Duplexer topological structure, radio frequency module and electronic equipment

Abstract

The invention discloses a duplexer topological structure, a radio frequency module and electronic equipment. The duplexer topological structure comprises a transmitting end filter connected between a transmitting end and an antenna port; a receiving end filter connected between the receiving end and the antenna port; wherein the receiving end filter comprises a plurality of first series resonators which are sequentially connected in series between the receiving end and the antenna port; every two adjacent first series resonators are grounded through a first parallel resonator; and the adjusting branch is connected with the receiving end filter and is used for adjusting the position of the parallel resonance point in the receiving end filter, so that the body wave of the resonator in the receiving end filter is located outside the passband of the receiving end filter. According to the technical scheme, the problem of insertion loss deterioration caused by the fact that the body wave of the resonator falls into the passband can be avoided, the insertion loss of the resonator can be reduced, and then the performance of the duplexer can be improved.

Description

Technical Field

[0001] The present application relates to the field of resonators, and more specifically, to a duplexer topology structure, a radio frequency module and an electronic device. Background Art

[0002] Surface acoustic wave resonator (SAW) is a device widely used in the RF field. It combines low insertion loss and good suppression performance with a small size. It mainly uses the piezoelectric effect to convert electrical energy and mechanical energy. Surface acoustic wave resonators can be used to combine signal transmission to achieve gating characteristics.

[0003] A plurality of surface acoustic wave resonators can be interconnected to form a filter, and the filter can be used to form a duplexer. In existing duplexers, the insertion loss problem of the surface acoustic wave resonator is serious, which will affect the performance of the duplexer. Summary of the invention

[0004] In view of this, the present application provides a duplexer topology structure, a radio frequency module and an electronic device, and the scheme is as follows:

[0005] The first aspect of the present application provides a duplexer topology structure, including: a transmitting filter connected between a transmitting end and an antenna port; a receiving filter connected between a receiving end and an antenna port; wherein the receiving filter includes a plurality of first series resonators connected in series between the receiving end and the antenna port in sequence; two adjacent first series resonators are respectively grounded via a first parallel resonator; and an adjustment branch connected to the receiving filter, the adjustment branch being used to adjust the position of the parallel resonance point in the receiving filter so that the body wave of the resonator in the receiving filter is located outside the passband of the receiving filter.

[0006] Optionally, in the above-mentioned duplexer topology structure, on the series path from the antenna port to the receiving end, the receiving end filter has N first series resonators connected in series in sequence, and along the series path, the N first series resonators are sequentially from the 1st-level receiving end series resonator to the Nth-level receiving end series resonator; wherein N is a positive integer greater than 1; on the series path, the adjustment branch is connected in parallel with the Nth-level receiving end series resonator.

[0007] In one embodiment, the regulating branch and the Nth stage receiving end series resonator are integrated on the same piezoelectric substrate. In other embodiments, the regulating branch and the Nth stage receiving end series resonator can be prepared independently.

[0008] Optionally, in the above-mentioned duplexer topology structure, at least the N-stage receiving end series resonator is a surface acoustic wave resonator, which includes: interdigitated electrodes and a reflection grating located on the same side surface of the piezoelectric substrate; wherein the adjustment branch is located outside the area where the interdigitated electrodes are provided on the piezoelectric substrate.

[0009] Optionally, in the above-mentioned duplexer topology structure, the adjustment branch is located on the side of the reflection grating away from the piezoelectric substrate; or, the adjustment branch is located on the same side surface of the piezoelectric substrate on which the reflection grating and the interdigitated electrodes are provided; in the direction perpendicular to the plane where the piezoelectric substrate is located, the adjustment branch has no overlapping part with the reflection grating and the interdigitated electrodes, and the adjustment branch is located on the side of the reflection grating away from the interdigitated electrodes; or, the adjustment branch is located on the side surface of the piezoelectric substrate away from the interdigitated electrodes.

[0010] Optionally, in the above duplexer topology, the regulating branch includes at least one capacitor. The regulating branch may include one capacitor, or multiple capacitors, which are interconnected and connected in parallel to both ends of the series resonator at the Nth stage receiving end.

[0011] A second aspect of the present application provides a radio frequency module, which includes any of the above-mentioned duplexer topology structures.

[0012] A third aspect of the present application provides an electronic device, comprising the above-mentioned radio frequency module.

[0013] From the above description, it can be seen that in the duplexer topology structure, RF module and electronic device provided in the embodiments of the present application, by setting an adjustment branch connected to the receiving end filter in the duplexer topology structure, the position of the parallel resonance point in the receiving end filter can be adjusted so that the body wave of the resonator in the receiving end filter is located outside the passband of the receiving end filter, which can avoid the problem of insertion loss deterioration caused by the body wave of the resonator falling into the passband, reduce the insertion loss of the resonator, and thus improve the performance of the duplexer. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the related technologies, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.

