CN107681990B

CN107681990B - Multimode LTCC filter

Info

Publication number: CN107681990B
Application number: CN201710875023.0A
Authority: CN
Inventors: 吴珺; 钱许芸; 唐雄心; 金娇
Original assignee: Jiaxing Glead Electronics Co ltd; Jiaxing Vocational and Technical College
Current assignee: Jiaxing Glead Electronics Co ltd; Jiaxing Vocational and Technical College
Priority date: 2017-09-25
Filing date: 2017-09-25
Publication date: 2023-06-27
Anticipated expiration: 2037-09-25
Also published as: CN107681990A

Abstract

The present utility model relates generally to a bandpass filter used in a microwave communication system, and more particularly, to a bandpass filter designed and manufactured by using a multimode technology. A multimode LTCC filter, comprising: a laminated body formed by a plurality of insulating medium layers laminated together along the lamination direction, wherein the surface of the laminated body is provided with an external input electrode output electrode and an external grounding electrode; 3 LC resonators connected in parallel, wherein the resonators are connected with external input and output electrodes and an external grounding electrode; two coupling capacitors; and two grounding shielding layers respectively connected with the external grounding electrode. The utility model makes the return loss waveform of the third-order filter generate 4 wave peaks through the multi-mode design, widens the pass band width and deepens the stop band inhibition.

Description

Multimode LTCC filter

Technical Field

The utility model mainly relates to a band-pass filter used in a microwave communication system, in particular to a band-pass filter designed and manufactured by adopting an LTCC technology.

Background

The conventional LTCC filter mainly comprises a resonator, a coupling between the resonator and the resonator, and n wave peaks of a return loss characteristic curve corresponding to the n-order filter are generally n.

As an example of such an LTCC filter, fig. 4 shows a frequency characteristic diagram of a conventional third order LTCC filter. In fig. 4, a characteristic curve S11 represents return loss, having three peaks; the characteristic S12 represents the transmission, including a passband and a stopband, with a transition of frequency from the stopband to the passband. Obviously, as shown in fig. 6, due to the limitation of the electrical principle of the third-order filter, the width of the passband is limited, the transition frequency from the passband to the stopband is wider, and the stopband is not deeply suppressed. However, the existing multimode filter, such as a filter with a ladder impedance resonator structure, can widen the bandwidth and deepen and inhibit the bandwidth, but has large product size and cannot be miniaturized, which brings great limitation to practical application.

Disclosure of Invention

In order to solve the problem of the LTCC filter, the present utility model provides a multimode third-order resonant filter, which adopts a multimode design scheme, increases the passband width, reduces the frequency transition from passband to stopband, and deepens stopband suppression.

In order to achieve the above purpose, the present utility model adopts the following technical scheme:

a multimode LTCC filter, the multimode LTCC filter comprising:

the laminated body comprises a plurality of insulating medium layers laminated together along the lamination direction, and the surface of the laminated body is provided with an external input electrode, an external output electrode and an external grounding electrode;

the three LC resonators are respectively a resonator A, a resonator B and a resonator C, wherein the resonator A, the resonator B and the resonator C are respectively connected with an external grounding electrode, and the resonator A and the resonator C are respectively connected with one of an external input electrode and an external output electrode;

two coupling capacitors;

two ground shield layers connected to the external ground electrode, respectively;

two multimode adjusting layers.

Preferably, each LC resonator described above is composed of 3 inductors and 2 capacitors connected in parallel;

the 3 inductor patterns are arranged on the 3 insulating medium layers and are connected through an external grounding electrode;

the 2 capacitor patterns are opposite to the 2 ground shield patterns.

As a preferred embodiment: the patterns of resonator a, resonator B and resonator C are arranged in 5 identical insulating medium layers.

