Multiplexer and radio frequency front-end module

Abstract

The invention discloses a multiplexer and a radio frequency front-end module, and relates to the technical field of radio frequency filtering. The multiplexer comprises an antenna port, a plurality of first filters, a first matching circuit and a second filter. Each first filter is connected to a first common node; the first matching circuit is connected in series between the first common node and the antenna port; the second filter is connected to the antenna port; wherein in a preset mode, the at least one first filter and the second filter transmit radio frequency signals at the same time, and the center frequency of the working frequency band of the second filter is higher than that of the working frequency band of the first filter. According to the invention, the number of matching elements can be reduced, and the CA performance of the multiplexer can be improved, so that the performance of the radio frequency front-end module is improved.

Description

Technical Field

[0001] This application relates to the field of radio frequency filtering technology, and in particular to a multiplexer and a radio frequency front-end module. Background Technology

[0002] A multiplexer typically consists of multiple transmit filters (TX filters) and multiple receive filters (RX filters). Taking a common quadruple multiplexer as an example, a quadruple multiplexer generally contains two TX filters and two RX filters. Multiplexers can be used in radio frequency front-end modules to filter received radio frequency signals and radio frequency signals to be transmitted.

[0003] In the background technology, the design of multiplexers is often based on the performance considerations of their individual filters. When applied in the Carrier Aggregation (CA) scenario, the mutual interference between different radio frequency signals will affect the performance of the multiplexer. Therefore, how to improve the CA performance of the multiplexer is an urgent problem to be solved. Summary of the Invention

[0004] This application provides a multiplexer and an RF front-end module that can improve the CA performance of the multiplexer while reducing the number of matching components, thereby improving the performance of the RF front-end module.

[0005] In a first aspect, this application provides a multiplexer, which includes an antenna port, a plurality of first filters, a first matching circuit, and a second filter; Each of the first filters is connected to the first common node; The first matching circuit is connected in series between the first common node and the antenna port; The second filter is connected to the antenna port; In the preset mode, at least one of the first filters and the second filter transmit radio frequency signals simultaneously, and the center frequency of the operating frequency band of the second filter is higher than the center frequency of the operating frequency band of the first filter.

[0006] Secondly, this application provides a multiplexer, which includes an antenna port, a plurality of first filters, a first matching circuit, a second filter, and a second matching circuit; Each of the first filters is connected to the first common node; The first matching circuit is connected in series between the first common node and the antenna port; The second filter is connected to the antenna port; One end of the second matching circuit is connected to the antenna port, and the other end of the second matching circuit is grounded; or, the second filter and the first matching circuit are both connected to the second common node, and the second matching circuit is connected in series between the second common node and the antenna port. In the preset mode, at least one of the first filters and the second filter transmit radio frequency signals simultaneously.

[0007] Thirdly, this application provides a multiplexer, which includes an antenna port, a plurality of first filters, a first matching circuit, and a second filter; Each of the first filters is connected to the first common node; The first matching circuit is connected in series between the first common node and the antenna port. The first matching circuit includes an inductive element and a second capacitive element. The inductive element is connected in series between the first common node and the antenna port. One end of the second capacitive element is connected to the first common node, and the other end of the second capacitive element is grounded. The second filter is connected to the antenna port; One end of the second matching circuit is connected to the antenna port, and the other end of the second matching circuit is grounded; or, the second filter and the first matching circuit are both connected to the second common node, and the second matching circuit is connected in series between the second common node and the antenna port. In the preset mode, at least one of the first filters and the second filter transmit radio frequency signals simultaneously.

[0008] Fourthly, this application provides a radio frequency front-end module, which includes the multiplexer as described above.

[0009] This application provides a multiplexer and an RF front-end module. The multiplexer includes an antenna port, multiple first filters, a first matching circuit, and a second filter. Each first filter is connected to a first common node. The first matching circuit is connected in series between the first common node and the antenna port. The second filter is connected to the antenna port. In a preset mode, at least one first filter and the second filter transmit RF signals simultaneously, and the center frequency of the operating frequency band of the second filter is higher than the center frequency of the operating frequency band of the first filter. Therefore, by setting the first matching circuit in series between the first common node and the antenna port, and controlling the center frequencies of the operating frequency bands of the first and second filters, when the RF signal transmitted by the multiplexer is carrier-aggregated with the target RF signal, the impedance phase of the antenna port to the target RF signal can be adjusted to the open-circuit region without adding a phase-shifting network. This ensures that the RF signal transmitted by the antenna port to the multiplexer does not leak into the signal transmission path of the target RF signal. This reduces the number of matching components while improving the CA performance of the multiplexer, thereby improving the performance of the RF front-end module. Attached Figure Description

[0010] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0011] Figure 1 This is a schematic block diagram of a multiplexer structure provided by related technologies; Figure 2 This is a schematic block diagram of a multiplexer provided in an embodiment of this application; Figure 3 This is a schematic diagram of the topology of a multiplexer provided in an embodiment of this application; Figure 4 This is a schematic diagram of the structure of a first filter and a first matching circuit provided in an embodiment of this application, and its corresponding Smith chart; Figure 5 This is a schematic diagram of the structure of a second filter provided in an embodiment of this application and its corresponding Smith chart; Figure 6 This is a schematic diagram of the structure of a multiplexer and its corresponding Smith chart provided in an embodiment of this application; Figure 7 This is a schematic block diagram of another multiplexer provided in the embodiments of this application; Figure 8 This is a schematic diagram of another multiplexer topology provided in an embodiment of this application; Figure 9 This is a schematic diagram of another multiplexer provided in the embodiments of this application and its corresponding Smith chart; Figure 10 yes Figure 9 A magnified view of a section of the Smith chart; Figure 11 This is a schematic diagram of another multiplexer topology provided in an embodiment of this application; Figure 12 This is a schematic diagram of another multiplexer provided in the embodiments of this application and its corresponding Smith chart; Figure 13 yes Figure 12 A magnified view of a section of the Smith chart; Figure 14 This is a schematic block diagram of another multiplexer provided in the embodiments of this application; Figure 15 This is a schematic diagram of another multiplexer topology provided in an embodiment of this application. Detailed Implementation

[0012] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0013] The flowchart shown in the attached diagram is for illustrative purposes only and does not necessarily include all content and operations / steps, nor does it necessarily have to be performed in the order described. For example, some operations / steps can be broken down, combined, or partially merged, so the actual execution order may change depending on the actual situation.

[0014] It should be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the scope of the application. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.

[0015] It should also be understood that the term “and / or” as used in this application specification and the appended claims means any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0016] The following detailed description of some embodiments of this application is provided in conjunction with the accompanying drawings. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0017] Please see Figure 1 , Figure 1 This is a structural schematic diagram of a multiplexer and its corresponding Smith chart provided by related technologies.

[0018] In related technologies, to meet its own performance requirements and simplify matching, multiplexers sometimes cause the impedance phase of the target RF signal at the multiplexer antenna port to be outside the open-circuit region during carrier aggregation of the multiplexer's transmitted RF signal and the target RF signal. Therefore, an additional phase-shifting network is needed to adjust the impedance phase of the antenna port relative to the target RF signal to the open-circuit region. For example... Figure 1 As shown, taking a quadrupler as an example, the quadruplers provided in related technologies generally use parallel inductor matching, which will cause the phase of the quadrupler's antenna port relative to the target RF signal to be outside the open circuit region. Therefore, a phase-shifting network needs to be added to move it to the open circuit region. However, the phase-shifting network generally contains 2-3 matching elements, and the use of additional components in the phase-shifting network will make the entire matching form more complicated and easily lead to the deterioration of the multiplexer's own performance in CA scenarios, that is, the deterioration of the multiplexer's CA performance.

