Dual-passband duplexer

Abstract

The invention discloses a dual-passband duplexer, and belongs to the field of surface acoustic wave filters. The dual-passband duplexer comprises a dual-passband filter connected between the antenna end and the receiving end, and a dual-passband filter connected between the antenna end and the transmitting end; the dual-passband filter comprises a plurality of first series units and a plurality of second series units, the plurality of first series units are connected in series between the antenna end and the receiving end or the transmitting end, a node exists between every two adjacent first series units, and each node is grounded through one second series unit; the first series unit comprises an A-type series resonator and a B-type series resonator which are connected in series, and the resonant frequency of the A-type series resonator is smaller than that of the B-type series resonator; the second series unit comprises an A-type parallel resonator and a B-type parallel resonator which are connected in series, and the resonant frequency of the A-type parallel resonator is smaller than that of the B-type parallel resonator. According to the invention, the volume of the dual-passband duplexer body is greatly compressed.

Description

Technical Field

[0001] The invention belongs to the field of surface acoustic wave filters, and in particular relates to a dual-passband duplexer. Background Art

[0002] With the development and progress of modern microwave communication technology, the complexity and integration of communication system components have gradually increased, and higher requirements have been put forward for multi-functional RF receiving front ends. Single-passband filters cannot meet the application requirements of multi-band integration. Based on the application requirements of multi-band high-throughput in the passability environment, there is an increasing demand for low-loss, high-suppression dual-passband filters. Dual-passband filters that support multi-frequency point communications and can accurately select multi-band signals required by the system have become key components. Summary of the invention

[0003] The purpose of the present invention is to overcome the deficiencies of the prior art and provide a dual-passband duplexer.

[0004] The present invention is implemented by the following technical scheme: a dual-passband duplexer, comprising an antenna end, a receiving end and a transmitting end, the dual-passband duplexer further comprising two dual-passband filters, one of which is connected between the antenna end and the receiving end, and the other is connected between the antenna end and the transmitting end;

[0005] The dual-passband filter comprises a plurality of first series units and a plurality of second series units, wherein the plurality of first series units are connected in series between the antenna end and the receiving end or the transmitting end, a node is provided between two adjacent first series units, and each node is grounded via a second series unit;

[0006] Among them, the first series unit includes a type A series resonator and a type B series resonator connected in series, and the resonant frequency of the type A series resonator is lower than the resonant frequency of the type B series resonator; the second series unit includes a type A parallel resonator and a type B parallel resonator connected in series, and the resonant frequency of the type A parallel resonator is lower than the resonant frequency of the type B parallel resonator.

[0007] Furthermore, the dual-passband filter includes four first series units, three second series units and two ground terminals, wherein one second series unit is connected to one ground terminal, and the other two second series units are connected to the other ground terminal.

[0008] Furthermore, the ground terminals of the two dual-passband filters are not connected to a common ground.

[0009] Further, the dual-passband filter connected between the antenna end and the receiving end is a first dual-passband filter, and the first dual-passband filter includes a first A-type series resonator, a second A-type series resonator, a third A-type series resonator, a fourth A-type series resonator, a first B-type series resonator, a second B-type series resonator, a third B-type series resonator, a fourth B-type series resonator, a first A-type parallel resonator, a second A-type parallel resonator, a third A-type parallel resonator, a first B-type parallel resonator, a second B-type parallel resonator, a third B-type parallel resonator, a first ground terminal and a second ground terminal, and the first ground terminal and the second ground terminal are not grounded in common;

[0010] One end of the first A-type series resonator is connected to the antenna end, the other end of the first A-type series resonator is connected to one end of the first B-type series resonator, the other end of the first B-type series resonator is connected to one end of the second A-type series resonator, the other end of the second A-type series resonator is connected to one end of the second B-type series resonator, the other end of the second B-type series resonator is connected to one end of the third A-type series resonator, the other end of the third A-type series resonator is connected to one end of the third B-type series resonator, the other end of the third B-type series resonator is connected to one end of the fourth A-type series resonator, the other end of the fourth A-type series resonator is connected to one end of the fourth B-type series resonator, and the other end of the fourth B-type series resonator is connected to the receiving end;

[0011] One end of the first A-type parallel resonator is connected to a node between the first B-type series resonator and the second A-type series resonator, the other end of the first A-type parallel resonator is connected to one end of the first B-type parallel resonator, and the other end of the first B-type parallel resonator is connected to the first ground terminal; one end of the second A-type parallel resonator is connected to a node between the second B-type series resonator and the third A-type series resonator, the other end of the second A-type parallel resonator is connected to one end of the second B-type parallel resonator, and the other end of the second B-type parallel resonator is connected to the second ground terminal; one end of the third A-type parallel resonator is connected to a node between the third B-type series resonator and the fourth A-type series resonator, the other end of the third A-type parallel resonator is connected to one end of the third B-type parallel resonator, and the other end of the third B-type parallel resonator is connected to the second ground terminal.

