A multiplexer, radio frequency module and electronic device

Abstract

This application provides a multiplexer, a radio frequency module, and an electronic device, relating to the field of resonator technology. The receiver filter of the multiplexer includes a first series resonator unit, a second series resonator unit, and a third series resonator unit. The first series resonator unit includes at least one first resonator connected in series, configuring the receiver filter passband as a first frequency band. The second series resonator unit includes at least two second resonators connected in parallel. The third series resonator unit includes at least one third resonator connected in series. A second preset size of the second resonator is larger than a first preset size of the first resonator, and the difference is a first difference value, such that the anti-resonance frequency of the second series resonator unit is outside the first frequency band, lower than the first frequency band, and the difference between the two is less than a second difference value. The second preset size is smaller than a third preset size of the third resonator, such that the anti-resonance frequency of the third series resonator unit is lower than the resonant frequency of the second series resonator unit.

Description

Technical Field

[0001] This application relates to the field of resonator technology, and more particularly to a multiplexer topology, radio frequency module, and electronic device. Background Technology

[0002] Multiplexers are widely used devices in the radio frequency (RF) field, and the kurtosis and suppression level of each filter are important parameters for evaluating their performance. Therefore, multiplexer design requires not only low insertion loss of the filters but also high kurtosis and high suppression levels. Consequently, improving the kurtosis and suppression level of filters in multiplexers has become an important topic for those skilled in the art. Summary of the Invention

[0003] In view of this, this application provides a multiplexer, an RF module, and an electronic device, as follows:

[0004] A multiplexer includes: an antenna end, a receiver filter, and a transmitter filter, wherein the receiver filter and the transmitter filter are both connected to the antenna end;

[0005] The receiver filter includes a first series resonator unit, a second series resonator unit, and a third series resonator unit connected in series, as well as a parallel resonator unit and a matching structure. The first series resonator unit is connected to the antenna and also to the parallel resonator unit, which is grounded through a first inductor. The third series resonator unit is connected to the matching structure.

[0006] The first series resonator unit includes at least one first resonator connected in series, and the passband of the receiving filter is configured as a first frequency band based on the first series resonator unit. The second series resonator unit includes at least two second resonators connected in parallel, and the third series resonator unit includes at least one third resonator connected in series. The resonant frequencies of the first, second, and third resonators are less than their anti-resonant frequencies. The second preset size of the second resonator is larger than the first preset size of the first resonator, such that the anti-resonant frequency of the second series resonator unit is less than the resonant frequency of the first series resonator unit. The anti-resonant frequency of the second series resonator unit is located outside the first frequency band and is less than the first frequency band. The second preset size of the second resonator is smaller than the third preset size of the third resonator, such that the anti-resonant frequency of the third series resonator unit is less than the resonant frequency of the second series resonator unit.

[0007] The difference between the second preset size and the first preset size is the first difference, so that the difference between the anti-resonance frequency of the second series resonator unit and the minimum frequency of the first frequency band is less than the second difference.

[0008] Optionally, the first resonator, the second resonator, and the third resonator are surface acoustic wave (SAW) resonators. The SAW resonator includes an interdigital transducer located on a piezoelectric substrate. The interdigital transducer includes first electrode fingers and second electrode fingers arranged alternately along a first direction, which is parallel to the mounting surface of the piezoelectric substrate.

[0009] The first preset size is the distance between adjacent first electrode fingers and second electrode fingers in the first resonator along the first direction, and the first preset size is inversely proportional to the resonant frequency and anti-resonant frequency of the first resonator; the second preset size is the distance between adjacent first electrode fingers and second electrode fingers in the second resonator along the first direction, and the second preset size is inversely proportional to the resonant frequency and anti-resonant frequency of the second resonator; the third preset size is the distance between adjacent first electrode fingers and second electrode fingers in the third resonator along the first direction, and the third preset size is inversely proportional to the resonant frequency and anti-resonant frequency of the third resonator.

[0010] Optionally, the second preset dimensions of the at least two second resonators are the same, and at least one of the five structural parameters of the at least two second resonators—the first structural parameter, the second structural parameter, the third structural parameter, the fourth structural parameter, and the fifth structural parameter—is the same.

[0011] The first structural parameter is the effective area of ​​the second resonator; the second structural parameter is the number of the first and second electrode fingers of the second resonator; the third structural parameter is the width of the first and second electrode fingers of the second resonator along the first direction; the fourth structural parameter is the length of the first and second electrode fingers of the second resonator along the second direction, the second direction being parallel to the extension direction of the first and second electrode fingers of the second resonator; and the fifth structural parameter is the aperture of the second resonator.

[0012] Optionally, the at least one first resonator includes a first sub-resonator, a second sub-resonator, a third sub-resonator, and a fourth sub-resonator connected in series; the at least two second resonators include a fifth sub-resonator and a sixth sub-resonator connected in parallel; the at least one third resonator includes a seventh sub-resonator; the first sub-resonator is connected to the input terminal of the receiving filter; the fifth sub-resonator is connected to the fourth sub-resonator; the fifth sub-resonator is also connected to the seventh sub-resonator; the seventh sub-resonator is also connected to the matching structure; and the matching structure is connected to the output terminal of the receiving filter.

[0013] The second preset size of the fifth sub-resonator is the same as the second preset size of the sixth sub-resonator.

[0014] Optionally, the matching structure includes a second inductor and a third inductor;

[0015] One end of the second inductor is connected to the seventh sub-resonator, and the other end is connected to one end of the third inductor and also to the output terminal of the receiving filter. The other end of the third inductor is grounded.

