The present disclosure relates to piezo microphones including micro electrical mechanical sensor (MEMS) microphones.
A piezoelectric sensor is designed to convert acoustic energy into an electrical signal. Thus, such a piezoelectric sensor can be configured as a microphone that converts sound into an electrical signal. In some applications, such a piezoelectric microphone can be implemented as a micro electrical mechanical sensor (MEMS).
In accordance with a number of implementations, the present disclosure relates to a microphone that includes a piezoelectric sensor configured to provide a response to acoustic energy in a frequency band. The response includes an in-band resonance having a peak frequency within the frequency band. The microphone further includes an equalizer coupled to the piezoelectric sensor and configured to provide equalization of the response of the piezoelectric sensor, such that the equalizer removes or adjusts the in-band resonance from the response of the piezoelectric sensor.
In some embodiments, the piezoelectric sensor can be implemented as a micro-electromechanical systems (MEMS) device. The MEMS device can be implemented as, for example, a cantilever structure.
In some embodiments, the equalizer can be configured to provide the equalization in digital domain. In some embodiments, the equalizer can be part of an application-specific integrated circuit.
In some embodiments, the application-specific integrated circuit can further include an analog-to-digital converter (ADC) that receives an analog signal from the piezoelectric sensor and generates a digital signal representative of the analog signal.
In some embodiments, the application-specific integrated circuit can further include a non-transitory computer readable medium having or capable of having calibration data specific for the piezoelectric sensor to allow the removal or adjustment of the in-band resonance from the response of the piezoelectric sensor.
In some embodiments, the calibration data specific for the piezoelectric sensor can be provided to the non-transitory computer readable medium in a calibration process during or after production of the microphone.
In some embodiments, the calibration data specific for the piezoelectric sensor can include data representative of temperature dependence of the equalization of the response of the piezoelectric sensor. In some embodiments, the application-specific integrated circuit can further include a temperature sensor configured to provide temperature information for the temperature dependence of the equalization of the response of the piezoelectric sensor.
In some embodiments, the calibration data specific for the piezoelectric sensor can include data representative of low frequency corner property of the piezoelectric sensor.
In some embodiments, the frequency band can include an audible frequency band, such as a range of 20 Hz to 20,000 Hz.
In some implementations, the present disclosure relates to a microphone that includes a piezoelectric sensor configured to provide a response to acoustic energy in a frequency band, with the response including an in-band resonance having a peak frequency within the frequency band. The microphone further includes a processing component coupled to the piezoelectric sensor and configured to provide an adjustment to the response of the piezoelectric sensor to correct for a low-frequency corner variation associated with the piezoelectric sensor.
In some embodiments, the processing component can be implemented as an equalizer. The equalizer can be further configured to provide equalization of the response of the piezoelectric sensor, such that the equalizer removes or adjusts the in-band resonance from the response of the piezoelectric sensor.
In some embodiments, the piezoelectric sensor can be implemented as a micro-electromechanical systems (MEMS) device.
In some implementations, the present disclosure relates to a microphone that includes a piezoelectric sensor configured to provide a response to acoustic energy in a frequency band, with the response including an in-band resonance having a peak frequency within the frequency band. The microphone further includes an equalizer coupled to the piezoelectric sensor and configured to provide equalization of the response of the piezoelectric sensor. The microphone further includes a temperature compensation component configured to adjust the equalization based on temperature dependence of the equalization.
In some embodiments, the temperature compensation component can include a temperature sensor implemented to sense temperature representative of the equalizer. In some embodiments, the equalizer can be further configured to remove or adjust the in-band resonance from the response of the piezoelectric sensor.
In some implementations, the present disclosure relates to a microphone that includes a packaging substrate and a microphone implemented on the packaging substrate. The microphone includes a piezoelectric sensor configured to provide a response to acoustic energy in a frequency band, with the response including an in-band resonance having a peak frequency within the frequency band. The microphone further includes an equalizer coupled to the piezoelectric sensor and configured to provide equalization of the response of the piezoelectric sensor, such that the equalizer removes or adjusts the in-band resonance from the response of the piezoelectric sensor.
