JPH0645804A - Dielectric filter - Google Patents

Abstract

PURPOSE:To decrease the number of parts and to reduce cost. CONSTITUTION:An electrode pattern is formed in the shape of an electrode film on the terminal part side of the upper face of a base board 22. This electrode pattern 42 is formed on the base board 22 by a printing pattern or thick film etching for example. This electrode pattern 42 is composed of three capacitor electrodes C1-C3 and two inductor electrodes L1 and L2. Capacitor substrates 43-45 forming capacitor electrode films on the upper and lower faces are packaged on the upper faces of the capacitor electrodes C1-C3 of the electrode pattern 42 by soldering or the like. Connecting terminals 9 from dielectric coaxial resonators 103 are connected to the capacitor electrode films on the upper faces of these capacitor substrates 43-45 by soldering or the like. Thus, a band elimination filter can be constituted without using any discrete parts. Therefore, the number of parts can be decreased and the cost can be reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to, for example, a car telephone,
The present invention relates to a microwave band dielectric filter used in mobile communication devices such as mobile phones.

[0002]

2. Description of the Related Art FIG. 21 is an equivalent circuit diagram of a three-stage band elimination filter, showing three dielectric coaxial resonators 1 to 3, 6 C components (C _{1 to} C ₆ ) and 2 It is composed of L components (L). The structure of the dielectric filter for this equivalent circuit is as shown in FIG. That is, the capacitors C _{4 to} C ₆ as discrete components are arranged on the base 48, and the capacitor C ₄
C _5, discrete components of the inductance L, L to crosslink each between the capacitor C ₅ and C _6, further capacitors C ₁ -C ₃ discrete components disposed on the capacitor C ₄ -C ₆ and ing. Then, the connection terminals 9 extending from the dielectric coaxial resonators 1 to ₃ are placed on the capacitors C _{1 to} C _{3 and} the components are connected and fixed by soldering or the like. Reference numerals 50 and 51 are input / output terminals for inputting / outputting signals.

[0003]

In [Problems that the Invention is to Solve the conventional example, in the case of a filter, a capacitor C ₁ -C ₆
In addition, the inductances L and L are all composed of discrete parts. Therefore, there are problems that the number of parts is large, the number of manufacturing processes is large, and the cost is high.

The present invention has been made in view of the above points, and it is an object of the present invention to provide a dielectric filter intended to reduce the number of parts and cost.

[0005]

DISCLOSURE OF THE INVENTION The present invention provides a dielectric filter comprising an L component, a C component, a dielectric coaxial resonator, etc., which passes or blocks a signal in a predetermined frequency band.
The L component or the C component is patterned into an electrode film pattern on an insulator on which the above-mentioned dielectric coaxial resonator is mounted.

According to a second aspect of the present invention, the insulator is formed of a multi-layer substrate, and the L component or the C component is patterned on the inner surface of the multi-layer substrate in the form of an electrode film.

[0007]

According to the present invention, unlike the conventional case where discrete components are used to form the L or C component, the L or C component is formed as an electrode film pattern on the insulator. As a result, the number of parts can be reduced, and the cost can be reduced accordingly.

According to the second aspect of the present invention, the insulator is formed of a multi-layer substrate, and the L component or the C component is patterned in the form of an electrode film on the inner surface side of the multi-layer substrate. Since the parts and the patterns are irrelevant to each other in position, the dimension between the parts can be reduced. Therefore, the size can be reduced as a whole, and a small dielectric filter can be realized.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. In FIG. 1, the dielectric coaxial resonators 1 to 3 are ¼
In the wavelength type, an inner conductor in the form of an electrode film is formed on the inner peripheral surface of the hole 8 penetrating the dielectric, and an outer conductor 41 is formed in the form of an electrode film on the side surface of the dielectric. Further, a short-circuit conductor (not shown) is formed in the shape of an electrode film on one of the end faces where the hole 8 is opened in order to short-circuit the inner conductor and the outer conductor. Metal connection terminals 9 are press-fitted into the holes 8 of the dielectric coaxial resonators 1 to 3 from the open end sides of the dielectric coaxial resonators 1 to 3, respectively, to contact the inner conductor to obtain conduction. . A ground electrode 26 is provided on a part of the upper surface and the bottom surface of the base substrate 22 on which the dielectric coaxial resonators 1 to 3 are mounted by soldering or the like.
Are formed. Base substrate 2 that constitutes this insulator
2 uses a dielectric substrate such as alumina or glass epoxy. The ground electrode 26 formed on the upper surface of the base substrate 22 is connected to the ground electrode on the lower surface by, for example, an electrode having a through hole structure for grounding.

