Method and apparatus for extracting bulk acoustic wave resonance frequency of resonator

Abstract

The application provides a method for extracting the bulk acoustic resonant frequency of a resonator, which is based on the rate of change of the electric conductance obtained by deriving the electric conductance with respect to the frequency, to obtain the bulk acoustic resonant frequency of the resonator, which is equivalent to solving the noise problem and the problem that the bulk acoustic corresponding admittance value is relatively fuzzy in the corresponding relationship between the admittance and the frequency by using a mathematical calculation method, thereby improving the accuracy of the extracted bulk acoustic resonant frequency. Moreover, because it is based on the corresponding relationship between the measured admittance and the frequency, the reliability of the extracted bulk acoustic resonant frequency can be improved. In addition, it also has at least higher scalability and calculation speed.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of radio frequency, in particular to a method and device for optimizing the performance of a filter. BACKGROUND

[0002] Radio Frequency (RF), also known as radio frequency, wireless radio frequency, or high frequency, refers to the frequency in the range of 300 kHz-300 GHz, which is used in the field of contemporary mobile communication. Typical RF devices include filters, diplexers / duplexers / multiplexers, power amplifiers (PA), low noise amplifiers (LNA), RF switches, monolithic microwave integrated chips (MICC), and RF modules with integrated functions, etc. The function of the filter is to filter out foreign signals (such as attenuating foreign signals) and allow signals of a specified frequency band to pass through to reduce the interference of foreign signals on the system.

[0003] The resonator is the basic unit of the filter, so the performance of the resonator is directly related to the performance of the filter.

[0004] Therefore, how to optimize the performance of the resonator is a problem to be solved. SUMMARY

[0005] The present application provides a method and device for extracting the bulk acoustic wave resonance frequency of a resonator, aiming to solve the problem of how to optimize the performance of the resonator.

[0006] In order to achieve the above-mentioned purpose, the present application provides the following technical solutions:

[0007] The first aspect of the present application provides a method for extracting the bulk acoustic wave resonance frequency of a resonator, comprising the following steps: measuring the correspondence between the admittance and the frequency of the resonator, obtaining the correspondence between the rate of change of conductance (i.e. conductance rate of change) as the real part of admittance and the frequency based on the correspondence between the admittance and the frequency, and extracting the frequency corresponding to a zero point (such as the zero point between the maximum and minimum values) of the conductance rate of change as the bulk acoustic wave resonance frequency of the resonator. Based on the rate of change of conductance obtained by taking the derivative of conductance with respect to frequency, the bulk acoustic wave resonance frequency of the resonator is obtained, which is equivalent to using mathematical calculation to solve the problem of noise and the problem that the admittance value corresponding to the bulk acoustic wave in the correspondence between the admittance and the frequency is relatively ambiguous, thereby improving the accuracy of the extracted bulk acoustic wave resonance frequency. Moreover, because the correspondence between the measured admittance and the frequency is used as the basis, the reliability of the extracted bulk acoustic wave resonance frequency can be improved. In addition, it also has at least higher scalability and calculation speed.

[0008] In some implementations, the specific way of obtaining the corresponding relationship between the conductance change rate and the frequency based on the corresponding relationship between the admittance and the frequency is: finding the anti-resonance frequency of the resonator from the corresponding relationship between the admittance and the frequency, and intercepting the corresponding relationship between the frequency and the admittance greater than the anti-resonance frequency as a target corresponding relationship, and then obtaining the corresponding relationship between the conductance change rate and the frequency based on the target corresponding relationship. The target corresponding relationship is the corresponding relationship after removing the data useless for extracting the bulk acoustic wave resonance frequency, so as to reduce the interference of the useless data on the extraction of the bulk acoustic wave resonance frequency, and further improve the accuracy of the extracted bulk acoustic wave resonance frequency.

[0009] In some implementations, the specific way of finding the anti-resonance frequency of the resonator is: finding the minimum value of the frequency in the corresponding relationship between the admittance and the frequency, so as to obtain the anti-resonance frequency of the resonator in a relatively simple and easy way.

[0010] In some implementations, the specific way of measuring the corresponding relationship between the admittance and the frequency of the resonator is: measuring the transmission characteristic curve of the resonator by the vector network analyzer, obtaining the corresponding relationship between the admittance and the frequency of the resonator based on the transmission characteristic curve, and specifically, obtaining the return loss parameter S11 based on the transmission characteristic curve, obtaining the admittance parameter based on Y=G0*(1-S11) / (1+S11), and an example of G0 is 0.02. This way of obtaining the corresponding relationship between the admittance and the frequency based on the transmission characteristic curve of the resonator has relatively high reliability and implementability.