[0019] To address the aforementioned issues, this application provides a multiplexer and an RF front-end module that can improve the CA performance of the multiplexer while reducing the number of matching components, thereby enhancing the performance of the RF front-end module.

[0020] Please see Figure 2 and Figure 3 , Figure 2 This application provides a schematic diagram of the structure of a multiplexer and its corresponding Smith chart. Figure 3 This is a schematic diagram of the topology of a multiplexer provided in an embodiment of this application.

[0021] like Figure 2 and Figure 3 As shown, the multiplexer 100 includes an antenna port ANT, multiple first filters 10, a first matching circuit 30, and a second filter 20; each first filter 10 is connected to a first common node n1; the first matching circuit 30 is connected in series between the first common node n1 and the antenna port ANT; and the second filter 20 is connected to the antenna port ANT.

[0022] For example, the multiplexer 100 may include a plurality of first filters 10. In this embodiment, the multiplexer 100 may be a triplexer, in which case the multiplexer 100 includes two first filters 10 and one second filter 20, and both first filters 10 are connected to a first common node n1; the multiplexer 100 may also be a quadruplexer, in which case the multiplexer 100 includes three first filters 10 and one second filter 20, and all three first filters 10 are connected to the first common node n1; the multiplexer 100 may also be a quintuplexer, in which case the multiplexer 100 includes four first filters 10 and one second filter 20, and all four first filters 10 are connected to the first common node n1. The number of filters in the multiplexer 100 can be set according to actual needs and is not specifically limited here.

[0023] For example, each first filter 10 can correspond to a radio frequency communication link, that is, the radio frequency communication links corresponding to multiple first filters 10 are all connected to the antenna port ANT via the first common node n1 and the first matching circuit 30. The second filter 20 is connected to the antenna port ANT, that is, the radio frequency communication link corresponding to the second filter 20 is not connected to the antenna port ANT via the first common node n1 and the first matching circuit 30.

[0024] For example, the multiple first filters 10 can each correspond to different wireless communication frequency bands. For instance, the operating frequency band of one first filter 10 may include a first wireless communication frequency band (e.g., band B1), and the operating frequency band of another first filter 10 may include a second wireless communication frequency band (e.g., band B3), without specific limitations. The operating frequency band of the second filter 20 may include the first wireless communication frequency band, the second wireless communication frequency band, or other wireless communication frequency bands, without specific limitations. Here, the operating frequency band of a filter can be understood as its passband.

[0025] In one implementation, the first matching circuit 30 includes at least an inductor, such as Figure 4As shown, the first matching circuit 30 is connected in series between the first common node n1 and the antenna port ANT. This means that at least one inductor is connected in series between the first common node n1 and the antenna port ANT. This ensures that when the first filter 10 is operating, the impedance phase of the antenna port ANT to the target RF signal is greater than 0°, without considering the influence of the second filter 20. In other words, for the antenna port ANT in the RF signal link where the first filter 10 is located, the first matching circuit 30 can adjust the impedance phase of the antenna port ANT to the target RF signal to be inductive. The target RF signal refers to the signal aggregated with the signal carrier transmitted by the multiplexer. For example, if the multiplexer is used to transmit signals in the B1 and B3 bands, and the signals in the B1, B3, and B41 bands are aggregated, the first matching circuit 30 can ensure that the impedance of the B41 band signal at the antenna port ANT is inductive when the first filter 10 is operating.

[0026] like Figure 5 As shown, the second filter 20 is directly connected to the antenna port ANT, ensuring that when the second filter is working, the impedance phase of the antenna port ANT to the target RF signal is less than 0° without considering the influence of the first filter 10. That is, for the antenna port ANT in the RF signal link where the second filter 20 is located, the impedance phase of the target RF signal is capacitive. Here, the target RF signal refers to the signal aggregated with the signal carrier transmitted by the multiplexer. For example, if the multiplexer is used to transmit signals in bands B1 and B3, and the signals in bands B1, B3, and B41 are aggregated, the second filter 20, being directly connected to the antenna port ANT, ensures that when the second filter 20 is working, the antenna port ANT exhibits a capacitive impedance phase to the B41 signal. Figure 5 The capacitive impedance phase is shown on the Smith chart on the right.

[0027] like Figure 6 As shown, when multiple first filters 10 are connected to the antenna port ANT via a first matching circuit 30, and the second filter 20 is not connected to the antenna port ANT via the first matching circuit 30, the impedance phase of the antenna port ANT with respect to the target frequency band can be adjusted to the open-circuit region, thereby improving the CA performance of the multiplexer. For example, when the second filter is used to process downlink signals in the B1 band, at least one first filter is used to process downlink signals in the B3 band, and the downlink signals in the B1 band, B3 band, and B41 band are carrier aggregated, the antenna port ANT presents the following to the downlink signal in the B41 band: Figure 6 The impedance phase near open circuit is shown on the Smith chart on the right.

[0028] In the preset mode, at least one first filter 10 and a second filter 20 transmit radio frequency signals simultaneously, and the center frequency of the operating frequency band of the second filter 20 is higher than the center frequency of the operating frequency band of the first filter 10.

[0029] For example, the preset mode may include a carrier aggregation mode, that is, in the carrier aggregation mode, at least one of the first filters 10 and the second filters 20 transmit radio frequency signals simultaneously, that is, at least one of the first filters 10 and the second filters 20 in the multiplexer 100 transmit radio frequency signals or receive radio frequency signals simultaneously, and the radio frequency signals transmitted through at least one first filter 10 and the radio frequency signals transmitted through the second filter 20 can be carrier aggregated.

[0030] For example, the center frequencies of the operating frequency bands corresponding to each first filter 10 and second filter 20 are generally different. In this embodiment, by controlling the center frequency of the operating frequency band of the second filter 20 to be higher than the center frequency of the operating frequency band of the first filter 10, the CA performance of the multiplexer 100 can be effectively improved, thereby improving the performance of the RF front-end module.

[0031] It should be noted that in non-preset modes (such as multi-band support mode, MIMO mode, and multi-standard coexistence mode), the first filter 10 and the second filter 20 may not transmit radio frequency signals simultaneously, that is, the radio frequency signal transmitted through the first filter 10 and the radio frequency signal transmitted through the second filter 20 do not perform carrier aggregation.

[0032] In this embodiment, by setting a first matching circuit 30 connected in series between the first common node n1 and the antenna port ANT, and controlling the center frequency of the operating frequency band of the first filter 10 and the second filter 20, when the RF signal transmitted by the multiplexer and the target RF signal carrier are aggregated, the impedance phase of the antenna port to the target RF signal can be adjusted to the open circuit region without adding a phase shifting network. This ensures that the RF signal transmitted by the antenna port to the multiplexer will not leak into the signal transmission path of the target RF signal. Thus, while reducing the number of matching components, the CA performance of the multiplexer can be improved, thereby improving the performance of the RF front-end module.

[0033] In some embodiments, the operating frequency band of at least one first filter 10 includes the uplink frequency band (TX) of a first wireless communication frequency band, and the operating frequency band of the second filter 20 includes the downlink frequency band (RX) of the first wireless communication frequency band.