[0016] Optionally, the parallel resonator unit includes a fourth resonator, a fifth resonator, a sixth resonator, and a seventh resonator, and the first inductor includes a first sub-inductor and a second sub-inductor;

[0017] One end of the fourth resonator is connected between the first sub-resonator and the second sub-resonator, one end of the fifth resonator is connected between the second sub-resonator and the third sub-resonator, the sixth resonator is connected between the third sub-resonator and the fourth sub-resonator, and the seventh resonator is connected between the fourth sub-resonator and the second series resonator unit. The fourth and fifth resonators are grounded through the first sub-inductor, and the sixth and seventh resonators are grounded through the second sub-inductor.

[0018] Optionally, a fourth inductor is also included, which is connected between the input terminal of the receiving filter and the first series resonator unit, and the fourth inductor is grounded.

[0019] Optionally, the transmitter filter includes a first transmitter filter, the passband of which is configured as a second frequency band, the second frequency band being outside the first frequency band and smaller than the first frequency band;

[0020] The anti-resonance frequency of the second series resonator unit is located within the second frequency band.

[0021] Optionally, the transmitter filter includes a second transmitter filter, the passband of which is configured as a third frequency band, the third frequency band being outside the second frequency band and smaller than the second frequency band;

[0022] The anti-resonance frequency of the third series resonator unit is located within the third frequency band.

[0023] A radio frequency module, comprising the multiplexer described in any of the above embodiments.

[0024] An electronic device comprising the aforementioned radio frequency module.

[0025] Compared with related technologies, the beneficial effects of the technical solution of this application are as follows:

[0026] The multiplexer includes an antenna end, a receiver filter, and a transmitter filter. The receiver filter includes a first series resonator unit, a second series resonator unit, and a third series resonator unit connected in series. The first series resonator unit includes at least one first resonator connected in series. The passband of the receiver filter is configured as a first frequency band based on the first series resonator unit. The second series resonator unit includes at least two second resonators connected in parallel. The third series resonator unit includes at least one third resonator connected in series. A second preset size of the second resonator is larger than a first preset size of the first resonator, such that the anti-resonance frequency of the second series resonator unit is outside the first frequency band and lower than the first frequency band. The second preset size of the second resonator is smaller than a third preset size of the third resonator, such that the anti-resonance frequency of the third series resonator unit is lower than the resonant frequency of the second series resonator unit. The difference between the second preset size and the first preset size is the first difference value. This ensures that the difference between the anti-resonance frequency of the second series resonator unit and the minimum frequency of the first frequency band is less than the second difference value. Consequently, the anti-resonance frequency of the second series resonator unit can be very close to the minimum frequency of the first frequency band, resulting in rapid suppression near the minimum frequency of the first frequency band. This leads to a high steepness near the minimum frequency of the first frequency band, achieving a high steepness for the receiver filter RX. Furthermore, the operating frequency bands of the second and third resonators are outside and lower than the first frequency band. By coordinating the operating frequency bands of the second and third resonators, the operating frequency bands of the second and third series resonator units can cover the operating frequency bands of the receiver filter RX. This allows the receiver filter RX to achieve high suppression of frequency bands lower than its passband frequency, thereby suppressing interference from the operating frequency bands on the receiver filter RX. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the embodiments of this application or related technologies, the drawings used in the description of the embodiments or prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this application. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0028] The structures, proportions, sizes, etc., shown in the accompanying drawings are only for the purpose of assisting those skilled in the art in understanding and reading the content disclosed in the specification, and are not intended to limit the implementation conditions of this application. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in the proportions, or adjustments to the size should still fall within the scope of the technical content disclosed in this application, provided that they do not affect the effects and purposes that this application can produce.

[0029] Figure 1 A schematic diagram of the topology of a multiplexer provided in this application;

[0030] Figure 2 and Figure 3 A schematic diagram of the Y-curve of the receiver filter RX in a multiplexer provided in this application;

[0031] Figure 4 This is a schematic diagram of the structure of a surface acoustic wave resonator;

[0032] Figure 5 A schematic diagram of another multiplexer topology provided in this application;

[0033] Figures 6-9 A performance comparison diagram of the receiver filter RX in a multiplexer provided in this application. Detailed Implementation

[0034] The embodiments of this application will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are merely one area of ​​this application, and not all of the embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0035] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0036] As described in the background section, improving the steepness and suppression level of filters in multiplexers has become an important topic for those skilled in the art.

[0037] For example, in a Band25_66(70) quad converter, the passband range of the Band25(70)RX filter (receiver filter) is 1930MHz~2020MHz, the passband range of the Band25TX filter (transmitter filter) is 1850MHz~1915MHz, and the passband range of the Band66(70)TX filter (transmitter filter) is 1695MHz~1780MHz. The passband range of the filter is its operating frequency band. In the operation of the Band25_66(70) quad converter, the Band25(70)RX filter needs to block the operating frequency bands of the Band25TX filter and the Band66(70)TX filter. Therefore, the Band25TX filter needs to have a high suppression level to block the operating frequency bands of the Band25TX filter and the Band66(70)TX filter. Because the operating frequency bands of the Band25(70)RX filter and the Band25TX filter are very close, the Band25(70)RX filter also requires extremely high kurtosis to prevent the passband of the Band25TX filter from falling into the operating frequency band of the Band25(70)RX filter, thus achieving isolation of the Band25TX filter's operating frequency band. Therefore, for multiplexers, the kurtosis and suppression level of their filters are important performance parameters. Thus, how to improve the kurtosis and suppression level of filters in multiplexers has become an important topic for those skilled in the art.