As a preferred technical scheme: the laminated body consists of 9 insulating medium layers, namely an insulating medium layer A, an insulating medium layer B, an insulating medium layer C, an insulating medium layer D, an insulating medium layer E, an insulating medium layer F, an insulating medium layer G, an insulating medium layer H and an insulating medium layer I from bottom to top; the inductor patterns and the capacitor patterns of the resonator A, the resonator B and the resonator C are respectively horizontally arranged, the inductor patterns are arranged on the insulating medium layer C, the insulating medium layer E and the insulating medium layer G, and the capacitor patterns are arranged on the insulating medium layer A, the insulating medium layer C, the insulating medium layer G and the insulating medium layer I.

As a preferred embodiment: in the above technical solution, the inductor patterns on the resonator a and the resonator C are respectively connected with one of the external input electrode and the external output electrode.

As a preferred embodiment: the first pattern on the insulating dielectric layer, the second pattern on the insulating dielectric layer, and the third pattern on the insulating dielectric layer are connected by an external ground electrode to form 3 inductors of the resonator a; the first pattern on the insulating dielectric layer is opposite to the first capacitor pattern on the insulating dielectric layer, the third pattern on the insulating dielectric layer is opposite to the second capacitor pattern on the insulating dielectric layer, and the first pattern and the second pattern are connected through an external grounding electrode to form 2 capacitors of the resonator A;

the fourth pattern on the insulating dielectric layer, the fifth pattern on the insulating dielectric layer, and the sixth pattern on the insulating dielectric layer are connected through an external ground electrode to form 3 inductors of the resonator B; the fourth pattern on the insulating dielectric layer is opposite to the first capacitor pattern on the insulating dielectric layer, the sixth pattern on the insulating dielectric layer is opposite to the second capacitor pattern on the insulating dielectric layer, and the fourth pattern and the second pattern are connected through an external ground electrode to form 2 capacitors of the resonator B;

the seventh pattern on the insulating dielectric layer, the eighth pattern on the insulating dielectric layer, the ninth pattern on the insulating dielectric layer are connected through an external ground electrode to form 3 inductors of the resonator C; the seventh pattern on the insulating dielectric layer 102 is opposite to the first capacitor pattern on the insulating dielectric layer, the ninth pattern on the insulating dielectric layer is opposite to the second capacitor pattern on the insulating dielectric layer, and the seventh pattern and the second capacitor pattern are connected through an external ground electrode, thereby forming 2 capacitors of the resonator C.

As a preferred embodiment: in the above technical solution, the first coupling capacitor pattern is disposed on the insulating dielectric layer E, the insulating dielectric layer F, and the insulating dielectric layer G, and the first coupling capacitor pattern is opposite to the capacitors of the resonators a and B, so as to form a coupling capacitance between the resonators a and B. In the above technical solution, the second coupling capacitor pattern is disposed on the insulating dielectric layer C, the insulating dielectric layer D, and the insulating dielectric layer E, and the second coupling capacitor pattern is opposite to the capacitors of the resonator B and the resonator C, so as to form a coupling capacitance between the resonator B and the resonator C.

As a preferred embodiment: in the above technical solution, two ground shielding layer patterns are respectively disposed on the insulating medium a and the insulating medium I, and are respectively connected with external ground electrodes.

As a preferred embodiment: in the above technical solution, two multimode adjusting layer patterns are respectively disposed on the insulating medium B and the insulating medium H.

In the technical scheme, each pattern coated on the insulating medium layer is a metal conductor.

According to the design of the utility model, as shown in fig. 1 and 5, resonator a and resonator B are horizontally positioned adjacently, and are coupled by a coupling capacitor to form coupling 1; the horizontal positions of the resonator B and the resonator C are adjacent, and the resonator B and the resonator C are coupled through a coupling capacitor to form coupling 2; after adding multiple layers, the resonator D is added, and the coupling is generated between the resonator C and the resonator D to form the coupling 3. Therefore, as shown in fig. 3, the echo loss waveform corresponding to the multimode three-order LTCC filter generates 4 peaks, so that the passband width is widened, the frequency transition between the stopband and the passband is reduced, and the stopband suppression is deepened. On the other hand, since the LTCC process is used, the size of the device can be absolutely miniaturized.

