Design method and device of low-frequency narrow-band device and low-frequency narrow-band filter

Abstract

The invention relates to a design method and device of a low-frequency narrow-band device and a low-frequency narrow-band filter. The method comprises the steps of obtaining an initial circuit for a low-frequency narrow band; the structure of the initial circuit and the parameters of the target element are updated based on preset constraint conditions, the constraint conditions comprise element limiting conditions until the initial circuit meets the preset simulation performance, and the target circuit of the low-frequency narrow-band device is obtained, the problem that the design effect of the low-frequency narrow-band device is poor is solved, and the design efficiency of the low-frequency narrow-band device is improved. And the design success rate and efficiency of the low-frequency narrow-band device are improved, so that the low-frequency narrow-band device which is excellent in performance and suitable for batch production is obtained.

Description

Technical Field

[0001] The present application relates to the technical field of data annotation, and in particular to a design method and device for a low-frequency narrowband device and a low-frequency narrowband filter. Background Art

[0002] A high-speed analog-to-digital converter (ADC) is an electronic device that converts analog signals into digital signals. Its performance is directly related to the accuracy and efficiency of digital signal processing. An ideal input signal can help ADC chip developers get the true performance of ADC chips better and faster. Currently, there is no signal source on the market that meets this requirement. Therefore, the industry usually uses low-frequency narrow-band devices to obtain a more ideal input signal, such as cascading low-pass and band-pass filters after the signal source to suppress the signal's higher harmonics and spurious, thereby obtaining an ideal input signal.

[0003] At present, the design of low-frequency narrowband devices has the following main difficulties: 1) Due to the low signal frequency and long signal wavelength, only lumped parameter components such as inductance (L) and capacitance (C) can be used for design. However, the current LC devices have problems such as discontinuous device values ​​and insufficient device precision, which cannot meet the requirements of conventional design methods; 2) The inductance in the conventional filter circuit model designed based on the requirements of narrowband performance is often extremely large, and there are no such products with large inductance and high quality factor on the market, so mass production cannot be achieved; 3) The lower the center frequency of the bandpass filter and the narrower the relative bandwidth, the more difficult it is to design in practice, because the main function of the filter is to filter out the higher harmonics of the fundamental signal. The lower the fundamental signal, the closer its harmonics are to the fundamental signal, which requires the filter to have a higher roll-off coefficient, making the actual design more difficult; 4) The bandwidth of the low-frequency narrowband bandpass filter is extremely narrow and very sensitive. Slight fluctuations in component precision, board-level circuit parasitics, component Q value, etc. may cause frequency deviation and deterioration of filtering performance of the narrowband bandpass filter, resulting in a low board launch success rate.

[0004] With regard to the problem of poor design effect of low-frequency narrow-band devices in related technologies, no effective solution has been proposed so far. Summary of the invention

[0005] In this embodiment, a design method and device for a low-frequency narrowband device and a low-frequency narrowband filter are provided to solve the problems of poor design effect and low success rate of board launch of low-frequency narrowband devices in related technologies.

[0006] In a first aspect, a design method for a low-frequency narrowband device is provided in this embodiment, the method comprising:

[0007] Get the initial circuit;

[0008] Based on preset constraints, the structure of the initial circuit and the parameters of the target components are updated, wherein the constraints include component restriction conditions, until the initial circuit meets the preset simulation performance, thereby obtaining the target circuit of the low-frequency narrowband device.

[0009] In some embodiments, based on preset constraints, updating the structure of the initial circuit and the parameters of the target component, the constraints include component restriction conditions, until the initial circuit meets the preset simulation performance, and obtaining the target circuit of the low-frequency narrowband device, including:

[0010] Based on the preset component restriction conditions, the structure in the initial circuit and the parameters of the target components are preliminarily adjusted to obtain the circuit to be simulated;

[0011] Based on the experimental results of the circuit to be simulated, the circuit to be simulated is optimized and iterated until it meets the preset simulation performance, thereby obtaining the target circuit of the low-frequency narrow-band device.

[0012] In some of the embodiments, based on the preset component restriction condition, the structure in the initial circuit and the parameters of the target component are initially adjusted to obtain the circuit to be simulated, including:

[0013] In the initial circuit, modifying the parameters of the target component that exceeds the preset component constraint condition to be within the component constraint condition;

[0014] In the initial circuit after the parameters are modified, based on the component restriction conditions, an equivalent transformation process of Norton transformation is performed on the resonant structure to obtain the circuit to be simulated.