[0034] For example, since the multiplexer 100 includes multiple first filters 10, at least one of the multiple first filters 10 operates in the uplink band of the first wireless communication band, and the second filter 20 operates in the downlink band of the first wireless communication band. Taking the first wireless communication band as the B1 band as an example, the operating frequency band of at least one first filter 10 is the uplink band of the B1 band, and the operating frequency band of the second filter 20 is the downlink band of the B1 band. That is, the operating frequency bands of at least one first filter 10 and the second filter 20 are the uplink and downlink bands of the same wireless communication band, respectively. This enables the impedance phase of the antenna port to the target RF signal to be adjusted to the open circuit region simply by setting the first matching circuit 30, ensuring that the RF signal transmitted from the antenna port to the multiplexer does not leak into the signal transmission path of the target RF signal. This reduces the number of matching components while improving the CA performance of the multiplexer 100, thereby improving the performance of the RF front-end module.

[0035] In some embodiments, the second filter 20 is a first receiving filter, and the operating frequency band of the first receiving filter includes the downlink frequency band of the first wireless communication frequency band; the plurality of first filters 10 include the second receiving filter, and the operating frequency band of the second receiving filter includes the downlink frequency band of the second wireless communication frequency band.

[0036] For example, the second filter 20 is a first receiving filter. The operating frequency band of the first receiving filter includes the downlink frequency band of the first wireless communication frequency band. Taking the first wireless communication frequency band as the B1 frequency band as an example, the operating frequency band of the first receiving filter includes the downlink frequency band of the B1 frequency band, which is a B1 RX filter. Multiple first filters 10 include second receiving filters. The operating frequency band of the second receiving filter includes the downlink frequency band of the second wireless communication frequency band. Taking the second wireless communication frequency band as the B3 frequency band as an example, the operating frequency band of the second receiving filter includes the downlink frequency band of the B3 frequency band, which is a B3 RX filter. Therefore, when the first and second receiving filters are operating in carrier aggregation mode and performing carrier aggregation with the target RF signal, the impedance phase of the antenna port to the target RF signal can be adjusted to the open-circuit region simply by setting the first matching circuit 30. This reduces the mutual interference between the signal transmission links of the multiplexer and the target RF signal, thereby improving the CA performance of the multiplexer 100 while reducing the number of matching components, and ultimately improving the performance of the RF front-end module.

[0037] It should be noted that in the embodiments of this application, the first filter 10 can be a transmitting filter or a receiving filter, and the second filter 20 is a receiving filter.

[0038] In some embodiments, the plurality of first filters 10 further include a first transmit filter and a second transmit filter, wherein the first transmit filter operates in the uplink band of a first wireless communication band, and the second transmit filter operates in the uplink band of a second wireless communication band.

[0039] For example, the first transmit filter operates in the uplink band of the first wireless communication band, and the second transmit filter operates in the uplink band of the second wireless communication band. Taking the first wireless communication band as B1 as an example, the first transmit filter operates in the uplink band of B1, i.e., it is a B1 TX filter; taking the second wireless communication band as B3 as an example, the second transmit filter operates in the uplink band of B3, i.e., it is a B3 TX filter. Therefore, when the first and second transmit filters operate in carrier aggregation mode and perform carrier aggregation with the target RF signal, the impedance phase of the antenna port to the target RF signal can be adjusted to the open-circuit region by setting the first matching circuit 30. This reduces the mutual interference between the signal transmission links of the multiplexer and the target RF signal, thereby reducing the number of matching components while improving the CA performance of the multiplexer 100, and ultimately improving the performance of the RF front-end module.

[0040] In some embodiments, in a first preset mode, the first receiving filter and the second receiving filter simultaneously transmit radio frequency signals; and / or, in a second preset mode, the first transmitting filter and the second transmitting filter simultaneously transmit radio frequency signals.

[0041] For example, the first preset mode is a carrier aggregation mode that can simultaneously receive radio frequency signals corresponding to different frequency bands. In the first preset mode, the first receiving filter and the second receiving filter in the multiplexer 100 simultaneously receive radio frequency signals, and the radio frequency signals received by the first receiving filter and the radio frequency signals received by the second receiving filter can perform carrier aggregation.

[0042] Taking the first receiving filter as B1 RX filter and the second receiving filter as B3 RX filter as an example, in the first preset mode, the B1 RX filter and the B3 RX filter in the multiplexer 100 simultaneously receive radio frequency signals, and the radio frequency signals received through the B1 RX filter and the radio frequency signals received through the B3 RX filter can perform carrier aggregation.

[0043] For example, the second preset mode is a carrier aggregation mode that can simultaneously transmit radio frequency signals of different frequency bands. In the second preset mode, the first transmit filter and the second transmit filter in the multiplexer 100 transmit radio frequency signals simultaneously, and the radio frequency signals transmitted through the first transmit filter and the radio frequency signals transmitted through the second transmit filter can be carrier aggregated.

[0044] Taking the first transmit filter as B1 TX filter and the second transmit filter as B3 TX filter as an example, in the first preset mode, the B1 TX filter and the B3 TX filter in the multiplexer 100 transmit radio frequency signals simultaneously, and the radio frequency signals transmitted through the B1 TX filter and the radio frequency signals transmitted through the B3 TX filter can perform carrier aggregation.

[0045] In some embodiments, the multiplexer 100 is applied to the radio frequency front-end module; wherein, in a third preset mode, when at least one filter in the multiplexer 100 transmits radio frequency signals of the first wireless communication frequency band and / or the second wireless communication frequency band, the radio frequency front-end module is also used to transmit radio frequency signals of the third wireless communication frequency band.

[0046] For example, the third preset mode is a carrier aggregation mode that can simultaneously transmit radio frequency signals corresponding to different frequency bands (including wireless communication frequency bands not covered by the multiplexer 100). Taking the first wireless communication frequency band as band B1, the second wireless communication frequency band as band B3, and the third wireless communication frequency band as band B41 as an example, in the third preset mode, when at least one filter in the multiplexer 100 transmits radio frequency signals of band B1 and / or band B3, the radio frequency front-end module is also used to transmit radio frequency signals of band B3. That is, in the third preset mode, the radio frequency front-end module can realize the simultaneous transmission of any two or three of the radio frequency signals of bands B1, B3, and B41, so that any two or three of the radio frequency signals transmitted in band B1, band B3, and band B41 can be carrier aggregated.

[0047] For example, the RF front-end module also includes a third filter; wherein, in a third preset mode, at least one filter in the multiplexer 100 transmits RF signals simultaneously with the third filter.

[0048] For example, in the third preset mode, any one of the first filters 10 in the multiplexer 100 can transmit radio frequency signals simultaneously with the third filter; the second filter 20 in the multiplexer 100 can also transmit radio frequency signals simultaneously with the third filter; any one of the first filters 10 and the second filter 20 in the multiplexer 100 can also transmit radio frequency signals simultaneously with the third filter.

[0049] For example, taking the first filter 10 as a B3 RX filter, the second filter 20 as a B1 RX filter, and the third filter as a B41 RX filter, at least one of the B3 RX filter and the B1 RX filter can transmit radio frequency signals simultaneously with the B41 RX filter.

[0050] In some embodiments, the first matching circuit 30 includes an inductive element connected in series between the first common node n1 and the antenna port ANT, so that when the first filter 10 is working, the impedance phase of the antenna port ANT to the target radio frequency signal is greater than 0°, and the target radio frequency signal is a signal aggregated with the signal carrier of the first wireless communication frequency band and / or the signal carrier of the second wireless communication frequency band.

