Horizontal symmetry axis weighted interdigital surface acoustic wave morlet wavelet processor and processing system

Abstract

This invention discloses a horizontally symmetry-axis-weighted interdigitated surface acoustic wave (SAW) Morlet wavelet processor and processing system, belonging to the technical field of SAW wavelet transform processors. The SAW Morlet wavelet processor includes a piezoelectric substrate and transmitting and receiving transducers integrated at both ends of the piezoelectric substrate. The transmitting transducer converts the received input signal into a SAW wavelet transform signal propagating along the surface of the piezoelectric substrate. The receiving transducer receives the SAW wavelet transform signal and converts it into an electrical wavelet transform signal for output. The length of the horizontal symmetry axis of each interdigitator is proportional to the envelope amplitude of the Morlet binary wavelet function, and the acoustic aperture is greater than or equal to the wavelength of the SAW wave. This invention can efficiently suppress diffraction phenomena, achieving a comprehensive performance improvement and providing strong support for technological upgrading and innovative development in various fields.

Description

Technical Field

[0001] This invention belongs to the technical field of surface acoustic wave wavelet transform processors, specifically relating to a horizontally symmetric axis weighted interdigital surface acoustic wave Morlet wavelet processor and processing system. Background Technology

[0002] Wavelet transform, as an advancement in mathematical analysis methods following Fourier transform, has pioneered a new paradigm in signal processing. Its breakthrough lies in constructing a frequency-adaptive time-frequency analysis window, capable of dynamically adjusting the observation scale according to signal characteristics, achieving precise focusing on signal features. This unique time-frequency localization analysis capability makes wavelet analysis an ideal tool for processing non-stationary signals and complex fractal structures, demonstrating significant advantages in both applied mathematical theory innovation and engineering practice. Currently, this technology has formed systematic solutions in numerous fields such as communications, image processing, and geophysical exploration, and has been widely applied.

[0003] Based on the unique analytical advantages of wavelet transform in multiple fields, the scientific community continues to advance the research and development of efficient implementation technologies. While traditional software implementations offer algorithmic adjustability, their exponentially increasing computational complexity leads to significantly increased processing latency when dealing with high-dimensional signals, making it difficult to meet real-time requirements. Therefore, hardware acceleration solutions have become a research hotspot. Parallel processing architectures based on FPGAs, dedicated computing units in DSPs, and customized circuit designs using VLSI have emerged, opening new avenues for real-time wavelet transform processing. However, the high hardware costs and continuously growing computing power demands still constrain its large-scale application.

[0004] To address the limitations of digital implementation, researchers have turned to simulation-driven approaches driven by physical fields, focusing on exploring novel device solutions such as optics, magnetostatic waves, and surface acoustic waves (SAWs). While optical solutions offer parallel processing capabilities, they are limited by the integration density of optoelectronic devices and the efficiency of optical modulation. Magnetostatic wave solutions perform excellently in the microwave band, but their complex material fabrication processes result in high costs. Against this backdrop, SAW technology, leveraging the inverse piezoelectric effect of piezoelectric materials, achieves signal transformation by exciting controllable mechanical waves on the substrate surface. This innovative approach enables the physical construction of multi-scale wavelet basis functions. This acoustically based solution significantly reduces system complexity and manufacturing costs while maintaining processing accuracy, providing a new technological path for real-time wavelet processing.

[0005] Compared to the complex computational architecture of digital circuits, surface acoustic wave (SAW) wavelet processors achieve a paradigm shift in signal processing through physical field coupling mechanisms. Their innovation lies in transforming mathematical wavelet basis functions into elastic wave propagation modes on a piezoelectric substrate, directly achieving multi-scale analysis through spatial scale mapping of waveguide structures, completely eliminating redundant steps such as sampling, quantization, and iterative calculations found in traditional digital schemes. This technology directly constructs waveguide structures using photolithography, simplifying chip design and reducing manufacturing costs through standard semiconductor processes, making it particularly suitable for applications with stringent real-time performance and energy efficiency requirements. As a cross-disciplinary innovation between analog signal processing and wavelet theory, SAW technology has formed a complete theoretical system for the physical implementation of continuous wavelet transforms and has demonstrated significant advantages in fields such as biosignal monitoring and array signal processing, opening up new directions for the engineering applications of wavelet transforms.

