Elastic wave device, duplexer, and multiplexer
By optimizing the matching circuit design and using inductors or capacitors to adjust the impedance characteristics, the problem of matching the size and performance of SAW filter chips was solved, resulting in a smaller and higher-performance filter.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- MAXSCEND MICROELECTRONICS CO LTD
- Filing Date
- 2025-03-31
- Publication Date
- 2026-04-21
AI Technical Summary
In existing technologies, methods for reducing the size of SAW filter chips have the problems of increased manufacturing difficulty and decreased filter performance. In particular, after reducing the resonator area, impedance mismatch affects the gain, rejection ratio and nonlinear characteristics.
By optimizing the matching circuit design, inductors or capacitors are used as passive electronic components, connected in series or in parallel between the antenna and the target resonator. The impedance characteristics of the circuit are adjusted to compensate for the reduction in capacitive impedance caused by the reduction in the area of the resonator, ensuring port impedance matching and suppressing unwanted signals in the high-frequency band.
A smaller filter chip was achieved, improving out-of-band rejection and nonlinear characteristics, avoiding increased losses caused by high-resistivity materials, and improving overall performance.
Smart Images
Figure CN224154192U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to an elastic wave device, specifically to an elastic wave device, a duplexer, and a multiplexer. Background Technology
[0002] With the continuous improvement of mobile communication technology, the number of communication frequency bands has also increased dramatically, and the number of filters used has also continued to increase. System applications require the integration of more filter chips within a limited space, that is, how to reduce the size of filter chips is a problem we are currently facing.
[0003] In existing technologies, reducing the chip size of surface acoustic wave (SAW) filters typically involves using low-velocity piezoelectric substrates. Further methods to reduce the velocity of sound using existing piezoelectric substrates employ heavy metals (such as platinum) as the electrode material for the transducer. These methods present several problems: First, heavy metals have high melting points, increasing manufacturing complexity. Second, the resistivity of heavy metals is higher than that of commonly used metals like aluminum, leading to increased filter losses. Furthermore, reducing the resonator area also decreases the equivalent capacitance, potentially causing impedance mismatch and affecting performance such as gain, rejection ratio, and nonlinear characteristics. Utility Model Content
[0004] This application provides an elastic wave device, a duplexer, and a multiplexer to solve the problem in related technologies of how to reduce the size of filter chips while ensuring out-of-band suppression and nonlinear characteristics of the devices.
[0005] To achieve the above objectives, according to one aspect of this application, an elastic wave device is provided, comprising: a matching circuit, a resonant unit, and an antenna terminal, wherein the matching circuit is connected between the resonant unit and the antenna terminal, the resonant unit includes at least one resonator, and the resonator directly connected to the matching circuit is a target resonator; the matching circuit includes a first passive electronic component and a second passive electronic component, both the first and second passive electronic components including a first terminal and a second terminal, the antenna terminal being connected to the first terminal of the first passive electronic component, and the second terminal of the first passive electronic component being connected to the target resonator; the first terminal of the second passive electronic component is connected to either the first or second terminal of the first passive electronic component, and the second terminal of the second passive electronic component is connected to a reference ground; the first and second passive electronic components are independently selected from inductors or capacitors.
[0006] Optionally, the second passive electronic component in the matching circuit is a capacitor, which includes a first metal layer, an insulating dielectric layer, and a second metal layer stacked together.
[0007] Optionally, the elastic wave device of this application further includes a packaging substrate, the first passive electronic component is an inductor, and the first passive electronic component and the second passive electronic component are independently selected from one of the following types: wire-wound inductors or surface-mount devices disposed on the packaging substrate.
[0008] Optionally, the target resonator is a surface acoustic wave resonator.
[0009] Optionally, the elastic wave device of this application further includes a digital signal processing module, a transmitting end and a receiving end. The digital signal processing module is connected to the resonant unit and is used to convert the analog signal output by the resonant unit into a digital signal. The transmitting end and the receiving end are respectively connected to the resonant unit, and the digital signal processing module is connected to the receiving end.
[0010] Optionally, the number of resonators in the resonant unit is 2 to 30.