[0015] The structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification so as to facilitate understanding and reading by persons familiar with this technology. They are not used to limit the conditions under which this application can be implemented, and therefore have no substantive technical significance. Any structural modification, change in proportion or adjustment of size, without affecting the effects and purposes that can be achieved by this application, should still fall within the scope of the technical contents disclosed in this application.

[0016] Figure 1 is a schematic diagram of a duplexer topology;

[0017] Figure 2 is a passband curve diagram of a surface acoustic wave resonator;

[0018] Figure 3 It is the admittance curve of the large-size resonator connected in series in the filter;

[0019] Figure 4 A schematic diagram of a duplexer topology structure provided in an embodiment of the present application;

[0020] Figure 5 A top view of a surface acoustic wave resonator integrated with an adjustment branch provided in an embodiment of the present application;

[0021] Figure 6 for Figure 5 Section along A-A' direction;

[0022] Figure 7 A top view of another surface acoustic wave resonator integrated with an adjustment branch provided in an embodiment of the present application;

[0023] Figure 8 An admittance curve diagram of a large-size resonator provided in an embodiment of the present application;

[0024] Fig. 9 A passband performance comparison test diagram of a large-size resonator provided in an embodiment of the present application;

[0025] Fig.10 A comparative test diagram of the isolation performance of a large-size resonator provided in an embodiment of the present application;

[0026] Fig.11 A top view of a reflective grating provided in an embodiment of the present application;

[0027] Fig.12 A top view of another reflective grating provided in an embodiment of the present application;

[0028] Fig.13 A top view of another reflective grating provided in an embodiment of the present application.

[0029] Reference numerals:

[0030] 11-receiving filter; 111-first series resonator; 112-first parallel resonator; 113-regulating branch; 12-transmitting filter; 121-second series resonator; 122-second parallel resonator; 13-piezoelectric substrate; 14-forked electrode; 141-first forked electrode 141; 142-second forked electrode; 143-first finger; 144-second finger; 15-reflection grating; 151-third finger; 152-gap; 153-floating finger; 154-plug; 16-temperature compensation layer; Rx-receiving end; Tx-transmitting end; Ant-antenna port. DETAILED DESCRIPTION

[0031] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the embodiments in the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0032] As described in the background art, a plurality of surface acoustic wave resonators can be interconnected to form a filter, and the filter can be used to construct a duplexer.

[0033] refer to Figure 1 , Figure 1 A schematic diagram of a duplexer topology. Figure 1 The circuit topology structure shown includes: a transmitting end filter 12 connected between a transmitting end Tx and an antenna port Ant; and a receiving end filter 11 connected between a receiving end Rx and an antenna port Ant.

[0034] The receiving filter 11 includes a plurality of first series resonators 111 sequentially connected in series between the receiving end Rx and the antenna port Ant; two adjacent first series resonators 111 are grounded via a first parallel resonator 112 respectively.

[0035] The transmitting filter 12 includes a plurality of second series resonators 121 connected in series between the transmitting terminal Tx and the antenna port Ant; a second parallel resonator 122 is respectively connected to ground between two adjacent second series resonators 121 and between the transmitting terminal Tx and the connected second series resonator 121.

[0036] The first series resonator 111 and the first parallel resonator 112 may be surface acoustic wave resonators. The second series resonator 121 and the second parallel resonator 122 may be surface acoustic wave resonators.

[0037] In the filter formed by the surface acoustic wave resonator, a large-size resonator (characterized by a large aperture and a large number of fingers, such as Figure 1 The steepness of the filter can be improved by using the method of rs5 in . The steeper the frequency response curve of the filter, the narrower the transition band of the cutoff frequency, and the better the performance of the filter.

[0038] However, when the steepness of the filter is increased, the body wave of the resonator may fall into the passband, resulting in the deterioration of the passband insertion loss of the resonator. Experimental results show that the passband insertion loss can deteriorate by as much as 0.8dB.

[0039] refer to Figure 2 , Figure 2 The figure is a passband curve of a surface acoustic wave resonator, with the horizontal axis being frequency in GHz and the vertical axis being signal power in dB. The passband performance of the filter is easily affected by the body wave of the surface acoustic wave resonator. This problem is reflected in the passband curve of the surface acoustic wave resonator in that if the body wave of the surface acoustic wave resonator falls into the passband, Figure 2 As shown in the dotted ellipse area, the passband curve of the SAW resonator collapses.

