Audio signal processing device

Abstract

The present invention relates to an audio signal processing device. The device includes: an audio application circuit and an impedance matching circuit, wherein the audio application circuit is configured to receive, process, and output an audio intermodulation signal; the impedance matching circuit includes: a plurality of impedance elements, at least one input end, and at least one output end, and is arranged before, inside, or after the audio application circuit, and the impedance matching circuit is configured to perform impedance matching and timing adjustment on the audio intermodulation signal. The audio signal processing device of the present invention can perform impedance matching and timing adjustment on the audio intermodulation signal generated by an audio signal source and an audio application circuit, so as to reduce the intermodulation distortion generated during the transmission of the audio intermodulation signal.

Description

Technical Field

[0001] The present invention generally relates to the technical field of signal processing. More specifically, the present invention relates to an audio signal processing device. Background Art

[0002] Generally speaking, the audio signal output by an audio signal source or transmitted in a circuit is a complex energy-synthesized intermodulation signal, which may contain fundamental signals and harmonic signals with multiple different frequency components, and the amplitudes of the fundamental signals and harmonic signals of each frequency component may also be different. The so-called "intermodulation" refers to the mutual influence and mutual modulation between the signals with different frequencies and / or different amplitudes mentioned above. For signals with different frequencies and amplitudes, the impedance characteristics and timing relationships of various components in existing audio signal processing circuits or devices will be different.

[0003] When existing audio signal processing circuits or devices transmit and process an audio signal, the audio signal is usually treated as a signal with a single frequency. However, since an audio signal is a mixture of intermodulation signals with multiple different frequencies and amplitudes, the impedance values it exhibits in an audio signal processing circuit or device are different for the signals of each frequency component. This will cause the impedance value of the audio signal processing circuit or device not to match the impedance value of the load or the impedance value of the audio signal source, and thus local standing waves may be generated in the audio signal processing circuit. The standing waves are superimposed on the signals of each frequency and amplitude component, and finally cause the signals of multiple frequency and amplitude components in the signal, especially the signals of harmonic components, to be filtered out, weakened or enhanced at a certain moment, resulting in intermodulation distortion of the original signal during transmission.

[0004] In addition, when the signals of multiple frequency and amplitude components in an audio intermodulation signal flow through the same audio signal processing circuit or device, their arrival times at the receiving end will be different because their reactance values are different. Before the audio intermodulation signal enters the circuit or device, the phases of the signals of each frequency and amplitude component are consistent with each other. After being transmitted and processed by the circuit or device, since the overall reactance characteristics of the circuit or device have different timing responses to the signals of different frequency and amplitude components, the phases and time delays of the signals of each frequency and amplitude component when they reach the output end of the circuit or device are inconsistent. This will cause the energy attenuation of the signals of each frequency and amplitude component, especially the signals of harmonic components. Finally, it causes intermodulation distortion of the total received signal synthesized by restoring the signals of each frequency component at the output end of the circuit or device.

[0005] In summary, the existing audio processing circuits can only transmit signals with a single frequency and amplitude without distortion, but are unable to handle composite audio intermodulation signals composed of multiple frequency and amplitude components effectively. Additionally, since audio signals can flow through any location in an audio signal processing circuit or device, such as the input stage, output stage, and feedback terminal of the circuit or device; they can also be output from an audio signal source to the circuit or device; or output from the circuit or device to a load. Therefore, there may be audio signal intermodulation distortion in corresponding local parts of the circuit or device. Based on this, it is necessary to transmit and process audio signals without distortion in the above different situations. Summary of the Invention

[0006] To solve one or more problems in the above background art, the present invention provides an audio signal processing device. The device includes an audio application circuit and an impedance matching circuit. For different audio application circuits, by setting the number and impedance values of impedance elements in each part and each layer of the impedance matching circuit, when the audio intermodulation signals generated in the audio application circuit flow through the impedance matching circuit, signals with different frequencies and / or amplitudes automatically select their respective optimal paths for transmission, thereby achieving impedance matching between the audio application circuit and the audio signal source or load, and at the same time making a consistency adjustment to the timing relationship of signals with different frequencies and / or amplitudes, ultimately achieving the purpose of balanced signal transmission.

[0007] Specifically, the present invention discloses an audio signal processing device. The device includes: an audio application circuit configured to receive, process, and output audio intermodulation signals; and an impedance matching circuit including: a plurality of impedance elements that form a mesh structure including at least one mesh, the mesh having sides and vertices and at least one side being formed by at least one impedance element; at least one input terminal, where each input terminal is connected to a vertex in the at least one mesh and is used to receive the audio intermodulation signals; and at least one output terminal, where each output terminal is connected to another vertex in the at least one mesh and is used to output the audio intermodulation signals processed by the impedance matching circuit. The impedance matching circuit is connected to the audio application circuit to perform impedance matching and timing adjustment on the audio intermodulation signals.

[0008] In one embodiment, at least two of the impedance elements have different impedance values so that signals with different frequencies and / or amplitudes in the audio intermodulation signals pass through different paths in the mesh structure.

[0009] In another embodiment, the impedance element is at least one of the following: capacitor; inductor; capacitor and inductor; resistor and capacitor; resistor and inductor; and resistor, capacitor, and inductor.

[0010] In yet another embodiment, the impedance matching circuit is arranged before, after, or inside the audio application circuit.

[0011] In yet another embodiment, the impedance matching circuit arranged before the audio application circuit includes that the impedance matching circuit is arranged between the audio application circuit and the audio signal source. The input end of the impedance matching circuit is connected to the audio signal source, the output end of the impedance matching circuit is connected to the audio application circuit, and it is configured to perform impedance matching and timing adjustment on the audio intermodulation signal output by the audio signal source.

[0012] In another embodiment, the impedance matching circuit arranged inside the audio application circuit includes that the impedance matching circuit is arranged at the input stage of the audio application circuit, so as to perform impedance matching and timing adjustment on the audio intermodulation signal at the input stage of the audio application circuit.

[0013] In another embodiment, the impedance matching circuit arranged inside the audio application circuit further includes that the impedance matching circuit is arranged at the output stage of the audio application circuit, so as to perform impedance matching and timing adjustment on the audio intermodulation signal at the output stage of the audio application circuit.

[0014] In another embodiment, the impedance matching circuit arranged inside the audio application circuit further includes that the impedance matching circuit is arranged at the feedback end of the audio application circuit, so as to perform impedance matching and timing adjustment on the audio intermodulation signal at the feedback end of the audio application circuit.