[0011] In some implementations, the specific way of measuring the transmission characteristic curve of the resonator by the vector network analyzer is: measuring the transmission characteristic curve of the single-port resonator prepared in advance by the vector network analyzer, which can save cost compared with the double-port resonator.

[0012] In some implementations, before extracting the frequency corresponding to a zero point of the conductance change rate as the bulk acoustic wave resonance frequency of the resonator, the corresponding relationship between the conductance change rate and the frequency is also smoothed to obtain a smoothed target corresponding relationship, so as to remove the noise data in the corresponding relationship between the conductance change rate and the frequency. On this basis, the zero point of the conductance change rate in the smoothed target corresponding relationship is searched, and the frequency corresponding to a zero point of the conductance change rate is extracted as the bulk acoustic wave resonance frequency of the resonator, so as to obtain the bulk acoustic wave resonance frequency with relatively high accuracy.

[0013] In some implementations, the specific way of extracting the frequency corresponding to the zero point of the conductance rate of change as the bulk acoustic wave resonance frequency of the resonator is: searching for the maximum value and the minimum value of the conductance rate of change in the smoothed target correspondence relationship, linearizing the correspondence relationship between the maximum value and the minimum value, and extracting the midpoint of the linearized curve as the zero point of the conductance rate of change. In view of the fact that the ordinate changes rapidly between the maximum value and the minimum value in the correspondence relationship between the conductance and the frequency, the linearization assumption can bring about double improvement in the extraction accuracy and the extraction speed.

[0014] The second aspect of the present application provides a system for extracting the bulk acoustic wave resonance frequency of a resonator, comprising: a processor and a measurement device for measuring the admittance-to-frequency correspondence relationship of the resonator, the processor being configured to obtain a conductance rate of change-to-frequency correspondence relationship based on the admittance-to-frequency correspondence relationship, the conductance rate of change including the rate of change of the conductance represented by the admittance with respect to the frequency, and extract the frequency corresponding to the zero point of the conductance rate of change as the bulk acoustic wave resonance frequency of the resonator, thereby obtaining a bulk acoustic wave resonance frequency with high accuracy.

[0015] The third aspect of the present application provides an apparatus for extracting the bulk acoustic wave resonance frequency of a resonator, comprising:

[0016] The processor and the memory for storing executable instructions of the processor. The processor is configured to implement the following functions in the process of executing the executable instructions: obtaining a conductance rate of change-to-frequency correspondence relationship based on the measured admittance-to-frequency correspondence relationship of the resonator, the conductance rate of change including the rate of change of the conductance represented by the admittance with respect to the frequency, and extracting the frequency corresponding to the zero point of the conductance rate of change as the bulk acoustic wave resonance frequency of the resonator, thereby obtaining a bulk acoustic wave resonance frequency with high accuracy.

[0017] The fourth aspect of the present application provides a computer-readable storage medium, when the instructions in the computer-readable storage medium are executed by the processor of an electronic device, the electronic device can perform the following steps: obtaining a conductance rate of change-to-frequency correspondence relationship based on the measured admittance-to-frequency correspondence relationship of the resonator, the conductance rate of change including the rate of change of the conductance represented by the admittance with respect to the frequency, and extracting the frequency corresponding to the zero point of the conductance rate of change as the bulk acoustic wave resonance frequency of the resonator, thereby obtaining a bulk acoustic wave resonance frequency with high accuracy.

[0018] The fifth aspect of the present application provides a computer program product comprising computer programs / instructions, characterized in that the computer programs / instructions, when executed by a processor, implement the following steps: obtaining a corresponding relationship between a conductance rate of change and a frequency based on a corresponding relationship between a measured admittance of a resonator and the frequency, the conductance rate of change comprising a rate of change of a conductance represented by the admittance with respect to the frequency, and extracting a frequency corresponding to a zero point of the conductance rate of change as a bulk acoustic wave resonant frequency of the resonator, so as to obtain a bulk acoustic wave resonant frequency with higher accuracy. BRIEF DESCRIPTION OF DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or prior art description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without any creative effort based on these drawings.