In some embodiments, the piezoelectric sensor can be implemented as a micro-electromechanical systems (MEMS) device.
In some implementations, the present disclosure relates to a microphone that includes a packaging substrate and a microphone implemented on the packaging substrate. The microphone includes a piezoelectric sensor configured to provide a response to acoustic energy in a frequency band, with the response including an in-band resonance having a peak frequency within the frequency band. The microphone further includes a processing component coupled to the piezoelectric sensor and configured to provide an adjustment to the response of the piezoelectric sensor to correct for a low-frequency corner variation associated with the piezoelectric sensor.
In some embodiments, the processing component can be implemented as an equalizer that is further configured to provide equalization of the response of the piezoelectric sensor, such that the equalizer removes or adjusts the in-band resonance from the response of the piezoelectric sensor.
In some embodiments, the piezoelectric sensor can be implemented as a micro-electromechanical systems (MEMS) device.
In some implementations, the present disclosure relates to a microphone that includes a packaging substrate and a microphone implemented on the packaging substrate. The microphone includes a piezoelectric sensor configured to provide a response to acoustic energy in a frequency band, with the response including an in-band resonance having a peak frequency within the frequency band. The microphone further includes an equalizer coupled to the piezoelectric sensor and configured to provide equalization of the response of the piezoelectric sensor. The microphone further includes a temperature compensation component configured to adjust the equalization based on temperature dependence of the equalization.
In some embodiments, the packaged module can further include a temperature sensor implemented to sense temperature representative of the equalizer.
In some embodiments, the equalizer can be further configured to remove or adjust the in-band resonance from the response of the piezoelectric sensor.
In some implementations, the present disclosure relates to an electronic device that includes a microphone having a piezoelectric sensor configured to provide a response to acoustic energy in a frequency band, with the response including an in-band resonance having a peak frequency within the frequency band. The microphone further includes an equalizer coupled to the piezoelectric sensor and configured to provide equalization of the response of the piezoelectric sensor, such that the equalizer removes or adjusts the in-band resonance from the response of the piezoelectric sensor. The electronic device further includes an electronic circuit configured to utilize a signal representative of an analog signal output by the piezoelectric sensor and equalized by the equalizer.
In some embodiments, the frequency band can include an audio frequency range such as a range of 20 to 20,000 Hz.
In some embodiments, the audio device can include a portable electronic device such as a wireless device.
In some implementations, the present disclosure relates to an electronic device that includes a microphone having a piezoelectric sensor configured to provide a response to acoustic energy in a frequency band, with the response including an in-band resonance having a peak frequency within the frequency band. The microphone further includes a processing component coupled to the piezoelectric sensor and configured to provide an adjustment to the response of the piezoelectric sensor to correct for a low-frequency corner variation associated with the piezoelectric sensor. The electronic device further includes an electronic circuit configured to utilize a signal representative of an analog signal output by the piezoelectric sensor and adjusted by the processing component.
In some implementations, the present disclosure relates to an electronic device that includes a microphone having a piezoelectric sensor configured to provide a response to acoustic energy in a frequency band, with the response including an in-band resonance having a peak frequency within the frequency band. The microphone further includes an equalizer coupled to the piezoelectric sensor and configured to provide equalization of the response of the piezoelectric sensor. The microphone further includes a temperature compensation component configured to adjust the equalization based on temperature dependence of the equalization. The electronic device further includes an electronic circuit configured to utilize a signal representative of an analog signal output by the piezoelectric sensor and equalized by the equalizer.