[0015] In yet another embodiment, the impedance matching circuit arranged after the audio application circuit includes that the impedance matching circuit is arranged between the audio application circuit and the load. The input end of the impedance matching circuit is connected to the audio application circuit, and the output end of the impedance matching circuit is connected to the load, so as to perform impedance matching and timing adjustment on the audio intermodulation signal output by the audio application circuit.

[0016] In yet another embodiment, there are multiple audio application circuits, and there is one or more impedance matching circuits, so as to perform impedance matching and timing adjustment on the multiple audio intermodulation signals generated by the multiple audio application circuits.

[0017] By processing and transmitting the audio signal through the audio signal processing device of the present invention, the signals with different frequencies and / or amplitudes in the audio signal can be subjected to impedance matching processing and timing consistency adjustment, and then the audio signal after being transmitted through the audio signal processing device can be restored without distortion. In addition, by setting different positions of the impedance matching circuit relative to the audio application circuit, the device of the present invention has a wide range of application scenarios. It can not only perform impedance matching between the audio signal source and the audio application circuit, but also perform impedance matching between the audio application circuit and the load, and can also perform impedance matching between various parts inside the audio application circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] By reading the following detailed description with reference to the accompanying drawings, the above and other objects, features, and advantages of the exemplary embodiments of the present invention will become readily understood. In the drawings, several embodiments of the present invention are shown in an exemplary rather than restrictive manner, and the same or corresponding reference numerals represent the same or corresponding parts, wherein:

[0019] Figure 1 is a schematic structural diagram showing an audio signal processing device according to an embodiment of the present invention;

[0020] Figure 2 is a two-dimensional structural diagram showing an impedance matching circuit according to an embodiment of the present invention;

[0021] Figure 3 is a three-dimensional structural diagram showing an impedance matching circuit according to an embodiment of the present invention;

[0022] Figure 4 is an exemplary audio signal flow diagram showing an impedance matching circuit according to an embodiment of the present invention;

[0023] Figure 5 is another exemplary audio signal flow diagram showing an impedance matching circuit according to an embodiment of the present invention;

[0024] Figure 6 is a schematic structural diagram showing an audio signal processing device with an impedance matching circuit located before the audio application circuit according to an embodiment of the present invention;

[0025] Figure 7 is a schematic structural diagram showing an audio signal processing device with an impedance matching circuit located after the audio application circuit according to an embodiment of the present invention;

[0026] Figure 8 is a connection schematic diagram showing an impedance matching circuit and a signal transformer according to an embodiment of the present invention;

[0027] Figure 9 is a connection schematic diagram showing an impedance matching circuit and an audio signal line according to an embodiment of the present invention;

[0028] Figure 10 is a schematic structural diagram of an audio signal processing apparatus in which an impedance matching circuit according to an embodiment of the present invention is located inside an audio application circuit;

[0029] Figure 11 is a schematic structural diagram of an audio signal processing apparatus in which an impedance matching circuit according to an embodiment of the present invention is located at an input stage and an output stage of an audio application circuit;

[0030] Figure 12 is a schematic structural diagram of an audio signal processing apparatus in which an impedance matching circuit according to an embodiment of the present invention is located at an input stage and a feedback terminal of an audio application circuit; and

[0031] Figure 13 is a schematic structural diagram of an audio signal processing apparatus including a plurality of impedance matching circuits and a plurality of audio application circuits according to an embodiment of the present invention. Detailed Embodiments

[0032] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0033] Figure 1 is a schematic structural diagram of an audio signal processing apparatus 100 according to an embodiment of the present invention. It can be understood that although Figure 1 only a limited number of impedance elements and meshes are drawn, the number of the impedance elements and meshes may be more or less according to different audio application circuits of the present invention. At the same time, for a better understanding of the structure and function of the present invention, Figure 1 an audio signal source and a load are also drawn, wherein the audio signal source is configured to generate and output an audio signal, and the load is configured to receive the audio signal processed and output by the audio signal processing apparatus 100.

[0034] As Figure 1 shown, the audio signal processing apparatus 100 of the present invention may include: an audio application circuit 110, which is configured to receive, process, and output an audio intermodulation signal; and an impedance matching circuit 120, which is arranged before, inside, or after the audio application circuit, and is configured to perform impedance matching and timing adjustment on the audio intermodulation signal.

[0035] Further, the impedance matching circuit may include a plurality of impedance elements 121. The plurality of impedance elements form a mesh structure 123 including a mesh 122. The mesh has sides 124 and vertices 125, and at least one of the sides is formed by at least one impedance element. The impedance matching circuit further includes at least one input terminal 126, where each input terminal is connected to one vertex of the plurality of meshes and is used to receive the audio intermodulation signal. The impedance matching circuit further includes at least one output terminal 127, where each output terminal is connected to another vertex of the plurality of meshes and is used to output the audio intermodulation signal processed by the impedance matching circuit.

[0036] In one embodiment, the mesh of the impedance matching circuit may be one or more of a triangle, a quadrilateral, a pentagon, a hexagon, or other shapes. As Figure 1 shown, for example, the mesh may be a quadrilateral mesh formed by 4 sides. There are 9 such meshes, which are connected to each other through common sides to form a mesh structure. A vertex at one corner of the mesh structure may be used as the input terminal of the impedance matching circuit, and a vertex at another corner of the mesh structure may be used as the output terminal of the impedance matching circuit.

[0037] In one embodiment, an impedance element may be connected to each side of each of the meshes through a wire. The impedance elements may be arranged in a matrix, for example, a 4×4 matrix. Each row of the matrix includes 3 impedance elements, and each column includes 4 impedance elements. At least two of the impedance elements have different impedance values, and the impedance elements may be at least one of the following: a capacitor; an inductor; a capacitor and an inductor; a resistor and a capacitor; a resistor and an inductor; a resistor, a capacitor, and an inductor. The input terminal, the output terminal, the wire, and the impedance elements may form a plurality of signal paths for the signal flowing through the impedance matching circuit.

[0038] By configuring the number and impedance values of the impedance elements, at least two of the plurality of signal paths of the impedance matching circuit have different impedance values. Also, according to the differences in specific audio application circuits, the number and impedance values of the capacitors, inductors, and resistors may be configured differently so that each of the plurality of signal paths has a different impedance value. In this way, when signals with different frequencies and / or amplitudes flow through the impedance matching circuit, they can reach the output terminal along different paths with different impedance values from the input terminal, thereby achieving impedance matching between signals with different frequencies and / or amplitudes and the audio application circuit, and ensuring that the signals are transmitted without distortion.

