A nonlinear harmonic signal generation circuit and method

Abstract

The present invention discloses a nonlinear harmonic signal generating circuit and method, which adopts a transistor working in a linear range to respond to an input signal and generate a nonlinear component of the input signal, thereby generating a second harmonic component, a third harmonic component and other nonlinear harmonic components of the input signal based on the input signal, and then the input signal can be compensated or shaped to ensure the DC component, linearity and the like of the input signal, thereby improving the comprehensive performance of the analog circuit.

Description

Technical Field

[0001] The present invention relates to the technical field of analog signal processing, and in particular to a nonlinear harmonic signal generating circuit and method capable of generating corresponding nonlinear harmonics from an input signal. Background Art

[0002] In many analog signal processing application fields, the input signal itself contains non-ideal nonlinear harmonic components, such as 2nd harmonic components, 3rd harmonic components, etc. The existence of these nonlinear harmonic components affects the DC component and linearity of the signal, so corresponding analog circuits are required to eliminate these nonlinear harmonic components.

[0003] For example, the large-scale use of nonlinear electrical equipment in the power grid has caused the nonlinear harmonic components of the power grid to account for an increasing proportion, resulting in harmonic pollution. At present, the methods for eliminating nonlinear harmonics in the power grid include: 1. Adding rectifier transformers; 2. Selecting rectifiers with high power factors, etc. These methods for eliminating nonlinear harmonics in the power grid are relatively bulky, inconvenient to maintain, and have little effect on eliminating harmonic generation.

[0004] Therefore, how to use a simple circuit structure to eliminate the nonlinear harmonic components of the input signal in the analog circuit and ensure the DC component and linearity of the input signal has become a technical problem that needs to be urgently solved in the development of analog circuit processing technology. Summary of the invention

[0005] The purpose of the present invention is to provide a nonlinear harmonic signal generation circuit and method to solve the technical problems existing in the prior art, which can generate corresponding nonlinear harmonics from the input signal to compensate or shape the input signal, thereby improving the comprehensive performance of the analog circuit.

[0006] To achieve the above-mentioned purpose, the present invention provides a nonlinear harmonic signal generating circuit, the circuit comprising: an input unit, a feedback unit and an operational amplifier unit, the operational amplifier unit and the feedback unit forming a closed-loop feedback amplifier circuit; the input end and the control end of the input unit are both used to receive an input signal, and the output end thereof is electrically connected to the input end of the operational amplifier unit; the input end of the feedback unit is electrically connected to the input end of the operational amplifier unit, the control end thereof is used to receive the input signal, and the output end thereof is electrically connected to the output end of the operational amplifier unit; at least one of the input unit and the feedback unit uses a transistor operating in a linear range to respond to the input signal and generate a nonlinear component of the input signal, wherein the nonlinear component generated by the input unit has an opposite polarity to the nonlinear component generated by the feedback unit; the operational amplifier unit generates and outputs a nonlinear harmonic component of the input signal based on the nonlinear component.

[0007] To achieve the above-mentioned purpose, the present invention also provides a method for generating a nonlinear harmonic signal, the method comprising the following steps: (1) using a transistor operating in a linear range to respond to an input signal to generate a nonlinear component of the input signal; (2) generating a nonlinear harmonic component of the input signal based on the nonlinear component and outputting the component.

[0008] The advantages of the present invention are: the nonlinear harmonic signal generating circuit and method of the present invention adopts a transistor working in a linear range to respond to an input signal and generate a nonlinear component of the input signal, thereby generating a second harmonic component, a third harmonic component and other nonlinear harmonic components of the input signal based on the input signal, and then the input signal can be compensated or shaped to ensure the DC component, linearity, etc. of the input signal, thereby improving the comprehensive performance of the analog circuit, and the circuit structure is simple. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 , a schematic diagram of the circuit architecture for generating a nonlinear harmonic signal according to the present invention;

[0010] Figure 2 , a schematic diagram of the working principle of the nonlinear harmonic signal generating circuit of the present invention;

[0011] Figure 3 , a circuit schematic diagram of a first embodiment of a nonlinear harmonic signal generating circuit according to the present invention;

[0012] Figure 4 , a circuit schematic diagram of a second embodiment of a nonlinear harmonic signal generating circuit according to the present invention;

[0013] Figure 5 , a circuit schematic diagram of amplitude adjustment of the nonlinear harmonic signal generating circuit of the present invention. DETAILED DESCRIPTION

[0014] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and are not to be construed as limiting the present invention. In addition, the present invention repeats reference numbers and / or reference letters in different examples, and such repetition is for the purpose of simplification and clarity, and does not itself indicate the relationship between the various embodiments and / or settings discussed.