[0011] Optionally, the elastic wave device further includes a packaging substrate, with a resonator located on one side of the packaging substrate. The target resonator includes a first target resonator connected to the transmitting end and a second target resonator connected to the receiving end. The projected area of the first target resonator on the substrate is larger than the projected area of the second target resonator on the substrate.
[0012] Optionally, the elastic wave device further includes a packaging substrate, with the resonator located on one side of the packaging substrate. The resonant unit also includes multiple resonators other than the target resonator, with the projected area of each target resonator on the packaging substrate being smaller than the projected area of each of the remaining resonators on the packaging substrate.
[0013] Alternatively, another aspect of this application provides a duplexer, including the aforementioned elastic wave device.
[0014] Alternatively, another aspect of this application provides a multiplexer that includes the aforementioned elastic wave device.
[0015] The technical solution of this application provides an elastic wave device. Through optimized matching circuit design, it specifically includes a first passive electronic component and a second passive electronic component. The first passive electronic component is connected between the antenna end and the target resonator, while the second passive electronic component is connected to the first passive electronic component or a reference ground. The smaller resonator has a smaller equivalent capacitance. The matching circuit provided in this application, by connecting the first passive electronic component in series between the antenna end and the target resonator, can increase the inductive impedance of the circuit, thereby compensating for the decrease in capacitive impedance caused by the reduction in the area of the resonator. The parallel connection of the second passive electronic component can further adjust the impedance characteristics of the circuit, especially suppressing unwanted signals in the high-frequency band, and thus effectively matching the equivalent capacitance of the smaller resonator to match the port impedance of the elastic wave device to the target value. Therefore, this application can use a smaller resonator, reducing the size of the target resonator, thereby realizing the miniaturization of the elastic wave device. Furthermore, the matching circuit of this application can provide accurate impedance matching over a wider frequency range, effectively enhancing out-of-band rejection capability, thereby significantly improving the out-of-band rejection and nonlinear characteristics of the elastic wave device, avoiding increased losses caused by the use of high-resistivity materials, and improving overall performance. Attached Figure Description
[0016] The accompanying drawings, which are included to provide a further understanding of the present invention and form part of this application, illustrate exemplary embodiments of the present invention and, together with the description thereof, serve to explain the present invention and do not constitute an undue limitation thereof. In the drawings:
[0017] Figure 1 This is a schematic diagram of an elastic wave device provided in an embodiment of this application;
[0018] Figure 2 This is a top view schematic diagram of a resonator provided in an embodiment of this application;
[0019] Figure 3 This is a schematic diagram of another elastic wave device provided in an embodiment of this application;
[0020] Figure 4 This is a schematic diagram of a matching circuit provided in Embodiment 3 of this application;
[0021] Figure 5 This is a schematic diagram of a matching circuit provided in Embodiment 4 of this application;
[0022] Figure 6 This is a schematic diagram of the topology of an elastic wave device provided in an embodiment of this application;
[0023] Figure 7 This is a schematic diagram of a matching circuit provided in Embodiment 1 of this application;
[0024] Figure 8 This is a layout of the filter in Embodiment 1 and Comparative Example 1 of this application;
[0025] Figure 9 This is a schematic diagram of a matching circuit provided in Embodiment 2 of this application;
[0026] Figure 10 This is a layout of the filter in Embodiment 2 and Comparative Example 2 of this application;
[0027] Figure 11 This is a schematic diagram of an elastic wave device provided in Comparative Example 1 of this application;
[0028] Figure 12 This is a schematic diagram of the topology of an elastic wave device provided in Comparative Example 2 of this application;
[0029] Figure 13 The graph shows the test results of the frequency response characteristics of the filters in Embodiment 1 and Comparative Example 1 of this application.
[0030] Figure 14 This is a small-signal response test diagram of the filter in Embodiment 2 of this application;
[0031] Figure 15 These are the out-of-band rejection test results of the filters in Embodiment 2 and Comparative Example 2 of this application;
[0032] Figure 16 The graph shows the frequency response characteristics test results of the filters in Embodiment 2 and Comparative Example 2 of this application.