[0039] In one embodiment, some of the plurality of impedance elements can be connected to form a filter circuit for performing noise filtering operations on signals of different frequencies and / or amplitudes flowing therethrough. The filter circuit can, for example, include a low-pass filter circuit composed of a resistor and a capacitor, which is configured to filter high-frequency noise; or can also include a band-pass filter circuit composed of an inductor and a capacitor, which is configured to filter out-of-band noise of the band-pass filter circuit.

[0040] Figure 2 FIG. 4 is a two-dimensional structural diagram showing an impedance matching circuit 200 according to an embodiment of the present invention. Figure 2 The impedance matching circuit 200 in FIG. 4 can be understood as Figure 1 an exemplary implementation of the impedance matching circuit 120 in FIG. 3. Therefore, in combination with Figure 1 the details of the impedance matching circuit 120 described in FIG. 3 are also equally applicable to Figure 2 the description of the impedance matching circuit 200 in FIG. 4.

[0041] As Figure 2 shown in FIG. 5, the structure of the impedance matching circuit can be a two-dimensional planar network structure composed of m rows and n columns. The impedance elements in the network structure can be arranged in a matrix, for example, it can be the Figure 2 m×n matrix shown in FIG. 5, where m and n are positive integers greater than or equal to 2. Specifically, the first row of the m rows can include impedance elements ZX11, ZX12... ZX1(n - 1), and ZX1n arranged in sequence, the second row can include impedance elements ZX21, ZX22... ZX2(n - 1), and ZX2n arranged in sequence,..., and so on. The mth row can include impedance elements ZXm1, ZXm2... ZXm(n - 1), and ZXmn arranged in sequence. The first column of the n columns can include impedance elements ZY11, ZY21... ZY(m - 1)1, and ZYm1 arranged in sequence, the second column can include impedance elements ZY12, ZY22... ZY(m - 1)2, and ZYm2 arranged in sequence,..., and so on. The nth column can include impedance elements ZY1n, ZY2n... ZY(m - 1)n, and ZYmn arranged in sequence.

[0042] In one embodiment, 4 of the impedance elements can be connected by wires to form a quadrilateral grid, and the grid includes sides and vertices. Further, the two-dimensional planar network structure can be formed by connecting the quadrilateral grids to each other, and adjacent grids have common sides. Specifically, as Figure 2The impedance elements ZX11, ZX21, ZY11, and ZY12 in [the circuit] are sequentially connected by wires to form a quadrilateral grid; similarly, the impedance elements ZX12, ZX22, ZY12, and ZY13 are also sequentially connected by wires to form a quadrilateral grid. The above two grids have a common side including the impedance element ZY12, and the two grids are connected into a mesh structure through this common side.

[0043] In one embodiment, each of the grids has four vertices. The input end of the impedance matching circuit can be led out from any one of the vertices of the grid and is configured to receive the audio intermodulation signal input to the impedance matching circuit. This audio intermodulation signal can be output by an audio signal source or output from the inside of an audio application circuit. The output end of the impedance matching circuit can be led out from another vertex of the grid and is configured to output the audio signal after being processed by the impedance matching circuit. Further, there can be multiple input ends and one or more output ends to meet the reception and output of multiple paths of the audio intermodulation signal. Specifically, for example, the input ends can be Figure 2 multiple of A, B, C, D, E, F, G, and H in [the circuit], the output ends can be one or more of A to H, and the input ends and output ends are different.

[0044] In one embodiment, the input end and the output end of the impedance matching circuit can be respectively connected to different vertices of the grid. In particular, the vertices can be located at the diagonals of the mesh structure so that the impedance elements between the input end and the output end form the most combinations, thereby achieving the purpose of more precise impedance matching. For example, the input end is connected to terminal A and the output end is connected to terminal F; or the input end is connected to terminal B and the output end is connected to terminal E. Through such a setting, the path that the signal flows through in the mesh structure can be made longer or the impedance elements that the signal flows through can be made more, thereby realizing more precise impedance matching of the audio signal.

[0045] In one embodiment, the input end, the output end, the wires, and the multiple impedance elements can form multiple signal paths for the signal flowing through the impedance matching circuit. Each of the multiple impedance elements can include at least one type of impedance element among capacitors and inductors, and at least one or more impedance elements of this type can be included in the at least one type of impedance element; or each of the multiple impedance elements can also include at least two types of impedance elements among capacitors, inductors, and resistors, and in each of the at least two types of impedance elements, at least one or more impedance elements of this type are included.

[0046] Further, by configuring the number and impedance values of the impedance elements, at least two of the multiple paths of the audio signal flowing through the impedance matching circuit have different impedance values. Moreover, according to different specific audio application circuits, the number and impedance values of the capacitors, inductors, and resistors can be configured differently so that each of the multiple audio signal paths has a different impedance value. In one embodiment, the audio signal may include a composite signal composed of multiple harmonic signals with different frequencies and / or amplitudes, where each harmonic signal flows through one of the multiple paths from the input end to the output end to perform impedance matching and timing adjustment on each harmonic signal, thereby ensuring the distortion-free transmission of the audio signal.

[0047] In one embodiment, some of the multiple impedance elements can be connected to form a filter circuit to filter out noise from signals with different frequencies and / or amplitudes flowing through. The filter circuit can, for example, include a low-pass filter circuit composed of a resistor and a capacitor, which is configured to filter out high-frequency noise; or it can also include a band-pass filter circuit composed of an inductor and a capacitor, which is configured to filter out out-of-band noise of the band-pass filter circuit.

[0048] Figure 3 FIG. 7 is a three-dimensional structure diagram showing the impedance matching circuit 300 according to an embodiment of the present invention. Figure 3 The circuit 300 in FIG. 7 can be understood as Figure 1 an exemplary implementation of the impedance matching circuit 120 in FIG. 5, and can also be understood as Figure 2 an extended implementation of the impedance matching circuit 200 in FIG. 6. Therefore, the details of the impedance matching circuits 120 and 200 described in FIGS. 5 and 6 also apply to the description of the impedance matching circuit 300 in Figure 1 FIG. 7. Figure 2 FIG. 7. Figure 3 The description of the impedance matching circuit 300 in FIG. 7.