An electrode pattern 42 is formed in the shape of an electrode film on the end portion of the upper surface of the base substrate 22. The electrode pattern 42 is formed on the base substrate 22 by, for example, a printing pattern or thick film etching. The electrode pattern 42 is composed of three capacitor electrodes C _{1 to} C ₃ and two inductor electrodes L ₁ and L ₂ . _On the upper surface of the capacitor electrodes C _{1 to} C ₃ of the electrode pattern 42, a capacitor substrate 43 having capacitor electrode films formed on the upper and lower surfaces thereof is formed.
To 45 are mounted by soldering or the like. The dielectric coaxial resonators 1 to 3 are formed on the capacitor electrode films on the upper surfaces of the capacitor substrates 43 to 45 made of this dielectric.
The connection terminals 9 from are connected by soldering or the like.

It should be noted that one ends of the metal input / output terminals 46 and 47 bent in a substantially Z shape are arranged on the capacitor electrodes C ₁ and C ₃ on both sides of the electrode pattern 42, and the capacitors on both sides are arranged on the capacitor electrodes C ₁ and C _3. Substrates 43 and 45 are arranged and connected and fixed together with the capacitor electrode film on the lower surface by soldering or the like.

FIG. 2 shows an equivalent circuit diagram of the band elimination filter constructed as described above. In FIG. 2, C ₁₁ , C ₂₁ , and C ₃₁ are capacitor substrate 43 to
45 is a capacitor formed by capacitor electrode films on the upper and lower surfaces of 45. C ₁₂ , C ₂₂ , and C ₃₂ are capacitor electrodes C _{1 to} C ₃ and the ground electrode 26 on the bottom surface of the base substrate 22.
Is a capacitor formed between and. Furthermore, L ₁ ,
L ₂ is the inductance due to the inductor electrodes L ₁ and L ₂ shown in FIG.

The L and C components formed by the electrode pattern on the base substrate 22 do not have to be all the L and C components required for the dielectric filter. That is, a part of the L component and the C component forming the dielectric filter may be formed on the base substrate 22 with the electrode pattern. For example, in the circuit of FIG. 2, the capacitors C ₁₂ , C ₂₂ , and C ₃₂ may be formed by electrode patterns on the base substrate 22, and the inductances L ₁ and L ₂ may be formed by discrete components.

If the required capacitance cannot be obtained only by the electrode pattern on the base substrate 22, the capacitor C ₁₂ ,
C ₃₂ may be formed as an electrode pattern on the base substrate 22, and the remaining capacitor C ₂₂ may be composed of discrete components. Further, FIG. 3A shows a part of the circuit of FIG. 2 described above, and the capacitor C ₁₂ shown in FIG.
As shown in (b), the two capacitors C _12a and C _12b may be divided, one capacitor C _12a may be formed by an electrode pattern, and the other capacitor C _12b may be formed by a discrete component. On the contrary, the capacitor C _12b may be formed by an electrode pattern and the capacitor C _12a may be formed by a discrete component. In this case also, the base substrate 22
This is a case where the required capacitance cannot be obtained only by the upper electrode pattern. The same applies to the other capacitors C ₂₂ and C ₃₂ .