[0020] Figure 1 An example diagram of a corresponding relationship between a bulk acoustic wave resonant frequency and a frequency wavenumber;

[0021] Figure 2 An example diagram of admittance-frequency curves of a SAW resonator under three different finger numbers;

[0022] Figure 3 An example diagram of an admittance-frequency curve of a TF-SAW resonator;

[0023] Figure 4 An example diagram of a simulation curve and a measured curve of an admittance-frequency curve that are consistent with each other;

[0024] Figure 5 An example diagram of a simulation curve and a measured curve of an admittance-frequency curve that have a large deviation;

[0025] Figure 6 A flowchart of extracting a bulk acoustic wave resonant frequency of a resonator disclosed in an embodiment of the present application;

[0026] Figure 7 An example diagram of a measured admittance-frequency curve in an embodiment of the present application;

[0027] Figure 8 An example diagram of a conductance-frequency curve obtained in an embodiment of the present application;

[0028] Figure 9 An example diagram of a conductance rate of change-frequency curve obtained in an embodiment of the present application;

[0029] Figure 10 An example diagram of a smoothed conductance rate of change-frequency curve obtained in an embodiment of the present application;

[0030] Figure 11 An example diagram of a system for extracting a bulk acoustic wave resonance frequency of a resonator disclosed in embodiments of the present application. DETAILED DESCRIPTION

[0031] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. The terms used in the following embodiments are only for the purpose of describing the specific embodiments and are not intended to be limiting on the present application. As used in the specification and the appended claims of the present application, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “one or more,” in embodiments of the present application, refer to one, two, or more than two; “and / or” describes the associated objects in the association relationship, which means that there can be three kinds of relationships; for example, A and / or B can mean that A exists alone, A and B exist together, B exists alone, where A and B can be singular or plural. The character “ / ” generally represents an “or” relationship between the associated objects.

[0032] In the present specification, the reference to “one embodiment” or “some embodiments” means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present application. Thus, the appearances of the phrases “in one embodiment,” “in some embodiments,” “in other embodiments,” “in additional embodiments,” and so on, in various places in the specification are not necessarily all referring to the same embodiment, unless otherwise indicated by the context. The terms “comprising,” “including,” “having,” and their variants, mean “including but not limited to,” unless otherwise indicated by the context.

[0033] The plurality referred to in embodiments of the present application means greater than or equal to two. It should be noted that in the description of embodiments of the present application, the terms “first,” “second,” and the like are used only for the purpose of distinguishing the described objects, and cannot be understood as indicating or implying relative importance, nor can they be understood as indicating or implying an order.

[0034] The function of the filter is to filter out signals of different frequencies (such as attenuating signals of different frequencies), and to allow signals of a specified frequency band to pass through, so as to reduce the interference of signals of different frequencies on the system.

[0035] For example, the fifth generation (5G) mobile communication uses frequency bands including FR1 (450 MHz-6 GHz, commonly known as Sub-6 GHz) and FR2 (24.25 GHz-52.6 GHz, commonly known as millimeter wave frequency band), and some typical examples of sub-bands are n77 (3300-4200 MHz), n78 (3300-3800 MHz), and n79 (4400-5000 MHz).

[0036] For filters applied to 5G mobile communication, a certain frequency band range in the above frequency band range is generally selected as a passband range, signals within the passband range of the filter are useful signals, and signals outside the passband range of the filter are out-of-band signals. After receiving a radio frequency signal, the filter filters out the out-of-band signals, and the useful signals can pass through the filter to lay the foundation for subsequent processing.

[0037] Resonators are the basic units of filters, and resonators include SAW resonators and bulk acoustic wave (BAW) resonators. According to the type of resonators constituting the filter, the filter is divided into SAW filters and BAW filters, etc.

[0038] In addition to being able to generate surface acoustic waves, SAW resonators can also generate bulk acoustic waves.

[0039] In practical applications, because SAW resonators mainly rely on surface waves to work, the demand for extracting bulk acoustic wave resonance frequencies is not high, and even if it is needed, the accuracy requirement is not high, especially in non-5G application scenarios, the bulk acoustic wave resonance frequency of the SAW resonator is not accurate, and the impact is not great. Therefore, the skilled person does not pay attention to whether the bulk acoustic wave resonance frequency extracted from the SAW resonator is accurate.