[0015] Please refer to Figure 1, a schematic diagram of the architecture of the nonlinear harmonic signal generating circuit of the present invention. The nonlinear harmonic signal generating circuit of the present invention comprises: an input unit 11, a feedback unit 13 and an operational amplifier unit 12, wherein the operational amplifier unit 12 and the feedback unit 13 constitute a closed-loop feedback amplifier circuit. The input end and the control end of the input unit 11 are both used to receive an input signal, and the output end thereof is electrically connected to the input end of the operational amplifier unit 12; the input end of the feedback unit 13 is electrically connected to the input end of the operational amplifier unit 12, the control end thereof is used to receive the input signal, and the output end thereof is electrically connected to the output end of the operational amplifier unit 12; at least one of the input unit 11 and the feedback unit 13 uses a transistor operating in a linear range to respond to the input signal and generate a nonlinear component of the input signal, wherein the nonlinear component generated by the input unit 11 has an opposite polarity to the nonlinear component generated by the feedback unit 13; the operational amplifier unit 12 generates and outputs a nonlinear harmonic component of the input signal according to the nonlinear component.

[0016] Optionally, the input unit 11 includes a first transistor and / or a second transistor operating in a linear range. The first transistor is used to respond to a negative input signal in the input signal to generate a negative first nonlinear component in its equivalent conductance, and the second transistor is used to respond to a positive input signal in the input signal to generate a positive first nonlinear component in its equivalent conductance. That is, by only controlling the transistor of the input unit to generate a nonlinear component, various nonlinear harmonic components such as the second harmonic component and the third harmonic component of the input signal required for analog circuit processing can be generated at the output end of the operational amplifier unit 12. At this time, the feedback unit 13 can use a resistor, or a transistor operating in a linear range, and the gate and source drive signals of the transistor are in phase, so that there is no nonlinear component in its equivalent conductance.

[0017] Optionally, the feedback unit 13 includes a third transistor and / or a fourth transistor operating in a linear range. The third transistor is used to respond to a positive input signal in the input signal to generate a positive second nonlinear component in its equivalent conductance; the fourth transistor is used to respond to a negative input signal in the input signal to generate a negative second nonlinear component in its equivalent conductance. That is, by only controlling the transistor of the feedback unit to generate a nonlinear component, various nonlinear harmonic components such as the second harmonic component and the third harmonic component of the input signal required for analog circuit processing can be generated at the output end of the operational amplifier unit 12. At this time, the input unit 11 can use a resistor, or a transistor operating in a linear range, and the gate and source drive signals of the transistor are in phase, so that there is no nonlinear component in its equivalent conductance.

[0018] Optionally, the input unit 11 includes a first transistor and a second transistor operating in a linear range; the feedback unit 13 includes a third transistor and a fourth transistor operating in a linear range. The first transistor responds to a negative input signal in the input signal to generate a negative nonlinear component in its equivalent conductance, and the third transistor responds to a positive input signal in the input signal to generate a positive nonlinear component in its equivalent conductance; or, the second transistor responds to a positive input signal in the input signal to generate a positive nonlinear component in its equivalent conductance, and the fourth transistor responds to a negative input signal in the input signal to generate a negative nonlinear component in its equivalent conductance. That is, by simultaneously controlling the transistors of the input unit and the transistors of the feedback unit to generate nonlinear components with opposite polarities, various nonlinear harmonic components such as the second harmonic component and the third harmonic component of the input signal required for analog circuit processing can be generated at the output end of the operational amplifier unit 12.