[0006] In practical engineering applications, the biggest challenge in wavelet analysis lies in the selection of wavelet bases and wavelet functions, a process that largely relies on researchers' experience or comparative analysis of experimental results. The Morlet wavelet, as a specially constructed wavelet function, is essentially a waveform obtained by modulating a Gaussian wave with a single-frequency complex sine wave. It possesses extremely prominent time-frequency localization characteristics, giving it a powerful advantage in signal analysis, enabling it to accurately and efficiently capture subtle features in time-varying and transient signals.

[0007] Based on the unique advantages of Morlet wavelets, existing technologies provide a surface acoustic wave wavelet transform processor. For example... Figure 1 As shown, the transducer's interdigitated overlapping envelope is designed according to the wavelet function envelope, belonging to the interdigitated envelope weighted type. It is typically defined as a surface acoustic wave (SAW) type interdigitated envelope weighted wavelet transform processor. However, such interdigitated envelope weighted wavelet transform processors still suffer from diffraction effects in practical applications. Summary of the Invention

[0008] This invention addresses the shortcomings of existing technologies by providing a horizontally symmetric axis-weighted interdigital surface acoustic wave (SAW) Morlet wavelet processor and processing system. This processor can efficiently suppress diffraction phenomena, achieve a comprehensive performance improvement, and effectively solve the diffraction problem faced by traditional SAW wavelet transform processors.

[0009] This invention provides the following technical solution: In a first aspect, a horizontally symmetric axis-weighted interdigitated surface acoustic wave (SAW) Morlet wavelet processor is provided, comprising: a piezoelectric substrate and a transmitting transducer and a receiving transducer integrated at both ends of the piezoelectric substrate. The transmitting transducer is used to convert a received input signal into a SAW wavelet transform signal propagating along the surface of the piezoelectric substrate. The receiving transducer is used to receive the SAW wavelet transform signal and convert it into an electrical wavelet transform signal for output. The length of the horizontal symmetry axis of each interdigitated finger of the transmitting transducer is proportional to the envelope amplitude of the Morlet binary wavelet function, and the acoustic aperture of the transmitting transducer is greater than or equal to the wavelength of the SAW wave.

[0010] Optionally, each interdigit of the transmitting transducer is uniformly divided into several sub-interdigits along its own horizontal axis of symmetry.

[0011] Optionally, the receiving transducer is an interdigital transducer with each interdigital period evenly distributed, of equal length, and overlapping with each other.

[0012] In a second aspect, a surface acoustic wave Morlet wavelet processing system is provided, comprising several processing units integrated in parallel, each processing unit corresponding to a wavelet basis function with a different center frequency, wherein the processing unit is a horizontally symmetric axis-weighted interdigitated surface acoustic wave Morlet wavelet processor as described in the first aspect.

[0013] Compared with the prior art, the beneficial effects of the present invention are: The horizontal symmetry axis length of each interdigitated finger of the transmitting transducer in this invention is proportional to the envelope amplitude of the Morlet binary wavelet function. The acoustic aperture is greater than or equal to the wavelength of the surface acoustic wave (SAW), effectively suppressing beam diffraction, reducing energy dispersion, and improving signal strength. This invention uniformly divides the interdigitated fingers into multiple sub-interdigitated fingers, achieving efficient suppression of beam offset. The horizontal symmetry axis-weighted interdigitated SAW Morlet wavelet processor of this invention ensures the accuracy and stability of signal transmission, and its manufacturing process is easy to implement, providing strong support for large-scale applications. It has significant application value in many disciplines and industries such as sensor engineering, radar technology, seismic exploration, atmospheric and oceanographic science, and plays a direct and significant role in promoting the scientific research, technological evolution, practical application, and industrialization of SAW and wavelet transform technologies. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of an interdigital transducer structure with interdigital envelope weighting, based on existing technology. Figure 2 This is a schematic diagram of the Morlet wavelet processor for horizontally symmetric axis weighted interdigital surface acoustic waves of the present invention; Figure 3This is a schematic diagram of the design of the transmitting transducer, as given in Embodiment 2 of the present invention. Figure 3 (a) in the diagram is a schematic diagram of the wavelet function and its envelope. Figure 3 (b) in the diagram is a schematic diagram of the wavelet function envelope and the wavelet function envelope amplitude. Figure 3 (c) in the diagram is a schematic diagram of the interdigitated fingers of the interdigitated horizontal symmetry axis weighted emitter transducer. Figure 3 (d) is a schematic diagram of the sub-interdigitation of the transmitting transducer. Figure 3 (e) in the diagram is a schematic diagram of the transmitting transducer in this example.