[0049] As Figure 2 an extended implementation of the impedance matching circuit 200 in FIG. 6, the structure of the impedance matching circuit 300 of the present invention can be a three-dimensional mesh structure formed by sequentially connecting the mesh structures shown in multiple layers in Figure 2 FIG. 7. Among them, adjacent two layers of the mesh structures are connected by multiple impedance elements. In one embodiment, each layer of the mesh structure can be disposed on a board, and thus multiple boards are connected to form the three-dimensional mesh structure.

[0050] As shown in Figure 3As shown, the structure of the impedance matching circuit 300 may be a three-dimensional structure composed of three dimensions X, Y, and Z. Among them, in the X dimension, there are m rows, in the Y dimension, there are n columns, and in the Z dimension, there are t vertical columns. Each row in the X dimension is composed of impedance elements ZXmnt, each column in the Y dimension is composed of impedance elements ZYmnt, and each vertical column in the Z dimension is composed of impedance elements ZZmnt, where m, n, and t are positive integers greater than or equal to 1. In particular, when m = n = t, the three-dimensional structure is a cube.

[0051] Specifically, in the X dimension, the first row and the first vertical column may include impedance elements ZX111, ZX121... ZX1(n - 1)1, and ZX1n1 arranged in sequence. The second row and the first vertical column may include impedance elements ZX211, ZX221... ZX2(n - 1)1, and ZX2n1 arranged in sequence,... and so on. The mth row and the first vertical column may include impedance elements ZXm11, ZXm21... ZXm(n - 1)1, and ZXmn1 arranged in sequence. It can be understood that although the second, third... tth vertical columns of the first row, the second, third... tth vertical columns of the second row, and the second, third... tth vertical columns of the third, fourth... mth rows are not drawn in the figure, but according to the above arrangement rules, the numbers and layout structures of these non-drawn impedance elements can be obtained.

[0052] In the Y dimension, the first column and the first vertical column may include impedance elements ZY111, ZY211... ZY(m - 1)11, and ZYm11 arranged in sequence. The second column and the first vertical column may include impedance elements ZY121, ZY221... ZY(n - 1)21, and ZYn21 arranged in sequence,... and so on. The nth column and the first vertical column may include impedance elements ZY1n1, ZY2n1... ZY(m - 1)n1, and ZYmn1 arranged in sequence. It can be understood that although the second, third... tth vertical columns of the first column, the second, third... tth vertical columns of the second column, and the second, third... tth vertical columns of the third, fourth... mth columns are not drawn in the figure, but according to the above arrangement rules, the numbers and layout structures of these non-drawn impedance elements can be obtained.

[0053] In the Z dimension, the first vertical row and the m-th row may include impedance elements ZZm11, ZZm21... ZZm(n - 1)1, and ZZmn1 arranged in sequence. The second vertical row and the m-th row may include impedance elements ZZm12, ZZm22... ZZm(n - 1)2, and ZZmn2 arranged in sequence,... and so on. The t-th vertical row and the m-th row may include impedance elements ZZm1t, ZZm2t... ZZm(n - 1)t, and ZZmnt arranged in sequence. It can be understood that although the first, second... (m - 1)-th rows of the first vertical row, the first, second... (m - 1)-th rows of the second vertical row, and the first, second... (m - 1)-th rows of the third, fourth... t-th vertical rows are not drawn in the figure, according to the above arrangement rules, the numbers and layout structures of these non-drawn impedance elements can be obtained.

[0054] In one embodiment, the input end and the output end of the impedance matching circuit may be respectively connected to different vertices of the three-dimensional structure. Any two of the different vertices may be away from each other. In particular, the input end and the output end may be respectively connected to the diagonal vertices of the three-dimensional structure. For example, the input end is connected to vertex A and the output end is connected to vertex F; or the input end is connected to vertex C and the output end is connected to vertex G. Through such an arrangement, the impedance elements between the input end and the output end form the most combinations, and further, the path that the signal flows through in the three-dimensional structure is longer, or in other words, the impedance elements that the signal flows through are more, so as to perform more precise impedance matching on the audio signal.

[0055] In one embodiment, the input end, the output end, the wires, and the multiple impedance elements may form multiple three-dimensional signal paths for the signal flowing through the impedance matching circuit. Each of the multiple impedance elements may include at least one type of reactance element such as a capacitor or an inductor, and at least one or more reactance elements of this type are included in the at least one type of impedance element; or each of the multiple impedance elements may further include at least two types of impedance elements among a capacitor, an inductor, and a resistor, and in each of the at least two types of impedance elements, at least one or more impedance elements of this type are included.

[0056] Further, by configuring the number and impedance values of the impedance elements, at least two of the multiple stereo channels of the audio signal flowing through the impedance matching circuit have different impedance values. Also, according to different specific audio application circuits, the number and impedance values of the capacitors, inductors, and resistors can be configured differently so that each of the multiple audio signal channels has a different impedance value. In one embodiment, the audio signal may include a composite signal composed of multiple harmonic signals with different frequencies and / or amplitudes, where each harmonic signal flows through one of the multiple channels from the input end to the output end, so as to perform impedance matching and timing adjustment on each harmonic signal, thereby ensuring the distortion-free transmission of the audio signal.

[0057] In one embodiment, some of the multiple impedance elements can be connected to form a filter circuit to filter out noise from the signals with different frequencies and / or amplitudes flowing through. The filter circuit can, for example, include a low-pass filter circuit composed of a resistor and a capacitor, which is configured to filter out high-frequency noise; or it can also include a band-pass filter circuit composed of an inductor and a capacitor, which is configured to filter out the out-of-band noise of the band-pass filter circuit.

[0058] Figure 4 is an exemplary audio signal flow diagram showing the impedance matching circuit according to an embodiment of the present invention. It can be understood that Figure 4 the shown audio signal flow diagram is drawn based on Figure 2 the shown impedance matching circuit, so Figure 4 the circuit structure in Figure 2 is the same as the circuit structure in Figure 4 . For the description of the impedance matching circuit in Figure 2 , please refer to the relevant description in

[0059] As Figure 4 shown, three audio signals with different frequencies enter the mesh-structured impedance matching circuit from the input end D, then flow through different signal channels composed of different impedance elements, and finally are output from the output end H. To distinguish the audio signals with different frequencies, the three different-frequency signals transmitted in the impedance matching circuit are represented by thick solid lines, thin solid lines, and dashed lines respectively. It can be seen from Figure 4 that the three audio signals represented by the thick solid line, thin solid line, and dashed line, although all enter from the input end and are all output from the output end, flow through different signal channels in the impedance matching circuit. Since the number and impedance values of the impedance elements on each channel can be different, the total impedance value of each signal channel is also different, thereby realizing the impedance matching of the three audio signals with different frequencies respectively and ensuring the distortion-free transmission of the signal.