[0015] In some embodiments, the experimental results of the circuit to be simulated include:

[0016] At least one of a circuit schematic simulation result, a layout simulation result, and a printed circuit board test result.

[0017] In some of the embodiments, obtaining an initial circuit includes:

[0018] Based on the obtained low-frequency narrowband design target, an initial circuit is generated using circuit design software.

[0019] In some of the embodiments, the low-frequency narrowband design objectives include: center frequency, relative bandwidth, and filter order.

[0020] In some of the embodiments, the target element includes an inductor element, and the parameters include a quality factor and an inductance value.

[0021] In a second aspect, a design device for a low-frequency narrowband device is provided in this embodiment, the device comprising:

[0022] An initial design module for obtaining an initial circuit with low-frequency narrowband performance;

[0023] The optimization iteration module is used to update the structure of the initial circuit and the parameters of the target element based on preset constraints, wherein the constraints include element restriction conditions, until the initial circuit meets the preset simulation performance, thereby obtaining the target circuit of the low-frequency narrowband device.

[0024] In a third aspect, the present application further provides a low-frequency narrow-band filter, wherein the low-frequency narrow-band filter is designed based on the method described in any one of the first aspects; the low-frequency narrow-band filter comprises:

[0025] At least one series-parallel combination module and a parallel resonance module; each of the series-parallel combination modules is connected in series, and the last series-parallel combination module is connected in series with the parallel resonance module;

[0026] Among them, the series-parallel combination module includes a first capacitor, a first inductor, a second capacitor, a second inductor, a third capacitor, a fourth capacitor and a fifth capacitor; one end of the first capacitor is connected to the input signal, and the other end of the first capacitor is connected to the second capacitor through the first inductor; one end of the first capacitor is also grounded through the second inductor and the third capacitor in parallel; the other end of the first capacitor is also grounded through the fourth capacitor; one end of the second capacitor is grounded through the fifth capacitor, and the other end of the second capacitor is connected to the next series-parallel combination module or to the parallel resonance module.

[0027] In a third aspect, the present application further provides a computer device, wherein the computer device comprises a memory and a processor, wherein the memory stores a computer program, and when the processor executes the computer program, the method for designing a low-frequency narrowband device as described in the first aspect is implemented.

[0028] In a fourth aspect, the present application further provides a computer-readable storage medium having a computer program stored thereon, and when the computer program is executed by a processor, the method for designing a low-frequency narrowband device in the first aspect is implemented.

[0029] Compared with the related art, the design method, device and low-frequency narrowband filter of the low-frequency narrowband device provided in this embodiment obtain an initial circuit for the low-frequency narrowband; based on preset constraints, update the structure of the initial circuit and the parameters of the target components, the constraints include component restriction conditions, until the initial circuit meets the preset simulation performance, and obtain the target circuit of the low-frequency narrowband device, which solves the problem of poor design effect of low-frequency narrowband devices and improves the design success rate and efficiency of low-frequency narrowband devices, thereby obtaining a low-frequency narrowband device with excellent performance suitable for mass production.

[0030] Details of one or more embodiments of the present application are set forth in the following drawings and description to make other features, objects, and advantages of the present application more readily apparent. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0032] Figure 1 A hardware structure block diagram of a terminal of a method for designing a low-frequency narrowband device in an embodiment;

[0033] Figure 2 is a schematic flow chart of a design method for a low-frequency narrowband device in one embodiment;

[0034] Figure 3 A schematic diagram of the structure of an initial circuit in a preferred embodiment;

[0035] Figure 4 is a schematic diagram of a Norton transform;

[0036] Figure 5 A schematic diagram of the structure of a low-frequency narrow-band filter in a preferred embodiment;

[0037] Figure 6 A schematic diagram of a circuit schematic simulation result in a preferred embodiment;

[0038] Figure 7 A schematic diagram of a layout simulation result in a preferred embodiment;

[0039] Figure 8 A schematic diagram of a PCB measurement result in a preferred embodiment;

[0040] Fig. 9 4 is a structural block diagram of a design apparatus for a low-frequency narrowband device in an embodiment. DETAILED DESCRIPTION

[0041] In order to more clearly understand the purpose, technical solutions and advantages of the present application, the present application is described and illustrated below in conjunction with the accompanying drawings and embodiments.