[0012] Further, the dual-passband filter connected between the antenna end and the transmitting end is a second dual-passband filter, and the second dual-passband filter includes a fifth A-type series resonator, a sixth A-type series resonator, a seventh A-type series resonator, an eighth A-type series resonator, a fifth B-type series resonator, a sixth B-type series resonator, a seventh B-type series resonator, an eighth B-type series resonator, a fourth A-type parallel resonator, a fifth A-type parallel resonator, a sixth A-type parallel resonator, a fourth B-type parallel resonator, a fifth B-type parallel resonator, a sixth B-type parallel resonator, a third ground terminal and a fourth ground terminal, and the third ground terminal and the fourth ground terminal are not connected to the same ground;

[0013] One end of the fifth A-type series resonator is connected to the antenna end, the other end of the fifth A-type series resonator is connected to one end of the fifth B-type series resonator, the other end of the fifth B-type series resonator is connected to one end of the sixth A-type series resonator, the other end of the sixth A-type series resonator is connected to one end of the sixth B-type series resonator, the other end of the sixth B-type series resonator is connected to one end of the seventh A-type series resonator, the other end of the seventh A-type series resonator is connected to one end of the seventh B-type series resonator, the other end of the seventh B-type series resonator is connected to one end of the eighth A-type series resonator, the other end of the eighth A-type series resonator is connected to one end of the eighth B-type series resonator, and the other end of the eighth B-type series resonator is connected to the transmitting end;

[0014] One end of the fourth A-type parallel resonator is connected to a node between the fifth B-type series resonator and the sixth A-type series resonator, the other end of the fourth A-type parallel resonator is connected to one end of the fourth B-type parallel resonator, the other end of the fourth B-type parallel resonator is connected to the third ground terminal, one end of the fifth A-type parallel resonator is connected to a node between the sixth B-type series resonator and the seventh A-type series resonator, the other end of the fifth A-type parallel resonator is connected to one end of the fifth B-type parallel resonator, the other end of the fifth B-type parallel resonator is connected to the fourth ground terminal, one end of the sixth A-type parallel resonator is connected to a node between the seventh B-type series resonator and the eighth A-type series resonator, the other end of the sixth A-type parallel resonator is connected to one end of the sixth B-type parallel resonator, and the other end of the sixth B-type parallel resonator is connected to the fourth ground terminal.

[0015] Furthermore, the wavelength of the A-type series resonator is 2.588 um, the number of pairs of the A-type series resonator is 150 pairs, and the aperture of the A-type series resonator is 16 times the wavelength.

[0016] Further, the wavelength of the B-type series resonator is 1.746 um, the number of pairs of the B-type series resonator is 150 pairs, and the aperture of the B-type series resonator is 13.6 times the wavelength.

[0017] Compared with the prior art, the present invention has the following advantages and beneficial effects: the present invention uses resonators in series to form a dual-passband filter without losing performance, and then connects two dual-passband filters in parallel to form a dual-passband duplexer, which reduces the volume of the resonator, reduces the grounding terminals, and greatly compresses the volume of the dual-passband duplexer body. The dual-passband duplexer can be implemented on one layout, and has the advantage of low packaging cost compared to the dual-passband duplexer that is pieced together from two traditional layouts. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The drawings described herein are used to provide a further understanding of the embodiments of the present invention, constitute a part of this application, and do not constitute a limitation of the embodiments of the present invention. In the drawings:

[0019] Figure 1 A circuit schematic diagram of a dual-passband duplexer in the present invention;

[0020] Figure 2 A circuit schematic diagram of a type A series resonator;

[0021] Figure 3 A circuit schematic diagram of a B-type series resonator;

[0022] Figure 4 A circuit schematic diagram of a type A series resonator and a type B series resonator connected in series;

[0023] Figure 5 is the admittance curve of type A series resonator;

[0024] Figure 6 is the admittance curve of the B-type series resonator;

[0025] Figure 7 It is the admittance curve diagram after the A-type series resonator and the B-type series resonator are connected in series;

[0026] Figure 8 is an admittance curve diagram of a type A series resonator and a type A series resonator and a type B series resonator connected in series;

[0027] Fig. 9 A Q value curve diagram of an A-type series resonator and a series connection of an A-type series resonator and a B-type series resonator;