[0040] However, the inventors found in the course of research that, with the expansion of the application scenarios of SAW resonators, such as application in 5G scenarios, the performance optimization of SAW resonators and filters cannot be separated from the accurate extraction of bulk acoustic wave resonance frequencies, for the following reasons:

[0041] The bulk acoustic wave resonance frequency generated by the SAW resonator corresponds to the upper edge of the forbidden band of the frequency-wave number curve of the SAW resonator.

[0042] Specifically, the corresponding relationship between the bulk acoustic wave resonance frequency and the frequency-wave number is as shown in Figure 1 Figure 1 where f0 represents the center frequency, k represents the reflection coefficient, p represents the period length, q' represents the real part of the wave number, and q" represents the imaginary part of the wave number. From Figure 1 It can be seen that when the relative frequency is greater than and less than​ At this time, the frequency and wavenumber are purely imaginary. As the wave propagates, the amplitude decays, indicating a bandgap. Therefore, the lower edge of the bandgap is the relative frequency equal to... The upper edge of the bandgap has a relative frequency equal to... Applying this dispersion relation to the admittance curve of the SAW resonator, the resonant frequency f in the shearhorizontal (SH) mode of the resonator is the lower edge of the bandgap, while the resonant frequency of the bulk acoustic wave corresponds to the upper edge of the bandgap.

[0043] Since the upper edge of the bandgap is related to the design of the filter's passband (bandwidth), accurately extracting the bulk acoustic resonant frequency of the SAW resonator is beneficial for obtaining better filtering performance.

[0044] During their research, the inventors also discovered that, in practice, the radiation intensity of bulk acoustic waves from SAW resonators is relatively weak, making it difficult to extract automatically by computer. In other words, current methods for automatically extracting the bulk acoustic wave resonant frequency of SAW resonators based on their admittance-frequency curves are limited by the ambiguity of the admittance value corresponding to the bulk acoustic wave in the admittance-frequency curve caused by noise and other factors (i.e., the contribution of bulk acoustic wave resonance to admittance is relatively smooth), making it difficult to extract the frequency of the bulk acoustic wave or resulting in inaccurate extraction results.

[0045] Specifically, with Figure 2 For example, Figure 2 The figure shows the admittance-frequency curves for SAW resonators with three different numbers of fingers. It can be seen that as the number of fingers decreases, the contribution of bulk acoustic resonance to the admittance becomes smoother, making it more difficult for a computer to automatically extract the corresponding frequency points. Figure 2 The peak points (local maxima of the entire curve) in the middle circle are difficult to extract, which further makes it difficult for the frequency values ​​corresponding to the peak points to be automatically extracted by the computer.

[0046] Figure 3 The admittance-frequency curves of the TF-SAW (TF stands for Thin Film) resonator show that the circled part has a smoother trend, and the peak value is more difficult to be automatically extracted by the computer.

[0047] Furthermore, because it is difficult to extract information automatically using computer technology... Figure 2 or Figure 3 The curve shown extracts the bulk acoustic resonant frequency of the SAW resonator. Therefore, if existing techniques are still used based on... Figure 2 or Figure 3 The curve shown is obtained by automatically extracting the bulk acoustic resonant frequency of the SAW resonator by a computer, so the extraction result may not be accurate enough.

[0048] During their research, the inventors further discovered that inaccurate extraction of the bulk acoustic resonant frequency of the SAW resonator would lead to inaccuracies in parameters related to the performance of the SAW resonator, thereby causing a decrease in the performance of the designed SAW resonator, and further a decrease in the performance of the filter.

[0049] Specifically, taking a COM modeling scenario (which simulates the coupling effect of two opposing sound fields to represent the acoustic-electric characteristics of a SAW resonator) as an example, let the extracted resonant frequency of the SAW resonator be fr, and the bulk acoustic resonant frequency of the SAW resonator be fb. Then, the center frequency of the SAW resonator is f0 = (fr + fb) / 2, and the sound velocity of the SAW resonator is v0 = f0 * p. For a synchronous acoustic resonator, the reflection coefficient k is a real number, so the reflection coefficient...

[0050] Therefore, if the volume acoustic resonant frequency fb is not extracted accurately, the sound velocity v0 and reflection coefficient k will also be calculated inaccurately. With inaccurate fb, v0, and k, the admittance-frequency simulation curve of the SAW resonator obtained based on these parameters will be distorted.

[0051] like Figure 4 as well as Figure 5 As shown, the dashed line represents the simulated admittance-frequency curve of the SAW resonator, and the solid line represents the measured admittance-frequency curve of the SAW resonator.