[0033] The above figures include the following reference numerals:
[0034] 1. First passive electronic component; 2. Second passive electronic component; 3. Resonant unit; 4. Matching circuit; 10. Piezoelectric substrate; 20. Finger strip; 30. Target resonator; 31. First target resonator; 32. Second target resonator; 40. Digital signal processing module; 50. Filter chip; 60. Substrate. Detailed Implementation
[0035] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.
[0036] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of the present invention.
[0037] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this utility model are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the utility model described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.
[0038] For ease of description, the following explains some of the nouns or terms used in the embodiments of this application:
[0039] Antenna terminal;
[0040] Tx (Transport Extended Specification) transmitter;
[0041] Rx (Receive Extended Specification) receiver;
[0042] SAWR (Surface Acoustic Wave Resonator)
[0043] As introduced in the background section, reducing the size of filter chips is a current challenge in increasing the number of communication bands and filters. Existing technologies for reducing SAW filter chip size employ low-velocity piezoelectric substrates, using heavy metals (such as platinum) as the electrode material for the transducer. The main problems with this method are: heavy metals have high melting points, increasing manufacturing complexity; and their resistivity is higher than commonly used metals like aluminum, increasing filter losses. Furthermore, when the resonator area of the filter decreases, the equivalent capacitance of the resonator also decreases, potentially leading to impedance mismatch and affecting performance such as gain, rejection ratio, and nonlinear characteristics.
[0044] According to embodiments of this application, one aspect of this application provides an elastic wave device, such as... Figure 1 As shown, it includes: a matching circuit 4, a resonant unit 3, and an antenna terminal Ant. The matching circuit 4 is connected between the resonant unit 3 and the antenna terminal Ant. The resonant unit 3 includes at least one resonator, and the resonator directly connected to the matching circuit 4 is the target resonator. The matching circuit 4 includes a first passive electronic component 1 and a second passive electronic component 2. Both the first passive electronic component 1 and the second passive electronic component 2 include a first terminal and a second terminal. The antenna terminal Ant is connected to the first terminal of the first passive electronic component 1, and the second terminal of the first passive electronic component 1 is connected to the target resonator. The first terminal of the second passive electronic component 2 is connected to either the first terminal or the second terminal of the first passive electronic component 1, and the second terminal of the second passive electronic component 2 is connected to a reference ground. The first passive electronic component 1 and the second passive electronic component 2 are independently selected from inductors or capacitors.
[0045] Through the above implementation, this combination can effectively adjust the capacitive reactance characteristics of the elastic wave device, reduce the equivalent capacitance required to match the port impedance of the elastic wave device to the target value, thereby allowing the use of a smaller resonator in the elastic wave device. The inductive element provides the required inductive impedance to compensate for the reduction in capacitive impedance caused by the reduction in the area of the resonator. The parallel connection of the second passive electronic component can further adjust the impedance characteristics of the circuit, especially suppressing unwanted signals in the high-frequency band to balance the capacitiveness of the resonator and ensure that the elastic wave device has low loss and high efficiency in the passband. Overall, this design can precisely adjust the capacitive effect of the target resonator, enhance the out-of-band rejection capability, thereby reducing the overall size and optimizing nonlinear performance, effectively improving the performance of the elastic wave device.
[0046] Specifically, such as Figure 1 As shown, the elastic wave device also includes a transmitter Tx and a receiver Rx, which are responsible for transmitting and receiving signals respectively. The two work together to achieve bidirectional communication. An inductor L1 and an inductor L2 are respectively provided between Tx and Rx and the resonant unit 3.
[0047] For example, the structure of the resonator is as follows Figure 2 As shown, the resonator includes multiple finger strips 20, and the finger strip 20 in the target resonator is the first finger strip, which has a first number of fingers and a first spacing.
[0048] Specifically, such as Figure 2 As shown, the resonator also includes a piezoelectric substrate 10. The piezoelectric substrate has piezoelectric properties. When mechanical stress is applied to it, it generates an electric field. Conversely, when it is subjected to an electric field, it generates mechanical stress.