For purposes of summarizing the disclosure, certain aspects, advantages and novel features of the inventions have been described herein. It is to be understood that not necessarily all such advantages may be achieved in accordance with any particular embodiment of the invention. Thus, the invention may be embodied or carried out in a manner that achieves or optimizes one advantage or group of advantages as taught herein without necessarily achieving other advantages as may be taught or suggested herein.
The headings provided herein, if any, are for convenience only and do not necessarily affect the scope or meaning of the claimed invention.
Described herein are various examples of devices, circuits and methods related to the piezoelectric micro-electromechanical systems (MEMS) sensor 102 of
In some embodiments, the IBR piezo MEMS microphone sensor 102 of
In some embodiments, the microphone 100 of
In some embodiments, the microphone 100 of
In the example of
It is noted that a microphone having an IBR piezo MEMS microphone sensor, such as the microphone 100 of
It is also noted that implementation of equalization and/or calibration (e.g., post-production equalization and/or calibration) for an IBR piezo MEMS microphone can provide a number of desirable features. For example, a piezo cantilever microphone typically has an issue with poor control over the microphone's low frequency roll off tolerance. Such an effect can result due to stress across a wafer causing sensor cantilever deflection to vary, thereby making air leak across the sensor to vary significantly. Production equalization can address this issue by providing each individual microphone with an ideal or desirable equalizer configuration so the end product has very tight control over the low frequency corner.
In another example, post-production equalization can remove variation in response around resonance, thereby making the resulting response far flatter than other solutions such as condenser solutions. It is noted that piezo MEMS microphones are typically less sensitive to port loading than condenser microphones, thereby enabling the foregoing post-production equalization.
In yet another example, post-production equalization's frequency response variations with temperature have low sensitivity and could be temperature compensated by using, for example, a lookup table for coefficients and an on-ASIC temperature sensor.
For the example of
In
The present disclosure describes various features, no single one of which is solely responsible for the benefits described herein. It will be understood that various features described herein may be combined, modified, or omitted, as would be apparent to one of ordinary skill. Other combinations and sub-combinations than those specifically described herein will be apparent to one of ordinary skill, and are intended to form a part of this disclosure. Various methods are described herein in connection with various flowchart steps and/or phases. It will be understood that in many cases, certain steps and/or phases may be combined together such that multiple steps and/or phases shown in the flowcharts can be performed as a single step and/or phase. Also, certain steps and/or phases can be broken into additional sub-components to be performed separately. In some instances, the order of the steps and/or phases can be rearranged and certain steps and/or phases may be omitted entirely. Also, the methods described herein are to be understood to be open-ended, such that additional steps and/or phases to those shown and described herein can also be performed.
Some aspects of the systems and methods described herein can advantageously be implemented using, for example, computer software, hardware, firmware, or any combination of computer software, hardware, and firmware. Computer software can comprise computer executable code stored in a computer readable medium (e.g., non-transitory computer readable medium) that, when executed, performs the functions described herein. In some embodiments, computer-executable code is executed by one or more general purpose computer processors. A skilled artisan will appreciate, in light of this disclosure, that any feature or function that can be implemented using software to be executed on a general purpose computer can also be implemented using a different combination of hardware, software, or firmware. For example, such a module can be implemented completely in hardware using a combination of integrated circuits. Alternatively or additionally, such a feature or function can be implemented completely or partially using specialized computers designed to perform the particular functions described herein rather than by general purpose computers.
Multiple distributed computing devices can be substituted for any one computing device described herein. In such distributed embodiments, the functions of the one computing device are distributed (e.g., over a network) such that some functions are performed on each of the distributed computing devices.