Drawings

FIG. 1 is an exploded perspective view of a multimode, third order LTCC filter in accordance with a preferred embodiment of the present utility model;

fig. 2 is an exploded perspective view of a conventional third-order LTCC filter;

FIG. 3 is a frequency characteristic diagram of the multimode, third-order LTCC filter of FIG. 1;

fig. 4 is a frequency characteristic diagram of the conventional third-order LTCC filter shown in fig. 2;

FIG. 5 is an equivalent electrical schematic diagram of the multimode, third order LTCC filter of FIG. 1;

fig. 6 to 8 are equivalent electrical schematic diagrams of the resonator a, the resonator B, and the resonator C, respectively;

fig. 9 to 10 are equivalent electrical schematic diagrams of two coupling capacitors, respectively;

FIG. 11 is an equivalent electrical schematic diagram of the conventional third order LTCC filter of FIG. 2;

fig. 12 is a schematic diagram of the external surface structure of the multimode third-order LTCC filter shown in fig. 1.

Detailed Description

Example 1 implemented in accordance with the present patent is described in detail below with reference to the accompanying drawings. Fig. 1 is an exploded perspective view of the filter of example 1, fig. 3 is a frequency characteristic diagram of the filter of example 1, fig. 5 is an equivalent electrical schematic diagram of the filter of example 1, and fig. 11 is a schematic view of an outer surface structure of the filter of example 1. In fig. 1, the hatched portion is a metal conductor, for example, ag, cu, au, or other metal compound, and is formed by printing, vapor coating, or other techniques.

A multimode LTCC filter as shown in fig. 1, 3, 5, 11, comprising: a laminated body 201 composed of 9 insulating dielectric layers, wherein the insulating

dielectric layers

100, 101, 102, 103, 104, 105, 106, 107, 108 are respectively arranged from bottom to top, and external input/

output electrodes

202, 203 and an external ground electrode 204 are arranged on the surface of the laminated body; 3 parallel LC resonators, namely a resonator a, a resonator B and a resonator C, respectively, connected with the external ground electrode 204, and connected with one of the external input and

output electrodes

202, 203, respectively; two coupling capacitors; two ground shield layers connected to the external ground electrode 204, respectively; two multimode adjusting layers.

As shown in fig. 6, the resonator a is composed of 3 inductors and 2 capacitors connected in parallel. The first pattern 1021 on the insulating medium layer 102, the second pattern 1041 on the insulating medium layer 104, and the third pattern 1061 on the insulating medium layer 106 are connected by the external ground electrode 204 to form 3 inductors of the resonator a; the first pattern on the insulating dielectric layer 102 is opposite to the first capacitor pattern 1001 on the insulating dielectric layer 100, the third pattern 1061 on the insulating dielectric layer 106 is opposite to the second capacitor pattern 1081 on the insulating dielectric layer 108, and the two capacitors of the resonator a are formed by connecting the external ground electrode 204. The inductor pattern 1041 on the insulating dielectric layer 104 is connected to the external input electrode 202 in fig. 7.

As shown in fig. 7, the resonator B is composed of 3 inductors and 2 capacitors connected in parallel. The fourth pattern 1022 on the insulating dielectric layer 102, the fifth pattern 1042 on the insulating dielectric layer 104, and the sixth pattern 1062 on the insulating dielectric layer 106 are connected by the external ground electrode 204 to form 3 inductors of the resonator B; the fourth pattern 1022 on the insulating dielectric layer 102 is opposite to the first capacitor pattern 1001 on the insulating dielectric layer 100, the sixth pattern 1062 on the insulating dielectric layer 106 is opposite to the second capacitor pattern 1081 on the insulating dielectric layer 108, and the second pattern is connected to the external ground electrode 204, thereby forming 2 capacitors of the resonator B.