[0019] Optionally, the operational amplifier unit 12 generates and outputs the nonlinear harmonic component of the input signal according to the first nonlinear component and / or the second nonlinear component. The operational amplifier unit 12 can use an operational amplifier (diff-op) with full differential input and full differential output. The first transistor M1 and the second transistor M2 serve as the input resistor of the operational amplifier, and the third transistor M3 and the third transistor M4 serve as the feedback resistor of the operational amplifier. Since the open-loop gain of the operational amplifier is large, it can be known from the feedback control principle that the gain from the differential input to the differential output of the operational amplifier is equal to the feedback resistor divided by the input resistor. That is, by only controlling the transistor of the input unit to generate a nonlinear component, or only controlling the transistor of the feedback unit to generate a nonlinear component, or simultaneously controlling the transistor of the input unit and the transistor of the feedback unit to generate a nonlinear component with opposite polarity, various nonlinear harmonic components such as the second harmonic component and the third harmonic component of the input signal required for analog circuit processing can be generated at the output end of the operational amplifier unit 12. These nonlinear harmonic components can compensate or shape the input signal to ensure the DC component, linearity, etc. of the input signal.

[0020] The nonlinear harmonic signal generating circuit of the present invention generates nonlinear harmonic components such as the second harmonic component and the third harmonic component of the input signal based on the input signal, can compensate or shape the input signal, ensure the DC component and linearity of the input signal, thereby improving the comprehensive performance of the analog circuit, and the circuit structure is simple.

[0021] Please refer to Figure 2 , a schematic diagram of the working principle of the nonlinear harmonic signal generating circuit of the present invention.

[0022] The input unit 11 includes a first potential adjustment module LS1 and a first transistor M1, a second potential adjustment module LS2 and a second transistor M2; the feedback unit 13 includes a third potential adjustment module LS3 and a third transistor M3, a fourth potential adjustment module LS4 and a fourth transistor M4.

[0023] In this embodiment, the first to fourth transistors M1 to M4 are all NMOS tubes, and the corresponding first to fourth potential adjustment modules LS1-LS4 are all potential down-adjustment modules, which are used to lower (shift down) the potential of the corresponding input signal by about a threshold voltage Vth of an NMOS tube, so that the corresponding NMOS tube works in a linear range. In other embodiments, the first to fourth transistors M1 to M4 can also be PMOS tubes, and the corresponding first to fourth potential adjustment modules LS1-LS4 are all potential up-adjustment modules, which are used to raise (shift up) the potential of the corresponding input signal by about a threshold voltage Vth of a PMOS tube, so that the corresponding PMOS tube works in a linear range. The first to fourth potential adjustment modules LS1-LS4 can all use simple source followers to achieve the above-mentioned effects.

[0024] Specifically, the source of the first transistor M1 receives the positive input signal in the input signal through the first potential adjustment module LS1, and the drain thereof is electrically connected to the positive input terminal of the operational amplifier unit 12 and the drain of the third transistor M1; the source of the second transistor M2 receives the negative input signal in the input signal through the second potential adjustment module LS2, and the drain thereof is electrically connected to the negative input terminal of the operational amplifier unit 12. By controlling the different coupling connection methods of the gate and source of the input MOS tube (the first transistor M1 and the second transistor M2), the gate of the input MOS tube obtains different driving voltages (the gate driving voltage vg1 of the first transistor M1 and the gate driving voltage vg2 of the second transistor M2 as shown in the figure), and different nonlinear components can be generated on the input MOS tube. For example, the gates of the first transistor M1 and the second transistor M2 are controlled to receive the negative input signal, so that the first transistor M1 responds to the negative input signal to generate a negative nonlinear component in its equivalent conductance, while the equivalent conductance of the second transistor M2 has no nonlinear component (equivalent to being connected in the form of a resistor); or, the gates of the first transistor M1 and the second transistor M2 are controlled to receive the positive input signal, so that the second transistor M2 responds to the positive input signal to generate a positive nonlinear component in its equivalent conductance, while the equivalent conductance of the first transistor M1 has no nonlinear component (equivalent to being connected in the form of a resistor).