[0051] like Figure 4 As shown, for example, the first matching circuit 30 includes an inductive element L1, which is connected in series between the first common node n1 and the antenna port ANT. The series connection of the inductive element L1 enables the impedance phase of the antenna port ANT to the target radio frequency signal to be greater than 0° when the first filter 10 is working. That is, for the antenna port ANT in the radio frequency signal link where the first filter 10 is located, the first matching circuit 30 can adjust the impedance phase of the antenna port ANT to the target radio frequency signal to be inductive.

[0052] For example, the inductive element L1 may include an inductor or other element that can impede changes in current (inductive reactance), such as a wire-wound inductor formed on the substrate of the multiplexer.

[0053] like Figure 7 and Figure 8 As shown, in some embodiments, the multiplexer 100 further includes a second matching circuit 40; one end of the second matching circuit 40 is connected to the antenna port ANT, and the other end of the second matching circuit 40 is grounded; or, the second filter 20 and the first matching circuit 30 are both connected to the second common node n2, and the second matching circuit 40 is connected in series between the second common node n2 and the antenna port ANT.

[0054] like Figure 7 As shown, for example, one end of the second matching circuit 40 is connected to the antenna port ANT, and the other end of the second matching circuit 40 is grounded. That is, the second matching circuit 40 is connected in parallel between the second common node n2 and the antenna port ANT. By setting the second matching circuit 40, the first matching circuit 30 and the second matching circuit 40 can generate a resonance effect, thereby effectively reducing the impedance phase change length of the antenna port ANT to the target radio frequency signal, and also facilitating the adjustment of the impedance phase position of the antenna port ANT to the target radio frequency signal.

[0055] like Figure 8 As shown, for example, the second filter 20 and the first matching circuit 30 are both connected to the second common node n2, and the second matching circuit 40 is connected in series between the second common node n2 and the antenna port ANT. By setting the second matching circuit 40, the first matching circuit 30 and the second matching circuit 40 can generate a resonance effect, thereby effectively reducing the impedance phase change length of the antenna port ANT to the target radio frequency signal, and also facilitating the adjustment of the impedance phase position of the antenna port ANT to the target radio frequency signal.

[0056] Due to limitations in the quality factor (Q value) of the inductive element L1 in the first matching circuit 30 and the size limitations of the filter, the impedance phase change region of the antenna port ANT to the target RF signal may be too long, i.e., the impedance phase angle change is too large, which may result in the multiplexer 100 not achieving optimal CA performance. However, by adding a second matching circuit 40 between the second common node n2 and the antenna port ANT, the impedance phase change length of the antenna port ANT to the target RF signal can be reduced, further improving the CA performance of the multiplexer 100.

[0057] In some embodiments, the second matching circuit 40 includes a first capacitive element C1, which is connected in series or in parallel between the second common node n2 and the antenna port ANT.

[0058] For example, the second matching circuit 40 includes a first capacitive element C1, which is connected in series or in parallel between the second common node n2 and the antenna port ANT. The arrangement of the first capacitive element C1 enables the inductive element L1 and the first capacitive element C1 to resonate, thereby effectively reducing the impedance phase change length of the antenna port ANT to the target radio frequency signal. It also facilitates the adjustment of the impedance phase position of the antenna port ANT to the target radio frequency signal, and further improves the CA performance of the multiplexer 100 while using fewer matching elements.

[0059] For example, the first capacitive element C1 may include a capacitor or other element capable of impeding voltage changes (capacitive reactance). The first capacitive element C1 is integrated within the multiplexer and can be formed as a parallel-plate capacitor or an interdigitated capacitor. For example, the first capacitive element C1 can be implemented using a surface acoustic wave resonator structure.

[0060] Taking the first capacitive element C1, which includes a capacitor, as an example, Figure 9 As shown, Figure 9 The solid lines in the Smith chart represent the impedance phase change region corresponding to the multiplexer 100 in Embodiment 1. Figure 9The dashed lines in the Smith chart represent the impedance phase change region corresponding to the multiplexer 100 of Embodiment 2. The multiplexer 100 of Embodiment 1 is... Figure 3 The corresponding multiplexer 100, the multiplexer 100 in embodiment 2 is Figure 8 The corresponding multiplexer 100. (By...) Figure 10 It can be seen that the impedance phase change angle corresponding to the multiplexer 100 in Embodiment 1 is 'a', and the impedance phase change angle corresponding to the multiplexer 100 in Embodiment 2 is 'b'. As can be seen from the figure, 'a'... b. Therefore, by setting the second matching circuit 40, the first matching circuit 30 and the second matching circuit 40 can resonate, thereby reducing the impedance phase change length of the antenna port ANT to the target radio frequency signal, and also making it easier to adjust the position of the impedance phase of the antenna port ANT to the target radio frequency signal.

[0061] like Figure 11 As shown, in some embodiments, the first matching circuit 30 includes an inductive element L1 and a second capacitive element C2. The inductive element L1 is connected in series between the first common node n1 and the antenna port ANT. One end of the second capacitive element C2 is connected to the first common node n1, and the other end of the second capacitive element C2 is grounded. That is, the second capacitive element C2 is connected in parallel between the first common node n1 and the inductive element L1.

[0062] For example, the first matching circuit 30 includes an inductive element L1 and a second capacitive element C2, with the inductive element L1 connected in series between the first common node n1 and the antenna port ANT. When the first filter 10 is working, due to the arrangement of the inductive element L1 and the second capacitive element C2, not only can the impedance phase of the antenna port ANT to the target RF signal be greater than 0°, enabling the first matching circuit 30 to adjust the impedance phase of the antenna port ANT to the target RF signal to be inductive, but it can also further reduce the impedance phase change length of the antenna port ANT to the target RF signal, further improving the CA performance of the multiplexer 100.

[0063] Due to limitations in the quality factor (Q value) of the inductive element L1 in the first matching circuit 30 and the size limitations of the filter, the impedance phase change region of the antenna port ANT to the target RF signal may be too long, i.e., the impedance phase angle change may be too large, thus preventing the multiplexer 100 from achieving optimal CA performance. However, by connecting the second capacitive element C2 in parallel between the first common node n1 and the inductive element L1, the impedance phase change length of the antenna port ANT to the target RF signal can be reduced, further improving the CA performance of the multiplexer 100.

[0064] Without considering the influence of the second filter, the impedance phase of the target RF signal at the antenna port ANT in the RF signal transmission path where the first filter is located is simulated, such as... Figure 12 As shown, Figure 12 The solid lines in the Smith chart represent the impedance phase change region corresponding to the first matching circuit 30 in Embodiment 3. Figure 12 The dashed lines in the Smith chart represent the impedance phase change region corresponding to the first matching circuit 30 in Embodiment 4. The first matching circuit 30 in Embodiment 3 is... Figure 3 The corresponding first matching circuit 30, in embodiment 4, is... Figure 11 The corresponding first matching circuit 30. In embodiment 3, the impedance phase change angle corresponding to the first matching circuit 30 is c, and in embodiment 4, the impedance phase change angle corresponding to the first matching circuit 30 is d. Figure 13 It can be seen that c Therefore, by adding a second capacitive element C2 in parallel to the first matching circuit 30, the inductive element L1 and the second capacitive element C2 are combined to form a low-pass filter. This effectively reduces the impedance phase change length of the antenna port ANT to the target radio frequency signal when the first filter 10 is working. It also facilitates the adjustment of the impedance phase position of the antenna port ANT to the target radio frequency signal. Furthermore, it can further improve the CA performance of the multiplexer 100 while using fewer matching elements.