[0049] In some alternative implementations, such as Figure 3As shown, the second passive electronic component in the matching circuit is a capacitor, which includes a first metal layer 71, an insulating dielectric layer 80, and a second metal layer 72 stacked together. By stacking the capacitor, a high-density capacitance value can be achieved within a limited space, compensating for the inductive impedance caused by the resonator and series inductor. By adjusting the capacitance value, the elastic wave device can be ensured to have low loss and high transmission efficiency within the band, while providing the required suppression level outside the band. This matching strategy not only contributes to the miniaturization of the elastic wave device but also optimizes its nonlinear characteristics and improves overall performance.
[0050] For example, the structure is as follows Figure 4 As shown, the first passive electronic component 1 in the matching circuit 4 is a capacitor, and the second passive electronic component 2 is an inductor. The second passive electronic component 2 can also be a capacitor, such as... Figure 5 As shown. The capacitor in matching circuit 4 is used to compensate for the inductive impedance of the target resonator, enabling the entire system to achieve impedance matching at a specific frequency and improving the out-of-band rejection performance of the filter.
[0051] In some alternative embodiments, the elastic wave device further includes a packaging substrate, and the first passive electronic component and / or the second passive electronic component are inductors, which are surface mount devices (SMD), i.e., surface-mount inductors. These devices allow electronic components to be mounted on the surface of a circuit board without needing to penetrate the board. This can improve the integration of the device, further reduce its size, decrease the use of external components, lower production costs, while ensuring performance stability and reliability.
[0052] In another example, the aforementioned inductor is a wire-wound inductor, which is implemented in the package substrate using wire-wound technology, making the device more compact.
[0053] In some alternative implementations, the target resonator is a surface acoustic wave (SAW) resonator. SAW resonators offer excellent out-of-band rejection and stability, allowing the resonator design to maintain good impedance matching while reducing size. The inclusion of a finger bar in the SAWR effectively reduces the device's size.
[0054] In some alternative implementations, such as Figure 1 and Figure 6 As shown, Figure 1 The resonant unit 3 in the middle corresponds to Figure 6The elastic wave device includes multiple resonators (IEF1 to IEF11) and a target resonator 30. It also includes a digital signal processing module 40, whose functions include: correcting nonlinear distortion and converting signals into digital signals. The digital signal processing module 40 is connected to the resonant unit 3. The elastic wave device also includes an antenna end Ant, a transmitting end Tx, and a receiving end Rx. The transmitting end Tx and the receiving end Rx are respectively connected to the resonant unit 3. The antenna end Ant is directly connected to the matching circuit. The digital signal processing module 40 is connected to the receiving end Rx. The addition of the digital signal processing module 40 enables the conversion of the analog signal output from the resonant unit 3 into a digital signal, corrects the nonlinear distortion caused by the resonator or matching circuit 4 through algorithms, enhances the signal's anti-interference capability, monitors the operating status of the elastic wave device, and adjusts the elastic wave device parameters to adapt to different operating conditions.
[0055] For example, the digital signal processing module includes a digital microwave system (DMS).
[0056] In some alternative implementations, the number of resonators in the resonant unit is 2 to 30, and each resonator has its specific resonant frequency. When multiple resonators are connected in series or in parallel, their frequency responses are superimposed to achieve more precise frequency selection.
[0057] For example, this embodiment provides a topology for the resonant unit including 13 resonators, such as... Figure 6As shown, the target resonator 30 is directly connected to the antenna terminal Ant. The target resonator 30 includes a first target resonator 31 connected to the transmitting terminal Tx and a second target resonator 32 connected to the receiving terminal Rx. The resonant unit 3 also includes multiple resonators other than the target resonator 30. Among them, the second resonator IEF2, the fourth resonator IEF4, and the sixth resonator IEF6 are connected in series with the first target resonator 31. The sixth resonator IEF6 is connected to the transmitting terminal Tx. The eighth resonator IEF8 and the tenth resonator IEF10, which are connected in series with the second target resonator 32, are connected to the receiving terminal Rx. The first resonator IEF1, the third resonator IEF3, the fifth resonator IEF5, the seventh resonator IEF7, and the ninth resonator IEF10 are connected in series with the first resonator IEF1, the third resonator IEF3, the fifth resonator IEF5, the seventh resonator IEF7, and the ninth resonator IEF10 are connected in series with the second target resonator 32. One end of resonator IEF9 and the eleventh resonator IEF11 are grounded. The other end of the first resonator IEF1 is connected between the first target resonator 31 and the second resonator IEF2. The other end of the third resonator IEF3 is connected between the second resonator IEF2 and the fourth resonator IEF4. The other end of the fifth resonator IEF5 is connected between the fourth resonator IEF4 and the sixth resonator IEF6. The other end of the seventh resonator IEF7 is connected between the sixth resonator IEF6 and the transmitting end Tx. The other end of the ninth resonator IEF9 is connected between the second target resonator 32 and the eighth resonator IEF8. The other end of the eleventh resonator IEF11 is connected between the eighth resonator IEF8 and the tenth resonator IEF10. This structure of the elastic wave device enables efficient filtering for bidirectional communication, ensuring the purity of the transmitted and received signals.