[0025] Specifically, the source of the third transistor M3 is connected to the negative output terminal of the operational amplifier unit 12 through the third potential adjustment module LS3, and the drain thereof is connected to the positive input terminal of the operational amplifier unit 12; the source of the fourth transistor M4 is connected to the positive output terminal of the operational amplifier unit 12 through the fourth potential adjustment module LS4, and the drain thereof is connected to the negative input terminal of the operational amplifier unit 12. By controlling the different coupling connection methods of the gate and the source of the feedback MOS tube (the third transistor M3 and the fourth transistor M4), the gate of the feedback MOS tube obtains different driving voltages (as shown in the figure, the gate driving voltage vg3 of the third transistor M3 and the gate driving voltage vg4 of the fourth transistor M4), and different nonlinear components can be generated on the feedback MOS tube. For example, the gates of the third transistor M3 and the fourth transistor M4 are controlled to receive the positive input signal, so that the third transistor M3 responds to the positive input signal to generate a positive nonlinear component in its equivalent conductance, while the equivalent conductance of the fourth transistor M4 has no nonlinear component (equivalent to being connected in the form of a resistor); or, the gates of the third transistor M3 and the fourth transistor M4 are controlled to receive the negative input signal, so that the fourth transistor M4 responds to the negative input signal to generate a negative nonlinear component in its equivalent conductance, while the equivalent conductance of the third transistor M3 has no nonlinear component (equivalent to being connected in the form of a resistor).

[0026] The operational amplifier unit 12 uses an operational amplifier (diff-op) with full differential input and full differential output. The first transistor M1 and the second transistor M2 serve as input resistors of the operational amplifier, and the third transistor M3 and the fourth transistor M4 serve as feedback resistors of the operational amplifier. Since the open-loop gain of the operational amplifier is large, it can be known from the feedback control principle that the gain from the differential input to the differential output of the operational amplifier is equal to the feedback resistor divided by the input resistor.

[0027] To perform small signal analysis, first define the following signals: x is the input differential small signal, x p and x n Corresponding to the positive / negative input small signal; y is the output differential small signal, y p and n Corresponding to positive / negative output small signal respectively; σ i is the ideal conductance of the input MOS tube, and σ f is the ideal conductance of the feedback MOS tube. g0 is the ideal gain of the closed-loop feedback amplifier circuit. In the nonlinear harmonic signal generating circuit of the present invention, the ideal gain of the operational amplifier is set to unity gain.

[0028] Since the input MOS tube and the feedback MOS tube operate in the linear range, the conductance formula of these MOS tubes can be expressed by the following formula:

[0029] σ r=σ(1±k*x) (1)

[0030] Among them, σ r is the actual conductance of the MOS tube, σ is the ideal conductance of the MOS tube, and k is the nonlinear component in the conductance of the MOS tube.

[0031] By using different coupling connection methods for the gate and source of the input MOS tube and the feedback MOS tube, the required nonlinear components can be generated on the input MOS tube or the feedback MOS tube respectively.

[0032] The gain G of the closed-loop feedback amplifier circuit of the present invention can be expressed by the following formula:

[0033]

[0034] Among them, σ ri is the actual conductance of the input MOS tube, σ rf is the actual conductance of the feedback MOS tube, k i is the nonlinear component in the conductance of the input MOS tube, k f It is the nonlinear component in the conductance of the feedback MOS tube.

[0035] It can be seen from formula (2) that by controlling only the input MOS tube to generate nonlinear components, or by controlling only the feedback MOS tube to generate nonlinear components, or by controlling both the input MOS tube and the feedback MOS tube to generate nonlinear components with opposite polarities, various nonlinear harmonic components such as the second harmonic and the third harmonic required for analog circuit processing can be generated at the output end of the operational amplifier.

[0036] Please refer to Figure 3 , a circuit diagram of the first embodiment of the nonlinear harmonic signal generating circuit of the present invention. In this embodiment, the gates of the first transistor M1 and the second transistor M2 both receive a negative input signal x n The gates of the third transistor M3 and the fourth transistor M4 both receive the positive input signal x p In this embodiment, the nonlinear harmonic signal generating circuit is implemented by the first transistor M1 and the third transistor M3.

[0037] The conductance formula of the MOS tube working in the linear range can be expressed as follows:

[0038] σ1=σ i (1-k1x) (3)

[0039] σ3=σ f (1+k3x) (4)

[0040] Wherein k1 is the nonlinear component in the conductance of the first transistor M1, and k3 is the nonlinear component in the conductance of the third transistor M3.

