 53, 5
5 ... conductor plate, 54 ... interval, 55 ... hole, 57, 58 ... conductor.

[Procedure amendment 2]

[Document name to be amended] Drawing

[Correction target item name] Fig. 7

[Correction method] Change

[Correction contents]

FIG. 7

Claims (4)

[Claims] 1. A delay time in which first to Nth (N ≧ 6) dielectric resonators are connected in a U-shape, and each dielectric resonator is main-coupled by a magnetic coupling circuit. In the compensated band-pass filter, when the two dielectric resonators located at the U-shaped turning point are the n (n <N) -th and (n + 1) -th dielectric resonators, respectively, (n− Between the (1) th dielectric resonator and the (n + 2) th dielectric resonator, and (n−
2) A delay time compensating band-pass filter characterized by sub-coupling an S-shaped coupling loop between the (d) th dielectric resonator and the (n + 3) th dielectric resonator. 2. The delay time compensating band-pass filter according to claim 1, wherein an interstage magnetic field coupling adjusting element is provided between each of the dielectric resonators. 3. The delay time compensating band-pass filter according to claim 2, wherein the interstage magnetic field coupling adjusting element is constituted by two conductive plates arranged at a predetermined interval. . 4. The delay time compensating band-pass according to claim 2, wherein the inter-stage magnetic field coupling adjusting element is constituted by a single conductive plate provided with a hole of a predetermined size. filter.