[0060] In one embodiment, the audio signal input to the input terminal may be, for example, one or more synthesized signals, and the synthesized signal may be composed of a fundamental wave signal of a certain frequency and a plurality of harmonic signals of different frequencies. When the synthesized signal is input to the impedance matching circuit, the fundamental wave and harmonic signals of different frequencies can automatically select paths for transmission according to different impedance values of the impedance elements, thereby achieving the purpose of impedance matching for the fundamental wave and harmonic signals of different frequencies respectively. In addition, when the fundamental wave and harmonic signals of different frequencies flow through different types and quantities of impedance elements, the generated time sequences will be different. By setting a reasonable quantity and type of impedance elements, the time sequences of the fundamental wave and harmonic signals of different frequencies at the output terminal are made to be consistent with their time sequences at the input terminal, so as to completely restore the synthesized signal at the output terminal.

[0061] In another embodiment, the audio signal input to the input terminal may also be, for example, a plurality of harmonic signals of different frequencies, where the plurality of harmonic signals of different frequencies respectively come from different synthesized signals; or the audio signal input to the input terminal may also be a combination of one or more synthesized signals and a plurality of harmonic signals of different frequencies, where the harmonic signals respectively come from another one or more synthesized signals. Its working principle is the same as the case where the signal input to the input terminal is one or more synthesized signals, and will not be elaborated here.

[0062] As a specific implementation manner, taking Figure 4 the audio signal flow direction of a local circuit in Figure 4 as an example, the principle of impedance matching of the impedance matching circuit for the audio signal will be described. As Figure 4 shown, taking the thick solid line path composed of ZX11, ZX21, ZX31, ZX32, ZY11, ZY12, ZY21, and ZY22 as an example. Further, for the convenience of description, ignoring the influence of this path on the time sequence of the audio signal, ZX11, ZX21, ZX31, and ZX32 can be set as resistors with a resistance value of 0. In addition, ZY11, ZY12, and ZY21 are set as capacitor elements C, and ZY22 is set as a resistor element R. Assume that the value of ZY11 is 470 uF, the value of ZY12 is 10 uF, the value of ZY21 is 220 uF, and the value of ZY22 is 1 kΩ. Then, the audio signal flows from the input terminal A to the intersection point of ZX32 and ZY23, and the impedance value of this path is the combined impedance value after the parallel connection of 470 uF and 10 uF, and then the series connection with the parallel impedance value of 220 u and 1 k.

[0063] Obviously, on the one hand, by setting different capacitance values and resistance values, the path of audio signals with different frequencies can be changed, thereby performing impedance matching on audio signals with different frequencies. On the other hand, different capacitance values can also be set, and by utilizing the timing response differences of capacitors to audio signals with different frequencies, the timing changes of audio signals with different frequencies can be adjusted so that the audio signals with different frequencies maintain timing consistency. Finally, after the audio signals flow through the above path, it can be ensured that they are transmitted without distortion.

[0064] Figure 5 FIG. is another exemplary audio signal flow diagram showing an impedance matching circuit according to an embodiment of the present invention. It should be noted that Figure 5 The shown audio signal flow diagram can be understood as Figure 4 An exemplary implementation of the shown audio signal flow diagram. Among them Figure 5 The frequencies of the three different audio signals in are the same as those of the three different audio signals in Figure 4 and correspond one by one. Different from the audio signal flow diagram in Figure 4 the audio signals with different frequencies shown in Figure 5 have different amplitudes from the audio signals with corresponding frequencies in Figure 4 Therefore, even if audio signals with the same frequency flow through the same impedance matching circuit, the paths they flow through are different.

[0065] As Figure 5 shown, in one embodiment, three audio signals with different frequencies enter a mesh-structured impedance matching circuit from the input terminal D, then flow through different signal paths composed of impedance elements, and finally output from the output terminal H. By comparing with Figure 4 it can be obtained that Figure 5 the paths of the three different frequency signals in are not exactly the same as those in Figure 4 The reason is that Figure 5 the three different frequency signals in respectively have different amplitudes from the three different frequency signals corresponding to them in Figure 4 Since the number and impedance values of the impedance elements on each signal path can be different, the total impedance value of each signal path is also different, thereby realizing impedance matching for audio signals with the same frequency but different amplitudes and ensuring the distortion-free transmission of audio signals.

[0066] Figure 6 FIG. is a schematic structural diagram of an audio signal processing device 600 in which an impedance matching circuit according to an embodiment of the present invention is located before an audio application circuit. To better understand the structure and function of the audio signal processing device 600 of the present invention, Figure 6An audio signal source and a load are also shown therein, where the audio signal source is configured to generate and output an audio signal, and the load is configured to receive the audio signal processed and output by the audio signal processing device 600.

[0067] As Figure 6 shown, in one embodiment, the impedance matching circuit 610 may be arranged before the audio application circuit 620. Specifically, the impedance matching circuit may be arranged between the audio application circuit and the audio signal source. The input terminals A and B of the impedance matching circuit may be connected to the audio signal source and may be configured to receive the audio intermodulation signal generated and output by the audio signal source. The output terminals E and F of the impedance matching circuit may be connected to the audio application circuit and may be configured to output the audio signal processed by it to the audio application circuit. Optionally, depending on the structure of the impedance matching circuit, the input and output terminals of the impedance matching circuit may also be vertices D and H or any other vertices. In particular, depending on the requirements of the audio application circuit, on the premise of ensuring that different vertices are connected to the input and output terminals, the input terminal may be used as the output terminal, and the output terminal may be used as the input terminal.

[0068] In one embodiment, the audio application circuit may be, for example, but not limited to, an audio pre-amplifier, an audio power amplifier, an audio acquisition circuit, an A / D conversion circuit, a D / A conversion circuit, and an audio mixer, etc. The audio signal source may be, for example, but not limited to, a CD, a mobile phone, an MP3, a medical device, a sports equipment, etc., which can output an audio signal. The load may be, for example, but not limited to, a speaker or other audio circuits or devices. The working principle of the audio signal processing device 600 of the present invention will be briefly described below.