[0038] Based on the above, this application provides a multiplexer, such as... Figure 1 As shown, Figure 1 This application provides a topology diagram of a multiplexer, which includes: an antenna (Ant), a receiver filter (RX), and a transmitter filter (TX). Figure 1 In the diagram, R1 represents the input terminal of the receiver filter RX, R2 represents the output terminal of the receiver filter RX, T1 represents the input terminal of the transmitter filter TX, and T2 represents the output terminal of the transmitter filter TX. Both the receiver filter RX and the transmitter filter TX are connected to the antenna terminal Ant; that is, the receiver filter RX is connected to the antenna terminal Ant, and the transmitter filter TX is also connected to the antenna terminal Ant. The receiver filter RX generates a first output signal and transmits this first output signal downlink through the antenna terminal Ant. The transmitter filter TX generates a second output signal and transmits this second output signal uplink through the antenna terminal Ant. It should be understood that the transmitter filter TX typically includes multiple series resonators and parallel resonators, but... Figure 1 The specific structure of the transmitter filter TX is not shown in the figure. It depends on the specific situation.

[0039] The receiver filter RX includes a first series resonator unit 10, a second series resonator unit 20, and a third series resonator unit 30 connected in series, as well as a parallel resonator unit 40 and a matching structure 50. The first series resonator unit 10 is connected to the antenna terminal Ant, and is also connected to the parallel resonator unit 40, which is grounded through a first inductor 60. The third series resonator unit 30 and the matching structure 50 are connected. The first series resonator unit 10 is connected to the input terminal R1 of the receiver filter RX, and the matching structure 50 is also connected to the output terminal R2 of the receiver filter RX and is grounded.

[0040] The first series resonator unit 10 includes at least one first resonator 11 connected in series. The passband of the receiver filter RX can be configured as a first frequency band based on the first series resonator unit 10, that is, the passband of the receiver filter RX can be configured as a first frequency band based on the aforementioned at least one first resonator 11 connected in series. The second series resonator unit 20 includes at least two second resonators 21 connected in parallel, that is, the second series resonator unit 20 includes at least two second resonators 21, and the at least two second resonators 21 are in a parallel state. The third series resonator unit 30 includes at least one third resonator 31 connected in series.

[0041] Based on the above, the resonant frequencies of the first resonator 11, the second resonator 21, and the third resonator 31 are lower than their anti-resonant frequencies. Specifically, the resonant frequency of the first resonator 11 is lower than its anti-resonant frequency, the resonant frequency of the second resonator 21 is lower than its anti-resonant frequency, and the resonant frequency of the third resonator 31 is lower than its anti-resonant frequency. This ensures that the resonant frequencies of the first series resonator unit 10, the second series resonator unit 20, and the third series resonator unit 30 are lower than their anti-resonant frequencies. The second preset size of the second resonator 21 is larger than the first preset size of the first resonator 11, so that the anti-resonant frequency of the second series resonator unit 20 is lower than the resonant frequency of the first series resonator unit 10. This further ensures that the anti-resonant frequency of the second series resonator unit 20 is outside the first frequency band and lower than the first frequency band. Furthermore, the second preset size of the second resonator 21 is also smaller than the third preset size of the third resonator 31, so that the anti-resonant frequency of the third series resonator unit 30 is lower than the resonant frequency of the second series resonator unit 20. The difference between the second preset size and the first preset size is the first difference, so that the difference between the anti-resonance frequency of the second series resonator unit 20 and the minimum frequency of the first frequency band is less than the second difference.

[0042] Since the resonant frequencies of the first resonator 11, the second resonator 21, and the third resonator 31 are all lower than their anti-resonant frequencies, and the anti-resonant frequency of the second series resonator unit 20 is lower than the resonant frequency of the first series resonator unit 10, and the anti-resonant frequency of the third series resonator unit 30 is lower than the resonant frequency of the second series resonator unit 20, the operating frequency band of the second resonator 21 is outside the operating frequency band of the first resonator 11 and is lower than the operating frequency band of the first resonator 11. That is, the operating frequency band of the second resonator 21 does not overlap with the operating frequency band of the first resonator 11, and the operating frequency band of the second resonator 21 is lower than the operating frequency band of the first resonator 11. Similarly, the operating frequency band of the third resonator 31 does not overlap with the operating frequency band of the second resonator 21, and the operating frequency band of the third resonator 31 is lower than the operating frequency band of the second resonator 21. In other words, the operating frequency bands of the first resonator 11, the second resonator 21, and the third resonator 31 do not overlap, and their operating frequency bands gradually decrease. This results in the operating frequency bands of the first series resonator unit 10, the second series resonator unit 20, and the third series resonator unit 30 not overlapping, and their operating frequency bands gradually decreasing. It should be noted that, in this application, the operating frequency bands of the first resonator 11, the second resonator 21, and the third resonator 31 refer to the frequency band between their respective resonant frequency and anti-resonant frequency.

[0043] As described above, the receiver filter RX is configured as the first frequency band based on the first series resonator unit 10, and the operating frequency band of the second series resonator unit 20 is outside and lower than the operating frequency band of the first series resonator unit 10. Therefore, the operating frequency band of the second series resonator unit 20 is outside and lower than the first frequency band. In other words, the operating frequency band of the second series resonator unit 20 is outside the first frequency band and lower than the minimum frequency of the first frequency band. Since the resonant frequency of the second resonator 21 is lower than its anti-resonant frequency, the operating frequency band of the second series resonator unit 20 is outside the first frequency band and lower than the minimum frequency of the first frequency band. That is, the anti-resonant frequency of the second series resonator unit 20 is outside the first frequency band and lower than the minimum frequency of the first frequency band. Since the operating frequency band of the third series resonator unit 30 is outside the operating frequency band of the second series resonator unit 20 and is smaller than the operating frequency band of the second series resonator unit 20, the anti-resonance frequency of the third series resonator unit 30 is smaller than the minimum frequency of the operating frequency band of the second series resonator unit 20, i.e., the resonant frequency. Consequently, the anti-resonance frequency of the third series resonator unit 30 is also smaller than the minimum frequency of the first frequency band.