[0052] Assumption Figure 4 The admittance-frequency simulation curve shown is based on the accurate bulk acoustic wave resonant frequency. It can be seen that, when the bulk acoustic wave resonant frequency is accurate, the simulation curve matches the measured curve. Figure 4 To facilitate observation, the measured curve was shifted 10 dB upwards along the longitudinal axis.

[0053] Assumption Figure 5 The admittance-frequency simulation curve shown is based on an inaccurate (larger than the true value) bulk acoustic wave resonant frequency. It can be understood that an inaccurate (larger than the true value) bulk acoustic wave resonant frequency will lead to a larger calculated bandgap, further resulting in a larger extracted reflection coefficient k. Figure 5 It can be seen that the simulated curve has a large distortion compared with the measured curve.

[0054] It is understandable that 5G mobile communication systems are characterized by higher frequencies and larger bandwidths (compared to other standards such as 4G). Therefore, if the volume acoustic resonant frequency is not extracted accurately, it will lead to greater distortion in the admittance-frequency simulation curve.

[0055] In summary, the bulk acoustic wave resonance frequency of the SAW resonator can be difficult to extract or not accurately extracted, which further leads to performance degradation of the resonator and the filter composed of the resonator and is difficult to optimize.

[0056] To solve the above problems, an embodiment of the present application provides a method for extracting the bulk acoustic wave resonance frequency of a resonator, aiming to accurately extract the bulk acoustic wave resonance frequency of the resonator.

[0057] The resonator whose bulk acoustic wave resonance frequency is extracted can be applied in a mobile communication scenario. It can be understood that the aforementioned 5G scenario is only an example of the mobile communication scenario, which includes but is not limited to 2G, 3G, 4G (LTE) and 5G communication systems, and also includes 4G and 5G hybrid architecture, 5G New Radio (5G NR) system, and new communication systems to be developed in future communication.

[0058] The aforementioned radio frequency chip and filter are only examples of products composed of resonators. From the perspective of products, the products containing resonators include but are not limited to radio frequency chips or other chips, and filters in radio frequency chips or other circuits.

[0059] It can be understood that in the above mobile communication scenarios and different product forms, not only SAW resonators but also BAW resonators can be used. The method provided by the embodiment of the present application can be used not only to extract the bulk acoustic wave resonance frequency of the SAW resonator in the scenario of using only the SAW resonator, but also to extract the bulk acoustic wave resonance frequency of the SAW resonator in the scenario of using the SAW resonator and the BAW resonator.

[0060] It can be understood that the above is only an example of the application scenario of the resonator whose bulk acoustic wave resonance frequency is extracted. The resonator whose bulk acoustic wave resonance frequency is extracted can also be applied in other scenarios or devices other than mobile communication. That is, the above scenarios do not limit the following flow.

[0061] Figure 6 The flow of the method for extracting the bulk acoustic wave resonance frequency of the resonator provided by the embodiment of the present application includes the following steps:

[0062] S101, measure the corresponding relationship between the admittance and the frequency of the SAW resonator.

[0063] In some implementations, taking the SAW resonator as a single-port resonator as an example, the transmission characteristic curve of the SAW resonator is measured using a vector network analyzer, and then the admittance parameter is obtained based on the formula Y=G0*(1-S11) / (1+S11), wherein the 50-ohm characteristic impedance corresponds to G0=0.02, and S11 is a return loss parameter obtained based on the transmission characteristic curve.

[0064] It can be understood that in the flow described in the embodiment, only the extraction S11 is needed, so the dual-port network does not need to be prepared, but if the parameters of the correspondence between the admittance and the frequency of the dual-port resonator are obtained by preparing the dual-port network, the measurement manner of the correspondence between the admittance and the frequency of the dual-port resonator is similar. In addition, other devices or manners can also be used to measure the correspondence between the admittance and the frequency of the SAW resonator.

[0065] It can be understood that the correspondence between the admittance and the frequency can be visualized as an admittance-frequency curve, for example. Figure 7

[0066] S102, find the minimum value of the frequency in the correspondence between the admittance and the frequency, to obtain the anti-resonance frequency fa of the SAW resonator.

[0067] In some implementations, the obtained fa is also displayed, for example, to visualize the execution result of the step and provide a reference for the researchers. Figure 7

[0068] S103, intercept the correspondence between the frequency and the conductance greater than fa from the correspondence between the admittance and the frequency.