[0069] First, the audio signal source generates and outputs an audio intermodulation signal to the impedance matching circuit, and the audio intermodulation signal includes fundamental wave and harmonic signals with multiple frequencies and / or amplitudes. Then, these fundamental wave and harmonic signals flow into the impedance matching circuit through the input terminals A and B and automatically select paths for transmission according to different impedance values. Subsequently, the audio signal processed by the impedance matching circuit is output from the output terminals E and F of the impedance matching circuit and flows to the audio application circuit. At the same time, the audio signal of the audio application circuit may also flow to the impedance matching circuit for impedance matching processing.

[0070] Finally, after the audio application circuit processes the received audio signal by amplifying, isolating, or reducing it, etc., it outputs the signal to the load for playback or further processing. Through the processing of the above process, on the one hand, the impedance of the audio signal source is impedance-matched with the impedance of the audio application circuit; on the other hand, the impedance of the audio application circuit is also impedance-matched with the impedance of the load. Finally, the audio signal output by the audio signal source is transmitted to the load without distortion.

[0071] Figure 7 FIG. 700 is a schematic structural diagram of an audio signal processing apparatus in which an impedance matching circuit is located after an audio application circuit according to an embodiment of the present invention. For a better understanding of the structure and function of the audio signal processing apparatus 700 of the present invention, Figure 7 an audio signal source and a load are also shown, where the audio signal source is configured to generate and output an audio signal, and the load is configured to receive the audio signal processed and output by the audio signal processing apparatus 700.

[0072] As Figure 7 shown, in one embodiment, the impedance matching circuit 710 is arranged after the audio application circuit 720. Specifically, the impedance matching circuit is arranged between the audio application circuit and the load. The input terminals A and B of the impedance matching circuit are connected to the audio application circuit and are used to receive the audio intermodulation signal processed and output by the audio application circuit. The output terminals E and F of the impedance matching circuit are connected to the load and are used to output the audio signal processed by it to the load. Optionally, according to the different configurations of the impedance matching circuit, the input terminals and output terminals of the impedance matching circuit may also be vertices D and H or any other vertices. In particular, according to the different requirements of the audio application circuit, on the premise of ensuring that different vertices are connected to the input terminal and the output terminal, the input terminal may be used as the output terminal, and the output terminal may be used as the input terminal. The working principle of the audio signal processing apparatus 700 of the present invention will be briefly described below.

[0073] First, the audio signal source generates and outputs an audio intermodulation signal, which includes fundamental wave and harmonic signals with multiple frequencies and / or amplitudes. Then, the audio application circuit processes the received fundamental wave and harmonic signals by amplifying, isolating, or reducing them, etc., and outputs them to the input terminals A and B of the impedance matching circuit. Finally, these signals with different frequencies and / or amplitudes are output from the output terminals E and F of the impedance matching circuit to the load through an automatic selection path for playback or further processing. Through the processing of the above process, the audio signal processing apparatus 700 of the present invention impedance-matches the total impedance of the audio signal source and the audio application circuit with the impedance of the load. Finally, the audio signal output by the audio signal source is transmitted to the load without distortion.

[0074] Figure 8 It is a schematic diagram showing the connection between an impedance matching circuit and a signal transformer according to an embodiment of the present invention. As Figure 8 shown, the signal transformer may include a primary coil, a secondary coil, and an iron core, where the primary coil is used to receive an audio signal, and the secondary coil is used to output the processed audio signal. The signal transformer may be arranged Figure 6 between the audio application circuit of the audio signal processing device in Figure 7 and the load, or may be arranged between the audio signal source in

[0075] and the audio application circuit.

[0076] Specifically, in Connection Method 1, the input terminal G of the impedance matching circuit 811 is connected to the negative pole of the primary coil of the signal transformer 821, and the output terminal C is connected to the negative pole of the secondary coil of the signal transformer 821, so as to perform impedance matching and timing adjustment on the audio signal input to the signal transformer 821, so that the audio signal is output without distortion from the secondary coil of the signal transformer 821.

[0077] In Connection Method 2, the input terminal G of the impedance matching circuit 812 is connected to the center tap N of the primary coil of the signal transformer 822, and the output terminal C is connected to the center tap N of the secondary coil of the signal transformer 822, so as to perform impedance matching and timing adjustment on the audio signal input to the signal transformer 822, so that the audio signal is output without distortion from the secondary coil of the signal transformer 822.

[0078] Figure 9 is a schematic diagram showing the connection between the impedance matching circuit and the audio signal line according to an embodiment of the present invention. Among them Figure 9 the connection method can be applied to Figure 6 between the load of the audio signal processing device in Figure 7 and the audio application circuit, or arranged between the audio signal source in Figure 9Only three connection methods are listed, but since the impedance matching circuit may have multiple input and output terminals, the impedance matching circuit and the audio signal line may also be connected by other connection methods without violating the concept of the present invention.

[0079] Specifically, in the one-end connection method, there is one audio signal input line and one audio signal output line. The core of the audio signal input line is connected to the input terminal A of the impedance matching circuit, and the protective line of the audio signal input line is connected to the input terminal C of the impedance matching circuit. The core of the audio signal output line is connected to the output terminal E of the impedance matching circuit, and the protective line of the audio signal output line is connected to the input terminal G of the impedance matching circuit. The input terminal C and the output terminal G of the impedance matching circuit can be internally connected and grounded. Through such a connection, the audio signal output by the audio signal input line is impedance-matched by the impedance matching circuit and then output without distortion on the audio signal output line.

[0080] In the two-end connection method, there are two audio signal input lines and two audio signal output lines. The cores of the two audio signal input lines are respectively connected to the input terminals A and B of the impedance matching circuit, and the protective lines of the two audio signal input lines are commonly connected to the input terminal C of the impedance matching circuit. The cores of the two audio signal output lines are connected to the output terminals E and F of the impedance matching circuit, and the protective lines of the two audio signal output lines are commonly connected to the input terminal G of the impedance matching circuit. The input terminal C and the output terminal G of the impedance matching circuit can be internally connected and grounded. Through such a connection, the audio signal output by the audio signal input line is impedance-matched by the impedance matching circuit and then output without distortion on the audio signal output line.