[0042] Unless otherwise defined, the technical terms or scientific terms involved in this application shall have the general meaning understood by people with ordinary skills in the technical field to which this application belongs. The words "one", "a", "a", "the", "these" and the like in this application do not represent quantitative restrictions, and they can be singular or plural. The terms "include", "comprise", "have" and any variants thereof involved in this application are intended to cover non-exclusive inclusions; for example, a process, method and system, product or device comprising a series of steps or modules (units) is not limited to the listed steps or modules (units), but may include unlisted steps or modules (units), or may include other steps or modules (units) inherent to these processes, methods, products or devices. The words "connect", "connected", "coupled" and the like involved in this application are not limited to physical or mechanical connections, but may include electrical connections, whether directly or indirectly. The "multiple" involved in this application refers to two or more. "And / or" describes the association relationship of associated objects, indicating that there can be three relationships. For example, "A and / or B" can mean: A exists alone, A and B exist at the same time, and B exists alone. Usually, the character " / " indicates that the objects associated with each other are in an "or" relationship. The terms "first", "second", "third", etc. involved in this application are only used to distinguish similar objects and do not represent a specific ordering of the objects.

[0043] The method embodiment provided in this embodiment can be executed in a terminal, a computer or a similar computing device. For example, running on a terminal, Figure 1 is a hardware structure block diagram of a terminal of the design method of a low-frequency narrowband device of this embodiment. Figure 1 As shown, the terminal may include one or more ( Figure 1 Only one is shown in the figure) processor 102 and memory 104 for storing data, wherein processor 102 may include but is not limited to a processing device such as a microprocessor MCU or a programmable logic device FPGA. The above terminal may also include a transmission device 106 and an input and output device 108 for communication functions. It can be understood by those skilled in the art that Figure 1 The structure shown is only for illustration and does not limit the structure of the above terminal. Figure 1 More or fewer components as shown, or with Figure 1 Different configurations shown.

[0044] The memory 104 can be used to store computer programs, for example, software programs and modules of application software, such as the computer program corresponding to the design method of the low-frequency narrowband device in the present embodiment. The processor 102 executes various functional applications and data processing by running the computer program stored in the memory 104, that is, to implement the above method. The memory 104 may include a high-speed random access memory, and may also include a non-volatile memory, such as one or more magnetic storage devices, flash memory, or other non-volatile solid-state memory. In some instances, the memory 104 may further include a memory remotely arranged relative to the processor 102, and these remote memories may be connected to the terminal via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0045] The transmission device 106 is used to receive or send data via a network. The above network includes a wireless network provided by the communication provider of the terminal. In one example, the transmission device 106 includes a network adapter (Network Interface Controller, referred to as NIC), which can be connected to other network devices through a base station so as to communicate with the Internet. In one example, the transmission device 106 can be a radio frequency (Radio Frequency, referred to as RF) module, which is used to communicate with the Internet wirelessly.

[0046] In this embodiment, a design method for a low-frequency narrowband device is provided. Figure 2 is a flow chart of the design method of the low-frequency narrowband device of this embodiment. Figure 2 As shown, the process includes the following steps:

[0047] Step S210, obtaining an initial circuit.

[0048] Specifically, the initial circuit can be automatically generated based on circuit design software, or an existing circuit design can be downloaded from a database or website to obtain the initial circuit.

[0049] Step S220, based on preset constraints, updating the structure of the initial circuit and the parameters of the target component, the constraints include component restriction conditions, until the initial circuit meets the preset simulation performance, and obtaining the target circuit of the low-frequency narrowband device.

[0050] Specifically, the component restriction condition is the selection criteria for the target component, so as to modify the design that does not meet the selection criteria in the initial circuit. The component restriction conditions include, but are not limited to, the numerical range, quality factor, precision parameter, specification parameter, manufacturer and other contents of the target component. The target components include lumped components such as capacitors and inductors. For example, in the low-frequency narrowband design, the initial circuit with high performance usually designs a very large inductance value for the inductor component, but in actual production, components with high inductance and high Q value (quality factor) are difficult to purchase, and there are many difficulties such as the need for customization, long construction period, and high cost, which makes the initial circuit unable to be mass-produced and applied. Therefore, the component parameters that adapt to the current production conditions can be sorted into a table as component restriction conditions.