As shown in fig. 8, the resonator C is composed of 3 inductors and 2 capacitors connected in parallel. The seventh pattern 1023 on the insulating dielectric layer 102, the eighth pattern 1043 on the insulating dielectric layer 104, and the ninth pattern 1063 on the insulating dielectric layer 106 are connected by the external ground electrode 204 to form 3 inductors of the resonator C; the seventh pattern 1023 on the insulating dielectric layer 102 is opposite to the first capacitor pattern 1001 on the insulating dielectric layer 100, the ninth pattern 1063 on the insulating dielectric layer 106 is opposite to the second capacitor pattern 1081 on the insulating dielectric layer 108, and the 2 capacitors of the resonator C are formed by being connected to the external ground electrode 204. The inductor pattern 1043 on the insulating dielectric layer 104 is connected to the external output electrode 203 in fig. 7.

As shown in fig. 9, in the above-described embodiment, the pattern 1051 on the insulating medium layer 105 is opposed to the

patterns

1041 and 1042 on the insulating medium layer 104, and is opposed to the

patterns

1061 and 1062 on the insulating medium layer 106, and a first coupling capacitance between the resonators a and B is formed. As shown in fig. 10, in the above-described embodiment, the pattern 1031 on the insulating medium layer 103 is opposed to the

patterns

1042 and 1043 on the insulating medium layer 104, and is opposed to the

patterns

1062 and 1063 on the insulating medium layer 102, and a second coupling capacitance between the resonators B and C is formed.

As shown in fig. 1, in the above-described embodiment, two

ground shield patterns

1001 and 1081 are disposed on the insulating dielectric layer 100 and the insulating dielectric layer 108, respectively, and are connected to the external ground electrode 204 in fig. 11, respectively.

As shown in fig. 1, in the above-described embodiment, two

multi-layer patterns

1011 and 1071 are respectively disposed on the insulating dielectric layer 101 and the insulating dielectric layer 107.

As shown in fig. 1 and 5, the resonators A, B are adjacent in a horizontal position, and coupling is generated between the resonators through coupling capacitors to form coupling 1; the resonators B, C are adjacent along the horizontal position, and coupling is generated between the resonators through the coupling capacitor to form coupling 2; resonator D is produced by a multimode design and a coupling is produced with resonator C to form coupling 3.

Fig. 2 is an exploded perspective view of a conventional third-order filter without a multimode layer, fig. 4 is a frequency characteristic diagram of the conventional third-order filter without a multimode layer, and fig. 3 is a frequency characteristic diagram of the filter of example 1. Therefore, after the multimode is added, 4 wave peaks are generated by the echo loss waveform corresponding to the third-order filter, so that the width of the pass band is widened, the frequency transition between the stop band and the pass band is reduced, and the stop band inhibition is deepened.

The LTCC filter of the present utility model is not limited to the above-described embodiments, and other similar structures are also within the scope of the present utility model.

Claims

1. A multimode LTCC filter, wherein the multimode LTCC filter comprises:

a laminated body (201) including a plurality of insulating dielectric layers laminated together in a lamination direction, the surface of which is provided with external input and output electrodes (202, 203) and an external ground electrode (204);

3 parallel LC resonators, namely a resonator A, a resonator B and a resonator C, wherein the resonator A, the resonator B and the resonator C are respectively connected with an external grounding electrode (204), and the resonator A and the resonator C are respectively connected with one of external input electrodes and external output electrodes (202 and 203);

two coupling capacitors;

two ground shield layers connected to the external ground electrode (204), respectively;

two multimode adjustment layers;

the LC resonator is formed by connecting 3 inductors and 2 capacitors in parallel; the inductor patterns of the 3 inductors are respectively arranged on the 3 insulating medium layers and are connected through an external grounding electrode (204); the capacitor pattern of 2 capacitors is opposite to the 2 ground shield patterns;

the patterns of the resonator A, the resonator B and the resonator C are arranged on 5 identical insulating medium layers;