[0028] Fig.10 is an admittance curve diagram of a B-type series resonator and a series connection of an A-type series resonator and a B-type series resonator;

[0029] Fig.11 It is a Q value curve diagram of a B-type series resonator and a series connection of an A-type series resonator and a B-type series resonator;

[0030] Fig.12is an electrical performance curve diagram of the dual-passband duplexer of the present invention;

[0031] Fig.13 is a low frequency filter loss diagram of the first dual passband filter in the present invention;

[0032] Fig.14 is a high frequency filter loss diagram of the first dual-passband filter in the present invention;

[0033] Fig.15 is a low-frequency filter loss diagram of the second dual-passband filter in the present invention;

[0034] Fig.16 is a high frequency filter loss diagram of the second dual-passband filter in the present invention;

[0035] Fig.17 A circuit schematic diagram of a comparative example;

[0036] In the figure, 1—first port, 2—second port, 3—third port, 4—fourth port, 5—fifth port, 6—sixth port, 7—seventh port, 8—eighth port, 9—ninth port, SL1—first A-type series resonator, SL2—second A-type series resonator, SL3—third A-type series resonator, SL4—fourth A-type series resonator, SL5—fifth A-type series resonator, SL6—sixth A-type series resonator, SL7—seventh A-type series resonator, SL8—eighth A-type series resonator, SL9—ninth A-type series resonator, SL10—tenth A-type series resonator, SL11—eleventh A-type series resonator , SL12—twelfth A-type series resonator, SL13—thirteenth A-type series resonator, SL14—fourteenth A-type series resonator, SL15—fifteenth A-type series resonator, SL16—sixteenth A-type series resonator, SH1—first B-type series resonator, SH2—second B-type series resonator, SH3—third B-type series resonator, SH4—fourth B-type series resonator, SH5—fifth B-type series resonator, SH6—sixth B-type series resonator, SH7—seventh B-type series resonator, SH8—eighth B-type series resonator, SH9—ninth B-type series resonator, SH10—tenth B-type series resonator , SH11—eleventh B-type series resonator, SH12—twelfth B-type series resonator, SH13—thirteenth B-type series resonator, SH14—fourteenth B-type series resonator, SH15—fifteenth B-type series resonator, SH16—sixteenth B-type series resonator, PL1—first A-type parallel resonator, PL2—second A-type parallel resonator, PL3—third A-type parallel resonator, PL4—fourth A-type parallel resonator, PL5—fifth A-type parallel resonator, PL6—sixth A-type parallel resonator, PL7—seventh A-type parallel resonator, PL8—eighth A-type parallel resonator, PL9—ninth A-type parallel resonator , PL10—the tenth A-type parallel resonator, PL11—the eleventh A-type parallel resonator, PL12—the twelfth A-type parallel resonator, PH1—the first B-type parallel resonator, PH2—the second B-type parallel resonator, PH3—the third B-type parallel resonator, PH4—the fourth B-type parallel resonator, PH5—the fifth B-type parallel resonator, PH6—the sixth B-type parallel resonator, PH7—the seventh B-type parallel resonator, PH8—the eighth B-type parallel resonator, PH9—the ninth B-type parallel resonator, PH10—the tenth B-type parallel resonator, PH11—the eleventh B-type parallel resonator, PH12—the twelfth B-type parallel resonator. DETAILED DESCRIPTION

[0037] The technical solution of the present invention is further described below with reference to the accompanying drawings and through specific implementation methods.

[0038] Among them, the drawings are only used for illustrative explanations, and they only represent schematic diagrams rather than actual pictures, and should not be understood as limitations on the present invention. In order to better illustrate the embodiments of the present invention, some parts of the drawings may be omitted, enlarged or reduced, and do not represent the size of actual products. For those skilled in the art, it is understandable that some well-known structures and their descriptions in the drawings may be omitted.

[0039] The same or similar numbers in the drawings of the embodiments of the present invention correspond to the same or similar parts; in the description of the present invention, it should be understood that if the terms "upper", "lower", "left", "right", "inside", "outside", etc. appear to indicate the orientation or position relationship, it is based on the orientation or position relationship shown in the drawings, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, the terms describing the position relationship in the drawings are only used for illustrative purposes and cannot be understood as a limitation on the present invention. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0040] In the description of the present invention, unless otherwise clearly specified and limited, if the term "connection" or the like appears to indicate the connection relationship between components, the term should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two components or the interaction relationship between two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0041] like Figures 1 to 17 As shown, this embodiment discloses a dual-passband duplexer.