[0051] In one embodiment, the initial circuit may be simulated and tested to obtain one or more experimental results, and based on the experimental results (or multi-dimensional experimental results), the initial circuit may be iteratively updated in combination with the component constraints. In other embodiments, the initial circuit may be parameter modified and equivalently transformed in combination with the component constraints, and the circuit may be simulated and tested on the basis that the component parameters meet the component constraints, and the circuit may be iteratively updated in combination with the multi-dimensional experimental results.

[0052] Among them, the experimental means adopted include at least one of circuit schematic simulation, layout simulation and printed circuit board test, and the corresponding experimental results obtained include circuit schematic simulation results, layout simulation results and printed circuit board test results, and at least two of the circuit schematic simulation results, layout simulation laser results and printed circuit board test results are taken as multi-dimensional experimental results.

[0053] Specifically, the low-frequency narrow-band device includes a low-frequency narrow-band filter, a low-frequency narrow-band signal generator, and the like.

[0054] In the present application, an initial circuit for a low-frequency narrowband is obtained; based on preset constraints, the structure in the initial circuit and the parameters of the target elements are iteratively updated until the initial circuit structure meets the preset simulation performance, thereby obtaining a target circuit for a low-frequency narrowband device. This solves the current design difficulties of low-frequency narrowband devices, improves device accuracy, facilitates mass production, reduces design difficulty, and increases the success rate of board issuance, thereby obtaining a low-frequency narrowband device with excellent performance that is suitable for mass production.

[0055] In some embodiments, based on step S220, based on preset constraints, the structure of the initial circuit and the parameters of the target component are updated, the constraints include component restriction conditions, until the initial circuit meets the preset simulation performance, and the target circuit of the low-frequency narrowband device is obtained, including:

[0056] Step S221 , based on preset component restriction conditions, the structure in the initial circuit and the parameters of the target components are preliminarily adjusted to obtain the circuit to be simulated.

[0057] Specifically, the initial adjustment includes methods such as modifying component parameters and performing equivalent transformation on series structures and parallel structures.

[0058] Step S222 , based on the experimental results of the circuit to be simulated, the circuit to be simulated is optimized and iterated until it meets the preset simulation performance, thereby obtaining a target circuit of a low-frequency narrow-band device.

[0059] Specifically, the constraints include component restrictions and experimental results. The optimization iteration includes modifying the component parameters based on the circuit structure after the initial adjustment to improve the device performance and make it have a higher roll-off coefficient under the premise of lower core frequency and relatively large bandwidth.

[0060] In this embodiment, by making preliminary adjustments based on component constraints, the design with large deviations in the initial design is improved, and the performance of the device is further improved through iterations of experimental results, thereby improving the efficiency of circuit design.

[0061] In one embodiment, when the simulation performance still fails to meet the requirements after the target number of optimizations, steps S222 to S223 are repeatedly performed to improve the success rate of the circuit design.

[0062] In some of the embodiments, based on step S221, based on the preset component restriction condition, the structure in the initial circuit and the parameters of the target component are initially adjusted to obtain the circuit to be simulated, including:

[0063] Step S301, in the initial circuit, modifying the parameters of the target component that exceeds the preset component restriction condition to be within the component restriction condition.

[0064] Specifically, taking the 5th-order parallel Chebyshev filter as an example, Figure 3 For the corresponding initial circuit, the inductance values ​​of the three parallel inductors L1\L3\L5 that exceed the preset component restriction conditions are modified so that the inductance values ​​of the parallel inductors are within the numerical range of the component restriction conditions.

[0065] Step S302: in the initial circuit after the parameters are modified, based on the component restriction conditions, an equivalent transformation process of Norton transformation is performed on the resonant structure to obtain a circuit to be simulated.

[0066] Specifically, yes Figure 3The two sets of series resonant structures in the Norton transformation are subjected to Norton transformation. After the Norton transformation, the capacitors that exceed the component restriction conditions are replaced by at least two equivalent parallel capacitors. Alternatively, multiple parallel capacitors can be replaced by one equivalent capacitor if the component restriction conditions are met. The Norton transformation has the following effects on the structural changes of the LC circuit: Figure 4 shown.