[0065] In some embodiments, the second capacitive element C2 is a capacitor or a resonator, with the first end of the capacitor or the first end of the resonator connected to the input terminal of the first filter 10, and the second end of the capacitor or the second end of the resonator grounded.

[0066] For example, the second capacitive element C2 may include a capacitor or other element that can impede voltage changes (capacitive reactance). The first capacitive element C1 is integrated within the multiplexer and can be formed as a parallel plate capacitor or an interdigitated capacitor. For example, the first capacitive element C1 can be implemented using a surface acoustic wave resonator structure.

[0067] For example, taking the second capacitive element C2 as a capacitor, the first end of the capacitor is connected to the input terminal of the first filter 10, and the second end of the capacitor is grounded. Taking the second capacitive element C2 as a resonator, the first end of the resonator is connected to the input terminal of the first filter 10, and the second end of the resonator is grounded.

[0068] By combining the inductive element L1 with a capacitor or resonator to form a low-pass filter, when the first filter 10 is working, it is possible not only to effectively reduce the impedance phase change length of the antenna port ANT to the target radio frequency signal, but also to facilitate the adjustment of the impedance phase position of the antenna port ANT to the target radio frequency signal. This allows for further improvement of the CA performance of the multiplexer 100 while using fewer matching components.

[0069] In some embodiments, when the second capacitive element C2 is a resonator, the anti-resonance frequency of the resonator is located outside the target carrier aggregation frequency band. The target carrier aggregation frequency band is the frequency band of the target radio frequency signal, that is, the frequency band of other radio frequency signals that are carrier aggregated with the radio frequency signal transmitted by the multiplexer. For example, if the multiplexer is used to transmit radio frequency signals in the B1 and B3 bands, and the radio frequency signals in the B1 and B3 bands are carrier aggregated with the radio frequency signals in the B41 band, then the target carrier aggregation frequency band can be the B41 band.

[0070] This embodiment controls the anti-resonance frequency of the resonator, which is the second capacitive element C2, to further reduce the impedance phase change length of the antenna port ANT to the target radio frequency signal when the first filter 10 is working. This allows for further improvement of the CA performance of the multiplexer 100 while using fewer matching components.

[0071] For example, when the center frequency of the target carrier aggregation band is higher than the center frequency of the operating band of each first filter, the anti-resonance frequency of the resonator, which is the second capacitive element C2, is lower than the lower limit of the target carrier aggregation band frequency.

[0072] In some embodiments, the first filter 10 includes at least one parallel resonator, the structural parameters of which are the same as those of at least one parallel resonator; or, the resonator is one of the parallel resonators.

[0073] In one implementation, the first filter 10 includes at least two series arms and at least one parallel arm. Each parallel arm includes at least one parallel resonator, which is connected between the connection node of two adjacent series arms and the ground terminal, or between the input / output port of the first filter 10 and the ground terminal.

[0074] For example, when the second capacitive element C2 is a resonator, setting the structural parameters of the resonator as the second capacitive element C2 to be the same as the structural parameters of at least one parallel resonator in the first filter 10 can simplify the design of the multiplexer. It can also further reduce the impedance phase change length of the antenna port ANT to the target radio frequency signal when the first filter 10 is working, and further improve the CA performance of the multiplexer 100 while using fewer matching components.

[0075] It should be noted that the structural parameters of the resonator and the structural parameters of the parallel resonator can include the relevant structural parameters of the interdigital transducer in the resonator, such as the electrode fingers (e.g., shape, length, width, material), pitch, busbars, and pseudo-finger parameters.

[0076] For example, when the second capacitive element C2 is a resonator, one of the parallel resonators in the first filter 10 is used as the second capacitive element C2. For example, the parallel resonator in the first filter 10 connected to the first node n1 is used as the second capacitive element C2. This allows a low-pass filter to be formed by combining one of the parallel resonators in the first filter 10 with the inductive element L1 without the need for additional capacitive elements. This makes full use of the components in the multiplexer 100, reduces component costs, and effectively reduces the impedance phase change length of the antenna port ANT to the target RF signal when the first filter 10 is working. It also facilitates the adjustment of the impedance phase position of the antenna port ANT to the target RF signal and further improves the CA performance of the multiplexer 100 while using fewer matching components.

[0077] like Figure 14 and Figure 15 As shown, in some embodiments, the first matching circuit 30 includes an inductive element L1 and a second capacitive element C2. The inductive element L1 is connected in series between the first common node n1 and the antenna port ANT. One end of the second capacitive element C2 is connected to the first common node n1, and the other end of the second capacitive element C2 is grounded. The multiplexer 100 also includes a second matching circuit 40. One end of the second matching circuit 40 is connected to the antenna port ANT, and the other end of the second matching circuit 40 is grounded. Alternatively, the second filter 20 and the first matching circuit 30 are both connected to the second common node n2, and the second matching circuit 40 is connected in series between the second common node n2 and the antenna port ANT. The second matching circuit 40 includes a first capacitive element C1, which is connected in series or parallel between the second common node n2 and the antenna port ANT.

[0078] It should be noted that the relevant embodiments of the first matching circuit 30 and the second matching circuit 40 can be referred to the above embodiments, and will not be repeated here.

[0079] In this embodiment, by setting a first matching circuit 30 including an inductive element L1 and a second capacitive element C2 and a second matching circuit 40 including the first capacitive element C1, the first matching circuit 30 and the second matching circuit 40 can not only generate a resonance effect, thereby effectively reducing the impedance phase change length of the antenna port ANT to the target radio frequency signal, but also facilitate the adjustment of the impedance phase position of the antenna port ANT to the target radio frequency signal. Furthermore, since the second capacitive element C2 is added in parallel in the first matching circuit 30, the inductive element L1 and the second capacitive element C2 are combined to form a low-pass filter. This further reduces the impedance phase change length of the antenna port ANT to the target radio frequency signal when the first filter 10 is working, and also improves the CA performance of the multiplexer 100 while using fewer matching elements. In this embodiment, the CA performance of the multiplexer 100 can be optimized.

[0080] The following will provide a detailed description of another multiplexer 100 provided in the embodiments of this application.

[0081] like Figure 7 and Figure 8 As shown, the multiplexer 100 includes an antenna port ANT, multiple first filters 10, a first matching circuit 30, a second filter 20, and a second matching circuit 40; each first filter 10 is connected to a first common node n1; the first matching circuit 30 is connected in series between the first common node n1 and the antenna port ANT; the second filter 20 is connected to the antenna port ANT, one end of the second matching circuit 40 is connected to the antenna port ANT, and the other end of the second matching circuit 40 is grounded; or, the second filter 20 and the first matching circuit 30 are both connected to the second common node n2, and the second matching circuit 40 is connected in series between the second common node n2 and the antenna port ANT.

[0082] In the preset mode, at least one first filter 10 and a second filter 20 transmit radio frequency signals simultaneously.

[0083] For example, the preset mode may include a carrier aggregation mode, that is, in the carrier aggregation mode, at least one of the first filters 10 and the second filters 20 simultaneously transmit radio frequency signals, that is, at least one of the first filters 10 and the second filters 20 in the multiplexer 100 simultaneously transmit or receive radio frequency signals, and the radio frequency signals transmitted through at least one first filter 10 and the radio frequency signals transmitted through the second filter 20 can be carrier aggregated.

[0084] It should be noted that the first filter 10, the first matching circuit 30, and the second filter 20 can be referred to the above embodiments, and will not be repeated here.