[0042] This embodiment discloses a dual-passband duplexer, such as Figure 1 As shown, the dual-passband duplexer includes two dual-passband filters, an antenna end, a receiving end and a transmitting end, wherein one dual-passband filter is connected between the antenna end and the receiving end, and the other dual-passband filter is connected between the antenna end and the transmitting end.

[0043] For example, the two dual-passband filters are respectively recorded as a first dual-passband filter and a second dual-passband filter, the first dual-passband filter is connected between the antenna end and the receiving end, and the second dual-passband filter is connected between the antenna end and the transmitting end.

[0044] The dual-passband filter includes a plurality of first series units and a plurality of second series units, wherein the plurality of first series units are connected in series between the antenna end and the receiving end or the transmitting end, a node exists between two adjacent first series units, and each node is grounded via a second series unit.

[0045] For example, the two dual-passband filters are respectively recorded as a first dual-passband filter and a second dual-passband filter, multiple first series units in the first dual-passband filter are connected in series between the antenna end and the receiving end, and multiple first series units in the second dual-passband filter are connected in series between the antenna end and the transmitting end.

[0046] The number of the first series units in the dual-passband filter is one more than the number of the second series units. For example, if the number of the first series units is four, the number of the second series units is three. The node between two adjacent first series units is connected to one end of a second series unit, and the other end of the second series unit is grounded, that is, the second series units are connected to the nodes one by one.

[0047] The first series unit includes an A-type series resonator and a B-type series resonator connected in series. For example, one end of the A-type series resonator is configured as a port of the first series unit, the other end of the A-type series resonator is connected to one end of the B-type series resonator, and the other end of the B-type series resonator is configured as another port of the first series unit. The resonant frequency of the A-type series resonator is less than the resonant frequency of the B-type series resonator. The circuit of the A-type series resonator is as follows: Figure 2 As shown, the circuit of the B-type series resonator is as follows Figure 3 As shown, the circuit after the A-type series resonator and the B-type series resonator are connected in series is as follows Figure 4 The second series unit includes an A-type parallel resonator and a B-type parallel resonator connected in series, the resonant frequency of the A-type parallel resonator is lower than the resonant frequency of the B-type parallel resonator, for example, one end of the A-type parallel resonator is configured as a port of the second series unit, the other end of the A-type parallel resonator is connected to one end of the B-type parallel resonator, and the other end of the B-type parallel resonator is configured as another port of the second series unit.

[0048] Figure 5 , Figure 6 and Figure 7 The horizontal axis is the frequency (in GHz), and the vertical axis is the admittance of the resonator (in dB). The wavelength of the A-type series resonator is 2.588um, the number of pairs of the A-type series resonator is 150 pairs, and the aperture of the A-type series resonator is 16 times the wavelength, such as Figure 5 As shown, the resonant frequency of the A-type series resonator is 1.49 GHz. The wavelength of the B-type series resonator is 1.746 um, the number of pairs of the B-type series resonator is 150 pairs, and the aperture of the B-type series resonator is 13.6 times the wavelength, as shown in Figure 6 As shown in Figure 1, the resonant frequency of the B-type series resonator is 2.157 GHz. After the A-type series resonator and the B-type series resonator are connected in series, their admittance curve becomes a double resonance curve, as shown in Figure 1. Figure 7As shown, the resonance peaks are at 1.525 GHz and 2.19 GHz respectively. Compared with the resonance frequency of a single resonator, the resonance frequency of the A-type series resonator and the B-type series resonator increases after cascading. According to the formula C=λ*f, when the wave velocity C of the resonator remains unchanged, the frequency f and the wavelength λ are inversely proportional, that is, the higher the frequency and the lower the wavelength, the smaller the corresponding resonator volume. Therefore, the A-type series resonator and the B-type series resonator can reduce the volume of the resonator after being connected in series, and the volume of the corresponding filter and duplexer is further reduced.

[0049] Figure 8 The horizontal axis is the frequency, the vertical axis is the admittance of the resonator, the dotted line in the figure is the admittance curve of the A-type series resonator, and the solid line is the admittance curve of the A-type series resonator and the B-type series resonator connected in series; Fig. 9 The horizontal axis is the frequency, and the vertical axis is the Q value of the resonator. The dotted line in the figure is the Q value curve of the A-type series resonator, and the solid line is the Q value curve of the A-type series resonator and the B-type series resonator in series. It can be seen from the admittance curve that after the two resonators (A-type series resonator and B-type series resonator) are connected in series, their resonant frequency moves to high frequency. Under the same sound speed conditions, the wavelength of the resonator in series with the same resonant frequency is smaller, which helps to reduce the size of the filter. From the Q value curve, the Q value curve becomes narrower after the two resonators are connected in series, but the maximum value of the Q value does not change, which is conducive to the realization of a high steepness filter.