[0067] In this embodiment, through parameter modification and equivalent transformation based on component restriction conditions, factors that lead to the inability to mass produce in the initial design are modified one by one, providing a more reliable circuit structure for subsequent optimization.

[0068] In some of the embodiments, the experimental results of the circuit to be simulated include at least one of: circuit schematic simulation results, layout simulation results and printed circuit board test results.

[0069] Specifically, components in the circuit to be simulated are replaced with actual device models to obtain a model-replaced circuit; circuit schematic simulation is performed on the model-replaced circuit to obtain circuit schematic simulation results; and layout simulation is performed on the model-replaced circuit to obtain layout simulation results.

[0070] The components in the circuit to be simulated are all ideal components, while the actual device model takes into account parasitic parameters, such as the Coilcraft 2014VS series inductor model and the capacitor simulation model provided by Murata, so that the simulation results are more accurate.

[0071] In addition, considering the impact of the actual layout and the sensitivity of narrowband devices, layout simulation is required to ensure the success rate of board making. Since low-frequency narrowband bandpass filters have extremely narrow bandwidths, they are very sensitive. Slight fluctuations in component accuracy, board-level circuit parasitics, component Q values, etc. may cause frequency deviation and deterioration of filtering performance of narrowband bandpass filters. Therefore, layout simulation before board release is extremely important and can greatly improve the success rate of board release.

[0072] The simulation software includes but is not limited to ADS (Advanced Design System, integrated circuit design software) and other electromagnetic simulation software.

[0073] The circuit to be simulated is optimized and iterated based on the circuit schematic simulation result and the layout simulation result, or the circuit to be simulated is optimized and iterated based on the circuit schematic simulation result, or the circuit to be simulated is optimized and iterated based on the layout simulation result.

[0074] Preferably, the circuit to be simulated is optimized and iterated based on the circuit schematic simulation results and the layout simulation results. By combining the layout simulation results, the success rate of the design is greatly improved, and the risk of board launch failure is further reduced.

[0075] In one embodiment, after the results of the circuit schematic simulation and the layout simulation meet the preliminary performance requirements, the current optimized circuit to be simulated is tested on a printed circuit board, that is, the circuit to be simulated is processed into a PCB, and a board verification is performed to obtain the printed circuit board test result. The printed circuit board test result is obtained; if the printed circuit board test result meets the target performance requirements, the design of the target circuit of the low-frequency narrowband device is completed; if the printed circuit board test result does not meet the target performance requirements, the circuit is continuously fine-tuned and simulated until the printed circuit board test result meets the target performance requirements.

[0076] In some embodiments, based on step S210, obtaining the initial circuit includes:

[0077] Step S211 : generating an initial circuit using circuit design software based on the acquired low-frequency narrowband design target.

[0078] Specifically, the low-frequency narrowband design target is input into the ADS software, and the low-frequency narrowband design target includes but is not limited to the device type, center frequency, relative bandwidth, filter order, etc. For example, when designing a filter, the design target is set as a center frequency of 5M, a 3dB bandwidth (ie, effective working bandwidth) of 0.9M, and a 5th-order parallel Chebyshev filter.

[0079] In some of the embodiments, the target element includes an inductor element, and the parameters include a quality factor and an inductance value.

[0080] Specifically, since the requirement for narrowband performance requires special attention in device selection, devices with higher quality factors (ie, Q values) are considered to quickly achieve performance requirements in the design.

[0081] The present application also provides a low-frequency narrowband filter, which is designed based on any of the above-mentioned design methods for low-frequency narrowband devices. Figure 5 As shown, the low-frequency narrowband filter includes: at least one series-parallel combination module 51 and a parallel resonance module 52; the series-parallel combination modules 51 are connected in series, and the last series-parallel combination module 51 is connected in series with the parallel resonance module 52.