[0040] refer to Figure 3 , Figure 3 It is the admittance curve diagram of the large-sized resonator connected in series in the filter. In the duplexer topology, based on the out-of-band suppression and isolation requirements, the pitch of the interdigital electrode (IDT) of the large-sized resonator connected in series in the receiving end filter 11 is usually relatively fixed, so that its parallel resonance point acts near the transition band.

[0041] In conventional technology, the insertion loss of the resonator is reduced by weakening the amplitude of the bulk wave, but the effect is limited and will affect other performance of the resonator. In addition, this also requires extremely high accuracy of the process design kit (PDK). However, the PDK can usually only accurately reflect the main mode resonance and cannot accurately estimate the effect of weakening the amplitude of the bulk wave.

[0042] Based on the above description, it can be seen that in a filter with a duplexer topology structure, how to make the body wave of the resonator perfectly stagger the passband of the filter without damaging the performance of the filter is an urgent problem to be solved in the field of duplexer topology design.

[0043] In order to solve the above problems, an embodiment of the present application provides a duplexer topology structure, including:

[0044] A transmitter filter connected between the transmitter and the antenna port;

[0045] A receiving end filter connected between the receiving end and the antenna port; wherein the receiving end filter comprises a plurality of first series resonators sequentially connected in series between the receiving end and the antenna port; two adjacent first series resonators are respectively grounded via a first parallel resonator;

[0046] An adjustment branch connected to the receiving end filter is used to adjust the position of the parallel resonance point in the receiving end filter so that the body wave of the resonator in the receiving end filter is located outside the passband of the receiving end filter.

[0047] From the above description, it can be seen that in the duplexer topology structure provided in the embodiment of the present application, by setting an adjustment branch connected to the receiving end filter in the duplexer topology structure, the position of the parallel resonance point in the receiving end filter can be adjusted so that the body wave of the resonator in the receiving end filter is located outside the passband of the receiving end filter, which can avoid the problem of insertion loss deterioration caused by the body wave of the resonator falling into the passband, reduce the insertion loss of the resonator, and thus improve the performance of the duplexer.

[0048] The above is the core inventive concept of the technical solution of the embodiment of the present application. In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, the present application is further described in detail below in conjunction with the drawings and specific implementation methods.

[0049] refer to Figure 4 , Figure 4 A schematic diagram of a duplexer topology structure provided in an embodiment of the present application, wherein the duplexer topology structure shown includes:

[0050] A transmitting filter 12 connected between the transmitting end Tx and the antenna port Ant;

[0051] A receiving filter 11 connected between the receiving end Rx and the antenna port Ant. The receiving filter 11 includes a plurality of first series resonators 111 sequentially connected in series between the receiving end Rx and the antenna port Ant; two adjacent first series resonators 111 are grounded via a first parallel resonator 112 respectively;

[0052] The regulating branch 113 connected to the receiving end filter 11 is used to adjust the position of the parallel resonance point in the receiving end filter 11 so that the body wave of the resonator in the receiving end filter 11 is located outside the passband of the receiving end filter.

[0053] In the duplexer topology structure provided in the embodiment of the present application, by setting an adjustment branch 113 connected to the receiving-end filter 11, the position of the parallel resonance point in the receiving-end filter 11 can be adjusted so that the body wave of the resonator in the receiving-end filter 11 is located outside the passband of the receiving-end filter 11, which can avoid the problem of insertion loss deterioration caused by the body wave of the resonator falling into the passband, reduce the insertion loss of the resonator, and thus improve the performance of the duplexer.

[0054] On the series path from the antenna port Ant to the receiving end Rx, the receiving end filter 11 has N first series resonators 111 connected in series in sequence. Along the series path, the N first series resonators 111 are sequentially connected from the first-stage receiving end series resonator rs1 to the N-stage receiving end series resonator rs N ; Wherein, N is a positive integer greater than 1.

[0055] Correspondingly, the receiving end filter 11 has N-1 first parallel resonators 112, and the N-1 first parallel resonators 112 are sequentially the first-stage receiving end parallel resonator rp1 to the N-1-stage receiving end parallel resonator rp N-1 The i-th stage receiving end series resonator rs i Connected to the i+1th stage receiving end in series with the resonator rs i+1 The circuit is connected to ground via the i-th receiving end parallel resonator rp1, where i is a positive integer less than N.

[0056] In order to improve the steepness of the frequency response curve of the receiving end filter 11, make the transition band of the cut-off frequency narrower, and improve the performance of the receiving end filter 11, set the Nth stage receiving end series resonator rs N The size is larger than the series resonator rs of the i-th stage receiving end i Since the Nth stage receiving end series resonator rs N Having a larger size can make it have a larger aperture, so that the number of fingers in its interdigitated electrode is larger, and the resonator has a higher impedance change rate at the corresponding frequency, thereby enhancing the out-of-band suppression capability of the filter and significantly improving the selectivity of the frequency response curve, that is, increasing the steepness of the transition band between the passband and the stopband.