[0044] For a series resonator, the impedance is maximum at its anti-resonance frequency. It is known that the difference between the second preset size of the second resonator 21 and the first preset size of the first resonator 11 is a first difference value. This allows the difference between the anti-resonance frequency of the second series resonator unit 20 and the minimum frequency of the first frequency band to be less than a second difference value. Therefore, the anti-resonance frequency of the second series resonator unit 20 can be very close to the minimum frequency of the first frequency band, and thus the frequency band near the minimum frequency of the first frequency band will be quickly suppressed by the second series resonator unit 20. Figure 2 As shown, Figure 2 This is a schematic diagram of the Y-curve of the receiver filter RX. Figure 2 The horizontal axis represents frequency in GHz, and the vertical axis represents decibels in dB. Curve 1 is the passband Y-curve of the receiver filter RX (characterizing the operating frequency band of the receiver filter RX), and curve 2 is the Y-curve of the second series resonator unit 20 (characterizing the operating frequency band of the second series resonator unit 20). In curve 2, the peak value represents the resonant frequency of the second series resonator unit 20, and the valley value represents the anti-resonant frequency of the second series resonator unit 20. According to Figure 2 It is known that the second series resonator unit 20 has the strongest blocking and suppression effect near its anti-resonance frequency, resulting in rapid suppression near the minimum frequency of the first frequency band and a faster frequency change rate, thus leading to a higher steepness near the minimum frequency of the first frequency band. Furthermore, since the passband frequency (operating frequency band) of the receiver filter RX in a multiplexer is usually higher than the operating frequency band of the transmitter filter TX, the steepness near the minimum frequency of the receiver filter RX is a crucial parameter for evaluating its performance. As mentioned above, the multiplexer provided in this application exhibits a high steepness near the minimum frequency of the receiver filter RX, thus achieving a high steepness for the receiver filter RX and providing a feasible solution for improving the performance of the multiplexer, contributing to the further development of multiplexers.

[0045] Furthermore, since the second resonator 21 and the third resonator 31 have the maximum impedance at their anti-resonance frequency, meaning that within the operating frequency band of the second resonator 21 and the third resonator 31, the blocking effect increases with increasing frequency, thus enhancing the suppression effect. Therefore, the receiving filter RX can suppress frequencies located within the operating frequency band of the second resonator 21 and the third resonator 31. Also, since the operating frequency bands of the second resonator 21 and the third resonator 31 are outside and lower than the first frequency band, by coordinating the operating frequency bands of the second resonator 21 and the third resonator 31, the operating frequency bands of the second series resonator unit 20 and the third series resonator unit 30 can cover the operating frequency band of the transmitting filter TX. This allows the receiving filter RX to achieve high suppression of frequencies lower than its passband frequency, suppressing interference from the transmitting filter TX's operating frequency band on the receiving filter RX, thereby improving the multiplexer's performance. For example... Figure 2 and Figure 3 As shown, Figure 3 This is a schematic diagram of the Y-curve of the receiver filter RX. Figure 3 The horizontal axis represents frequency in GHz, and the vertical axis represents decibels in dB. Curve 1 is the passband Y-curve of the receiver filter RX (characterizing the operating frequency band of the receiver filter RX), and curve 3 is the Y-curve of the third series resonator unit 30 (characterizing the operating frequency band of the third series resonator unit 30). In curve 3, the peak value represents the resonant frequency of the third series resonator unit 30, and the valley value represents the anti-resonant frequency of the third series resonator unit 30. Figure 2 and Figure 3 The operating frequency bands of the second series resonator unit 20 and the third series resonator unit 30 can cover the operating frequency band of the transmitter filter TX, enabling the receiver filter RX to achieve high suppression of frequency bands lower than its passband frequency, thereby improving the performance of the multiplexer.

[0046] In one embodiment of this application, the first resonator 11, the second resonator 21, and the third resonator 31 can all be surface acoustic wave resonators. Figure 4 As shown, the surface acoustic wave resonator includes an interdigital transducer 200 located on a piezoelectric substrate 100. The interdigital transducer 200 includes first electrode fingers 201 and second electrode fingers 202 alternately arranged along a first direction parallel to the mounting surface of the piezoelectric substrate 100. It should be noted that, as... Figure 4 As shown, the interdigital transducer 200 also includes a first busbar 203, a second busbar 204, and a reflective grid structure 205, wherein the first electrode finger 201 is electrically connected to the first busbar 203 and extends toward the second busbar 204, and the second electrode finger 202 is electrically connected to the second busbar 204 and extends toward the first busbar 203.

[0047] The first preset size of the first resonator 11 is the distance L1 between adjacent first electrode fingers 201 and 202 along the first direction. This first preset size is inversely proportional to the resonant frequency and anti-resonant frequency of the first resonator 11; that is, the larger the first preset size, the smaller the resonant frequency and anti-resonant frequency of the first resonator 11. The second preset size of the second resonator 21 is the distance L2 between adjacent first electrode fingers 201 and 202 along the first direction. This second preset size is inversely proportional to the resonant frequency and anti-resonant frequency of the second resonator 21; that is, the larger the second preset size, the smaller the resonant frequency and anti-resonant frequency of the second resonator 21. The third preset size of the third resonator 31 is the distance L2 between adjacent first electrode fingers 201 and 202 along the first direction. This second preset size is inversely proportional to the resonant frequency and anti-resonant frequency of the third resonator 31; that is, the larger the third preset size, the smaller the resonant frequency and anti-resonant frequency of the third resonator 31.