[0041] The gain G1 of the closed-loop feedback amplifier circuit in this embodiment can be expressed by the following formula:

[0042]

[0043] The gate of the first transistor M1 is driven by a negative input signal, and the source of the first transistor M1 is driven by a positive input signal after the potential is lowered, resulting in the potential difference signal (a positive signal) between the gate and the source of the first transistor M1 being in phase with the input signal (i.e., the negative input signal) received by its gate, so that a negative nonlinear component k1 is generated in the equivalent conductance of the first transistor M1. The gate and source drive signals of the second transistor M2 are in phase, so there is no nonlinear component in the equivalent conductance of the second transistor M2 (equivalent to being connected in the form of a resistor). The gate of the third transistor M3 is driven by a positive input signal, and the source of the third transistor M3 is driven by a negative output signal after the potential is lowered, resulting in the potential difference signal (a positive signal) between the gate and the source of the third transistor M3 being in phase with the input signal (i.e., the positive input signal) received by its gate, so a positive nonlinear component k3 is generated in the equivalent conductance of the third transistor M3. The gate and source drive signals of the fourth transistor M4 are in phase, so there is no nonlinear component in the equivalent conductance of the fourth transistor M4 (equivalent to being connected in the form of a resistor).

[0044] It can be seen from formula (5) that by simultaneously controlling the first transistor M1 and the third transistor M3 to generate nonlinear components with opposite polarities, various required nonlinear harmonic components are generated at the output end of the operational amplifier, including negative 2nd harmonic, positive 3rd harmonic, negative 4th harmonic and other nonlinear harmonic components. That is, in this embodiment, the transistors of the input unit and the transistors of the feedback unit are simultaneously controlled to generate nonlinear components with opposite polarities. In other embodiments, the gate of the first transistor M1 may be driven by a positive input signal, and the source of the first transistor M1 may be driven by a positive input signal after the potential is lowered, so that the driving signals of the gate and source of the first transistor M1 are in phase, so that there is no nonlinear component in its equivalent conductance, that is, only the transistor of the feedback unit is controlled to generate a nonlinear component (that is, a positive nonlinear component k3 is generated in the equivalent conductance of the third transistor M3); or the gate of the third transistor M3 may be driven by a negative input signal, and the source of the third transistor M3 may be driven by a negative output signal after the potential is lowered, so that the driving signals of the gate and source of the third transistor M3 are in phase, so that there is no nonlinear component in its equivalent conductance, that is, only the transistor of the input unit is controlled to generate a nonlinear component (that is, a negative nonlinear component k1 is generated in the equivalent conductance of the first transistor M1).

[0045] Please refer to Figure 4, a circuit schematic diagram of a second embodiment of a nonlinear harmonic signal generating circuit of the present invention. Figure 3 The difference of the embodiment shown is that, in this embodiment, the gates of the first transistor M1 and the second transistor M2 both receive the positive input signal x p The gates of the third transistor M3 and the fourth transistor M4 both receive the negative input signal x n In this embodiment, the nonlinear harmonic signal generating circuit is implemented by the second transistor M2 and the fourth transistor M4.

[0046] The conductance formula of the MOS tube working in the linear range can be expressed as follows:

[0047] σ2=σ i (1+k2x) (6)

[0048] σ4=σ f (1-k4x) (7)

[0049] Wherein k2 is the nonlinear component in the conductance of the second transistor M2, and k4 is the nonlinear component in the conductance of the fourth transistor M4.

[0050] The gain G2 of the closed-loop feedback amplifier circuit in this embodiment can be expressed by the following formula:

[0051]

[0052] The gate of the second transistor M2 is driven by the positive input signal, and the source of the second transistor M2 is driven by the negative input signal after the potential is lowered, resulting in the potential difference signal (a positive signal) between the gate and the source of the second transistor M2 being in the same phase as the input signal (i.e., the positive input signal) received by its gate, so a positive nonlinear component k2 is generated in the equivalent conductance of the second transistor M2. The gate and source drive signals of the first transistor M1 are in phase, so there is no nonlinear component in the equivalent conductance of the first transistor M1. The gate of the fourth transistor M4 is driven by the negative input signal, and the source of the fourth transistor M4 is driven by the positive output signal after the potential is lowered, resulting in the potential difference signal (a positive signal) between the gate and the source of the fourth transistor M4 being in opposite phase to the input signal (i.e., the negative input signal) received by its gate, so a negative nonlinear component k4 is generated in the equivalent conductance of the fourth transistor M4. The gate and source drive signals of the third transistor M3 are in phase, so there is no nonlinear component in the equivalent conductance of the third transistor M3.