(Embodiment 2) FIG. 4 shows Embodiment 2 in which capacitor electrodes C _{1 to} C ₃ are formed on the upper surface (front surface) of the base substrate 22.
The ground electrode 26 is formed on one surface of the lower surface (back surface) of the base substrate 22, and the inductor electrodes L ₁ and L ₂ are formed in a substantially U-shape on the lower surface of the base substrate 22. Then, the capacitor electrodes C _{1 to} C ₃ and the inductor electrodes L ₁ and L ₂ are electrically connected by the terminal electrode 49 having a through hole structure. The capacitor electrodes C _{1 to} C ₃ on the upper surface of the base substrate 22 and the ground electrode 26 on the lower surface form the capacitors C ₁₂ , C ₂₂ , and C ₃₂ shown in FIG. 2, respectively. Further, the capacitors C ₁₁ , C ₂₁ , and C ₃₁ shown in FIG. 2 are obtained by the capacitor electrode films on the upper and lower surfaces of the capacitor substrates 43 to 45 as in the previous embodiment.

(Embodiment 3) FIG. 5 shows Embodiment 3 in which the base substrate 22 is a multi-layer substrate type. Figure 5
(A) shows the upper surface (front surface) of the base substrate 22, and (b) shows the lower surface (back surface). Further, FIG. 5C shows an inner layer base substrate 22 a stacked inside the base substrate 22. Capacitor electrodes C _{1 to} C ₃ are formed on the upper surface of the base substrate 22 as in the previous embodiment, and inductor electrodes L ₁ and L ₂ are formed on the inner layer base substrate 22a. In addition, each electrode of the base substrate 22 is configured to obtain conduction by the terminal electrode 49 having a through hole structure. Further, the capacitor electrodes C _{1 to} C _{3 on} the upper surface of the base substrate 22 are
And the ground electrode 26 on the lower surface, the capacitor C shown in FIG.
₁₂ , C ₂₂ and C ₃₂ are obtained.

(Embodiment 4) By the way, FIG.
1 is an equivalent circuit diagram of a dielectric filter which is used in mobile communication devices such as a car phone and a mobile phone and is used in a microwave band and is a so-called antenna duplexer.
The dielectric filter has a band-elimination filter on the transmission side and a band-pass filter on the reception side. The band elimination filter of this surface mount type dielectric filter has a three-stage resonator structure, and has three quarter-wave dielectric coaxial resonators 1 to 3, and the bandpass filter has four. The resonator has a stage structure, and has four quarter-wave dielectric coaxial resonators 4 to 7.

FIG. 7 shows an exploded perspective view of the entire dielectric filter, and FIG. 8 shows a perspective view of a state in which each component is mounted. First, the configuration of a dielectric filter called an antenna duplexer in this embodiment will be described with reference to FIGS. 7 and 8.

Dielectric coaxial resonators 1 to 1 similar to those of the previous embodiment
Reference numeral 7 denotes an electrode film-shaped inner conductor formed on the inner peripheral surface of the dielectric hole 8 formed in a rectangular parallelepiped shape, an electrode film-shaped outer conductor formed on the side surface of the dielectric, and the inner conductor. And a short-circuit conductor (not shown) formed on one of the end faces where the hole 8 is opened in order to short-circuit the outer conductor and resonate at a predetermined frequency. This dielectric coaxial resonator 1-7
The metal connection terminals 9 each having one end formed in a substantially cylindrical shape are press-fitted into the hole 8 from the open end sides of the dielectric coaxial resonators 1 to 7, respectively, and contact with the inner conductor in the hole 8 to conduct electricity. Is getting The other end side of the connection terminal 9 is formed in a tongue shape and serves as a capacitor substrate 10 to 12 and a coupling substrate 13 which will be described later.
Are connected to the electrode films 14 to 17 formed on the upper surface thereof by soldering or the like.