[0085] like Figure 7 As shown, for example, one end of the second matching circuit 40 is connected to the antenna port ANT, and the other end of the second matching circuit 40 is grounded. That is, the second matching circuit 40 is connected in parallel between the second common node n2 and the antenna port ANT. By setting the second matching circuit 40, the first matching circuit 30 and the second matching circuit 40 can generate a resonance effect, thereby effectively reducing the impedance phase change length of the antenna port ANT to the target radio frequency signal, and also facilitating the adjustment of the impedance phase position of the antenna port ANT to the target radio frequency signal.

[0086] like Figure 8 As shown, for example, the second filter 20 and the first matching circuit 30 are both connected to the second common node n2, and the second matching circuit 40 is connected in series between the second common node n2 and the antenna port ANT. By setting the second matching circuit 40, the first matching circuit 30 and the second matching circuit 40 can generate a resonance effect, thereby effectively reducing the impedance phase change length of the antenna port ANT to the target radio frequency signal, and also facilitating the adjustment of the impedance phase position of the antenna port ANT to the target radio frequency signal.

[0087] Due to limitations in the quality factor (Q value) of the inductive element L1 in the first matching circuit 30 and the size limitations of the filter, the impedance phase change region of the antenna port ANT to the target RF signal may be too long, i.e., the impedance phase angle change is too large, which may result in the multiplexer 100 not achieving optimal CA performance. However, by adding a second matching circuit 40 between the second common node n2 and the antenna port ANT, the impedance phase change length of the antenna port ANT to the target RF signal can be reduced, further improving the CA performance of the multiplexer 100.

[0088] In some embodiments, the second matching circuit 40 includes a first capacitive element C1, which is connected in series or in parallel between the second common node n2 and the antenna port ANT.

[0089] For example, the second matching circuit 40 includes a first capacitive element C1, which is connected in series or in parallel between the second common node n2 and the antenna port ANT. The arrangement of the first capacitive element C1 enables the inductive element L1 and the first capacitive element C1 to resonate, thereby effectively reducing the impedance phase change length of the antenna port ANT to the target radio frequency signal. It also facilitates the adjustment of the impedance phase position of the antenna port ANT to the target radio frequency signal, and further improves the CA performance of the multiplexer 100 while using fewer matching elements.

[0090] For example, the first capacitive element C1 may include a capacitor or other element capable of impeding voltage changes (capacitive reactance). The first capacitive element C1 is integrated within the multiplexer and can be formed as a parallel-plate capacitor or an interdigitated capacitor. For example, the first capacitive element C1 can be implemented using a surface acoustic wave resonator structure.

[0091] Taking the first capacitive element C1, which includes a capacitor, as an example, Figure 9 As shown, Figure 9 The solid lines in the Smith chart represent the impedance phase change region corresponding to the multiplexer 100 in Embodiment 1. Figure 9 The dashed lines in the Smith chart represent the impedance phase change region corresponding to the multiplexer 100 of Embodiment 2. The multiplexer 100 of Embodiment 1 is... Figure 3 The corresponding multiplexer 100, the multiplexer 100 in embodiment 2 is Figure 8 The corresponding multiplexer 100. (By...) Figure 9 It can be seen that the impedance phase change angle corresponding to the multiplexer 100 in Embodiment 1 is 'a', and the impedance phase change angle corresponding to the multiplexer 100 in Embodiment 2 is 'b'. As can be seen from the figure, 'a'... b. Therefore, by setting the second matching circuit 40, the first matching circuit 30 and the second matching circuit 40 can resonate, thereby reducing the impedance phase change length of the antenna port ANT to the target radio frequency signal, and also making it easier to adjust the position of the impedance phase of the antenna port ANT to the target radio frequency signal.

[0092] In this embodiment, by setting a first matching circuit 30 between the first common node n1 and the antenna port ANT, and setting a second matching circuit 40 between the second common node n2 and the antenna port ANT, when the RF signal transmitted by the multiplexer and the target RF signal carrier are aggregated, the impedance phase of the antenna port to the target RF signal can be adjusted to the open circuit region without adding a phase shifting network. This ensures that the RF signal transmitted by the antenna port to the multiplexer will not leak into the signal transmission path of the target RF signal. Furthermore, the first matching circuit 30 and the second matching circuit 40 can also generate a resonance effect, thereby effectively reducing the impedance phase change length of the antenna port ANT to the target RF signal. This facilitates the adjustment of the impedance phase position of the antenna port ANT to the target RF signal, thereby reducing the number of matching components while improving the CA performance of the multiplexer, and thus improving the performance of the RF front-end module.

[0093] The following will provide a detailed description of another multiplexer 100 provided in the embodiments of this application.

[0094] like Figure 11As shown, the multiplexer 100 includes an antenna port ANT, multiple first filters 10, a first matching circuit 30, and a second filter 20; each first filter 10 is connected to a first common node n1; the first matching circuit 30 is connected in series between the first common node n1 and the antenna port ANT; and the second filter 20 is connected to the antenna port ANT.

[0095] In the preset mode, at least one first filter 10 and a second filter 20 transmit radio frequency signals simultaneously.

[0096] For example, the preset mode may include a carrier aggregation mode, that is, in the carrier aggregation mode, at least one of the first filters 10 and the second filters 20 simultaneously transmit radio frequency signals, that is, at least one of the first filters 10 and the second filters 20 in the multiplexer 100 simultaneously transmit or receive radio frequency signals, and the radio frequency signals transmitted through at least one first filter 10 and the radio frequency signals transmitted through the second filter 20 can be carrier aggregated.

[0097] It should be noted that the first filter 10 and the second filter 20 can be referred to the above embodiments, and will not be repeated here.

[0098] For example, the first matching circuit 30 includes an inductive element L1 and a second capacitive element C2, with the inductive element L1 connected in series between the first common node n1 and the antenna port ANT. When the first filter 10 is working, due to the arrangement of the inductive element L1 and the second capacitive element C2, not only can the impedance phase of the antenna port ANT to the target RF signal be greater than 0°, enabling the first matching circuit 30 to adjust the impedance phase of the antenna port ANT to the target RF signal to be inductive, but it can also further reduce the impedance phase change length of the antenna port ANT to the target RF signal, further improving the CA performance of the multiplexer 100.

[0099] Due to limitations in the quality factor (Q value) of the inductive element L1 in the first matching circuit 30 and the size limitations of the filter, the impedance phase change region of the antenna port ANT to the target RF signal may be too long, i.e., the impedance phase angle change may be too large, thus preventing the multiplexer 100 from achieving optimal CA performance. However, by connecting the second capacitive element C2 in parallel between the first common node n1 and the inductive element L1, the impedance phase change length of the antenna port ANT to the target RF signal can be reduced, further improving the CA performance of the multiplexer 100.

[0100] Without considering the influence of the second filter, the impedance phase of the target RF signal at the antenna port ANT in the RF signal transmission path where the first filter is located is simulated, such as... Figure 12 As shown, Figure 12The solid lines in the Smith chart represent the impedance phase change region corresponding to the first matching circuit 30 in Embodiment 3. Figure 12 The dashed lines in the Smith chart represent the impedance phase change region corresponding to the first matching circuit 30 in Embodiment 4. The first matching circuit 30 in Embodiment 3 is... Figure 3 The corresponding first matching circuit 30, in embodiment 4, is... Figure 11 The corresponding first matching circuit 30. (By...) Figure 13 It can be seen that the impedance phase change angle corresponding to the first matching circuit 30 in Embodiment 3 is c, and the impedance phase change angle corresponding to the first matching circuit 30 in Embodiment 4 is d. As can be seen from the figure, c Therefore, by adding a second capacitive element C2 in parallel to the first matching circuit 30, the inductive element L1 and the second capacitive element C2 are combined to form a low-pass filter. This effectively reduces the impedance phase change length of the antenna port ANT to the target radio frequency signal when the first filter 10 is working. It also facilitates the adjustment of the impedance phase position of the antenna port ANT to the target radio frequency signal. Furthermore, it can further improve the CA performance of the multiplexer 100 while using fewer matching elements.