[0082] Among them, the series-parallel combination module 51 includes a first capacitor C21, a first inductor L21, a second capacitor C22, a second inductor L22, a third capacitor C23, a fourth capacitor C24 and a fifth capacitor C25; one end of the first capacitor C21 is connected to the input signal, and the other end of the first capacitor C21 is connected to the second capacitor C22 through the first inductor L21; one end of the first capacitor C21 is also grounded through the second inductor L22 and the third capacitor C23 connected in parallel; the other end of the first capacitor C21 is also grounded through the fourth capacitor C24; one end of the second capacitor C22 is grounded through the fifth capacitor C25, and the other end of the second capacitor C22 is connected to the next series-parallel combination module 51 or the parallel resonance module 52.

[0083] In some of the embodiments, the low-frequency narrow-band filter includes two serial-parallel combination modules 51 .

[0084] In some embodiments, the low-frequency narrow-band filter further includes: a sixth capacitor C26 and a seventh capacitor C27, the input end of the first series-parallel combination module 51 is connected to the input signal through the sixth capacitor C26; the output end of the parallel resonance module 52 is connected to one end of the seventh capacitor C27, and the other end of the seventh capacitor C27 is used as the signal output end. Preferably, the values ​​of the sixth capacitor C26 and the seventh capacitor C27 are 1uF DC isolation capacitors. Thus, the low-frequency narrow-band filter can be applied to DC input, avoiding the serious offset voltage generated when used in a circuit containing a DC component (such as an operational amplifier circuit).

[0085] The low-frequency narrow-band filter in this embodiment has the advantages of simple structure, low cost and excellent performance. It can be realized by using only 16 conventional LC devices and ordinary FR4 boards, and is suitable for mass production.

[0086] The present embodiment is described and illustrated below through preferred embodiments.

[0087] Figure 6 Flow chart of the design method of the low-frequency narrowband device of the preferred embodiment. In the preferred embodiment, the low-frequency narrowband filter is taken as the target, and the implementation method is as follows:

[0088] S1. Based on the filter design software, aiming at the design goal of a 5th-order parallel Chebyshev filter with a center frequency of 5M and a 3dB bandwidth of 0.9M, an initial circuit structure of a required bandpass filter is obtained, such as Figure 3 shown.

[0089] S2. Setting component restriction conditions based on parameter information of mass-producible components provided by component suppliers;

[0090] S3, fine-tune the circuit parameters, Figure 3The three parallel inductors L1 / L3 / L5 in the circuit are adjusted to components with the highest quality factor within the component limit conditions to achieve the purpose of reducing the manufacturing cost. In this preferred embodiment, they are adjusted to 257nH or 149.3nH. The 2014VS series inductors of Coilcraft on the market can meet this requirement.

[0091] S4. Figure 3 The two resonant circuits C2 / L2 and L4 / C4 in the circuit are subjected to Norton transformation, that is, L2 / L4 is converted into a component with a smaller inductance, such as 257nH, and then the resonant capacitor is adjusted accordingly to satisfy the 1:N impedance transformation to achieve the equivalent transformation of the circuit. For capacitors that do not meet the component restriction conditions, two capacitors can be connected in parallel to achieve the equivalent transformation. Furthermore, a DC blocking capacitor is connected in series on the input side and the output side of the circuit after the equivalent transformation, and the circuit is obtained as follows Figure 5 shown.

[0092] S5. Because the capacitors and inductors used in the above circuits are ideal devices and do not consider the parasitic parameters of the actual devices, the above devices need to be replaced with the actual device models provided by the supplier during simulation. The circuit model and simulation results after replacing with the actual capacitor and inductor device models are shown in Figure 1. Figure 6 As shown. Figure 6 It can be seen that after the actual device model is introduced, the bandpass filter still has good performance, and the second harmonic suppression is around -96dB.

[0093] S6. After the schematic simulation is completed, considering the influence of the actual layout and the fact that the narrowband bandpass filter is very sensitive, layout simulation is required to ensure the success rate of board making. The present invention is based on ADS (Advanced Design System) simulation software for simulation. The layout simulation results are as follows: Figure 7 As shown, by comparison Figure 6 and Figure 7 , it can be seen that the layout simulation and schematic simulation are basically the same.

[0094] S7. After the simulation is completed, the PCB board is verified. The actual measurement results of the PCB are as follows: Figure 8 As shown, in Figure 8 In the test, the second harmonic suppression can reach about -78dB, and the harmonic signal can be basically suppressed to the bottom noise level, meeting the performance requirements.