The capacitor substrates 10 to 12 are made of a dielectric material, and electrode films are formed on the upper and lower surfaces thereof to form capacitors. Further, a plurality of electrode films 14 to 17 are arranged in parallel on the upper surface of the coupling substrate 13 made of a dielectric material, and the electrode films 14 to 16 are formed in a comb-tooth shape at the opposing portions in order to increase the coupling capacitance. ing. Furthermore, electrode films are formed on both sides of the lower surface of the combined substrate 13. In addition, coil-shaped inductors L _{1 to} L ₃ are connected between the capacitor substrates 10 to 12. The inductors L _{1 to} L
Electrode films 19 and 20 are formed on the upper surface of a combined substrate 18 made of a dielectric material for mounting ₃ , and an electrode film serving as a ground electrode is formed on the entire lower surface of the combined substrate 18.

Base board 2 on which the above-mentioned members are mounted
Reference numeral 2 denotes an electrode film-shaped input / output terminal 23 connected to the antenna side and an electrode film-shaped input / output terminal 2 connected to the transmitter side.
4 and an input / output terminal 25 in the form of an electrode film to which the receiver side is connected
And are formed respectively. Further, an electrode film-shaped ground electrode 26 is formed on substantially the entire upper surface and lower surface of the base substrate 22. The base substrate 22 is made of a dielectric material or an insulating material. The combined substrate 13 mounted on the upper surface of the base substrate 22 includes two spacers 2.
The other spacer 21 is mounted on the upper surface of the input / output terminal 24 of the base substrate 22. The three spacers 21 are made of a conductive material such as metal.

The cover 27 that covers the base substrate 22 is made of metal, and the top plate of the cover 27 is used for soldering the outer conductors of the upper surfaces of the dielectric coaxial resonators 1 to 7 and the cover 27. And an elongated hole 28 and a hole 29 for inserting a jig for adjusting the characteristics of the dielectric coaxial resonators 1 to 7 are formed. Further, a plurality of ground terminals 30 are formed which are connected to the upper surface ground electrode 26 of the base substrate 22 from the lower edge front part / back part (not shown) of the cover 27. Notches 31 for exposing the input / output terminals 23 to 25 of the base substrate 22 are formed on the side plates of the cover 27, respectively. As shown in FIG. 8, the label 3 is provided on the upper surface of the cover 27.
2 is attached and the holes 28 and 29 are covered.

In the above case, the case where the cover 27 is used has been described. However, the dielectric filter may be formed without using the cover 27. The label 32 is formed of a resin called Kapton (trade name) having high heat resistance. When the label 32 is made of resin, it does not serve as a shield, but when it has the function of a shield, it is made of metal.

Next, the arrangement of each member will be described. As shown in FIGS. 7 and 8, on the band elimination filter side, one spacer 21 is provided on the base substrate 2
2 is mounted on the input / output terminal 24 and the combined substrate 1
8 is mounted on the ground electrode 26 between the input / output terminals 24 and 23 of the base substrate 22 and soldered. Furthermore,
The spacers 21 are mounted on the upper surfaces of the input / output terminals 23 and 25, and the combined substrate 13 is bridged and soldered on the upper surfaces of the two spacers 21 so that the electrode films on the lower surfaces are in contact with each other.

As shown in FIG. 8, one end of the inductor L ₁ is mounted on the upper surface of the spacer 21, the capacitor substrate 10 is mounted thereon, and the dielectric coaxial resonator 1 is mounted on the electrode film on the upper surface of the capacitor substrate 10. Is connected to the connection terminal 9. The other end of the inductor L ₁ is mounted on the electrode film 19 of the combined substrate 18, and the inductor L ₂ is connected to the combined substrate 1
8 is mounted between the electrode films 19 and 20. Then, the capacitor substrate 11 is placed on the connecting portion between the inductors L ₁ and L _2.
Is mounted, and the connection terminal 9 from the dielectric coaxial resonator 2 is connected to the electrode film on the upper surface of the capacitor substrate 11. One end of the inductor L ₃ is mounted on the electrode film 20 of the coupling substrate 18, and the other end is mounted on the input / output terminal 23. Also,
Capacitor board 1 above the connection between inductors L ₂ and L _3.
2 is mounted, and the connection terminal 9 from the dielectric coaxial resonator 3 is connected to the electrode film on the upper surface of the capacitor substrate 12.