[0053] It can be seen from formula (8) that the nonlinear components with opposite polarities are generated by simultaneously controlling the second transistor M2 and the fourth transistor M4, thereby generating various required nonlinear harmonic components at the output end of the operational amplifier, including positive 2nd harmonic, positive 3rd harmonic, positive 4th harmonic and other nonlinear harmonic components. That is, in this embodiment, the transistors of the input unit and the transistors of the feedback unit are simultaneously controlled to generate nonlinear components with opposite polarities. In other embodiments, the gate of the second transistor M2 may be driven by a negative input signal, and the source of the second transistor M2 may be driven by a negative input signal after the potential is lowered, so that the driving signals of the gate and source of the second transistor M2 are in phase, so that there is no nonlinear component in its equivalent conductance, that is, only the transistor of the feedback unit is controlled to generate a nonlinear component (that is, a positive nonlinear component k4 is generated in the equivalent conductance of the fourth transistor M4); or the gate of the fourth transistor M4 may be driven by a positive input signal, and the source of the fourth transistor M4 may be driven by a positive output signal after the potential is lowered, so that the driving signals of the gate and source of the fourth transistor M4 are in phase, so that there is no nonlinear component in its equivalent conductance, that is, only the transistor of the input unit is controlled to generate a nonlinear component (that is, a nonlinear component k2 is generated in the equivalent conductance of the second transistor M2).

[0054] Please refer to Figure 5 , a circuit schematic diagram of the amplitude adjustment of the nonlinear harmonic signal generating circuit of the present invention. Figure 3 The difference between the illustrated embodiment is that, in this embodiment, the circuit further includes a first multiplexer MUX1 and a second multiplexer MUX2. In other embodiments, the circuit may also include any one of the first multiplexer MUX1 and the second multiplexer MUX2.

[0055] The first input terminal of the first multiplexer MUX1 receives a positive input signal x p , whose second input terminal receives the negative input signal x n The output end of the transistor is connected to the gate of the first transistor M1 and the gate of the second transistor M2. By controlling the first multiplexer MUX1 to select the positive input signal x p Or negative input signal x n The first multiplexer MUX1 selects the positive input signal x p When outputting, the connection mode of the gates of the first transistor M1 and the second transistor M2 is equivalent to Figure 4 The connection mode of the gates of the first transistor M1 and the second transistor M2 in the embodiment shown. The first multiplexer MUX1 selects the negative input signal x n When outputting, the connection mode of the gates of the first transistor M1 and the second transistor M2 is equivalent to Figure 3 The connection mode of the gates of the first transistor M1 and the second transistor M2 in the embodiment shown.

[0056] The first input terminal of the second multiplexer MUX1 receives the negative input signal x n , whose second input terminal receives the positive input signal x p The output end of the transistor is connected to the gate of the third transistor M3 and the gate of the fourth transistor M4. By controlling the second multiplexer MUX2 to select the positive input signal x p Or negative input signal x n The second multiplexer MUX2 selects the positive input signal x p When outputting, the connection mode of the gates of the third transistor M3 and the fourth transistor M4 is equivalent to Figure 3 The second multiplexer MUX2 selects the negative input signal x n When outputting, the connection mode of the gates of the third transistor M3 and the fourth transistor M4 is equivalent to Figure 4 The connection mode of the gates of the third transistor M3 and the fourth transistor M4 in the embodiment shown.

[0057] Preferably, the first multiplexer MUX1 can distribute the received positive input signal and negative input signal in proportion, so as to adjust the ratio of the positive / negative input signal input to the gate of the first transistor M1 and the second transistor M2.<k:1> ) respectively receive the positive / negative input signal and output it to the gate of the corresponding transistor, thereby adjusting the amplitude of the first nonlinear component. When one of the positive and negative input signals is 0 and the other is at the maximum, the polarity of the input signal input to the gate of the first transistor M1 and the second transistor M2 is also adjusted.