[0095] The lower the center frequency of the filter and the narrower the relative bandwidth, the more difficult it is to design in practice, because the main function of the filter is to filter out the higher harmonics of the fundamental signal. The lower the fundamental signal, the closer its harmonics are to the fundamental signal, thus requiring a higher roll-off factor for the filter.

[0096] In this preferred embodiment, the low-frequency narrowband filter design method has a relatively simple process and high simulation accuracy. The designed filter has the advantages of simple structure, low cost, excellent performance, good performance consistency, and suitability for mass production.

[0097] It should be noted that the steps shown in the above process or the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer executable instructions, and although a logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0098] In this embodiment, a design device for a low-frequency narrowband device is also provided, which is used to implement the above-mentioned embodiments and preferred implementation modes, and the descriptions that have been made will not be repeated. The terms "module", "unit", "subunit" and the like used below can implement a combination of software and / or hardware of a predetermined function. Although the devices described in the following embodiments are preferably implemented in software, the implementation of hardware, or a combination of software and hardware, is also possible and conceivable.

[0099] Fig. 9 is a structural block diagram of the design device of the low-frequency narrow-band device of this embodiment, such as Fig. 9 As shown, the device includes: an initial design module 10 and an optimization iteration module 20.

[0100] The initial design module 10 is used to obtain an initial circuit.

[0101] The optimization iteration module 20 is used to update the structure of the initial circuit and the parameters of the target components based on preset constraints, including component restriction conditions, until the initial circuit meets the preset simulation performance to obtain the target circuit of the low-frequency narrowband device.

[0102] In some of the embodiments, the optimization iteration module 20 is also used to preliminarily adjust the structure in the initial circuit and the parameters of the target components based on preset component constraints to obtain the circuit to be simulated; based on the experimental results of the circuit to be simulated, the circuit to be simulated is optimized and iterated until it meets the preset simulation performance, thereby obtaining the target circuit of the low-frequency narrowband device.

[0103] In some of the embodiments, the optimization iteration module 20 is also used to modify the parameters of the target components that exceed the preset component constraints in the initial circuit to be within the component constraints; in the initial circuit after the parameter modification, based on the component constraints, the resonant structure is subjected to an equivalent transformation processing of the Norton transform to obtain the circuit to be simulated.

[0104] In some of the embodiments, the experimental results of the circuit to be simulated include: at least one of circuit schematic simulation results, layout simulation results and printed circuit board test results.

[0105] In some of the embodiments, the initial design module 10 is further used to generate an initial circuit using circuit design software based on the acquired low-frequency narrowband design target.

[0106] In some of the embodiments, the low-frequency narrowband design objectives include: center frequency, relative bandwidth, and filter order.

[0107] In some of the embodiments, the target element includes an inductor element, and the parameters include a quality factor and an inductance value.

[0108] It should be noted that the above modules can be functional modules or program modules, and can be implemented by software or hardware. For modules implemented by hardware, the above modules can be located in the same processor; or the above modules can be located in different processors in any combination.

[0109] In this embodiment, a computer device is further provided, including a memory and a processor, wherein a computer program is stored in the memory, and the processor is configured to run the computer program to execute the steps in any one of the above method embodiments.

[0110] Optionally, the computer device may further include a transmission device and an input / output device, wherein the transmission device is connected to the processor, and the input / output device is connected to the processor.

[0111] It should be noted that the specific examples in this embodiment can refer to the examples described in the above embodiments and optional implementation modes, and will not be repeated in this embodiment.

[0112] In addition, in combination with the design method of the low-frequency narrowband device provided in the above embodiments, a storage medium can also be provided in this embodiment to implement the design method of the low-frequency narrowband device. The storage medium stores a computer program; when the computer program is executed by the processor, any one of the design methods of the low-frequency narrowband device in the above embodiments is implemented.

[0113] It should be understood that the specific embodiments described herein are only used to explain the application, rather than to limit it. Based on the embodiments provided in this application, all other embodiments obtained by ordinary technicians in this field without creative work are within the protection scope of this application.

[0114] Obviously, the drawings are only some examples or embodiments of the present application. For ordinary technicians in the field, the present application can also be applied to other similar situations based on these drawings without creative work. In addition, it is understandable that although the work done in this development process may be complicated and lengthy, for ordinary technicians in the field, certain changes in design, manufacturing or production based on the technical content disclosed in this application are only conventional technical means and should not be regarded as insufficient content disclosed in this application.