The connection terminals 9 from the dielectric coaxial resonators 4 to 7 are connected to the electrode films 14 to 17 on the upper surface of the coupling substrate 13 mounted on the two spacers 21, respectively. There is.

The ground electrodes 26 are formed on the entire surface of the upper and lower surfaces of the base substrate 22 except for the input / output terminals 23 to 25. The ground electrodes 26 on the upper and lower surfaces are formed in a straight line in the horizontal direction. Conduction is obtained by a plurality of through holes 33. Further, the ground electrodes 26 on the upper and lower surfaces are electrically connected via the electrode film formed on the end surface of the semicircular cutout 34 formed around the base substrate 22. Further, the input / output terminals 23 to 25 are also electrically connected to the upper and lower surfaces of the base substrate 22 via the electrode films formed on the end surfaces.

In the equivalent circuit shown in FIG. 6, the capacitors C _{1 to} C ₃ on the band elimination filter side are formed by the upper and lower electrode films of the capacitor substrates 10 to 12, and the capacitor C ₄ is formed on the input / output terminal 24 and the lower surface. It is formed between the ground electrode. The capacitors C ₅ and C ₆ are
It is formed by the electrode films 19 and 20 on the upper surface of the combined substrate 18 and the electrode film on the lower surface. The capacitor C ₇ is formed between the input / output terminal 23 and the ground electrode on the lower surface.

The capacitor C ₈ on the side of the bandpass filter is formed between the electrode film 14 of the combined substrate 13 and the electrode film on the lower surface, and the capacitors C _{9 to} C ₁₀ are formed on the combined substrate 1.
3 between the electrode films 14 to 16. Further, the capacitor C ₁₁ is formed by the electrode film 16 on the upper surface and the electrode film (not shown) on the lower surface of the combined substrate 13. The electrode film on the lower surface is electrically connected to the spacer 21 on the right side in FIG. Further, the capacitor C ₁₂ is formed by the electrode film 17 on the upper surface of the combined substrate 13 and the electrode film (not shown) on the lower surface. The dielectric coaxial resonator 7 and the capacitor C ₁₂ form a trap circuit of a series resonance circuit.

Further, in FIG. 6, an inductor L for phase adjustment is grounded at the input / output terminal 23 on the antenna side. In this embodiment, the inductor L is connected to the base substrate 22.
The electrode pattern 42 is formed on the upper surface of the. As shown in FIG. 7, an electrode pattern 42 forming the inductor L is formed into an approximately U-shaped electrode film shape, one end of which is integrated with the input / output terminal 23, and the other end of which is formed through the through hole 33 of the base substrate 22. Has electrical continuity with the ground electrode on the bottom.

By thus forming the coil (inductor L) for phase adjustment used in the antenna duplexer as the electrode pattern 42 on the base substrate 22 as shown in FIG. 7, the component constant is reduced, The cost can be reduced. Further, since the inductance value of the electrode pattern 42 having the inductor L formed by soldering does not change, the characteristics of the filter are stabilized.

(Fifth Embodiment) Further, the present invention can be applied not only to the phase adjusting coil as in the fourth embodiment but also to the inductor L of the band pass filter as shown in FIG. In FIG. 9, 1 to 4 are dielectric coaxial resonators similar to those in the previous embodiment, and capacitors C _{1 to} C ₄ perform capacitive coupling. The dielectric coaxial resonator 4 and the capacitor C _{5 form} a trap circuit.