[0057] In one implementation of the embodiment of the present application, for the receiving end filter 11, in the series path, the regulating branch 113 and the Nth stage receiving end series resonator rs N In this way, the Nth stage receiving end series resonator rs can be adjusted by adjusting branch 113. N The position of the corresponding parallel resonance point is so that the Nth stage receiving end series resonator rs NThe body wave of the receiving end filter 11 is outside the passband, thereby reducing the Nth stage receiving end series resonator rs N The insertion loss is reduced, thereby improving the performance of the receiving end filter 11.

[0058] In other implementations of the embodiments of the present application, the adjustment branch 113 may also be connected in parallel with other first series resonators 111 in the receiving-end filter 11 .

[0059] The transmitting filter 12 includes a plurality of second series resonators 121 connected in series between the transmitting terminal Tx and the antenna port Ant. A second parallel resonator 122 is connected to ground between two adjacent second series resonators 121 and between the transmitting terminal Tx and the connected second series resonator 121.

[0060] Specifically, on the series path from the antenna port Ant to the transmitting end Tx, the transmitting end filter 12 has N-1 second series resonators 121 connected in series in sequence. Along the series path, the N-1 second series resonators 121 are sequentially connected from the first-stage transmitting end series resonator ts1 to the N-1-stage transmitting end series resonator ts N-1 .

[0061] Correspondingly, the transmitting end filter 12 has N-1 second parallel resonators 122, and the N-1 second parallel resonators 122 are sequentially the first-stage transmitting end parallel resonator tp1 to the N-1-stage transmitting end parallel resonator tp N-1 The jth stage transmitting end parallel resonator ts j The resonator ts is connected in parallel with the j+1th stage transmitting end j+1 Through the jth level sending end parallel resonator tp j Ground, the N-1th level sending end parallel resonator ts N-1 Between the transmitter Tx and the transmitter Tx, the N-1th level transmitter parallel resonator tp N-1 Ground. j is a positive integer less than N-1.

[0062] exist Figure 4 In the illustrated method, N=5 is used as an example for illustration. It is easy to know that the value of N can be set according to the requirements, and the value of N is not limited in the embodiment of the present application, and is not limited to N=5.

[0063] In the embodiment of the application, the regulating branch 113 is connected to the Nth stage receiving end in series with the resonator rs N By integrating on the same piezoelectric substrate, the integration level of the duplexer topology structure can be improved, and no additional layout space is required in the duplexer topology structure to install the regulating branch 113 .

[0064] As described above, in the embodiment of the present application, each resonator of the duplexer topology structure can be a surface acoustic wave resonator, or at least the Nth level receiving end series resonator rs N It is a surface acoustic wave resonator.

[0065] refer to Figure 5 , Figure 5 A top view of a surface acoustic wave resonator integrated with an adjustment branch provided in an embodiment of the present application, wherein the surface acoustic wave resonator includes: a piezoelectric substrate 13; interdigitated electrodes 14 and a reflective grating 15 located on the same side surface of the piezoelectric substrate 13; wherein the adjustment branch 113 is located outside the region where the interdigitated electrodes 14 are provided on the piezoelectric substrate 13, so that the adjustment branch 113 can be prevented from interfering with the interdigitated electrodes 14, thereby preventing the adjustment branch 113 from interfering with the N-th level receiving end series resonator rs N .

[0066] The reflection grating 15 can reflect the sound waves back to the interdigital transducer region corresponding to the interdigital electrode 14 to form a better resonance, thereby improving the transmission performance of the surface acoustic wave resonator.

[0067] The interdigital electrode 14 includes a first interdigital electrode 141 and a second interdigital electrode 142. The first interdigital electrode 141 has a plurality of first fingers 143 arranged in sequence along a first direction X, and the second interdigital electrode 142 has a plurality of second fingers 144 arranged in sequence along the first direction X. In the first direction X, the first fingers 143 and the second fingers 144 are alternately arranged on the surface of the piezoelectric substrate 13. All the first fingers 143 are connected to one side of the same bus bar extending along the first direction X. All the second fingers 144 are connected to one side of the same bus bar extending along the first direction X. The bus bars connected to the first fingers 143 and the second fingers 144 are arranged opposite to each other in the second direction Y. There is a gap between the bus bar connected to the first fingers 143 and the second fingers 144, and there is a gap between the bus bar connected to the second fingers 144 and the first fingers 143.