[0069] The admittance is a complex parameter of the conductance and the susceptance, the real part of the admittance is the conductance, and the imaginary part of the admittance is the susceptance. Because the conductance part contributes to the extraction of the bulk acoustic wave resonance frequency of the resonator, the correspondence between the frequency and the conductance is obtained based on the correspondence between the frequency and the admittance.

[0070] It can be understood that from Figure 1 It can be understood that the resonance frequency point of the bulk acoustic wave must be in the region greater than the anti-resonance frequency of the resonator, so the purpose of intercepting the frequency greater than fa and the corresponding conductance is to remove the correspondence useless for the subsequent steps, to reduce interference, thereby improving the accuracy of the extracted bulk acoustic wave resonance frequency.

[0071] In some implementations, the correspondence between the conductance greater than fa and the frequency is visualized as a conductance-frequency curve, denoted as G-f curve, for example. Figure 8

[0072] S104, derive the conductance with respect to the frequency in the correspondence between the frequency and the conductance greater than fa, to obtain the correspondence between the conductance change rate and the frequency.

[0073] For ease of description, the correspondence between the conductance change rate and the frequency is referred to as the target correspondence.

[0074] It can be understood that the target correspondence reflects the change rate of the conductance with respect to the frequency.

[0075] ​​​In some implementations, the target correspondence is visualized as a curve, denoted as G'-f curve. Figure 9 For example, the G'-f curve is shown in FIG. 1.

[0076] S105, smoothing the target correspondence to obtain a smoothed target correspondence.

[0077] In some implementations, the frequency points in the target correspondence are sampled at intervals, and an example of interval sampling is: interval between the sampled frequency points = 2MHz / delta(freq). The frequency points in the target correspondence are sampled at this interval. The sampled frequency points are new frequency points, and it can be understood that the interval between the new frequency points is greater than the interval between the frequency points in the target correspondence. The change rate of conductance corresponding to each interval between two adjacent new frequency points is obtained to obtain the smoothed target correspondence. The purpose of the smoothing is to remove noise to reduce the adverse effect of noise on the accuracy of the zero point of the change rate of conductance.

[0078] An example of the smoothed target correspondence is shown in FIG. 2. Figure 10

[0079] S106, searching for the zero point of the change rate of conductance in the smoothed target correspondence.

[0080] In some specific implementations, the maximum value and the minimum value of the change rate of conductance are searched in the smoothed correspondence respectively, and the maximum value and the minimum value represent the inflection points of the conductance G with respect to the frequency. For example, the G'-f curve is shown in FIG. 1. Figure 10 As can be seen, the maximum value of the change rate of conductance is positive and the minimum value is negative.

[0081] In order to further improve the accuracy of the extraction result, in some implementations, the part between the two inflection points of the G'-f curve is linearized, and the midpoint of the linearized curve is extracted as the zero point of the change rate of conductance.

[0082] Since the ordinate of the original function (G-f curve) changes rapidly between the maximum value and the minimum value of the G'-f curve (the first derivative of the G-f curve with respect to the frequency), the linearization assumption can bring double improvement in extraction accuracy and extraction speed.

[0083] S107, extracting the frequency corresponding to the zero point of the change rate of conductance as the bulk acoustic wave resonance frequency.

[0084] The method described in the embodiment is used to extract the bulk acoustic wave resonance frequency. Figure 6 ​The flowchart shown, the first aspect, is based on the correspondence between the measured admittance and the frequency, and on this basis, by taking the derivative of the conductance with respect to the frequency, the analysis object (the rate of change of conductance with respect to the frequency) is obtained, and the bulk acoustic wave resonance frequency is obtained based on the analysis object. Taking the derivative of the admittance with respect to the frequency is equivalent to solving the problem of existing noise by mathematical method, and the problem of the admittance value corresponding to the bulk acoustic wave in the admittance-frequency curve being relatively fuzzy, which is conducive to obtaining a bulk acoustic wave resonance frequency with high accuracy. Further, the sound velocity v0 and the reflection coefficient k and other parameters with high accuracy can be obtained based on the bulk acoustic wave resonance frequency, and then the performance of the filter or the performance of the radio frequency chip is conducive to obtaining better performance.

[0085] Taking the 5G scenario as an example, in the COM modeling, the sound velocity v0 and the reflection coefficient k and other parameters are obtained by using the bulk acoustic wave resonance frequency extracted by the method described in the embodiment, and then the SAW resonator is further obtained, which has better filtering performance and can pass the signals in the passband range of the filter while filtering out the signals in the frequency band outside the passband range of the filter.