When the resonance frequency of the trap circuit is higher than the pass band of the band pass filter, the inductor L is arranged to perform parallel resonance of the trap circuit so as not to adversely affect the pass band characteristic due to the resonance frequency of the trap circuit. Is provided. By forming the inductor L as an electrode pattern on the upper surface of the base substrate, the number of parts can be reduced and the cost can be reduced.
Moreover, since the inductance value of the electrode pattern on which the inductor L is formed does not change by soldering, the characteristics of the filter are stabilized.

(Sixth Embodiment) FIGS. 10 to 13 show a sixth embodiment. In this embodiment, the base substrate 22 is composed of two substrates 22.
_The multilayer substrate ₁ and 22 ₂ is formed, and the electrode pattern 42 for forming the inductor is formed on the lower surface of the upper substrate 22 ₁ . The inductors are, for example, inductors L _{1 to} L ₃ on the band elimination filter side as shown in FIG. The capacitor substrates 10 and 11 having capacitor electrode films (not shown) formed on the upper and lower surfaces are electrically connected to each other through through holes 35 formed in the substrate 22 ₁ .

As described above, the circuit structure can be simplified in a space-saving manner by forming the electrode pattern 42 as the line pattern in the resin multilayer substrate instead of realizing the inductor by the coil of the discrete component. In particular, as shown in FIG.
The inductor (electrode pattern 42) between 11 and the substrate 22 ₁
Since it is formed on the lower surface of the capacitor substrate 10,
It is possible to reduce the size of the space between the two and to reduce the size. In addition, the upper substrate 22 ₁ of the base substrate 22
There is no problem in forming the inductor (electrode pattern 42) even if other mounting components and the like are present on the upper surface of the substrate and the lower surface of the substrate 22 ₂ .

In this embodiment, the base substrate 22 is a multi-layer substrate having two layers, but by increasing the number to three layers, four layers, etc., it is possible to realize a larger inductance. Become.

In the present embodiment, the filter can be miniaturized by forming the inductance forming the filter in the base substrate 22 having a multi-layer structure as described above. Further, by using glass epoxy, bismaleimide-triazine resin or the like as the material of the base substrate 22, these substrates can be formed into a multi-layer substrate at low cost, so that the inductance can be easily formed in the multi-layer substrate.

(Embodiment 7) FIG. 13 shows an equivalent circuit diagram of a band elimination filter, which has a three-stage resonator structure, in which 1 to 3 are dielectric coaxial resonators, C _{1 to} C ₆ are capacitors, and L is a capacitor. ₁ and L ₂ are inductors. Further, in FIG. 13, reference numeral 52 is an input terminal and 53 is an output terminal. Figure 1
As shown in FIG. 4, in this embodiment, the base substrate 22 is composed of a multilayer substrate of _two substrates 22 ₁ and 22 ₂ , and the capacitors C _{1 to} C ₆ and the inductors L ₁ and L ₂ are connected to the electrode pattern 42. It is composed of.

Capacitors C _{1 to} C are provided on the upper substrate 22 _1.
3 is formed, the capacitor C ₄ -C ₆ on substrate 22 ₂ lower
And inductors L ₁ and L ₂ are formed. That is, the upper and lower surfaces of the substrate 22 ₁ of the upper forming an independent electrode film 54, 56, 58, the lower surface to the electrode film of the substrate 22 ₁ so as to face the respective electrode films 54, 56, 58 55, 57, Forming 59. The capacitors C ₁ , C ₂ , C ₃ are formed by the capacitances between the upper and lower electrode films 54, 55, 56, 57, 58, 59, respectively.
The electrode films 54, 56, 58 of the top surface of the substrate 22 ₁ is adapted to be connected to the dielectric coaxial resonators 1-3 and the like.

The substrate 22 ₂ below the base substrate 22
On the upper surface of the electrode film 55, 5 on the lower surface of the upper substrate 22.
Electrode films 60, 61, 62 that come into contact with 7, 59 to obtain conduction
Are formed. The electrode films 60 and 61 and the electrode films 61 and 62 are bridged by linear electrode films 63 and 64.