[0068] In the embodiment of the present application, the bus bar connected to the first finger 143 may be provided with a plurality of dummy fingers, the dummy fingers in the bus bar are opposite to the second finger 144 one by one, and there is a gap between the opposite second finger 144. The bus bar connected to the second finger 144 may be provided with a plurality of dummy fingers, the dummy fingers in the bus bar are opposite to the first finger 143 one by one, and there is a gap between the opposite first finger 143. By providing dummy fingers in the bus bar of the interdigitated electrode 14, the propagation of the acoustic wave can be adjusted and optimized to improve the performance of the surface acoustic wave resonator.

[0069] In the first direction X, a reflection grating 15 is respectively disposed on opposite sides of the interdigital electrode 14, and the reflection grating 15 has a plurality of third fingers 151 sequentially arranged along the first direction X. The first fingers 143, the second fingers 144 and the third fingers 151 all extend along the second direction Y. The first direction X is perpendicular to the second direction Y, and the XY plane is parallel to the plane where the piezoelectric substrate 13 is located.

[0070] refer to Figure 6 , Figure 6 for Figure 5 The cross-sectional view along the A-A' direction, combined with Figure 5 and Figure 6 As shown, the adjustment branch 113 can be located on the side of the reflective grating 15 away from the piezoelectric substrate 13. In this way, the adjustment branch 113 is arranged above the reflective grating 15, so that the adjustment branch 113 and the reflective grating 15 are stacked, and the space above the reflective grating 15 can be used to arrange the adjustment branch 113, so that the adjustment branch 113 does not occupy the additional layout area of ​​the piezoelectric substrate 13, and does not increase the N-th level receiving end series resonator rs N size.

[0071] In addition, since the reflection grating 15 is designed through a physical structure, it can effectively reflect the incident surface acoustic wave back to the interdigital transducer area formed by the interdigital electrode 14. Since the reflection grating 15 reflects the acoustic wave based on physical properties, no modulation of the electrical signal is required, and the adjustment branch 113 is set above the reflection grating 15, which will not generate interference with the electrical signal and will not affect the performance of the reflection grating 15.

[0072] Optionally, the surface acoustic wave resonator further includes a temperature compensation layer 16 disposed on the surface of the piezoelectric substrate 13 , and the temperature compensation layer 16 covers the interdigital electrodes 14 and the reflection grating 15 . The adjustment branch 113 is located on the surface of the temperature compensation layer 16 .

[0073] A TC-SAW (temperature-compensated surface acoustic wave resonator) can be formed based on the temperature compensation layer 16, which can overcome the temperature drift problem.

[0074] In the surface acoustic wave resonator, the interdigital electrodes 14 are used to excite and detect surface acoustic waves. The performance of the interdigital electrodes 14 will be affected by temperature changes, causing the frequency response of the surface acoustic wave resonator to change with temperature fluctuations. The temperature compensation layer 16 can adjust the piezoelectric properties of the interdigital electrodes 14 so that the interdigital electrodes 14 maintain a relatively stable oscillation frequency at different temperatures. By providing the temperature compensation layer 16 in the surface acoustic wave resonator, the negative impact of temperature on the surface acoustic wave resonator can be effectively offset, ensuring that the surface acoustic wave resonator can maintain high performance and high reliability over a wide temperature range, and can improve temperature characteristics and frequency stability.

[0075] The regulating branch 113 is located on the surface of the temperature compensation layer 16. Based on the fact that the temperature compensation layer 16 carries the regulating branch 113, the temperature compensation layer 16 provides a flat layout surface for the regulating branch 113, so as to facilitate the integration of the regulating branch 113 in the surface acoustic wave resonator.

[0076] In the embodiment of the present application, the surface acoustic wave resonator may be a TF-SAW (Thin Film Surface Acoustic Wave Resonator), and the piezoelectric substrate 13 includes a substrate and a piezoelectric film disposed on the surface of the substrate.

[0077] In the embodiment of the present application, if the regulating branch 113 is disposed above the reflective grating 15 , the regulating branch 113 may be disposed on one reflective grating 15 or two reflective gratings 15 .

[0078] When the adjustment branch 113 is arranged above the reflection grating 15, the adjustment branch 113 can be connected to the reflection grating below, and the connected reflection grating is reused as an electrode of the adjustment branch 113. As described above, in the surface acoustic wave resonator, since the reflection grating 15 reflects the sound wave based on the physical reflection characteristics, the reflection of the sound wave does not need to be controlled by an electrical signal, so the adjustment branch 113 can reuse the reflection grating 15 as one of its own electrodes, thereby improving the integration.