[0015] Figure reference numerals: 1 is piezoelectric substrate, 2 is transmitting transducer, 3 is receiving transducer, 4 is interdigitated finger, and 5 is sub-interdigitated finger. Detailed Implementation

[0016] The present invention will now be described in further detail with reference to the accompanying drawings. It should be noted that terms such as "horizontal" used in the invention are for clarity of description only and are not intended to limit the scope of the invention. Changes or adjustments to the relative relationships, without substantially altering the technical content, should also be considered within the scope of the invention.

[0017] Example 1: like Figure 2 As shown, the present invention provides a horizontally symmetric axis weighted interdigital surface acoustic wave Morlet wavelet processor, which uses a piezoelectric substrate 1 as a carrier, with a transmitting transducer 2 integrated at one end of the piezoelectric substrate 1 and a receiving transducer 3 integrated at the other end.

[0018] In operation, the transmitting transducer 2 uses the inverse piezoelectric effect to convert the input electrical signal into a surface acoustic wave (SAW) wavelet transform signal. The converted SAW wavelet transform signal propagates stably along the surface of the piezoelectric substrate 1. The receiving transducer 3 receives the SAW wavelet transform signal, converts it back into an electrical wavelet transform signal, and outputs it.

[0019] The length of the horizontal symmetry axis of each interdigitated finger 4 of the transmitting transducer 2 is proportional to the envelope amplitude of the Morlet binary wavelet function. That is, the transmitting transducer 2 adopts the interdigitated horizontal symmetry axis weighted design. This design can effectively optimize the transmission characteristics of surface acoustic waves and lay a solid foundation for improving the overall performance of the processor.

[0020] To ensure that the acoustic aperture is large enough, the acoustic aperture of the transmitting transducer 2 is greater than or equal to the wavelength of the surface acoustic wave. By setting the horizontal symmetry axis length of the interdigitated finger 4 and the acoustic aperture as described above, the diffraction problem faced by existing surface acoustic wave wavelet transform processors can be solved.

[0021] Each interdigit 4 of the transmitting transducer 2 is uniformly divided into several sub-interdigitates 5 along its own horizontal axis of symmetry. The number of sub-interdigitates 5 can be determined based on experimental results and expert experience, such as... Figure 2 As shown, the interdigitated finger 4 is uniformly divided into two sub-interdigitated fingers 5. By dividing the interdigitated finger 4 into multiple smaller sub-interdigitated fingers 5, the beam offset problem of existing surface acoustic wave wavelet transform processors can be solved.

[0022] The receiving transducer 3 is an interdigital transducer with each interdigital period evenly distributed, of equal length and overlapping with each other.

[0023] In this invention, the horizontal symmetry axis length of each interdigitate 4 of the transmitting transducer 2 is proportional to the envelope amplitude of the Morlet binary wavelet function. The acoustic aperture is greater than or equal to the wavelength of the surface acoustic wave, which can effectively suppress the diffraction of the sound beam, reduce energy dispersion, and improve signal strength. This invention uniformly divides the interdigitate 4 into multiple sub-interdigitates 5, achieving efficient suppression of beam offset. The horizontal symmetry axis weighted interdigitate surface acoustic wave Morlet wavelet processor provided by this invention ensures the accuracy and stability of signal transmission, and its manufacturing process is easy to implement, providing strong support for large-scale applications. It has important application value in many disciplines and industries such as sensor engineering, radar technology, seismic exploration, atmospheric and oceanographic science, and plays a direct and significant role in promoting the scientific research, technological evolution, practical application, and industrialization of surface acoustic wave technology and wavelet transform technology.