[0101] In this embodiment, by setting a first matching circuit 30 including an inductor L1 and a second capacitive element C2 connected between the first common node n1 and the antenna port ANT, when the first filter 10 is working, the impedance phase change length of the antenna port ANT to the target RF signal can be effectively reduced. It can also facilitate the adjustment of the impedance phase position of the antenna port ANT to the target RF signal. Thus, when the RF signal transmitted by the multiplexer is carrier-aggregated with the target RF signal, the impedance phase of the antenna port to the target RF signal can be adjusted to the open circuit region without adding a phase shifting network. This ensures that the RF signal transmitted by the antenna port to the multiplexer will not leak into the signal transmission path of the target RF signal, further reducing the impedance phase change length of the antenna port ANT to the target RF signal. This can improve the CA performance of the multiplexer while reducing the number of matching elements, thereby improving the performance of the RF front-end module.

[0102] In some embodiments, the second capacitive element C2 is a capacitor or a resonator, with the first end of the capacitor or the first end of the resonator connected to the input terminal of the first filter 10, and the second end of the capacitor or the second end of the resonator grounded.

[0103] For example, the second capacitive element C2 may include a capacitor or other element that can impede voltage changes (capacitive reactance). The first capacitive element C1 is integrated within the multiplexer and can be formed as a parallel plate capacitor or an interdigitated capacitor. For example, the first capacitive element C1 can be implemented using a surface acoustic wave resonator structure.

[0104] For example, taking the second capacitive element C2 as a capacitor, the first end of the capacitor is connected to the input terminal of the first filter 10, and the second end of the capacitor is grounded. Taking the second capacitive element C2 as a resonator, the first end of the resonator is connected to the input terminal of the first filter 10, and the second end of the resonator is grounded.

[0105] By combining the inductive element L1 with a capacitor or resonator to form a low-pass filter, when the first filter 10 is working, it is possible not only to effectively reduce the impedance phase change length of the antenna port ANT to the target radio frequency signal, but also to facilitate the adjustment of the impedance phase position of the antenna port ANT to the target radio frequency signal. This allows for further improvement of the CA performance of the multiplexer 100 while using fewer matching components.

[0106] In some embodiments, when the second capacitive element C2 is a resonator, the anti-resonance frequency of the resonator is located outside the target carrier aggregation frequency band. The target carrier aggregation frequency band is the frequency band of the target radio frequency signal, that is, the frequency band of other radio frequency signals that are carrier aggregated with the radio frequency signal transmitted by the multiplexer. For example, if the multiplexer is used to transmit radio frequency signals in the B1 and B3 bands, and the radio frequency signals in the B1 and B3 bands are carrier aggregated with the radio frequency signals in the B41 band, then the target carrier aggregation frequency band can be the B41 band.

[0107] This embodiment controls the anti-resonance frequency of the resonator, which is the second capacitive element C2, to further reduce the impedance phase change length of the antenna port ANT to the target radio frequency signal when the first filter 10 is working. This allows for further improvement of the CA performance of the multiplexer 100 while using fewer matching components.

[0108] For example, when the center frequency of the target carrier aggregation band is higher than the center frequency of the operating band of each first filter, the anti-resonance frequency of the resonator, which is the second capacitive element C2, is lower than the lower limit of the target carrier aggregation band frequency.

[0109] In some embodiments, the first filter 10 includes at least one parallel resonator, the structural parameters of which are the same as those of at least one parallel resonator; or, the resonator is one of the parallel resonators.

[0110] In one implementation, the first filter 10 includes at least two series arms and at least one parallel arm. Each parallel arm includes at least one parallel resonator, which is connected between the connection node of two adjacent series arms and the ground terminal, or between the input / output port of the first filter 10 and the ground terminal.

[0111] For example, when the second capacitive element C2 is a resonator, setting the structural parameters of the resonator as the second capacitive element C2 to be the same as the structural parameters of at least one parallel resonator in the first filter 10 can simplify the design of the multiplexer. It can also further reduce the impedance phase change length of the antenna port ANT to the target radio frequency signal when the first filter 10 is working, and further improve the CA performance of the multiplexer 100 while using fewer matching components.

[0112] It should be noted that the structural parameters of the resonator and the structural parameters of the parallel resonator can include the relevant structural parameters of the interdigital transducer in the resonator, such as the electrode fingers (e.g., shape, length, width, material), pitch, busbars, and pseudo-finger parameters.

[0113] For example, when the second capacitive element C2 is a resonator, one of the parallel resonators in the first filter 10 is used as the second capacitive element C2. For example, the parallel resonator in the first filter 10 connected to the first node n1 is used as the second capacitive element C2. This allows a low-pass filter to be formed by combining one of the parallel resonators in the first filter 10 with the inductive element L1 without the need for additional capacitive elements. This makes full use of the components in the multiplexer 100, reduces component costs, and effectively reduces the impedance phase change length of the antenna port ANT to the target RF signal when the first filter 10 is working. It also facilitates the adjustment of the impedance phase position of the antenna port ANT to the target RF signal and further improves the CA performance of the multiplexer 100 while using fewer matching components.

[0114] like Figure 14 and Figure 15As shown, in some embodiments, the first matching circuit 30 includes an inductive element L1 and a second capacitive element C2. The inductive element L1 is connected in series between the first common node n1 and the antenna port ANT. One end of the second capacitive element C2 is connected to the first common node n1, and the other end of the second capacitive element C2 is grounded. The multiplexer 100 also includes a second matching circuit 40. One end of the second matching circuit 40 is connected to the antenna port ANT, and the other end of the second matching circuit 40 is grounded. Alternatively, the second filter 20 and the first matching circuit 30 are both connected to the second common node n2, and the second matching circuit 40 is connected in series between the second common node n2 and the antenna port ANT. The second matching circuit 40 includes a first capacitive element C1, which is connected in series or parallel between the second common node n2 and the antenna port ANT.

[0115] This application also provides an RF front-end module, which includes the multiplexer 100 described in any of the above embodiments. This RF front-end module can improve CA performance while using fewer matching components, thereby improving the performance, reliability, security, and practicality of the RF front-end module.

[0116] The radio frequency front-end module may also include at least one other device such as an antenna, a power amplifier, a low-noise amplifier, and a switch, without being specifically limited here.

[0117] In some embodiments, the RF front-end module further includes a third filter; wherein, in a third preset mode, at least one filter in the multiplexer and the third filter simultaneously transmit RF signals.

[0118] For example, the third preset mode is a carrier aggregation mode that can simultaneously transmit radio frequency signals corresponding to different frequency bands (including wireless communication frequency bands not covered by the multiplexer). Taking the first wireless communication frequency band as band B1, the second wireless communication frequency band as band B3, and the third wireless communication frequency band as band B41 as an example, in the third preset mode, when at least one filter in the multiplexer transmits radio frequency signals of band B1 and / or band B3, the radio frequency front-end module is also used to transmit radio frequency signals of band B3. That is, in the third preset mode, the radio frequency front-end module can realize the simultaneous transmission of any two or three of the radio frequency signals of bands B1, B3, and B41, so that any two or three of the radio frequency signals transmitted in band B1, band B3, and band B41 can be carrier aggregated.