[0079] refer to Figure 7 , Figure 7 A top view of another surface acoustic wave resonator integrated with an adjustment branch provided in an embodiment of the present application, based on the above-mentioned embodiment, the adjustment branch 113 is located on the same side surface of the piezoelectric substrate 13 where the reflection grating 15 and the interdigitated electrodes 14 are provided; in the direction perpendicular to the plane of the piezoelectric substrate 13, the adjustment branch 113 has no overlapping part with the reflection grating 15 and the interdigitated electrodes 14, and the adjustment branch 113 is located on the side of the reflection grating 15 away from the interdigitated electrodes 14.

[0080] exist Figure 7 In the manner shown, the adjustment branch 113, the reflection grid 15 and the interdigital electrode 14 are arranged on the same side surface of the piezoelectric substrate 13, and the reflection grid 15 is arranged between the adjustment branch 113 and the interdigital electrode 14. The adjustment branch 113 and the interdigital electrode 14 can be isolated by the reflection grid 15 to prevent interference between the two.

[0081] Optionally, in the surface acoustic wave resonator, the interdigital electrodes 14 and the reflective grating 15 can be made of the same metal layer. The metal layer can be used to prepare an electrode of the regulating branch 113 to reduce the number of metal layers and the thickness of the device.

[0082] In one implementation of the embodiment of the present application, the regulating branch 113 may be arranged on a surface of the piezoelectric substrate 13 on a side away from the interdigital electrodes 14. In this way, the regulating branch 113 is arranged on a surface of the piezoelectric substrate 13 on a side away from the interdigital electrodes 14, which can make it more convenient to arrange the regulating branch 113 on the piezoelectric substrate 13.

[0083] In the embodiment of the present application, the regulating branch 113 includes at least one capacitor Crs. When the regulating branch 113 has multiple capacitors Crs, the multiple capacitors Crs can be connected in parallel, in series, or in mixed connection to form the regulating branch 113. The regulating branch 113 can be connected in parallel at both ends of a first series resonator 111 of the receiving filter 11 to adjust the position of the parallel resonance point corresponding to the first series resonator 111 so that its body wave is located outside the passband of the receiving filter 11, thereby reducing the insertion loss of the first series resonator 111. In one embodiment, it can be as follows Figure 4 As shown, the adjustment branch 113 includes a capacitor Crs, which is connected in parallel with the N-stage receiving end series resonator rs N If N=5, the capacitor Crs is connected in parallel at both ends of the 5th level receiving end series resonator rs5.

[0084] In the embodiment of the present application, the capacitor Crs can be integrated in a first series resonator 111 of the receiving filter 11. In this case, the capacitor Crs can be set as an interdigital capacitor on the piezoelectric substrate of the first series resonator 111, and the capacitor Crs can be directly integrated into the chip of the resonator to improve the integration.

[0085] From the above description, it can be seen that the duplexer topology structure provided in the embodiment of the present application can be connected in parallel with the resonator in the filter by adjusting the branch 113 to adjust the position of its parallel resonance point, so as to perfectly stagger the passband of the filter without damaging the performance of the filter.

[0086] The following is combined with Figure 4 Taking the duplexer topology structure of the circuit structure as an example, specific experimental data are used to further illustrate the technical effect that can be achieved by the technical solution of the embodiment of the present application.

[0087] For the receiving filter 11 having a large-sized fifth-stage receiving-end series resonator rs5 in series, the admittance and real part curve of the fifth-stage receiving-end series resonator rs5 can be shown as follows: Figure 8 shown.

[0088] refer to Figure 8 , Figure 8 An admittance curve diagram of a large-size resonator provided in an embodiment of the present application, Figure 8In FIG. 1 , curve L1 represents a test curve of the admittance and the real part of the resonator when there is no capacitor Crs, and curve L2 represents a test curve of the admittance and the real part of the resonator when the capacitor Crs is connected in parallel.

[0089] based on Figure 8 As shown in the figure, the bulk wave position can be moved from 1880MHz to 1905MHz by the parallel capacitor Crs, away from the passband (1805MHz~1880MHz) of the receiving filter 11 in the duplexer topology, avoiding the influence of the resonator bulk wave on the performance of the receiving filter 11, and the loss on the right side of the passband of the receiving filter 11 is also improved, as shown in FIG. Fig. 9 At the same time, this method also hardly damages the isolation performance of the device, as shown in the middle curve L3. Fig.10 shown.

[0090] refer to Fig. 9 , Fig. 9 A passband performance comparison test diagram of a large-size resonator provided in an embodiment of the present application, Fig. 9 The middle curve L3 is the test curve when the resonator is connected in parallel with the capacitor Crs, and L4 is the test curve when there is no parallel capacitor Crs. Fig. 9 It can be seen that the loss on the right side of the passband of the receiving-end filter 11 is also improved.