[0081] In the three-end connection method, the audio signal input line and the audio signal output line both include a positive terminal 2, a negative terminal 3, and a ground terminal 1. The positive terminal 2, the negative terminal 3, and the ground terminal 1 of the audio signal input line are respectively connected to the input terminals A, B, and C of the impedance matching circuit. The positive terminal 2, the negative terminal 3, and the ground terminal 1 of the audio signal output line are respectively connected to the output terminals E, F, and G of the impedance matching circuit. The input terminal C and the output terminal G of the impedance matching circuit can be internally connected and grounded. Through such a connection, the audio signal output by the audio signal input line is impedance-matched by the impedance matching circuit and then output without distortion on the audio signal output line.

[0082] Figure 10 FIG. 13 is a schematic structural diagram of an audio signal processing apparatus 1000 in which an impedance matching circuit according to an embodiment of the present invention is located inside an audio application circuit. To better understand the structure and function of the audio signal processing apparatus 1000 of the present invention, Figure 10An audio signal source and a load are also shown therein, where the audio signal source is configured to generate and output an audio signal, and the load is configured to receive the audio signal processed and output by the audio signal processing device 1000.

[0083] As Figure 10 shown, in one embodiment, the audio application circuit 1010 may include an input stage 1011, an output stage 1012, and a feedback terminal 1013. The impedance matching circuit 1020 may be arranged inside the audio application circuit. Further, the impedance matching circuit may be arranged in at least one of the input stage, the output stage, and the feedback terminal.

[0084] Specifically, the impedance matching circuit may be arranged in the input stage of the audio application circuit to perform impedance matching and timing adjustment on the audio intermodulation signal of the input stage of the audio application circuit. The impedance matching circuit may also be arranged in the output stage of the audio application circuit to perform impedance matching and timing adjustment on the audio intermodulation signal of the output stage of the audio application circuit. The impedance matching circuit may also be arranged in the feedback terminal of the audio application circuit to perform impedance matching and timing adjustment on the audio intermodulation signal of the feedback terminal of the audio application circuit.

[0085] It can be understood that although Figure 10 the audio application circuit in only shows the input stage, the output stage, and the feedback terminal. However, based on the disclosure and teachings of the present invention, those skilled in the art can conceive that the audio application circuit may further include other structures or units through which the audio intermodulation signal flows, such as a coupling terminal. The impedance matching circuit may be arranged in the coupling terminal to perform impedance matching and timing adjustment on the audio intermodulation signal of the coupling terminal.

[0086] Figure 11 is a schematic structural diagram of an audio signal processing device 1100 in which the impedance matching circuit according to an embodiment of the present invention is located in the input stage and the output stage of the audio application circuit. It can be understood that Figure 11 the audio signal processing device 1100 shown is Figure 10 an exemplary circuit implementation of the audio signal processing device 1000 shown. Therefore, the above description of Figure 10 the audio signal processing device 1000 in also applies to Figure 11 the description of the audio signal processing device 1100 in.

[0087] As Figure 11As shown in the figure, the audio signal processing device 1100 of the present invention may include a two-stage amplification circuit composed of a first electron tube 1121, a second electron tube 1122 and other auxiliary components. Wherein the first electron tube constitutes the input stage 1131 of the two-stage amplification circuit, and the second electron tube constitutes the output stage 1132 of the two-stage amplification circuit. Further, an impedance matching circuit 1111 is arranged at the input stage of the amplification circuit, and an impedance matching circuit 1112 is arranged at the output stage of the amplification circuit.

[0088] Specifically, at the input stage of the two-stage amplification circuit, the input end D of the impedance matching circuit 1111 is connected to the cathode of the first electron tube, and the output end H of the impedance matching circuit 1111 is grounded. In this way, an audio intermodulation signal loop composed of the first electron tube, the impedance matching circuit 1111, capacitors and resistors is formed at the input stage of the two-stage amplification circuit. During the operation of the audio signal processing device, the audio signal Vi is input into the first electron tube through a resistor, then flows through the loop, and its impedance is matched and its timing is adjusted through the impedance matching circuit 1111, finally realizing the distortion-free transmission of the audio signal at the input stage.

[0089] Further, at the output stage of the two-stage amplification circuit, the input end D of the impedance matching circuit 1112 is connected to the cathode of the second electron tube, and the output end H of the impedance matching circuit 1112 is grounded. In this way, an audio intermodulation signal loop composed of the second electron tube, the impedance matching circuit 1112, capacitors and resistors is formed at the output stage of the two-stage amplification circuit. During the operation of the audio signal processing device, the audio signal output from the input stage of the two-stage amplification circuit enters the second electron tube, then flows through the loop, and its impedance is matched and its timing is adjusted through the impedance matching circuit 1112, finally realizing the distortion-free transmission of the audio signal to the signal transformer.

[0090] Figure 12 FIG. is a schematic structural diagram of an audio signal processing device 1200 in which an impedance matching circuit is located at the input stage and the feedback end of an audio application circuit according to an embodiment of the present invention. It can be understood that Figure 12 The illustrated audio signal processing device 1200 is Figure 10 An exemplary circuit implementation of the audio signal processing device 1000 shown in the figure. Therefore, the above description of Figure 10 the audio signal processing device 1000 in also applies to Figure 12 the description of the audio signal processing device 1200 in.

[0091] As Figure 12As shown, the audio signal processing device 1200 of the present invention may include an amplification circuit composed of an amplifier AMP, a load RL, and other auxiliary components such as resistors and capacitors. The amplifier may be, for example, an integrated operational amplifier or a power amplifier, and a negative feedback loop is formed through a resistor. The load may be, for example, a speaker. The input terminal of the amplifier AMP and other auxiliary components form the input stage 1211 of the amplification circuit, and the feedback loop of the amplifier AMP forms the feedback terminal 1212 of the amplification circuit. An impedance matching circuit 1221 is connected to the input stage of the amplification circuit, and an impedance matching circuit 1222 is connected to the feedback terminal of the amplification circuit.

[0092] Specifically, at the input stage of the amplification circuit, the input terminal D of the impedance matching circuit 1221 is connected to the port 1 of the amplifier AMP through a resistor, and the output terminal H of the impedance matching circuit 1221 is grounded. In this way, an audio intermodulation signal loop composed of the amplifier AMP, the impedance matching circuit 1221, capacitors, resistors, etc. is formed at the input stage of the amplification circuit. During the operation of the audio signal processing device, the audio signal Vi is input into the port 1 of the amplifier AMP through a capacitor, then flows through the audio intermodulation signal loop, and its impedance is matched and its timing is adjusted through the impedance matching circuit 1221, finally realizing the distortion-free transmission of the audio signal at the input stage of the amplification circuit.