the laminated body consists of 9 insulating medium layers, namely an insulating medium layer A (100), an insulating medium layer B (101), an insulating medium layer C (102), an insulating medium layer D (103), an insulating medium layer E (104), an insulating medium layer F (105), an insulating medium layer G (106), an insulating medium layer H (107) and an insulating medium layer I (108) from bottom to top; inductor patterns and capacitor patterns of the resonator A, the resonator B and the resonator C are respectively horizontally arranged, the inductor patterns are arranged on the insulating medium layer C (102), the insulating medium layer E (104) and the insulating medium layer G (106), and the capacitor patterns are arranged on the insulating medium layer A (100), the insulating medium layer C (102), the insulating medium layer G (106) and the insulating medium layer I (108);

the first pattern (1021) on the insulating medium layer (102), the second pattern (1041) on the insulating medium layer (104) and the third pattern (1061) on the insulating medium layer (106) are connected through the external ground electrode (204) to form 3 inductors of the resonator A; the first pattern on the insulating dielectric layer (102) is opposite to the first capacitor pattern (1001) on the insulating dielectric layer (100), the third pattern (1061) on the insulating dielectric layer (106) is opposite to the second capacitor pattern (1081) on the insulating dielectric layer (108), and the two patterns are connected through the external ground electrode (204) to form 2 capacitors of the resonator A;

a fourth pattern (1022) on the insulating dielectric layer (102), a fifth pattern (1042) on the insulating dielectric layer (104), and a sixth pattern (1062) on the insulating dielectric layer (106) are connected by an external ground electrode (204), thereby forming 3 inductors of the resonator B; the fourth pattern (1022) on the insulating dielectric layer (102) is opposite to the first capacitor pattern (1001) on the insulating dielectric layer (100), the sixth pattern (1062) on the insulating dielectric layer (106) is opposite to the second capacitor pattern (1081) on the insulating dielectric layer (108), and the fourth pattern and the first capacitor pattern are connected through the external ground electrode (204) to form 2 capacitors of the resonator B;

a seventh pattern (1023) on the insulating dielectric layer (102), an eighth pattern (1043) on the insulating dielectric layer (104), and a ninth pattern (1063) on the insulating dielectric layer (106) are connected by an external ground electrode (204), thereby forming 3 inductors of the resonator C; the seventh pattern 1023 on the insulating dielectric layer (102) is opposite to the first capacitor pattern (1001) on the insulating dielectric layer (100), the ninth pattern (1063) on the insulating dielectric layer (106) is opposite to the second capacitor pattern (1081) on the insulating dielectric layer (108), and the capacitors are connected by the external ground electrode (204) to form 2 capacitors of the resonator C.

2. A multimode LTCC filter as claimed in claim 1, characterized in that the inductor pattern on resonator a and resonator C is connected to one of the external input and output electrodes (202, 203), respectively.

3. A multimode LTCC filter as claimed in claim 1, wherein a first coupling capacitor pattern is disposed on the insulating dielectric layer E (104), the insulating dielectric layer F (105), and the insulating dielectric layer G (106), the first coupling capacitor pattern being opposite to the capacitors of the resonators a and B, and being formed as a coupling capacitance between the resonators a and B; the second coupling capacitor pattern is provided on the insulating dielectric layer C (102), the insulating dielectric layer D (103), and the insulating dielectric layer E (104), and faces the capacitors of the resonators B and C to form a coupling capacitance between the resonators B and C.

4. A multimode LTCC filter as claimed in claim 1, characterized in that two ground shield patterns are provided on the insulating medium a (100) and the insulating medium I (108), respectively, and are connected to the external ground electrode (204), respectively.

5. A multimode LTCC filter as claimed in claim 1, characterized in that the pattern of the two multimode tuning layers is respectively U-shaped, the U-shaped pattern being provided on the insulating medium B (101) and the insulating medium H (107), respectively.

6. A multimode LTCC filter as recited in any one of claims 1-5, wherein each pattern coated on the dielectric layer is a metallic conductor.