[0086] The second aspect, because it is based on the correspondence between the measured admittance and the frequency, the bulk acoustic wave resonance frequency obtained has high reliability.

[0087] The third aspect, in some cases, on the G-f curve, there are several maximum points after the anti-resonance frequency point, the method described in the embodiment selects the zero point between the two values with the largest difference between the maximum value and the minimum value of the first derivative of the several maximum points to determine the accurate bulk acoustic wave frequency point, so it can be applied to the case of several maximum points, and therefore it can adapt to the relatively complex correspondence between the conductance and the frequency, that is, it has high scalability.

[0088] The fourth aspect, the method described in the embodiment can be automatically implemented based on software, and has high calculation speed.

[0089] The embodiment of the application also discloses another method for extracting the bulk acoustic wave resonance frequency of a resonator. Figure 6 The method is further summarized based on the method, including the following steps:

[0090] Step A, measure the correspondence between the admittance and the frequency of the resonator.

[0091] The specific implementation of step A can be referred to S101. In addition, other ways can also be used to measure the correspondence between the admittance and the frequency of the resonator.

[0092] Step B, based on the correspondence between the admittance and the frequency, obtain the rate of change of the conductance with respect to the frequency.

[0093] The conductance change rate includes a rate of change of the conductance represented by the admittance with respect to the frequency. The specific implementation of step B can refer to S102-S104. It can be understood that the purposes of S102-S103 are to remove data meaningless for subsequent steps, and therefore, S102-S103 can also not be executed, and after S101, the conductance with respect to the frequency is derived from the corresponding relationship between the admittance and the frequency, to obtain a corresponding relationship between the conductance change rate and the frequency.

[0094] In some implementations, the derivation is to calculate a first-order derivative, and in other implementations, the derivation is to calculate a high-order derivative, which is not limited here.

[0095] Step C extracts the frequency corresponding to the zero point of the conductance change rate as the bulk acoustic wave resonance frequency of the resonator.

[0096] The specific implementation of step C can refer to S105-S107. It can be understood that the purpose of S105 is to improve the accuracy of the searched zero point of the conductance change rate, and therefore, S105 can also not be executed, and the zero point of the conductance change rate is searched in the target corresponding relationship.

[0097] The flow described in the embodiment is advantageous to obtain a bulk acoustic wave resonance frequency with high accuracy and high reliability, and has high scalability and high calculation speed.

[0098] Figure 11 A system for extracting a bulk acoustic wave resonance frequency of a resonator disclosed in an embodiment of the present application includes a processor and a measurement device.

[0099] The measurement device is used to measure a corresponding relationship between an admittance and a frequency of the resonator, and in some implementations, the measurement device is a vector network analyzer.

[0100] The processor is used to calculate a bulk acoustic wave resonance frequency of the resonator based on the corresponding relationship between the admittance and the frequency. The specific implementation can refer to S102-S107 shown in Figure 6 or steps A-C.

[0101] The system described in the embodiment can obtain a bulk acoustic wave resonance frequency with high accuracy.

[0102] An embodiment of the present application also discloses a system for extracting a bulk acoustic wave resonance frequency of a resonator, including:

[0103] a processor, and a memory for storing executable instructions of the processor;

[0104] The processor is configured to, in the process of executing the executable instructions, obtain a corresponding relationship between a rate of change of conductance and frequency based on a measured corresponding relationship between the admittance of the resonator and the frequency, the rate of change of conductance including a rate of change of conductance represented by the admittance with respect to the frequency, and extract a frequency corresponding to a zero point of the rate of change of conductance as the bulk acoustic wave resonant frequency of the resonator.

[0105] The specific flow executed by the processor can refer to Figure 6 S102-S107 shown in the figure, or steps A-step C.

[0106] The device described in the embodiment can obtain a bulk acoustic wave resonant frequency with high accuracy.