[0058] In some alternative implementations, the elastic wave device further includes a packaging substrate, with the resonator located on one side of the packaging substrate, such as... Figure 6 As shown, the target resonator 30 includes a first target resonator 31 connected to the transmitting end and a second target resonator 32 connected to the receiving end; the projected area of the first target resonator 31 on the packaging substrate is larger than the projected area of the second target resonator 32 on the packaging substrate. By adjusting the size of the resonators, the signal transmission characteristics can be optimized, and the bandwidth and selectivity of the elastic wave device can be improved.
[0059] In some alternative implementations, the projected area of each target resonator on the package substrate is smaller than the projected area of each of the remaining resonators on the package substrate. Smaller target resonators have smaller equivalent capacitance, which means that the resonator exhibits higher impedance at frequencies outside the passband, thus contributing to improved out-of-band rejection performance.
[0060] According to another aspect of this application, a duplexer is provided, including the aforementioned elastic wave device. The duplexer enables simultaneous transmission and reception on the same device. The duplexer provided in this application, through an optimized elastic wave device, effectively improves the isolation of the duplexer, reduces interference between transmitted and received signals, integrates more elastic wave device chips within a limited space, increases the number of communication bandwidths, and significantly improves the stability and reliability of the communication system.
[0061] According to another aspect of this application, a multiplexer is also provided, including the aforementioned elastic wave device. The multiplexer can process signals from multiple frequency bands simultaneously. The multiplexer provided in this application, through its optimized elastic wave device, can integrate more elastic wave devices within the same space compared to existing multiplexers, and can effectively improve the out-of-band rejection capability of the multiplexer, reduce interference between signals from different frequency bands, and significantly improve the communication capability and compatibility of the device.
[0062] The elastic wave device of this application will now be described in conjunction with specific embodiments and comparative examples.
[0063] Example 1
[0064] Embodiment 1 of this application provides a filter, such as Figure 1 As shown, it includes: a matching circuit 4, a resonant unit 3, an antenna terminal Ant, a receiver terminal Rx, and a transmitter terminal Tx. The matching circuit 4 is connected between the resonant unit 3 and the antenna terminal Ant. An inductor, L1, is provided between the transmitter terminal Tx and the receiver terminal Rx and the resonant unit 3, respectively.
[0065] The structure of matching circuit 4 is as follows Figure 7 As shown, the matching circuit 4 consists of a first passive electronic component 1 and a second passive electronic component 2. Both the first passive electronic component 1 and the second passive electronic component 2 have a first terminal and a second terminal. The antenna terminal is connected to the first terminal of the first passive electronic component 1, and the second terminal of the first passive electronic component 1 is connected to the target resonator. The first terminal of the second passive electronic component 2 is connected to either the first terminal or the second terminal of the first passive electronic component 1, and the second terminal of the second passive electronic component 2 is connected to the reference ground. Both the first passive electronic component 1 and the second passive electronic component 2 are inductors. The first passive electronic component 1 is implemented by wire winding in the packaging substrate of the filter.
[0066] The filter topology is as follows Figure 6 As shown, the digital signal processing module 40 is connected to the receiving end Rx;
[0067] like Figure 6As shown, the target resonator 30 is directly connected to the antenna end Ant. The target resonator 30 includes a first target resonator 31 connected to the transmitting end Tx and a second target resonator 32 connected to the receiving end Rx.