[0024] Example 2: like Figure 3 As shown, a specific example of a horizontally symmetric axis-weighted interdigital surface acoustic wave Morlet wavelet processor is given. In this example, the length of the horizontal symmetry axis of the transmitting transducer is calculated according to scale 2. -3 Design of the envelope amplitude of Morlett's binary wavelet function.

[0025] The transmitting transducer's interdigitated structure employs a horizontally symmetrical axis weighted design, weighted according to the Morlet wavelet function envelope amplitude. When the length of the interdigitated horizontal axis of symmetry is proportional to the wavelet function envelope amplitude, its impulse response function equals the wavelet function. The acoustic aperture size must be greater than or equal to the wavelength of the surface acoustic wave. Simultaneously, each interdigitate is uniformly divided into multiple sub-interdigitates. The receiving transducer is an interdigitated transducer structure with equal and overlapping interdigitates, and a uniformly distributed periodicity.

[0026] exist Figure 3 In (b) of the middle, Scale 2 at equal time intervals T -3 The envelope magnitude of the Morlet binary wavelet function. Figure 3 (c) The length of the horizontal axis of symmetry of each interdigital finger. This represents the spacing between adjacent interdigitated fingers. ; M Let T be the propagation distance of the surface acoustic wave. W The acoustic aperture of the transmitting transducer. Figure 3 In (d) of the middle, The length of the horizontal axis of symmetry of each sub-interdigital finger. The spacing between adjacent interdigitated fingers after each interdigitated finger is divided into sub-interdigitated fingers. .

[0027] Example 3: A surface acoustic wave Morlet wavelet processing system is provided, comprising several processing units integrated in parallel. Each processing unit corresponds to a wavelet basis function with a different center frequency. The processing unit is the horizontal symmetry axis weighted interdigital surface acoustic wave Morlet wavelet processor in Embodiment 1.

[0028] By integrating multiple processing units in parallel, with each processor unit corresponding to a wavelet basis function with a different center frequency, a surface acoustic wave Morlet wavelet processing system with multi-scale analysis capabilities can be constructed, thereby expanding the dimensions of signal processing.

[0029] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0030] The above are merely preferred embodiments of the present invention. The scope of protection of the present invention is not limited to the above embodiments. All technical solutions falling within the scope of the present invention's concept are within the scope of protection of the present invention. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principles of the present invention should be considered within the scope of protection of the present invention.

Claims

1. A Morlet wavelet processor for horizontally symmetric axis-weighted interdigital surface acoustic waves, characterized in that, include: The piezoelectric substrate (1) and the transmitting transducer (2) and receiving transducer (3) integrated at both ends of the piezoelectric substrate (1) are provided. The transmitting transducer (2) is used to convert the received input signal into a surface acoustic wave wavelet transform signal that propagates along the surface of the piezoelectric substrate (1). The receiving transducer (3) is used to receive the surface acoustic wave wavelet transform signal and convert it into a wavelet transform signal in the form of an electrical signal for output. The length of the horizontal axis of symmetry of each interdigit (4) of the transmitting transducer (2) is proportional to the envelope amplitude of the Morlet binary wavelet function. The acoustic aperture of the transmitting transducer (2) is greater than or equal to the wavelength of the surface acoustic wave.

2. The Morlet wavelet processor for horizontally symmetric axis-weighted interdigital surface acoustic waves according to claim 1, characterized in that, Each interdigit (4) of the transmitting transducer (2) is uniformly divided into several sub-interdigits (5) in the direction of its own horizontal axis of symmetry.

3. The Morlet wavelet processor for horizontally symmetric axis-weighted interdigital surface acoustic waves according to claim 1, characterized in that, The receiving transducer (3) is an interdigital transducer with each interdigital period evenly distributed, of equal length and overlapping with each other.

4. A surface acoustic wave Morlet wavelet processing system, characterized in that, It includes several processing units integrated in parallel, each processing unit corresponding to a wavelet basis function with a different center frequency, and the processing unit is the horizontal symmetry axis weighted interdigital surface acoustic wave Morlet wavelet processor as described in any one of claims 1-3.

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