[0048] Based on the above, the second preset size of the second resonator 21 is larger than the first preset size of the first resonator 11, which makes the anti-resonance frequency of the second series resonator unit 20 smaller than the resonant frequency of the first series resonator unit 10. This, in turn, ensures that the anti-resonance frequency of the second series resonator unit 20 is outside the first frequency band and is smaller than the first frequency band. Furthermore, the second preset size of the second resonator 21 is smaller than the third preset size of the third resonator 31, which also makes the anti-resonance frequency of the third series resonator unit 30 smaller than the resonant frequency of the second series resonator unit 20. This, in turn, ensures that the anti-resonance frequency of the third series resonator unit 30 is outside the first frequency band and is smaller than the first frequency band.

[0049] In one embodiment of this application, such as Figure 1As shown, for the first series resonator unit 10, at least one first resonator 11 may include a first sub-resonator S1, a second sub-resonator S2, a third sub-resonator S3, and a fourth sub-resonator S4 connected in series. For the second series resonator unit 20, at least two second resonators 21 may include a fifth sub-resonator S5-1 and a sixth sub-resonator S5-2 connected in parallel. For the third series resonator unit 30, at least one third resonator 31 may include a seventh sub-resonator S6. Based on the above, the first sub-resonator S1 is electrically connected to the input terminal R1 of the receiver filter RX, the fifth sub-resonator S5-1 is electrically connected to the fourth sub-resonator S4, the sixth sub-resonator S5-2 is connected in parallel with the fifth sub-resonator S5-1, the fifth sub-resonator S5-1 is also electrically connected to the seventh sub-resonator S6, and the seventh sub-resonator S6 is also electrically connected to the matching structure 50. The second preset size of the fifth sub-resonator S5-1 is the same as the second preset size of the sixth sub-resonator S5-2. That is to say, the resonant frequency and anti-resonant frequency of the fifth sub-resonator S5-1 and the sixth sub-resonator S5-2 are equal, and the operating frequency bands of the fifth sub-resonator S5-1 and the sixth sub-resonator S5-2 are the same. This can ensure the consistency of the operating performance of each second resonator 21 in the second series resonator unit 20, and thus help to simplify the parameter design difficulty of the second series resonator unit 20.

[0050] It should be noted that the number of first resonators 11 in the first series resonator unit 10 can also be other numbers, such as 2, 3 or 5, etc. The number of second resonators 21 in the second series resonator unit 20 and the number of third resonators 31 in the third series resonator unit 30 can also be other numbers. For example, the second series resonator unit 20 may include 3, 4 or 5 second resonators 21 connected in parallel, and the third series resonator unit 30 may include 2, 3, 4 or 5 third resonators 31 connected in series. This application does not limit this, and it depends on the specific circumstances.

[0051] In one embodiment of this application, provided that at least two second resonators 21 have the same second preset size, that is, provided that each second resonator 21 in the second series resonator unit 20 has the same operating frequency band, at least one of the five structural parameters of the fifth sub-resonator S5-1 and the sixth sub-resonator S5-2 is the same, that is, at least one of the five structural parameters of the first, second, third, fourth and fifth structural parameters of each second resonator 21 connected in parallel in the second series resonator unit 20 is the same.

[0052] The first structural parameter is the effective area of ​​the surface acoustic wave (SAW) resonator, specifically the area of ​​the region capable of effectively generating resonance. The second structural parameter is the number of the first and second electrodes of the SAW resonator. It should be noted that the number of first and second electrodes in a typical SAW resonator is the same; therefore, the second structural parameter can simultaneously characterize the number of both electrodes. The third structural parameter is the width of the first and second electrodes along a first direction; this can also be referred to as the bar width of the first and second electrodes. The fourth structural parameter is the length of the first and second electrodes along a second direction, which is parallel to the extension directions of the first and second electrodes. Typically, the extension directions of the first and second electrodes are parallel to each other, so the second direction can be parallel to both the extension directions of the first and second electrodes. This fourth structural parameter can also be referred to as the length of the first and second electrodes. The fifth structural parameter is the aperture of the surface acoustic wave resonator, where the aperture of the surface acoustic wave resonator is the width of the intersection region of the first electrode finger and the second electrode finger along the first direction. The intersection region refers to the overlapping region of the projection of the first electrode finger along the first direction and the projection of the second electrode finger along the first direction.

[0053] It should be noted that the third structural parameters of the fifth sub-resonator S5-1 and the sixth sub-resonator S5-2 are the same, meaning that the width of the first electrode finger of the fifth sub-resonator S5-1 is equal to the width of the first electrode finger of the sixth sub-resonator S5-2, and the width of the second electrode finger of the fifth sub-resonator S5-1 is equal to the width of the second electrode finger of the sixth sub-resonator S5-2. Furthermore, the fourth structural parameters of the fifth sub-resonator S5-1 and the sixth sub-resonator S5-2 are the same, meaning that the length of the first electrode finger of the fifth sub-resonator S5-1 is equal to the length of the first electrode finger of the sixth sub-resonator S5-2, and the length of the second electrode finger of the fifth sub-resonator S5-1 is equal to the length of the second electrode finger of the sixth sub-resonator S5-2.