[0050] Fig.10 The horizontal axis is the frequency, the vertical axis is the admittance of the resonator, the dotted line in the figure is the admittance curve of the B-type series resonator, and the solid line is the admittance curve of the A-type series resonator and the B-type series resonator connected in series; Fig.11 The horizontal axis is the frequency, and the vertical axis is the Q value of the resonator. The dotted line in the figure is the Q value curve of the B-type series resonator, and the solid line is the Q value curve of the A-type series resonator and the B-type series resonator in series. It can be seen from the admittance curve that after the two resonators are connected in series, their resonant frequency moves to high frequency. Under the same sound speed conditions, the wavelength of the resonator in series with the same resonant frequency is smaller, which helps to reduce the size of the filter. From the Q value curve, after the two resonators are connected in series, their Q value curve remains basically unchanged, that is, for high-frequency filters, the two resonators connected in series do not affect the performance of a single filter.

[0051] In some implementations of this embodiment, the dual-passband filter includes four first series units, three second series units and two ground terminals, the four first series units are connected in series between the antenna terminal and the receiving end or the transmitting end, wherein one second series unit is connected to one ground terminal, and the other two second series units are each connected to another ground terminal.

[0052] In some implementations of this embodiment, the ground terminals of the two dual passband filters are not grounded. Each dual passband filter has two ground terminals, and a dual passband duplexer has four ground terminals, and the four ground terminals of the dual passband duplexer are not grounded.

[0053] The scheme of this embodiment is further illustrated by an example below. The dual-passband duplexer in this example includes a first port, a second port, a third port, a first dual-passband filter and a second dual-passband filter. The first port 1 is the antenna end, the second port 2 is the receiving end, and the third port 3 is the transmitting end.

[0054] like Figure 1 As shown, the first dual-passband filter includes a plurality of A-type series resonators, a plurality of B-type series resonators, a plurality of A-type parallel resonators, a plurality of B-type parallel resonators, a first ground terminal and a second ground terminal, the resonant frequency of the A-type series resonator is less than the resonant frequency of the B-type series resonator, and the resonant frequency of the A-type parallel resonator is less than the resonant frequency of the B-type parallel resonator. The plurality of A-type series resonators include a first A-type series resonator SL1, a second A-type series resonator SL2, a third A-type series resonator SL3 and a fourth A-type series resonator SL4, the plurality of B-type series resonators include a first B-type series resonator SH1, a second B-type series resonator SH2, a third B-type series resonator SH3 and a fourth B-type series resonator SH4, the plurality of A-type parallel resonators include a first A-type parallel resonator PL1, a second A-type parallel resonator PL2 and a third A-type parallel resonator PL3, and the plurality of B-type parallel resonators include a first B-type parallel resonator PH1, a second B-type parallel resonator PH2 and a third B-type parallel resonator PH3.

[0055] One end of the first A-type series resonator SL1 is connected to the antenna end, the other end of the first A-type series resonator SL1 is connected to one end of the first B-type series resonator SH1, the other end of the first B-type series resonator SH1 is connected to one end of the second A-type series resonator SL2, the other end of the second A-type series resonator SL2 is connected to one end of the second B-type series resonator SH2, the other end of the second B-type series resonator SH2 is connected to one end of the third A-type series resonator SL3, the other end of the third A-type series resonator SL3 is connected to one end of the third B-type series resonator SH3, the other end of the third B-type series resonator SH3 is connected to one end of the fourth A-type series resonator SL4, the other end of the fourth A-type series resonator SL4 is connected to one end of the fourth B-type series resonator SH4, and the other end of the fourth B-type series resonator SH4 is connected to the receiving end.

[0056] One end of the first A-type parallel resonator PL1 is connected to the node between the first B-type series resonator SH1 and the second A-type series resonator SL2, the other end of the first A-type parallel resonator PL1 is connected to one end of the first B-type parallel resonator PH1, and the other end of the first B-type parallel resonator PH1 is connected to the first ground terminal; one end of the second A-type parallel resonator PL2 is connected to the node between the second B-type series resonator SH2 and the third A-type series resonator SL3, the other end of the second A-type parallel resonator PL2 is connected to one end of the second B-type parallel resonator PH2, and the other end of the second B-type parallel resonator PH2 is connected to the second ground terminal; one end of the third A-type parallel resonator PL3 is connected to the node between the third B-type series resonator SH3 and the fourth A-type series resonator SL4, the other end of the third A-type parallel resonator PL3 is connected to one end of the third B-type parallel resonator PH3, and the other end of the third B-type parallel resonator PH3 is connected to the second ground terminal.