Some embodiments may be described with reference to equations, algorithms, and/or flowchart illustrations. These methods may be implemented using computer program instructions executable on one or more computers. These methods may also be implemented as computer program products either separately, or as a component of an apparatus or system. In this regard, each equation, algorithm, block, or step of a flowchart, and combinations thereof, may be implemented by hardware, firmware, and/or software including one or more computer program instructions embodied in computer-readable program code logic. As will be appreciated, any such computer program instructions may be loaded onto one or more computers, including without limitation a general purpose computer or special purpose computer, or other programmable processing apparatus to produce a machine, such that the computer program instructions which execute on the computer(s) or other programmable processing device(s) implement the functions specified in the equations, algorithms, and/or flowcharts. It will also be understood that each equation, algorithm, and/or block in flowchart illustrations, and combinations thereof, may be implemented by special purpose hardware-based computer systems which perform the specified functions or steps, or combinations of special purpose hardware and computer-readable program code logic means.
Furthermore, computer program instructions, such as embodied in computer-readable program code logic, may also be stored in a computer readable memory (e.g., a non-transitory computer readable medium) that can direct one or more computers or other programmable processing devices to function in a particular manner, such that the instructions stored in the computer-readable memory implement the function(s) specified in the block(s) of the flowchart(s). The computer program instructions may also be loaded onto one or more computers or other programmable computing devices to cause a series of operational steps to be performed on the one or more computers or other programmable computing devices to produce a computer-implemented process such that the instructions which execute on the computer or other programmable processing apparatus provide steps for implementing the functions specified in the equation(s), algorithm(s), and/or block(s) of the flowchart(s).
Some or all of the methods and tasks described herein may be performed and fully automated by a computer system. The computer system may, in some cases, include multiple distinct computers or computing devices (e.g., physical servers, workstations, storage arrays, etc.) that communicate and interoperate over a network to perform the described functions. Each such computing device typically includes a processor (or multiple processors) that executes program instructions or modules stored in a memory or other non-transitory computer-readable storage medium or device. The various functions disclosed herein may be embodied in such program instructions, although some or all of the disclosed functions may alternatively be implemented in application-specific circuitry (e.g., ASICs or FPGAs) of the computer system. Where the computer system includes multiple computing devices, these devices may, but need not, be co-located. The results of the disclosed methods and tasks may be persistently stored by transforming physical storage devices, such as solid state memory chips and/or magnetic disks, into a different state.
Unless the context clearly requires otherwise, throughout the description and the claims, the words “comprise,” “comprising,” and the like are to be construed in an inclusive sense, as opposed to an exclusive or exhaustive sense; that is to say, in the sense of “including, but not limited to.” The word “coupled”, as generally used herein, refers to two or more elements that may be either directly connected, or connected by way of one or more intermediate elements. Additionally, the words “herein,” “above,” “below,” and words of similar import, when used in this application, shall refer to this application as a whole and not to any particular portions of this application. Where the context permits, words in the above Detailed Description using the singular or plural number may also include the plural or singular number respectively. The word “or” in reference to a list of two or more items, that word covers all of the following interpretations of the word: any of the items in the list, all of the items in the list, and any combination of the items in the list. The word “exemplary” is used exclusively herein to mean “serving as an example, instance, or illustration.” Any implementation described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other implementations.
The disclosure is not intended to be limited to the implementations shown herein. Various modifications to the implementations described in this disclosure may be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other implementations without departing from the spirit or scope of this disclosure. The teachings of the invention provided herein can be applied to other methods and systems, and are not limited to the methods and systems described above, and elements and acts of the various embodiments described above can be combined to provide further embodiments. Accordingly, the novel methods and systems described herein may be embodied in a variety of other forms; furthermore, various omissions, substitutions and changes in the form of the methods and systems described herein may be made without departing from the spirit of the disclosure. The accompanying claims and their equivalents are intended to cover such forms or modifications as would fall within the scope and spirit of the disclosure.
This application claims priority to U.S. Provisional Application No. 63/318,575 filed Mar. 10, 2022, entitled IN-BAND RESONANCE PIEZO MEMS MICROPHONES, the disclosure of which is hereby expressly incorporated by reference herein in its entirety.
Number | Date | Country | |
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63318575 | Mar 2022 | US |