[0054] Based on the above, for the second series resonator unit 20, provided that at least two second resonators 21 have the same second preset size, at least one of the following parameters of the at least two second resonators 21 is the same: effective area, electrode index quantity, electrode finger width, electrode finger length, and aperture. That is, the second series resonator unit 20 can be formed by connecting multiple second resonators 21 with similar or even identical structures in parallel. In other words, the structures of each second resonator 21 in the second series resonator unit 20 can remain the same or similar, thereby further ensuring the consistency of the working performance of each second resonator 21 in the second series resonator unit 20, and further simplifying the parameter design difficulty of the second series resonator unit 20. Furthermore, the fact that the structures of each second resonator 21 in the second series resonator unit 20 can remain the same or similar improves the structural consistency of each second resonator 21, simplifies the structural layout of the second series resonator unit 20, reduces the design difficulty of the second series resonator unit 20, and increases the design flexibility of the second series resonator unit 20.

[0055] Similarly, if the third series resonator unit 30 includes two or more third resonators 31, other structural parameters, except for the third preset size, can also be at least partially the same. Thus, the third series resonator unit 30 can be formed by connecting multiple third resonators 31 with the same or similar structures in series. In other words, the second series resonator unit 20 can be formed by connecting multiple second resonators 21 with the same or similar structures in parallel, and the third series resonator unit 30 can be formed by connecting multiple third resonators 31 with the same or similar structures in series. This can reduce the design and fabrication difficulty of the receiver filter RX in the multiplexer, thereby reducing the design and fabrication difficulty of the multiplexer, resulting in excellent performance of the multiplexer, while having lower design and fabrication difficulty and strong practicality.

[0056] In one embodiment of this application, such as Figure 1 As shown, the matching structure 50 (also known as the output matching structure) includes a second inductor Ls and a third inductor Lp connected in series. One end of the second inductor Ls is electrically connected to the seventh sub-resonator S6, the other end of the second inductor Ls is connected to one end of the third inductor Lp, and is also connected to the output terminal R2 of the receiver filter RX. The other end of the third inductor Lp is grounded.

[0057] Based on the above, the matching structure 50 can be an L-shaped output matching structure, employing a series connection of the second inductor Ls followed by a parallel connection of the third inductor Lp. Since the second preset size of the second resonator 21 and the third preset size of the third resonator 31 are larger than the first preset size of the first resonator 11, the operating frequency bands of the second resonator 21 and the third resonator 31 are outside the passband of the receiver filter RX and smaller than the passband frequency band of the receiver filter RX. Therefore, the second resonator 21 and the third resonator 31 can exhibit capacitive characteristics within the passband frequency band of the receiver filter RX. The L-shaped output matching structure can first cancel the capacitive reactance of the second resonator 21 and the third resonator 31 within the passband frequency band of the receiver filter RX through the series connection of the second inductor Ls, and then achieve overall output matching of the receiver filter RX through the parallel connection of the third inductor Lp, thus realizing the output matching of the receiver filter RX.

[0058] It should be noted that, as Figure 5 As shown, the matching structure 50 can also be a π-type output matching structure, and the matching structure 50 includes matching inductor Lp-1, matching inductor Lp-2 and matching inductor Ls. However, this application does not limit this, and it depends on the specific circumstances.

[0059] In one embodiment of this application, such as Figure 1As shown, the parallel resonator unit 40 includes a fourth resonator P1, a fifth resonator P2, a sixth resonator P3, and a seventh resonator P4. The first inductor 60 includes a first sub-inductor L1 and a second sub-inductor L2. One end of the fourth resonator P1 is connected between the first sub-inductor S1 and the second sub-inductor S2, meaning the fourth resonator P1 is electrically connected to both the first and second sub-inductor S1 and S2. One end of the fifth resonator P2 is connected between the second and third sub-inductor S2, meaning the fifth resonator P2 is electrically connected to both the second and third sub-inductor S2 and S3. The sixth resonator P3 is connected between the third and fourth sub-inductor S3, meaning the sixth resonator P3 is electrically connected to both the third and fourth sub-inductor S4. The seventh resonator P4 is connected between the fourth sub-resonator S4 and the second series resonator unit 20. That is, the seventh resonator P4 is electrically connected to the fourth sub-resonator S4 and also to the second series resonator unit 20. Additionally, the fourth resonator P1 and the fifth resonator P2 are grounded through the first sub-inductor L1, and the sixth resonator P3 and the seventh resonator P4 are grounded through the second sub-inductor L2. It should be noted that the seventh resonator P4 is connected between the fourth sub-resonator S4 and the second series resonator unit 20. That is, the seventh resonator P4 is electrically connected to the fourth sub-resonator S4, and also to the fifth sub-resonator S5-1 and the sixth sub-resonator S5-2. It should also be noted that the aforementioned fourth resonator P1, fifth resonator P2, sixth resonator P3, and seventh resonator P4 are also referred to as parallel resonators. In other words, a parallel resonator is connected between each of the first resonators 11 in the first series resonator unit 10, and this parallel resonator is grounded through an inductor.

[0060] In one embodiment of this application, such as Figure 1 As shown, the multiplexer also includes a fourth inductor A_Lp, which is connected between the input terminal R1 of the receiver filter RX and the first series resonator unit 10, and is grounded. Regarding the aforementioned fourth inductor A_Lp, its connection between the input terminal R1 of the receiver filter RX and the first series resonator unit 10 means that the fourth inductor A_Lp is electrically connected to the input terminal R1 of the receiver filter RX, and is also electrically connected to the first sub-resonator S1, which can be used to achieve output matching of the receiver filter RX.

[0061] In one embodiment of this application, the transmitter filter TX includes a first transmitter filter TX1, the passband of which is configured as a second frequency band, which is located outside the first frequency band and is smaller than the first frequency band. Wherein, as... Figure 2As shown, the anti-resonance frequency of the second series resonator unit 20 is located within the second frequency band. It is known that the receiver filter RX has the strongest impedance near the anti-resonance frequency of the second series resonator unit 20. Therefore, since the anti-resonance frequency of the second series resonator unit 20 is located within the second frequency band, the receiver filter RX can achieve high suppression of the passband frequency of the first transmitter filter TX1, thereby achieving high isolation between the receiver filter RX and the first transmitter filter TX1. This effectively avoids frequency interference between the receiver filter RX and the first transmitter filter TX1, and helps improve the performance of the multiplexer.