[0057] The second dual-passband filter includes a plurality of A-type series resonators, a plurality of B-type series resonators, a plurality of A-type parallel resonators, a plurality of B-type parallel resonators, a third ground terminal and a fourth ground terminal, the resonant frequency of the A-type series resonator is less than the resonant frequency of the B-type series resonator, and the resonant frequency of the A-type parallel resonator is less than the resonant frequency of the B-type parallel resonator. The plurality of A-type series resonators include a fifth A-type series resonator SL5, a sixth A-type series resonator SL6, a seventh A-type series resonator SL7 and an eighth A-type series resonator SL8, the plurality of B-type series resonators include a fifth B-type series resonator SH5, a sixth B-type series resonator SH6, a seventh B-type series resonator SH7 and an eighth B-type series resonator SH8, the plurality of A-type parallel resonators include a fourth A-type parallel resonator PL4, a fifth A-type parallel resonator PL5 and a sixth A-type parallel resonator PL6, and the plurality of B-type parallel resonators include a fourth B-type parallel resonator PH4, a fifth B-type parallel resonator PH5 and a sixth B-type parallel resonator PH6.

[0058] One end of the fifth A-type series resonator SL5 is connected to the antenna end, the other end of the fifth A-type series resonator SL5 is connected to one end of the fifth B-type series resonator SH5, the other end of the fifth B-type series resonator SH5 is connected to one end of the sixth A-type series resonator SL6, the other end of the sixth A-type series resonator SL6 is connected to one end of the sixth B-type series resonator SH6, the other end of the sixth B-type series resonator SH6 is connected to one end of the seventh A-type series resonator SL7, the other end of the seventh A-type series resonator SL7 is connected to one end of the seventh B-type series resonator SH7, the other end of the seventh B-type series resonator SH7 is connected to one end of the eighth A-type series resonator SL8, the other end of the eighth A-type series resonator SL8 is connected to one end of the eighth B-type series resonator SH8, and the other end of the eighth B-type series resonator SH8 is connected to the transmitting end.

[0059] One end of the fourth A-type parallel resonator PL4 is connected to the node between the fifth B-type series resonator SH5 and the sixth A-type series resonator SL6, the other end of the fourth A-type parallel resonator PL4 is connected to one end of the fourth B-type parallel resonator PH4, the other end of the fourth B-type parallel resonator PH4 is connected to the third ground terminal, one end of the fifth A-type parallel resonator PL5 is connected to the node between the sixth B-type series resonator SH6 and the seventh A-type series resonator SL7, the other end of the fifth A-type parallel resonator PL5 is connected to one end of the fifth B-type parallel resonator PH5, the other end of the fifth B-type parallel resonator PH5 is connected to the fourth ground terminal, one end of the sixth A-type parallel resonator PL6 is connected to the node between the seventh B-type series resonator SH7 and the eighth A-type series resonator SL8, the other end of the sixth A-type parallel resonator PL6 is connected to one end of the sixth B-type parallel resonator PH6, and the other end of the sixth B-type parallel resonator PH6 is connected to the fourth ground terminal.

[0060] The first ground terminal, the second ground terminal, the third ground terminal and the fourth ground terminal are not grounded together. In this embodiment, the two ground terminals in the same dual-passband filter are not grounded together, which can make the layout more reasonable and symmetrical. At the same time, adding ground terminals can increase heat dissipation and improve power capacity; the four ground terminals in the dual-passband duplexer are not grounded together, which can increase heat dissipation and improve power capacity.

[0061] from Figure 1 It can be seen that the first dual-passband filter has only two grounding terminals, and the second dual-passband filter also has only two grounding terminals. The dual-passband duplexer has a total of four grounding terminals, which greatly reduces the number of grounding terminals, reduces crosstalk between grounding terminals, and increases device reliability.

[0062] Fig.12The electrical performance curve of the dual-passband duplexer is shown. The horizontal axis is the frequency, and the vertical axis is the transmission curve of the filter. The solid line is the curve of the first dual-passband filter. The two passbands of the first dual-passband filter are both the receiving end of the duplexer. The dotted line is the curve of the second dual-passband filter. The two passbands of the second dual-passband filter are both the transmitting end of the duplexer. Fig.12 It can be seen that the duplexer in this embodiment has the advantages of low loss, small size and high reliability.