[0068] The resonant unit also includes multiple resonators besides the target resonator 30. In this embodiment, it also includes 11 resonators, wherein the second resonator IEF2, the fourth resonator IEF4, and the sixth resonator IEF6 are connected in series with the first target resonator 31. The sixth resonator IEF6 is connected to the transmitting end Tx. The eighth resonator IEF8 and the tenth resonator IEF10, which are connected in series with the second target resonator 32, are connected to the receiving end Rx. One end of the first resonator IEF1, the third resonator IEF3, the fifth resonator IEF5, the seventh resonator IEF7, the ninth resonator IEF9, and the eleventh resonator IEF11 are respectively grounded. The other end of resonator IEF1 is connected between the first target resonator 31 and the second resonator IEF2; the other end of the third resonator IEF3 is connected between the second resonator IEF2 and the fourth resonator IEF4; the other end of the fifth resonator IEF5 is connected between the fourth resonator IEF4 and the sixth resonator IEF6; the other end of the seventh resonator IEF7 is connected between the sixth resonator IEF6 and the transmitter Tx; the other end of the ninth resonator IEF9 is connected between the second target resonator 32 and the eighth resonator IEF8; and the other end of the eleventh resonator IEF11 is connected between the eighth resonator IEF8 and the tenth resonator IEF10. The layout of Embodiment 1 is as follows... Figure 8 As shown in (a), the layout size is 1300*900.
[0069] Example 2
[0070] Embodiment 2 of this application provides an elastic wave device, which differs from Embodiment 1 in that:
[0071] The structure of matching circuit 4 is as follows Figure 9 As shown, it includes a first passive electronic component 1 and a second passive electronic component 2, wherein the second passive electronic component 2 is a capacitor;
[0072] The layout of Example 2 is as follows Figure 10 As shown in (a), the layout size is 1100*700.
[0073] Comparative Example 1
[0074] This comparative example provides an elastic wave device, such as... Figure 11As shown, it includes: an inductor element L3, a resonant unit 3, an antenna terminal Ant, a receiver terminal Rx, and a transmitter terminal Tx. The matching circuit 4 is connected between the resonant unit 3 and the antenna terminal Ant. An inductor L1 and an inductor L2 are provided between the transmitter terminal Tx and the receiver terminal Rx and the resonant unit 3, respectively. The resonant unit 3 includes the same number of resonators as in Embodiment 1, and the filter topology is the same as in Embodiment 1. The two ends of the inductor element are connected to the antenna terminal Ant and the reference ground, respectively.
[0075] The map of Comparative Example 1 is as follows Figure 8 As shown in (b), the layout size is 1350*950.
[0076] Comparative Example 2
[0077] This comparative example provides an elastic wave device, which differs from Comparative Example 1 in that:
[0078] Comparative Scale 2 map reference Figure 10 (b) The size of the map is 1300*900.
[0079] like Figure 12 As shown, this embodiment includes 11 resonators. The topology of the resonant unit includes: a first resonator IEF1 and a ninth resonator IEF9 connected to the antenna terminal Ant; a digital signal processing module 40 connected to the receiver terminal Rx, wherein the third resonator IEF3, the fifth resonator IEF5, and the seventh resonator IEF7 are connected in series with the first resonator IEF1, the seventh resonator IEF7 is connected to the transmitter terminal Tx, and the digital signal processing module 40 is connected in series with the ninth resonator IEF9; the second resonator IEF2, the fourth resonator IEF4, the sixth resonator IEF6, the eighth resonator IEF8, the tenth resonator IEF10, and the tenth resonator IEF9 are connected in series with the transmitter terminal Tx. One end of the resonator IEF11 is grounded. The other end of the second resonator IEF2 is connected between the first resonator IEF1 and the third resonator IEF3. The other end of the fourth resonator IEF4 is connected between the third resonator IEF3 and the fifth resonator IEF5. The other end of the sixth resonator IEF6 is connected between the fifth resonator IEF5 and the seventh resonator IEF7. The other end of the tenth resonator IEF10 is connected between the ninth resonator IEF9 and the digital signal processing module 40. The other end of the eleventh resonator IEF11 is connected between the digital signal processing module 40 and the receiver Rx. The eleventh resonator IEF11 is also connected in parallel with a capacitor.