[0093] Furthermore, at the feedback terminal of the amplification circuit, the input terminal D of the impedance matching circuit 1222 is connected to the port 2 of the amplifier AMP through a resistor, and the output terminal H of the impedance matching circuit 1222 is grounded. In this way, an audio intermodulation signal loop composed of the amplifier AMP, the impedance matching circuit 1222, and resistors, etc. is formed at the feedback terminal of the amplification circuit. During the operation of the audio signal processing device, the audio signal output from the input stage of the amplification circuit flows through the loop after being processed by the amplifier AMP, and its impedance is matched and its timing is adjusted through the impedance matching circuit 1222, finally realizing the distortion-free output of the audio signal to the load.

[0094] Figure 13 FIG. is a schematic structural diagram of an audio signal processing device 1300 including a plurality of impedance matching circuits and a plurality of audio application circuits according to an embodiment of the present invention. It can be understood that Figure 13 the shown audio signal processing device 1300 may include a plurality of Figure 6 the shown audio signal processing device 600, or may also include a plurality of Figure 7The audio signal processing device 700 shown. Among them, there can be multiple audio application circuits 1320, and the impedance matching circuit 1310 can be one or more. When the impedance matching circuit can be one, it performs impedance matching and timing adjustment on multiple audio application circuits respectively. In addition, the multiple audio application circuits can be an integrated structure for implementing audio signal processing with specific functions; the multiple audio application circuits can also be a split structure, where each audio application circuit is used to implement audio signal processing with different functions.

[0095] It should be noted that although the present invention takes audio signals as an example and describes various processing embodiments of audio signals. However, without violating the spirit and scope of the present invention, the processing device of the present invention can also be applied to the processing of various ultrasonic detection signals, vibration detection signals, instrument test signals, and other various signals below 1 megahertz.

[0096] It should be understood that the terms "first", "second", "third", "fourth", etc. in the claims, the description, and the drawings of the present invention are used to distinguish different objects, rather than to describe a specific order. The terms "comprising" and "including" used in the description and claims of the present invention indicate the presence of the described features, wholes, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components, and / or their combinations.

[0097] It should also be understood that the terms used in the description of the present invention herein are only for the purpose of describing specific embodiments, and are not intended to limit the present invention. As used in the description and claims of the present invention, unless the context clearly indicates otherwise, the singular forms "a", "an", and "the" are intended to include the plural forms. It should be further understood that the term "and / or" used in the description and claims of the present invention refers to any combination and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0098] As used in this specification and the claims, the term "if" can be interpreted as "when", "once", "in response to a determination", or "in response to a detection" depending on the context. Similarly, the phrase "if a determination" or "if a [described condition or event] is detected" can be interpreted as meaning "once a determination is made", "in response to a determination", "once a [described condition or event] is detected", or "in response to a detection of a [described condition or event]" depending on the context.

[0099] Although the embodiments of the present invention are as described above, the above content is only an example adopted for the convenience of understanding the present invention, and is not intended to limit the scope and application scenarios of the present invention. Any person skilled in the art within the technical field of the present invention can make any modifications and changes in the form of implementation and details without departing from the spirit and scope disclosed by the present invention. However, the scope of patent protection of the present invention shall still be subject to the scope defined by the appended claims.

Claims

1. An audio signal processing device, comprising: An audio application circuit configured to receive, process, and output an audio intermodulation signal; And An impedance matching circuit, which includes: A plurality of impedance elements, the plurality of impedance elements constituting a mesh structure including at least one mesh, the mesh having sides and vertices and at least one of the sides being constituted by at least one impedance element, at least two of the impedance elements having different impedance values, so that signals of different frequencies and / or amplitudes in the audio intermodulation signal pass through different paths in the mesh structure; At least one input terminal, where each input terminal is connected to a vertex in the at least one mesh and is configured to receive the audio intermodulation signal; and At least one output terminal, where each output terminal is connected to another vertex in the at least one mesh and is configured to output the audio intermodulation signal processed by the impedance matching circuit, The impedance matching circuit is connected to the audio application circuit to perform impedance matching and timing adjustment on the audio intermodulation signal.

2. The device according to claim 1, wherein The impedance element is at least one of the following: capacitor; inductor; capacitor and inductor; resistor and capacitor; resistor and inductor; and resistor, capacitor, and inductor.

3. The device according to claim 1, wherein, The impedance matching circuit is arranged before, after, or inside the audio application circuit.

4. The apparatus according to claim 3, wherein, The impedance matching circuit arranged before the audio application circuit includes that the impedance matching circuit is arranged between the audio application circuit and the audio signal source, the input terminal of the impedance matching circuit is connected to the audio signal source, the output terminal of the impedance matching circuit is connected to the audio application circuit, and is configured to perform impedance matching and timing adjustment on the audio intermodulation signal output by the audio signal source.

5. The apparatus according to claim 3, wherein, The impedance matching circuit arranged inside the audio application circuit includes that the impedance matching circuit is arranged at the input stage of the audio application circuit to perform impedance matching and timing adjustment on the audio intermodulation signal at the input stage of the audio application circuit.

6. The device according to claim 3, wherein The impedance matching circuit arranged inside the audio application circuit further includes that the impedance matching circuit is arranged at the output stage of the audio application circuit to perform impedance matching and timing adjustment on the audio intermodulation signal at the output stage of the audio application circuit.

7. The apparatus according to claim 3, wherein The impedance matching circuit arranged inside the audio application circuit further includes that the impedance matching circuit is arranged at the feedback terminal of the audio application circuit to perform impedance matching and timing adjustment on the audio intermodulation signal at the feedback terminal of the audio application circuit.

8. The apparatus according to claim 3, wherein The impedance matching circuit arranged after the audio application circuit includes that the impedance matching circuit is arranged between the audio application circuit and the load, the input terminal of the impedance matching circuit is connected to the audio application circuit, the output terminal of the impedance matching circuit is connected to the load, so as to perform impedance matching and timing adjustment on the audio intermodulation signal output by the audio application circuit.

9. The device according to any one of claims 1 to 8, wherein There are a plurality of the audio application circuits, and one or more of the impedance matching circuits, so as to perform impedance matching and timing adjustment on the plurality of audio intermodulation signals generated by the plurality of audio application circuits.

Images