Claims

1. A method for extracting the bulk acoustic resonant frequency of a resonator, characterized in that, include: Measure the relationship between the admittance and frequency of the resonator; Based on the correspondence between admittance and frequency, the correspondence between the rate of change of conductivity and frequency is obtained, wherein the rate of change of conductivity includes the rate of change of conductivity relative to frequency expressed by admittance; The frequency corresponding to a zero point of the rate of change of conductivity is extracted as the bulk acoustic resonant frequency of the resonator. The process of obtaining the relationship between the rate of change of conductivity and frequency based on the correspondence between admittance and frequency includes: From the correspondence between admittance and frequency, the correspondence between target frequency and admittance is extracted, wherein the target frequency includes frequencies greater than the anti-resonant frequency of the resonator; wherein the resonator is a SAW resonator; Based on the correspondence between the target frequency and admittance, the correspondence between the rate of change of conductivity and frequency is obtained.

2. The method according to claim 1, characterized in that, Before stating the correspondence between the target frequency and the admittance, the following is also included: The minimum admittance value in the relationship between admittance and frequency is found to obtain the anti-resonance frequency of the resonator.

3. The method according to any one of claims 1-2, characterized in that, The process of obtaining the relationship between the rate of change of conductivity and frequency includes: By differentiating the conductivity with respect to frequency, the relationship between the rate of change of conductivity and frequency can be obtained.

4. The method according to claim 1, characterized in that, The relationship between the admittance and frequency of the measured resonator includes: The transmission characteristic curve of the resonator was measured using a vector network analyzer. The relationship between the admittance and frequency of the resonator is obtained based on the transmission characteristic curve.

5. The method according to claim 4, characterized in that, The measurement of the resonator's transmission characteristic curve using a vector network analyzer includes: The transmission characteristic curve of a pre-prepared single-port resonator was measured using a vector network analyzer.

6. The method according to claim 1, characterized in that, Before extracting the frequency corresponding to a zero point of the rate of change of conductivity as the bulk acoustic resonant frequency of the resonator, the method further includes: The relationship between the rate of change of conductivity and frequency is smoothed to obtain the smoothed target relationship; The step of extracting the frequency corresponding to a zero point of the rate of change of conductivity as the bulk acoustic resonant frequency of the resonator includes: Search for the zero point of the rate of change of conductivity in the correspondence of the smoothed targets; The frequency corresponding to a zero point of the rate of change of conductivity is extracted as the bulk acoustic resonant frequency of the resonator.

7. The method according to claim 6, characterized in that, The step of extracting the frequency corresponding to a zero point of the rate of change of conductivity as the bulk acoustic resonant frequency of the resonator includes: Search for the maximum and minimum values ​​of the rate of change of conductivity in the correspondence of the smoothing targets; The correspondence between the maximum and minimum values ​​is assumed to be linearized. The midpoint of the curve after the linearization assumption is extracted as the zero point of the rate of change of conductivity.

8. A system for extracting the bulk acoustic resonant frequency of a resonator, characterized in that, include: Processors and measuring devices; The measuring device is used to measure the relationship between the admittance and frequency of the resonator; The processor is used to obtain the correspondence between the rate of change of conductivity and the frequency based on the correspondence between the admittance and the frequency. The rate of change of conductivity includes the rate of change of conductivity relative to the frequency expressed by the admittance, and extracts the frequency corresponding to the zero point of the rate of change of conductivity as the bulk acoustic resonant frequency of the resonator. The process of obtaining the correspondence between the rate of change of conductance and frequency based on the correspondence between admittance and frequency includes: extracting the correspondence between a target frequency and admittance from the correspondence between admittance and frequency, wherein the target frequency includes frequencies greater than the anti-resonance frequency of the resonator; wherein the resonator is a SAW resonator; and obtaining the correspondence between the rate of change of conductance and frequency based on the correspondence between the target frequency and admittance.

9. A device for extracting the bulk acoustic resonant frequency of a resonator, characterized in that, include: A processor, and a memory for storing executable instructions of the processor; The processor is configured to perform the following functions during the execution of the executable instructions: based on the measured correspondence between the admittance and frequency of the resonator, obtain the correspondence between the rate of change of conductance and frequency, wherein the rate of change of conductance includes the rate of change of conductance relative to frequency expressed by the admittance, and extract the frequency corresponding to the zero point of the rate of change of conductance as the bulk acoustic resonant frequency of the resonator. The process of obtaining the correspondence between the rate of change of conductance and frequency based on the correspondence between admittance and frequency includes: extracting the correspondence between a target frequency and admittance from the correspondence between admittance and frequency, wherein the target frequency includes frequencies greater than the anti-resonance frequency of the resonator; wherein the resonator is a SAW resonator; and obtaining the correspondence between the rate of change of conductance and frequency based on the correspondence between the target frequency and admittance.

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