[0080] The resonator areas inside the filters obtained in the above embodiments are all reduced. Taking the areas of the first-stage Tx resonator and the first-stage Rx resonator near the antenna Ant as examples, the first-stage resonator mentioned above is the target resonator, the first-stage Tx resonator is the first target resonator, and the first-stage Rx resonator is the second target resonator. The areas of the target resonators are shown in Table 1.
[0081] Table 1
[0082]
[0083] As shown in Table 1, the area of the first-stage resonator at the antenna end is reduced by about 30%, and the other resonators that make up the filter can also be further reduced, ultimately achieving an overall chip area reduction of about 10%.
[0084] Specific details are as follows: Figure 8 As shown, the filter layouts of Embodiment 1 and Comparative Example 1 are presented, including a substrate 60 and a filter chip 50. Figure 8 (a) is the filter layout of Example 1. Figure 8 (b) is the filter layout of Comparative Example 1. Figure 8 Comparison of filter layout areas in (a) Figure 8 The filter layout area in (b) is reduced by about 10%, from the original 1350*950 to 1300*900.
[0085] Figure 10 The filter layouts of Embodiment 2 and Comparative Example 2 are shown, including a substrate 60 and a filter chip 50. Figure 10 (a) is the filter layout of Example 2. Figure 10 (b) shows the filter layout of Comparative Example 2. Figure 10 The filter layout area in (a) is compared to Figure 10 (b) The filter layout was reduced from 1300*900 to 1100*700, a reduction of 34.2% in area.
[0086] Harmonic tests were performed on Example 1 and Comparative Example 1 with B20 at an input power of 30 dBm under mismatch conditions, and harmonic tests were performed on Example 2 and Comparative Example 2 with B8 at an input power of 30 dBm under mismatch conditions. The test results are shown in Table 2.
[0087] Table 2
[0088]
[0089] As shown in Table 2, after applying the embodiments of this utility model, the nonlinear harmonics of the filter body are improved by more than 5dBm. For bandpass filters, when the loss in the passband is basically the same, the higher the out-of-band rejection, the better the performance in the overall application. Higher out-of-band rejection can better suppress the nonlinear harmonic characteristics generated by the filter body in the application.
[0090] Frequency response characteristics were tested for Example 1 and Comparative Example 1, and the results are as follows: Figure 13 As shown, a frequency response comparison diagram of the filter is presented, representing the system's response strength to signals of different frequencies. Figure 13 (a) The frequency response diagram of the filter under high-frequency conditions Tx is given. Figure 13 (b) The frequency response diagram of the filter under high-frequency conditions, Rx is given. Figure 13 (c) The frequency response diagram of the isolation of the filter under high frequency conditions is given, where the dashed line is the frequency response characteristic of the comparative example and the solid line is the frequency response characteristic of Example 1. It can be seen that the overall frequency response characteristic is improved to a certain extent.
[0091] Figure 14 The small-signal response of Example 2 is given, representing the response characteristics of the system in Example 2 to small signals. The figure shows the response strength of the system to signals of different frequencies. As can be seen from the figure, the response strength of the system increases with the increase of frequency.
[0092] Figure 15 The comparison of out-of-band suppression improvement between Example 1 and Comparative Example 1 is given, where the dashed line represents the small-signal response of Comparative Example 1 and the solid line represents the small-signal response of Example 1. Figure 15 As can be seen, the system's response strength is improved in the frequency range of 0.5GHz to 6GHz.
[0093] Frequency response characteristics were tested for Example 2 and Comparative Example 2, and the results are as follows: Figure 16 As shown, a frequency response comparison diagram of the filter is presented, representing the system's response strength to signals of different frequencies. Figure 16 (a) The frequency response diagram of filter Tx is given. Figure 16 (b) The frequency response diagram of filter Rx is given. Figure 16 (c) The frequency response diagram of the filter isolation is given, where the dashed line is the frequency response characteristic of Comparative Example 2 and the solid line is the frequency response characteristic of Example 2. It can be seen that the overall frequency response characteristic is improved to a certain extent.