[0058] Preferably, the second multiplexer MUX2 can proportionally distribute the received positive input signal and negative input signal, thereby adjusting the ratio of the positive / negative input signal input to the gate of the third transistor M3 and the fourth transistor M4.<k:1> ) respectively receive the positive / negative input signal and output it to the gate of the corresponding transistor, thereby adjusting the amplitude of the second nonlinear component. When one of the positive and negative input signals is 0 and the other is maximum, the polarity of the input signal input to the gate of the third transistor M3 and the fourth transistor M4 is also adjusted.

[0059] from Figure 3 and Figure 4It can be seen from the derivation analysis that the polarities of the nonlinear harmonics generated by the two implementations are opposite, as shown in formula (5) and formula (8). Therefore, by adjusting the proportion of the input signal of the first transistor M1 and the second transistor M2, and adjusting the proportion of the input signal of the third transistor M3 and the fourth transistor M4, the polarity of the output signal can be adjusted, and the amplitude of the nonlinear harmonics of the output signal can also be adjusted.

[0060] Based on the same inventive concept, the present invention also provides a method for generating a nonlinear harmonic signal. The method comprises the following steps: (1) using a transistor operating in a linear range to respond to an input signal and generate a nonlinear component of the input signal; (2) generating a nonlinear harmonic component of the input signal based on the nonlinear component and outputting the nonlinear harmonic component.

[0061] Specifically, step (1) further includes: 11) using an input transistor operating in a linear range to respond to an input signal so that a first nonlinear component of the input signal is generated in its equivalent conductance; and / or 12) using a feedback transistor operating in a linear range to respond to an input signal so that a second nonlinear component of the input signal is generated in its equivalent conductance, wherein the first nonlinear component has an opposite polarity to the second nonlinear component. Accordingly, step (2) further includes: performing operational amplification on the first nonlinear component and / or the second nonlinear component to generate and output a nonlinear harmonic component of the input signal. That is, by only controlling the input transistor to generate a nonlinear component, or only controlling the feedback transistor to generate a nonlinear component, or simultaneously controlling the input transistor and the feedback transistor to generate nonlinear components of opposite polarities, various nonlinear harmonic components such as the second harmonic component and the third harmonic component of the input signal required for analog circuit processing can be generated. These nonlinear harmonic components can compensate or shape the input signal to ensure the DC component, linearity, etc. of the input signal.

[0062] Preferably, the polarity of the first nonlinear component can be adjusted by adjusting the polarity of the input signal input to the input transistor; and the polarity of the second nonlinear component can be adjusted by adjusting the polarity of the input signal input to the feedback transistor.

[0063] Preferably, the amplitude of the first nonlinear component can be adjusted by adjusting the ratio of the positive input signal to the negative input signal in the input signal input to the input transistor; and the amplitude of the second nonlinear component can be adjusted by adjusting the ratio of the positive input signal to the negative input signal in the input signal input to the feedback transistor. When one of the positive and negative input signals is 0 and the other is at the maximum, the polarity of the input signal input to the gate of the corresponding transistor is also adjusted.

[0064] That is, by adjusting the proportion of the input signal of the input transistor and the proportion of the input signal of the feedback transistor, it is possible to adjust the polarity of the output signal and the nonlinear harmonic amplitude of the output signal.

[0065] The method can use the nonlinear harmonic signal generating circuit of the present invention. The connection mode and working principle of the circuit can be referred to Figure 1-5 And the corresponding instructions will not be repeated here.