[0091] refer to Fig.10 , Fig.10 This is a comparative test diagram of the isolation performance of a large-size resonator provided in an embodiment of the present application. Fig.10 The middle curve L5 is the isolation performance test curve after the body wave is adjusted by the parallel capacitor Csr. The curve L5 is the isolation performance test curve when there is no parallel capacitor Crs. By comparing the curves L5 and L6, it can be seen that based on the embodiment of the present application, while adjusting the resonator body wave by the parallel capacitor Crs, the isolation performance of the device is almost not damaged.

[0092] Based on the above experimental data, it is shown that based on the technical solution described in the embodiment of the present application, the body wave of the fifth-level receiving-end series resonator rs5 can be adjusted to the outside of the band of the receiving-end filter 11 by connecting the two-terminal capacitors Crs of the large-sized fifth-level receiving-end series resonator rs5 of the receiving-end filter 11, thereby improving the right-side loss of the passband of the receiving-end filter 11, and basically does not affect the isolation performance. In addition, the potential risk of inaccurate PDK simulation body wave amplitude can also be avoided. The technical solution of the present application does not require unexpected design parameters of the fifth-level receiving-end series resonator rs5, which greatly improves the feasibility.

[0093] It can be seen from the above description that the technical solution of the embodiment of the present application can effectively submit the body wave position to avoid its influence on the filter passband without damaging the performance of the device.

[0094] The embodiment of the present application provides a solution for adjusting the body wave by the adjustment branch 113, which can be adjusted in conjunction with other relevant parameters of the resonator to present better performance, such as combining a reflection grating with the function of adjusting the body wave with the adjustment branch 113 to simultaneously optimize the performance of the resonator and the filter.

[0095] like Figure 5 As shown, the reflective grid 15 can be a rectangular frame structure. The third fingers 151 in the reflective grid 15 are all of the same length. The reflective grid 15 has two opposite bus bars in the second direction Y. The two ends of the third fingers 151 are respectively connected to the two bus bars in one piece.

[0096] refer to Fig.11 , Fig.11 FIG. 1 is a top view of a reflective grating provided in an embodiment of the present application. The length of the third fingers 151 in the reflective grating 15 is gradually reduced along the third direction Z. The third direction Z is the direction in which the reflective grating is away from the interdigital electrodes 14. In this case, the reflective grating 15 can be as follows: Fig.11 The trapezoidal structure shown may also be a conical structure, or may be a special-shaped structure in which the two bus bars are arc-shaped.

[0097] The length of the third finger 151 in the reflection grating 15 is arranged to decrease successively along the third direction Z, so that the length of the third finger 151 in the reflection grating 15 decreases successively in the direction away from the interdigitated electrode 14, so as to adjust the body wave through the reflection grating 15 so that the body wave of the resonator is located outside the passband of the filter.

[0098] refer to Fig.12 , Fig.12 A top view of another reflection grating provided in an embodiment of the present application, in which, on the basis of the rectangular reflection grating, a third finger 151 with a gap 152 is arranged along a third direction Z, and starting from the third finger 151 adjacent to the interdigitated electrode 14, a plurality of third fingers 151 arranged continuously have two gaps 152, and a portion of the same third finger 151 located between the two gaps 152 forms a floating finger 153, and along the third direction Z, the length of the floating finger 153 decreases successively, and based on the floating finger 153 that decreases successively along the third direction Z, the body wave can be adjusted so that the body wave of the resonator is outside the passband of the filter.

[0099] refer to Fig.13 , Fig.13A top view of another reflector provided in an embodiment of the present application, in which two bus bars of the reflector 15 are respectively connected to third fingers 151, and the third fingers 151 connected to the two bus bars are arranged alternately along the first direction X. The end of the third finger 151 away from the connected bus bar has a plug 154, and a plug 154 is also provided in a preset area between the end and the bus bar connected to the third finger 151. In this manner, the body wave can be adjusted by the plug 154 provided on the third finger 151, so that the body wave of the resonator is located outside the passband of the filter.

[0100] Based on the duplexer topology structure provided in the above embodiments, another embodiment of the present application further provides a radio frequency module, and the radio frequency module includes the duplexer topology structure provided in any one of the above embodiments.

[0101] The RF module provided in the embodiment of the present application adopts the duplexer topology structure provided in the above embodiment. The body wave of the resonator can be adjusted by setting an adjustment branch 113 in the duplexer topology structure so that the body wave of the resonator is outside the passband of the filter, thereby improving the performance of the filter, thereby improving the performance of the duplexer topology structure and the RF module having the duplexer topology structure.