[0062] In one embodiment of this application, the transmitter filter TX further includes a second transmitter filter TX2, the passband of which is configured as a third frequency band, which is located outside the first frequency band and is smaller than the first frequency band. Wherein, as... Figure 3 As shown, the anti-resonance frequency of the third series resonator unit 30 is located within the second frequency band. Similarly to the above embodiment, the receiver filter RX can achieve high suppression of the passband frequency band of the second transmitter filter TX2, thereby achieving high isolation between the receiver filter RX and the second transmitter filter TX2, effectively avoiding frequency interference between the receiver filter RX and the second transmitter filter TX2, and helping to improve the working performance of the multiplexer.

[0063] To clearly understand the multiplexer topology provided in this application, a detailed description is given below through a specific embodiment. Taking a Band25_66(70) quad-multiplexer as an example, the above-mentioned receiver filter RX is a Band25(70)RX filter with a passband range of 1930MHz~2020MHz; the first transmitter filter TX1 is a Band25TX filter with a passband range of 1850MHz~1915MHz; and the second transmitter filter TX2 is a Band66(70)TX filter with a passband range of 1695MHz~1780MHz.

[0064] like Figure 6 As shown, Figure 6 This is a comparison chart of the narrowband performance of the receiver filter RX in the Band25_66(70) quad-multiplexer based on the multiplexer topology of this application. Figure 6 The red Y-curve is the Y-curve of the receiver filter RX in the Band25_66(70) quad-multiplexer based on the multiplexer topology of this application, and the blue Y-curve is the Y-curve of the receiver filter RX in the Band25_66(70) quad-multiplexer of related technology. Figure 6As can be seen, the red Y-curve is narrower and steeper, with a steepness of 60dB at 1917MHz, while the blue Y-curve has a steepness of 29dB at the same frequency. Therefore, the receiver filter RX of the multiplexer topology provided in this application can also achieve high suppression of the passband of the Band25TX filter, which is very close to its frequency band. In other words, the receiver filter RX of the multiplexer topology provided in this application has a higher steepness and better suppression of important frequency bands.

[0065] like Figure 7 As shown, Figure 7 This is a comparison chart of the isolation performance of the receiver filter RX in the Band25_66(70) quad-multiplexer based on the multiplexer topology of this application. Figure 7 The red Y-curve is the Y-curve of the receiver filter RX in the Band25_66(70) quad-multiplexer based on the multiplexer topology of this application, and the blue Y-curve is the Y-curve of the receiver filter RX in the Band25_66(70) quad-multiplexer of related technology. Figure 7 As can be seen, the receiver filter RX in the topology provided in this application has an improved isolation margin of approximately 5MHz and an improved isolation level of approximately 2dB compared to related technologies, resulting in better isolation performance.

[0066] like Figure 8 As shown, Figure 8 This is a comparison diagram of the cross-isolation performance of the receiver filter RX in the Band25_66(70) quad-multiplexer based on the multiplexer topology of this application. Figure 8 The red Y-curve is the Y-curve of the receiver filter RX in the Band25_66(70) quad-multiplexer based on the multiplexer topology of this application, and the blue Y-curve is the Y-curve of the receiver filter RX in the Band25_66(70) quad-multiplexer of related technology. Figure 8 As can be seen, the receiver filter RX in the topology provided in this application has a cross isolation improvement of approximately 5dB compared to related technologies, resulting in better cross isolation performance.

[0067] like Figure 9 As shown, Figure 9 This is a comparison diagram of the passband loss of the receiver filter RX in the Band25_66(70) quad-multiplexer based on the multiplexer topology of this application. Figure 9 The red Y-curve is the Y-curve of the receiver filter RX in the Band25_66(70) quad-multiplexer based on the multiplexer topology of this application, and the blue Y-curve is the Y-curve of the receiver filter RX in the Band25_66(70) quad-multiplexer of related technology. Figure 9As can be seen, the passband loss of the receiver filter RX in the topology provided in this application is approximately 0.3dB compared to related technologies, and the passband energy loss is small. In other words, the multiplexer topology provided in this application achieves high steepness and high suppression of the receiver filter RX with very small passband energy loss, and is highly practical.

[0068] It should be noted that, Figures 6-9 The purple diagonal line in the middle represents the passband of the first transmitter filter TX1 and the second transmitter filter TX2, which is also the suppression band of the receiver filter RX.

[0069] Based on the multiplexer described above, this application also provides a radio frequency module, which includes the multiplexer described in any of the above embodiments.

[0070] Accordingly, this application also provides an electronic device that includes the aforementioned radio frequency module.

[0071] The various embodiments in this specification are described in a progressive, parallel, or combined manner. Each embodiment focuses on its differences from other embodiments, and similar or identical areas between embodiments can be referred to interchangeably. For the apparatuses disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the descriptions are relatively simple, and relevant details can be found in the description of the method area.

[0072] It should be noted that, in the description of this application, the terms "upper," "lower," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. When a component is considered to be "connected" to another component, it can be directly connected to the other component or there may be a component centrally located at the same time.

[0073] It should also be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that an article or apparatus comprising a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such an article or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the article or apparatus that includes the aforementioned element.