Here, each electrode film 60 of the electrode pattern 42
Numerals 62 to 62 are earth electrodes (not shown) on the lower surface of the substrate 22 ₂ , which form capacitors C ₄ , C ₅ and C ₆ , respectively, and inductors L ₁ and L ₂ are formed by the line-shaped electrode films 63 and 64. is doing. The line-shaped electrode films 63 and 64 form a circuit that connects the capacitors C ₄ and C ₅ , and C ₅ and C ₆ . In addition, if the interelectrode capacitance is not required,
The surface circuit element and ground electrode are connected through the through hole.

In the present embodiment, the case of the band elimination filter has been described, but the present invention is not limited to the band elimination filter and can be applied to all matching circuits and band pass filters. Further, although the multilayer substrate is composed of two substrates, it is a matter of course that the inductor and the capacitor may be formed by an electrode pattern by forming the multilayer substrate with two or more substrates.

As described above, in this embodiment, since all of the inductors and capacitors forming the filter circuit are formed by the electrode patterns, the number of parts can be reduced and the cost can be reduced as compared with the case of forming the discrete parts. Can be planned. Moreover, the assembly is facilitated and the mass productivity is improved.

(Embodiment 8) Embodiment 8 is shown in FIGS. 15 and 16.
Indicates. FIG. 15 shows a circuit diagram of a main part of the antenna duplexer shown in FIG. 6, in which the inductor L for phase adjustment used for matching the transmitting side and the receiving side is formed of a multilayer substrate. An electrode pattern 42 is formed on the upper surface of the substrate 22 ₂ below the base substrate 22 to form the inductor L.
The upper substrate 22 ₁ has lands 65, which are connected to other circuits,
66, and the lower substrate 2 through the through hole 70
Conduction is obtained with the lands 67 and 68 at the ends of the 2 ₂ electrode pattern 42.

Although the present embodiment is applied to the inductor for adjusting the phase of the antenna duplexer, the present invention is also applicable to the inductor for the inductance coupling in the case of the bandpass filter as in the case of FIG. You can

(Embodiment 9) Embodiment 9 is shown in FIGS.
Shown in. The present embodiment is applied to the case of the anti-resonance inductance of the bandpass filter. Figure 1
7 shows a circuit diagram of a bandpass filter, 1 to 3 show dielectric coaxial resonators, and C _{1 to} C ₄ show capacitors. Substrate 22 below base substrate 22 that is a multilayer substrate
Electrode pattern 42 for forming inductor L on the upper surface of ₂
Is formed, and conduction is obtained with the ground electrode on the lower surface through a through hole 71 formed in the center of the electrode pattern 42.
In addition, the land 72 at the end of the electrode pattern 42 is connected to the substrate 2 through the through hole 73 formed in the upper substrate 22 _1.
It is designed to be connected to 2 ₁ surface circuits.

(Embodiment 10) FIGS. 19 and 20 show Embodiment 10 in which an inductor L ₁ and a capacitor C ₁ of a low pass filter are formed by an electrode pattern 42.
In this embodiment, the base substrate 22 is a multi-layer substrate having three layers, and the inductor L _{1 is provided on} the upper surface of the inner layer substrate 22 _2.
The electrode pattern 42 as a substrate is formed on the lower substrate 22 ₃
Electrode pattern 42 to form capacitor C ₁ on the upper surface of
Is formed. The capacitor C ₁ is the substrate 2
It is formed by the capacitance between the 2 ₃ electrode pattern 42 and the ground electrode on the lower surface.

The pattern 74 formed on the upper substrate 22 ₁ and one end of the electrode pattern 42 of the inner substrate 22 ₂ are connected via a through hole 75, and the other end of the electrode pattern 42 of the substrate 22 ₂ is connected to the substrate. The electrode pattern 42 of 22 ₃ is connected through a through hole 76.

Although the band elimination filter, the bandpass filter, the lowpass filter and the like have been described in the above embodiments, the present invention can also be applied to a highpass filter, and further, various filters of these types can be used. It is also applicable to the combination of. That is, when the filter is formed, the present invention can be applied by forming the L component and the C component by the pattern electrode in the form of an electrode film, not by the discrete component.