[0115] The term "embodiment" in this application refers to a specific feature, structure or characteristic described in conjunction with the embodiment that can be included in at least one embodiment of the present application. The appearance of this phrase in various locations in the specification does not necessarily mean the same embodiment, nor does it mean that it is mutually exclusive with other embodiments and is independent or optional. It is clearly or implicitly understood by those of ordinary skill in the art that the embodiments described in this application can be combined with other embodiments without conflict.

[0116] The above-mentioned embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of patent protection. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the scope of protection of the present application. Therefore, the scope of protection of the present application shall be subject to the attached claims.

Claims

1. A design method for a low-frequency narrowband device, characterized in that: The method comprises: Get the initial circuit; Based on preset constraints, the structure of the initial circuit and the parameters of the target components are updated, wherein the constraints include component restriction conditions, until the initial circuit meets the preset simulation performance, thereby obtaining the target circuit of the low-frequency narrowband device.

2. The design method of a low-frequency narrowband device according to claim 1, characterized in that: Based on preset constraints, updating the structure of the initial circuit and the parameters of the target element, wherein the constraints include element restriction conditions, until the initial circuit meets the preset simulation performance, and obtaining the target circuit of the low-frequency narrowband device, including: Based on the preset component restriction conditions, the structure in the initial circuit and the parameters of the target components are preliminarily adjusted to obtain the circuit to be simulated; Based on the experimental results of the circuit to be simulated, the circuit to be simulated is optimized and iterated until it meets the preset simulation performance, thereby obtaining the target circuit of the low-frequency narrow-band device.

3. The design method of a low-frequency narrowband device according to claim 2, characterized in that: Based on the preset component restriction conditions, the structure in the initial circuit and the parameters of the target component are preliminarily adjusted to obtain the circuit to be simulated, including: In the initial circuit, modifying the parameters of the target component that exceeds the preset component constraint condition to be within the component constraint condition; In the initial circuit after the parameters are modified, based on the component restriction conditions, an equivalent transformation process of Norton transformation is performed on the resonant structure to obtain the circuit to be simulated.

4. The design method of a low-frequency narrowband device according to claim 2, characterized in that: The experimental results of the circuit to be simulated include: At least one of a circuit schematic simulation result, a layout simulation result, and a printed circuit board test result.

5. The design method of a low-frequency narrowband device according to claim 1, characterized in that: Get the initial circuit, including: Based on the obtained low-frequency narrowband design target, an initial circuit is generated using circuit design software.

6. The design method of a low-frequency narrowband device according to claim 5, characterized in that: Low-frequency narrowband design objectives include: center frequency, relative bandwidth, and filter order.

7. The design method of a low-frequency narrowband device according to any one of claims 1 to 6, characterized in that: The target element includes an inductor element, and the parameters include a quality factor and an inductance value.

8. A design device for a low-frequency narrowband device, characterized in that: The device comprises: An initial design module for obtaining an initial circuit with low-frequency narrowband performance; The optimization iteration module is used to update the structure of the initial circuit and the parameters of the target element based on preset constraints, wherein the constraints include element restriction conditions, until the initial circuit meets the preset simulation performance, thereby obtaining the target circuit of the low-frequency narrowband device.

9. A low-frequency narrow-band filter, characterized in that: The low-frequency narrow-band filter is designed based on the steps of the method described in any one of claims 1 to 8; the low-frequency narrow-band filter comprises: At least one series-parallel combination module and a parallel resonance module; each of the series-parallel combination modules is connected in series, and the last series-parallel combination module is connected in series with the parallel resonance module; Among them, the series-parallel combination module includes a first capacitor, a first inductor, a second capacitor, a second inductor, a third capacitor, a fourth capacitor and a fifth capacitor; one end of the first capacitor is connected to the input signal, and the other end of the first capacitor is connected to the second capacitor through the first inductor; one end of the first capacitor is also grounded through the second inductor and the third capacitor in parallel; the other end of the first capacitor is also grounded through the fourth capacitor; one end of the second capacitor is grounded through the fifth capacitor, and the other end of the second capacitor is connected to the next series-parallel combination module or to the parallel resonance module.

10. A computer device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 8 are implemented.

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