[0066] The above is only a preferred embodiment of the present invention. It should be pointed out that ordinary technicians in this technical field can make several improvements and modifications without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A nonlinear harmonic signal generating circuit, characterized in that: The circuit comprises: an input unit, a feedback unit and an operational amplifier unit, wherein the operational amplifier unit and the feedback unit constitute a closed-loop feedback amplifier circuit; The input end and the control end of the input unit are both used to receive input signals, and the output end thereof is electrically connected to the input end of the operational amplifier unit; The input end of the feedback unit is electrically connected to the input end of the operational amplifier unit, the control end thereof is used to receive the input signal, and the output end thereof is electrically connected to the output end of the operational amplifier unit; At least one of the input unit and the feedback unit uses a transistor operating in a linear range to respond to the input signal and generate a nonlinear component of the input signal, wherein the nonlinear component generated by the input unit has an opposite polarity to the nonlinear component generated by the feedback unit; The operational amplifier unit generates and outputs a nonlinear harmonic component of the input signal according to the nonlinear component; The input unit includes a first transistor and / or a second transistor operating in a linear range; The first transistor is configured to generate a negative first nonlinear component in its equivalent conductance in response to a negative input signal in the input signal; The second transistor is used for generating a positive first nonlinear component in its equivalent conductance in response to a positive input signal in the input signal; The first transistor and the second transistor are both MOS transistors; the source of the first transistor receives the positive input signal through the first potential adjustment module, and the drain of the first transistor is connected to the positive input terminal of the operational amplifier unit; The source of the second transistor receives the negative input signal through the second potential adjustment module, and the drain of the second transistor is connected to the negative input terminal of the operational amplifier unit; The gates of the first transistor and the second transistor are both used to receive the negative input signal, so that only the first transistor generates a negative first nonlinear component; or The gates of the first transistor and the second transistor are both used to receive the positive input signal, so that only the second transistor generates a positive first nonlinear component.

2. The circuit according to claim 1, characterized in that The circuit further includes a first multiplexer; The first input terminal of the first multiplexer receives the positive input signal, the second input terminal receives the negative input signal, and the output terminal is connected to the gates of the first transistor and the second transistor for adjusting the ratio of the positive input signal to the negative input signal.

3. The circuit according to claim 1, characterized in that The feedback unit includes a third transistor and / or a fourth transistor operating in a linear range; The third transistor is used for generating a positive second nonlinear component in its equivalent conductance in response to a positive input signal in the input signal; The fourth transistor is configured to generate a negative second nonlinear component in its equivalent conductance in response to a negative input signal in the input signal.

4. The circuit according to claim 3, characterized in that The third transistor and the fourth transistor are both MOS transistors; the source of the third transistor is connected to the negative output terminal of the operational amplifier unit through the third potential adjustment module, and the drain is connected to the positive input terminal of the operational amplifier unit; The source of the fourth transistor is connected to the positive output terminal of the operational amplifier unit through the fourth potential adjustment module, and the drain of the fourth transistor is connected to the negative input terminal of the operational amplifier unit; The gates of the third transistor and the fourth transistor are both used to receive the positive input signal, so that only the third transistor generates a positive second nonlinear component; The gates of the third transistor and the fourth transistor are both used to receive the negative input signal, so that only the fourth transistor generates a negative second nonlinear component.

5. The circuit according to claim 4, characterized in that The circuit further includes a second multiplexer; The first input terminal of the second multiplexer receives the negative input signal, the second input terminal receives the positive input signal, and the output terminal is connected to the gates of the third transistor and the fourth transistor to adjust the ratio of the positive input signal to the negative input signal.

6. A method for generating a nonlinear harmonic signal, characterized in that: Using the nonlinear harmonic signal generating circuit according to any one of claims 1 to 5, the method comprises the following steps: (1) using a transistor operating in a linear range to respond to an input signal and generate a nonlinear component of the input signal; (2) Generating a nonlinear harmonic component of the input signal based on the nonlinear component and outputting the resultant signal.

7. The method according to claim 6, characterized in that Step (1) further comprises: (11) using an input transistor operating in a linear range to respond to an input signal so that a first nonlinear component of the input signal is generated in its equivalent conductance; and / or (12) using a feedback transistor operating in a linear range to respond to an input signal so that a second nonlinear component of the input signal is generated in its equivalent conductance, wherein the first nonlinear component has an opposite polarity to the second nonlinear component; Step (2) further includes: performing operational amplification on the first nonlinear component and / or the second nonlinear component to generate and output a nonlinear harmonic component of the input signal.

8. The method according to claim 7, characterized in that Step (11) further includes adjusting the ratio of the positive input signal to the negative input signal in the input signal of the input transistor, thereby adjusting the polarity and amplitude of the first nonlinear component.

9. The method according to claim 7, characterized in that Step (12) further includes adjusting the ratio of the positive input signal to the negative input signal in the input signal of the feedback transistor, thereby adjusting the polarity and amplitude of the second nonlinear component.

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