[0050]

According to the present invention, the dielectric coaxial resonator is mounted in a dielectric filter which is composed of an L component, a C component, a dielectric coaxial resonator, and the like and passes or blocks a signal in a predetermined frequency band. Conventionally, since the L component or the C component is patterned on the insulator in the form of an electrode film,
Unlike the case where discrete components are used when forming the L component or C component, the number of components can be reduced by forming the L component or C component as an electrode film pattern on the insulator. Therefore, there is an effect that the cost can be reduced.

In the second aspect, the insulator is formed of a multi-layer substrate, and the L component or the C component is patterned on the inner surface of the multi-layer substrate in the form of an electrode film. Since the parts and the patterns are irrelevant to each other in position, the dimension between the parts can be reduced. Therefore, the size can be reduced as a whole, and a small dielectric filter can be realized.

[Brief description of drawings]

FIG. 1 is an exploded perspective view of an entire dielectric filter according to an embodiment of the present invention.

FIG. 2 is an equivalent circuit diagram of the dielectric filter shown in FIG. 1 of the present invention.

FIG. 3 is an explanatory diagram of a case where a part of the capacitor shown in FIG. 2 of the present invention is composed of discrete components.

FIG. 4 is an explanatory diagram showing an electrode pattern on a substrate according to a second embodiment of the present invention.

FIG. 5 is an explanatory diagram showing an electrode pattern on a substrate according to a third embodiment of the present invention.

FIG. 6 is an equivalent circuit diagram of a dielectric filter called an antenna duplexer according to a fourth embodiment of the present invention.

FIG. 7 is an exploded perspective view of a dielectric filter according to a fourth embodiment of the present invention.

FIG. 8 is a perspective view of a dielectric filter in a state where components of Example 4 of the present invention are mounted.

FIG. 9 is an equivalent circuit diagram of a bandpass filter according to a fifth embodiment of the present invention.

FIG. 10 is a cross-sectional view of the essential parts of Embodiment 6 of the present invention.

FIG. 11 is a perspective view of the essential parts of Embodiment 6 of the present invention.

FIG. 12 is an exploded perspective view of essential parts of Embodiment 6 of the present invention.

FIG. 13 is an equivalent circuit diagram of a band elimination filter according to a seventh embodiment of the present invention.

FIG. 14 is an exploded perspective view of a base substrate according to a seventh embodiment of the present invention.

FIG. 15 is a circuit diagram of an essential part of an antenna duplexer according to an eighth embodiment of the present invention.

FIG. 16 is an exploded perspective view of essential parts of Embodiment 8 of the present invention.

FIG. 17 is a circuit diagram of a bandpass filter according to a ninth embodiment of the present invention.

FIG. 18 is an exploded perspective view of essential parts of Embodiment 9 of the present invention.

FIG. 19 is a main part circuit diagram showing a part of a low-pass filter according to a tenth embodiment of the present invention.

FIG. 20 is an exploded perspective view of essential parts of Embodiment 10 of the present invention.

FIG. 21 is an equivalent circuit diagram of a band elimination filter.

FIG. 22 is a plan view of a conventional dielectric filter including discrete components.

[Explanation of symbols]

 1 to 7 dielectric coaxial resonator 22 base substrate 42 electrode pattern

Claims (2)

[Claims] 1. A dielectric filter comprising an L component, a C component, a dielectric coaxial resonator, etc., which passes or blocks a signal in a predetermined frequency band, wherein an L component is provided on an insulator on which the dielectric coaxial resonator is mounted. A dielectric filter characterized by patterning C to C components in the form of an electrode film. 2. The dielectric filter according to claim 1, wherein the insulator is composed of a multilayer substrate, and the L component or the C component is patterned on the inner surface of the multilayer substrate in the form of an electrode film.