[0063] Fig.13 , Fig.14 , Fig.15 and Fig.16 for Fig.12 The enlarged view of the mid-passband, the horizontal axis is the frequency, and the vertical axis is the transmission curve of the filter. Fig.13 This is the loss diagram of the low-frequency filter in the first dual-passband filter. It can be seen that its passband loss is within 1dB; Fig.14 This is the loss diagram of the high frequency filter in the first dual passband filter. It can be seen that its passband loss is within 1.5dB; Fig.15 This is the loss diagram of the low-frequency filter in the second dual-passband filter. It can be seen that its passband loss is within 1dB; Fig.16 This is the loss diagram of the high frequency filter in the second dual-passband filter. It can be seen that its passband loss is within 1dB.

[0064] Fig.17A comparative circuit is given, and the dual-passband duplexer shown in the comparative example is composed of two separate duplexers connected in parallel. The fourth port 4 is the antenna end of the first duplexer, the fifth port 5 is the receiving end of the first duplexer, and the sixth port 6 is the transmitting end of the first duplexer. The ninth A-type series resonator SL9, the tenth A-type series resonator SL10, the eleventh A-type series resonator SL11, the twelfth A-type series resonator SL12, the seventh A-type parallel resonator PL7, the eighth A-type parallel resonator PL8 and the ninth A-type parallel resonator PL9 constitute a filter located between the antenna end and the receiving end of the first duplexer, and the thirteenth A-type series resonator SL13, the fourteenth A-type series resonator SL14, the fifteenth A-type series resonator SL15, the sixteenth A-type series resonator SL16, the tenth A-type parallel resonator PL10, the eleventh A-type parallel resonator PL11 and the twelfth A-type parallel resonator PL12 constitute a filter located between the antenna end and the transmitting end of the first duplexer. The seventh port 7 is the antenna end of the second duplexer, the eighth port 8 is the receiving end of the second duplexer, the ninth port 9 is the transmitting end of the second duplexer, the ninth B-type series resonator SH9, the tenth B-type series resonator SH10, the eleventh B-type series resonator SH11, the twelfth B-type series resonator SH12, the seventh B-type parallel resonator PH7, the eighth B-type parallel resonator PH8 and the ninth B-type parallel resonator PH9 constitute a filter located between the antenna end and the receiving end of the second duplexer, the thirteenth B-type series resonator SH13, the fourteenth B-type series resonator SH14, the fifteenth B-type series resonator SH15, the sixteenth B-type series resonator SH16, the tenth B-type parallel resonator PL10, the eleventh B-type parallel resonator PL11 and the twelfth B-type parallel resonator PL12 constitute a filter located between the antenna end and the transmitting end of the second duplexer. The fourth port 4 is connected to the seventh port 7, the fifth port 5 is connected to the eighth port 8, and the sixth port 6 is connected to the ninth port 9. That is, the dual-passband duplexer in the comparative example is composed of two separate duplexers, but the ports are connected together. This dual-passband duplexer is large in size, and the two duplexers need to be packaged together in the package, which increases the packaging cost and difficulty.

[0065] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A dual-passband duplexer, comprising an antenna end, a receiving end and a transmitting end, characterized in that: The dual-passband duplexer further includes two dual-passband filters, one of which is connected between the antenna end and the receiving end, and the other is connected between the antenna end and the transmitting end; The dual-passband filter comprises a plurality of first series units and a plurality of second series units, wherein the plurality of first series units are connected in series between the antenna end and the receiving end or the transmitting end, a node is provided between two adjacent first series units, and each node is grounded via a second series unit; Among them, the first series unit includes a type A series resonator and a type B series resonator connected in series, and the resonant frequency of the type A series resonator is lower than the resonant frequency of the type B series resonator; the second series unit includes a type A parallel resonator and a type B parallel resonator connected in series, and the resonant frequency of the type A parallel resonator is lower than the resonant frequency of the type B parallel resonator.

2. A dual passband duplexer according to claim 1, characterized in that: The dual-passband filter comprises four first series units, three second series units and two ground terminals, wherein one second series unit is connected to one ground terminal, and the other two second series units are connected to the other ground terminal.

3. A dual passband duplexer according to claim 2, characterized in that: The ground terminals of the two dual-passband filters are not grounded in common.