[0094] As can be seen from the above description, the embodiments of this utility model achieve the following technical effects:
[0095] A matching architecture is introduced into the peripheral matching circuit of the elastic wave device. That is, a first passive electronic component is connected in series between the antenna end and the resonant unit, and a second passive electronic component is connected in parallel on this basis. The passive electronic components are inductors or capacitors to reduce the impedance characteristics of the resonator and achieve effective matching between the small resonator and the system impedance. This significantly reduces the size of the elastic wave device chip. The matching architecture in this application enables the elastic wave device to have higher out-of-band rejection, thereby significantly improving the nonlinear harmonic characteristics of the filter.
[0096] Obviously, those skilled in the art will understand that the modules or steps of the present invention described above can be implemented using general-purpose computing devices. They can be centralized on a single computing device or distributed across a network of multiple computing devices. They can be implemented using computer-executable program code, and thus can be stored in a storage device for execution by a computing device. In some cases, the steps shown or described can be performed in a different order than those presented here, or they can be fabricated as separate integrated circuit modules, or multiple modules or steps can be fabricated as a single integrated circuit module. Thus, the present invention is not limited to any particular combination of hardware and software.
[0097] The above description is merely a preferred embodiment of this utility model and is not intended to limit the scope of this utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the principles of this utility model should be included within the protection scope of this utility model.
Claims
1. An elastic wave device characterized by comprising: Includes matching circuit, resonant unit, and antenna terminal, wherein: The matching circuit is connected between the resonant unit and the antenna end. The resonant unit includes at least one resonator, and the resonator directly connected to the matching circuit is the target resonator. The matching circuit includes a first passive electronic component and a second passive electronic component, wherein both the first passive electronic component and the second passive electronic component include a first end and a second end, the antenna end is connected to the first end of the first passive electronic component, the second end of the first passive electronic component is connected to the target resonator, the first end of the second passive electronic component is connected to either the first end or the second end of the first passive electronic component, and the second end of the second passive electronic component unit is connected to a reference ground. The first passive electronic component and the second passive electronic component are independently selected from inductors or capacitors.
2. The elastic wave device of claim 1, wherein, The second passive electronic component unit in the matching circuit is a capacitor element, which includes a first metal layer, an insulating dielectric layer, and a second metal layer stacked together.
3. The elastic wave device according to claim 1 or 2, characterized by, It also includes a packaging substrate, wherein the first passive electronic component and the second passive electronic component are independently selected from one of the following types: wire-wound inductors or surface-mount devices disposed on the packaging substrate.
4. The elastic wave device according to claim 1 or 2, characterized by The target resonator is a surface acoustic wave resonator.
5. The elastic wave device according to claim 1 or 2, characterized by, Also includes: The system includes a digital signal processing module, a transmitter, and a receiver. The digital signal processing module is connected to the resonant unit and is used to convert the analog signal output by the resonant unit into a digital signal. The transmitter and the receiver are respectively connected to the resonant unit. The digital signal processing module is connected to the receiving end.
6. The elastic wave device of claim 1, wherein The number of stages of the resonator in the resonant unit is 2 to 30.
7. The elastic wave device of claim 5, wherein It also includes a packaging substrate, the resonator is located on one side of the packaging substrate, the target resonator includes a first target resonator connected to the transmitting end and a second target resonator connected to the receiving end, the projected area of the first target resonator on the packaging substrate is larger than the projected area of the second target resonator on the packaging substrate.
8. The elastic wave device of claim 1, wherein, It also includes a packaging substrate, the resonator is located on one side of the packaging substrate, and the resonant unit also includes a plurality of resonators other than the target resonator, wherein the projected area of each target resonator on the packaging substrate is smaller than the projected area of each of the remaining resonators on the packaging substrate.
9. A diplexer, characterized by The elastic wave device includes any one of claims 1 to 8.
10. A multiplexer, characterized by The elastic wave device includes any one of claims 1 to 8.