[0119] For example, in the third preset mode, any one of the first filters in the multiplexer can transmit radio frequency signals simultaneously with the third filter; the second filter in the multiplexer can also transmit radio frequency signals simultaneously with the third filter; any one of the first filters and the second filter in the multiplexer can also transmit radio frequency signals simultaneously with the third filter.

[0120] For example, taking the first filter as a B3 RX filter, the second filter as a B1 RX filter, and the third filter as a B41 RX filter, at least one of the B3 RX and B1 RX filters can transmit radio frequency signals simultaneously with the B41 RX filter.

[0121] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this application, and these modifications or substitutions should all be covered within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A multiplexer, characterized by The multiplexer comprises: an antenna port; a plurality of first filters, each of the first filters being connected to a first common node; a first matching circuit connected in series between the first common node and the antenna port; a second filter connected to the antenna port; in a preset mode, at least one of the first filters and the second filter simultaneously transmit radio frequency signals, and a center frequency of a frequency band of the second filter is higher than a center frequency of a frequency band of the first filter.

2. The multiplexer of claim 1, wherein, The frequency band of at least one of the first filters comprises an uplink frequency band of a first wireless communication frequency band, and the frequency band of the second filter comprises a downlink frequency band of the first wireless communication frequency band.

3. The multiplexer of claim 1, wherein, The second filter is a first receive filter, and the frequency band of the first receive filter comprises a downlink frequency band of a first wireless communication frequency band. The plurality of first filters comprises a second receive filter, and the frequency band of the second receive filter comprises a downlink frequency band of a second wireless communication frequency band.

4. The multiplexer of claim 3, wherein, The plurality of first filters further comprises a first transmit filter and a second transmit filter, the frequency band of the first transmit filter is an uplink frequency band of the first wireless communication frequency band, and the frequency band of the second transmit filter is an uplink frequency band of the second wireless communication frequency band.

5. The multiplexer of claim 4, wherein, In a first preset mode, the first receive filter and the second receive filter simultaneously transmit radio frequency signals; and / or In a second preset mode, the first transmit filter and the second transmit filter simultaneously transmit radio frequency signals.

6. The multiplexer of claim 1, wherein, The multiplexer is applied to a radio frequency front-end module; in a third preset mode, when at least one filter in the multiplexer transmits radio frequency signals of a first wireless communication frequency band and / or radio frequency signals of a second wireless communication frequency band, the radio frequency front-end module is further configured to transmit radio frequency signals of a third wireless communication frequency band.

7. The multiplexer of claim 1, wherein, The first matching circuit comprises an inductive element connected in series between the first common node and the antenna port.

8. The multiplexer according to any of claims 1-7, characterized by The multiplexer further comprises a second matching circuit; one end of the second matching circuit is connected to the antenna port, and the other end of the second matching circuit is grounded; or The second filter and the first matching circuit are connected to a second common node, and the second matching circuit is connected in series between the second common node and the antenna port.

9. The multiplexer of claim 8, wherein, The second matching circuit comprises a first capacitive element connected in series or in parallel between the second common node and the antenna port.

10. The multiplexer according to any one of claims 1-6, wherein, The first matching circuit comprises an inductive element and a second capacitive element, the inductive element is connected in series between the first common node and the antenna port, one end of the second capacitive element is connected to the first common node, and the other end of the second capacitive element is grounded.

11. The multiplexer of claim 10, wherein, The second capacitive element is a capacitor or a resonator, a first end of the capacitor or a first end of the resonator is connected to an input end of the first filter, and a second end of the capacitor or a second end of the resonator is grounded.

12. The multiplexer of claim 11, wherein, The anti-resonance frequency of the resonator is located outside a target carrier aggregation frequency band, the target carrier aggregation frequency band being a frequency band of a target radio frequency signal, and the target radio frequency signal being a radio frequency signal that is carrier aggregated with the signal transmitted by the multiplexer.

13. The multiplexer of claim 11, wherein, The first filter includes at least one parallel resonator, and a structural parameter of the resonator is the same as a structural parameter of at least one of the parallel resonators; or the resonator is one of the parallel resonators.

14. The multiplexer of claim 10, wherein, The multiplexer further includes a second matching circuit, one end of the second matching circuit being connected to the antenna port, and the other end of the second matching circuit being grounded; or the second filter and the first matching circuit are both connected to a second common node, and the second matching circuit is connected in series between the second common node and the antenna port. The second matching circuit includes a first capacitive element, and the first capacitive element is connected in series or in parallel between the second common node and the antenna port.

15. A multiplexer, comprising: The multiplexer includes: an antenna port; a plurality of first filters, each of the first filters being connected to a first common node; a first matching circuit, the first matching circuit being connected in series between the first common node and the antenna port; a second filter, the second filter being connected to the antenna port; a second matching circuit, one end of the second matching circuit being connected to the antenna port, and the other end of the second matching circuit being grounded; or the second filter and the first matching circuit are both connected to a second common node, and the second matching circuit is connected in series between the second common node and the antenna port. In a preset mode, at least one of the first filters and the second filter simultaneously transmit radio frequency signals.

16. The multiplexer of claim 15, wherein, The second matching circuit includes a first capacitive element, and the first capacitive element is connected in series or in parallel between the second common node and the antenna port.

17. A multiplexer, comprising: The multiplexer includes: an antenna port; a plurality of first filters, each of the first filters being connected to a first common node; a first matching circuit, the first matching circuit being connected in series between the first common node and the antenna port, the first matching circuit including an inductive element and a second capacitive element, the inductive element being connected in series between the first common node and the antenna port, and one end of the second capacitive element being connected to the first common node and the other end of the second capacitive element being grounded; a second filter, the second filter being connected to the antenna port; In a preset mode, at least one of the first filters and the second filter simultaneously transmit radio frequency signals.

18. The multiplexer of claim 17, wherein, The second capacitive element is a capacitor or a resonator, a first end of the capacitor or a first end of the resonator being connected to an input end of the first filter, and a second end of the capacitor or a second end of the resonator being grounded.

19. The multiplexer of claim 18, wherein, The anti-resonance frequency of the resonator is located outside a target carrier aggregation frequency band, the target carrier aggregation frequency band including at least a working frequency band of any one of the filters in the multiplexer.

20. The multiplexer of claim 18, wherein, The first filter comprises at least one parallel resonator, a structural parameter of the resonator being the same as a structural parameter of at least one of the parallel resonators; or the resonator is one of the parallel resonators.

21. The multiplexer of claim 17, wherein, The multiplexer further comprises a second matching circuit, one end of the second matching circuit being connected to the antenna port, and the other end of the second matching circuit being grounded; or the second filter and the first matching circuit are both connected to a second common node, and the second matching circuit is connected in series between the second common node and the antenna port. The second matching circuit comprises a first capacitive element, and the first capacitive element is arranged in series or in parallel between the second common node and the antenna port.

22. A radio frequency front end module, comprising: The radio frequency front-end module comprises the multiplexer according to any one of claims 1 to 21.

23. The radio frequency front end module of claim 22, wherein, The radio frequency front-end module further comprises a third filter. In the third preset mode, at least one filter in the multiplexer and the third filter simultaneously transmit radio frequency signals.

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