4. The dual-passband duplexer according to claim 1, characterized in that: The dual-passband filter connected between the antenna end and the receiving end is a first dual-passband filter, and the first dual-passband filter includes a first A-type series resonator, a second A-type series resonator, a third A-type series resonator, a fourth A-type series resonator, a first B-type series resonator, a second B-type series resonator, a third B-type series resonator, a fourth B-type series resonator, a first A-type parallel resonator, a second A-type parallel resonator, a third A-type parallel resonator, a first B-type parallel resonator, a second B-type parallel resonator, a third B-type parallel resonator, a first ground terminal and a second ground terminal, and the first ground terminal and the second ground terminal are not grounded in common; One end of the first A-type series resonator is connected to the antenna end, the other end of the first A-type series resonator is connected to one end of the first B-type series resonator, the other end of the first B-type series resonator is connected to one end of the second A-type series resonator, the other end of the second A-type series resonator is connected to one end of the second B-type series resonator, the other end of the second B-type series resonator is connected to one end of the third A-type series resonator, the other end of the third A-type series resonator is connected to one end of the third B-type series resonator, the other end of the third B-type series resonator is connected to one end of the fourth A-type series resonator, the other end of the fourth A-type series resonator is connected to one end of the fourth B-type series resonator, and the other end of the fourth B-type series resonator is connected to the receiving end; One end of the first A-type parallel resonator is connected to a node between the first B-type series resonator and the second A-type series resonator, the other end of the first A-type parallel resonator is connected to one end of the first B-type parallel resonator, and the other end of the first B-type parallel resonator is connected to a first ground terminal; One end of the second A-type parallel resonator is connected to a node between the second B-type series resonator and the third A-type series resonator, the other end of the second A-type parallel resonator is connected to one end of the second B-type parallel resonator, and the other end of the second B-type parallel resonator is connected to the second ground terminal; One end of the third A-type parallel resonator is connected to the node between the third B-type series resonator and the fourth A-type series resonator, the other end of the third A-type parallel resonator is connected to one end of the third B-type parallel resonator, and the other end of the third B-type parallel resonator is connected to the second ground terminal.

5. The dual-passband duplexer according to claim 1, characterized in that: The dual-passband filter connected between the antenna end and the transmitting end is a second dual-passband filter, and the second dual-passband filter includes a fifth A-type series resonator, a sixth A-type series resonator, a seventh A-type series resonator, an eighth A-type series resonator, a fifth B-type series resonator, a sixth B-type series resonator, a seventh B-type series resonator, an eighth B-type series resonator, a fourth A-type parallel resonator, a fifth A-type parallel resonator, a sixth A-type parallel resonator, a fourth B-type parallel resonator, a fifth B-type parallel resonator, a sixth B-type parallel resonator, a third ground terminal and a fourth ground terminal, and the third ground terminal and the fourth ground terminal are not connected to the same ground; One end of the fifth A-type series resonator is connected to the antenna end, the other end of the fifth A-type series resonator is connected to one end of the fifth B-type series resonator, the other end of the fifth B-type series resonator is connected to one end of the sixth A-type series resonator, the other end of the sixth A-type series resonator is connected to one end of the sixth B-type series resonator, the other end of the sixth B-type series resonator is connected to one end of the seventh A-type series resonator, the other end of the seventh A-type series resonator is connected to one end of the seventh B-type series resonator, the other end of the seventh B-type series resonator is connected to one end of the eighth A-type series resonator, the other end of the eighth A-type series resonator is connected to one end of the eighth B-type series resonator, and the other end of the eighth B-type series resonator is connected to the transmitting end; One end of the fourth A-type parallel resonator is connected to a node between the fifth B-type series resonator and the sixth A-type series resonator, the other end of the fourth A-type parallel resonator is connected to one end of the fourth B-type parallel resonator, the other end of the fourth B-type parallel resonator is connected to the third ground terminal, one end of the fifth A-type parallel resonator is connected to a node between the sixth B-type series resonator and the seventh A-type series resonator, the other end of the fifth A-type parallel resonator is connected to one end of the fifth B-type parallel resonator, the other end of the fifth B-type parallel resonator is connected to the fourth ground terminal, one end of the sixth A-type parallel resonator is connected to a node between the seventh B-type series resonator and the eighth A-type series resonator, the other end of the sixth A-type parallel resonator is connected to one end of the sixth B-type parallel resonator, and the other end of the sixth B-type parallel resonator is connected to the fourth ground terminal.

6. The dual-passband duplexer according to claim 1, characterized in that: The wavelength of the A-type series resonator is 2.588um, the number of pairs of the A-type series resonator is 150 pairs, and the aperture of the A-type series resonator is 16 times the wavelength.

7. The dual-passband duplexer according to claim 1, characterized in that: The wavelength of the B-type series resonator is 1.746 um, the number of pairs of the B-type series resonator is 150 pairs, and the aperture of the B-type series resonator is 13.6 times the wavelength.

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