[0074] The above description of the disclosed embodiments enables those skilled in the art to make or use this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A multiplexer, characterized in that, include: The system includes an antenna end, a receiver end filter, and a transmitter end filter, wherein both the receiver end filter and the transmitter end filter are connected to the antenna end. The receiving filter includes a first series resonator unit, a second series resonator unit, and a third series resonator unit connected in series, as well as a parallel resonator unit and a matching structure; the first series resonator unit is connected to the antenna end and also to the parallel resonator unit, the parallel resonator unit is grounded through a first inductor, and the third series resonator unit is connected to the matching structure. The first series resonator unit includes at least one first resonator connected in series, the passband of the receiver filter is configured as a first frequency band based on the first series resonator unit, the second series resonator unit includes at least two second resonators connected in parallel, and the third series resonator unit includes at least one third resonator connected in series; the resonant frequencies of the first resonator, the second resonator, and the third resonator are less than their anti-resonant frequencies. The second preset size of the second resonator is larger than the first preset size of the first resonator, so that the anti-resonance frequency of the second series resonator unit is smaller than the resonance frequency of the first series resonator unit, and the anti-resonance frequency of the second series resonator unit is outside the first frequency band and smaller than the first frequency band. The second preset size of the second resonator is smaller than the third preset size of the third resonator, so that the anti-resonance frequency of the third series resonator unit is smaller than the resonance frequency of the second series resonator unit. The difference between the second preset size and the first preset size is the first difference, so that the difference between the anti-resonance frequency of the second series resonator unit and the minimum frequency of the first frequency band is less than the second difference.

2. The multiplexer according to claim 1, characterized in that, The first resonator, the second resonator, and the third resonator are surface acoustic wave (SAW) resonators. The SAW resonator includes an interdigital transducer located on a piezoelectric substrate. The interdigital transducer includes first electrode fingers and second electrode fingers arranged alternately along a first direction, which is parallel to the mounting surface of the piezoelectric substrate. The first preset size is the distance between adjacent first electrode fingers and second electrode fingers in the first resonator along the first direction, and the first preset size is inversely proportional to the resonant frequency and anti-resonant frequency of the first resonator; the second preset size is the distance between adjacent first electrode fingers and second electrode fingers in the second resonator along the first direction, and the second preset size is inversely proportional to the resonant frequency and anti-resonant frequency of the second resonator; the third preset size is the distance between adjacent first electrode fingers and second electrode fingers in the third resonator along the first direction, and the third preset size is inversely proportional to the resonant frequency and anti-resonant frequency of the third resonator.

3. The multiplexer according to claim 2, characterized in that, The at least one first resonator includes a first sub-resonator, a second sub-resonator, a third sub-resonator, and a fourth sub-resonator connected in series. The at least two second resonators include a fifth sub-resonator and a sixth sub-resonator connected in parallel. The at least one third resonator includes a seventh sub-resonator. The first sub-resonator is connected to the input terminal of the receiving filter. The fifth sub-resonator is connected to the fourth sub-resonator. The fifth sub-resonator is also connected to the seventh sub-resonator. The seventh sub-resonator is also connected to the matching structure. The matching structure is connected to the output terminal of the receiving filter. The second preset size of the fifth sub-resonator is the same as the second preset size of the sixth sub-resonator.

4. The multiplexer according to claim 3, characterized in that, At least one of the first structural parameter, second structural parameter, third structural parameter, fourth structural parameter and fifth structural parameter of the fifth sub-resonator and the sixth sub-resonator is the same; Wherein, the first structural parameter is the effective area of ​​the surface acoustic wave resonator; the second structural parameter is the number of the first and second electrode fingers of the surface acoustic wave resonator; the third structural parameter is the width of the first and second electrode fingers of the surface acoustic wave resonator along the first direction; the fourth structural parameter is the length of the first and second electrode fingers of the surface acoustic wave resonator along the second direction, the second direction being parallel to the extension direction of the first and second electrode fingers of the surface acoustic wave resonator; and the fifth structural parameter is the aperture of the surface acoustic wave resonator.

5. The multiplexer according to claim 3, characterized in that, The matching structure includes a second inductor and a third inductor; One end of the second inductor is connected to the seventh sub-resonator, and the other end is connected to one end of the third inductor and also to the output terminal of the receiving filter. The other end of the third inductor is grounded.

6. The multiplexer according to claim 3, characterized in that, The parallel resonator unit includes a fourth resonator, a fifth resonator, a sixth resonator, and a seventh resonator, and the first inductor includes a first sub-inductor and a second sub-inductor. One end of the fourth resonator is connected between the first sub-resonator and the second sub-resonator, one end of the fifth resonator is connected between the second sub-resonator and the third sub-resonator, the sixth resonator is connected between the third sub-resonator and the fourth sub-resonator, and the seventh resonator is connected between the fourth sub-resonator and the second series resonator unit. The fourth and fifth resonators are grounded through the first sub-inductor, and the sixth and seventh resonators are grounded through the second sub-inductor.

7. The multiplexer according to any one of claims 1-6, characterized in that, It also includes a fourth inductor, which is connected between the input terminal of the receiving filter and the first series resonator unit, and the fourth inductor is grounded.

8. The multiplexer according to claim 1, characterized in that, The transmitter filter includes a first transmitter filter, the passband of which is configured as a second frequency band, which is located outside the first frequency band and is smaller than the first frequency band; The anti-resonance frequency of the second series resonator unit is located within the second frequency band.

9. The multiplexer according to claim 8, characterized in that, The transmitter filter includes a second transmitter filter, the passband of which is configured as a third frequency band, which is located outside the second frequency band and is smaller than the second frequency band; The anti-resonance frequency of the third series resonator unit is located within the third frequency band.

10. A radio frequency module, characterized in that, Includes the multiplexer as described in any one of claims 1-9.

11. An electronic device, characterized in that, Includes the radio frequency module as described in claim 10.

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