[0102] Based on the above embodiments, another embodiment of the present application further provides an electronic device, which includes the above radio frequency module.

[0103] Optionally, the electronic device may be a wireless communication device such as a smart phone, a satellite communication device, a radar system, etc. The embodiment of the present application does not limit the type of the electronic device, and it may be any electronic device with a radio frequency module.

[0104] The electronic device provided in the embodiment of the present application adopts the above-mentioned RF module, and can adjust the body wave of the resonator by setting the adjustment branch 113 in the duplexer topology structure so that the body wave of the resonator is outside the passband of the filter, so as to improve the performance of the filter, and then improve the performance of the duplexer topology structure and the RF module having the duplexer topology structure, and finally improve the performance of the electronic device.

[0105] In the specification of this application, each embodiment is described in a progressive, parallel, or progressive and parallel manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. The implementation methods provided in the embodiments of this application can be combined with each other if there is no contradiction.

[0106] It should be noted that in the description of the present application, it should be understood that the description of the drawings and embodiments is illustrative rather than restrictive. The same reference numerals throughout the embodiments of the specification identify the same structure. In addition, for the sake of understanding and ease of description, the drawings may exaggerate the thickness of some layers, films, panels, regions, etc. It is also understood that when an element such as a layer, film, region, or substrate is referred to as "on" another element, the element may be directly on the other element or there may be an intermediate element. In addition, "on" refers to positioning an element on or below another element, but does not essentially refer to positioning on the upper side of another element according to the direction of gravity.

[0107] The terms "upper", "lower", "top", "bottom", "inner", "outer", etc. indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present application. When a component is considered to be "connected" to another component, it may be directly connected to the other component or there may be a centrally arranged component at the same time.

[0108] It should also be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "comprises", "comprising" or any other variants thereof are intended to cover non-exclusive inclusion, so that an article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such article or device. In the absence of further restrictions, the elements defined by the sentence "comprising a ..." do not exclude the existence of other identical elements in the article or device including the above elements.

[0109] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present application. Various modifications to these embodiments will be 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 the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A duplexer topology structure, characterized in that: include: A transmitter filter connected between the transmitter and the antenna port; A receiving end filter connected between the receiving end and the antenna port; wherein the receiving end filter comprises a plurality of first series resonators sequentially connected in series between the receiving end and the antenna port; two adjacent first series resonators are grounded via a first parallel resonator respectively; an adjusting branch connected to the receiving end filter, the adjusting branch being used to adjust the position of the parallel resonance point in the receiving end filter so that the body wave of the resonator in the receiving end filter is located outside the passband of the receiving end filter; Among them, on the series path from the antenna port to the receiving end, the receiving end filter has N first series resonators connected in series in sequence, and along the series path, the N first series resonators are sequentially from the 1st-level receiving end series resonator to the Nth-level receiving end series resonator; wherein N is a positive integer greater than 1; on the series path, the adjustment branch is connected in parallel with the Nth-level receiving end series resonator.

2. The duplexer topology structure according to claim 1, characterized in that: The regulating branch and the Nth stage receiving end series resonator are integrated on the same piezoelectric substrate.

3. The duplexer topology structure according to claim 2, characterized in that: At least the N-stage receiving end series resonator is a surface acoustic wave resonator, and the surface acoustic wave resonator includes: Interdigital electrodes and a reflective grating located on the same side surface of the piezoelectric substrate; Wherein, the regulating branch is located outside the region of the piezoelectric substrate where the interdigital electrodes are provided.

4. The duplexer topology structure according to claim 3, characterized in that: The adjustment branch is located at a side of the reflection grating away from the piezoelectric substrate.

5. The duplexer topology structure according to claim 3, characterized in that: The regulating branch is located on the same side surface of the piezoelectric substrate where the reflection grating and the interdigital electrodes are provided; In a direction perpendicular to the plane where the piezoelectric substrate is located, the adjustment branch has no overlapping portion with the reflection grating and the interdigital electrodes, and the adjustment branch is located on a side of the reflection grating away from the interdigital electrodes.

6. The duplexer topology structure according to claim 5, characterized in that: The regulating branch reuses the reflection grating as one of its own electrodes.

7. The duplexer topology structure according to claim 3, characterized in that: The regulating branch is located on a surface of the piezoelectric substrate that is away from the interdigital electrodes.

8. The duplexer topology structure according to any one of claims 1 to 7, characterized in that: The regulating branch includes at least one capacitor.

9. A radio frequency module, characterized in that: It comprises a duplexer topology structure as described in any one of claims 1 to 8.

10. An electronic device, characterized in that: Comprising the radio frequency module as described in claim 9.

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