Triangular wave linear frequency modulation simulation predistorter

Abstract

The utility model discloses a triangular wave linear frequency modulation analog predistorter, which belongs to the technical field of signal processing and comprises a first operational amplifier circuit, a second operational amplifier circuit and an analog predistortion conversion circuit. The nonlinear characteristic of diodes in the first operational amplifier circuit and the second operational amplifier circuit is utilized to generate an analog voltage which is opposite to the nonlinear response slope of the voltage-controlled oscillator so as to offset the nonlinearity of the voltage-controlled oscillator, nonlinear correction is completed, and the problem that in the application of triangular wave simulation linear frequency modulation distance measurement fuze, the nonlinear response slope of the voltage-controlled oscillator is low is solved. The problem of frequency nonlinear response of the device during broadband modulation of the voltage-controlled oscillator is solved.

Description

Technical Field

[0001] This utility model belongs to the field of signal processing technology, specifically relating to a triangular wave linear frequency modulation analog predistorter. Background Technology

[0002] In radar technology, linear frequency modulation (LFM) is a commonly used radar signal. The methods for generating LFM are divided into two main categories: digital and analog. Analog methods typically use triangular waves and sawtooth waves to control voltage-controlled oscillators to generate the required broadband frequency modulation signal. The advantages of analog methods are simple circuit topology and low cost, which makes them widely used in engineering. The disadvantage is that the voltage-controlled oscillator has poor frequency modulation linearity. In a ranging fuze system with self-mixing, the poor linearity leads to a large amount of spurious signals introduced into the echo signal. This makes it difficult to distinguish between spurious signals and true / false echo signals during echo signal processing, resulting in false alarms and low ranging accuracy. Utility Model Content

[0003] To address the problem of low echo signal quality in existing technologies, this invention proposes a triangular wave linear frequency modulation analog predistorter, the purpose of which is to: cancel the nonlinearity of the voltage-controlled oscillator, complete linear correction, and purify the echo signal.

[0004] To achieve the above objectives, the technical solution adopted by this utility model is as follows:

[0005] A triangular wave linear frequency modulation analog predistorter is characterized by comprising a first operational amplifier circuit, a second operational amplifier circuit, and an analog predistortion conversion circuit; wherein the first operational amplifier circuit is connected to the second operational amplifier circuit through the analog predistortion conversion circuit.

[0006] Preferably, the first circuit includes: resistors R1, R2, R8, R4, R5, capacitors C2, C4, C5, C6, and operational amplifier A1.

[0007] One end of resistor R1 is grounded, and the other end is connected to resistor R2. The other end of resistor R2 is connected to the second interface of operational amplifier A1. One end of resistor R4 is grounded, and the other end is connected to the third interface of operational amplifier A1. One end of capacitor C5 is grounded, and the other end is connected to the fourth interface of operational amplifier A1. One end of capacitor C6 is grounded, and the other end is connected to the fourth interface of operational amplifier A1. One end of resistor R8 is grounded, and the other end is connected to resistor R5. The other end of resistor R5 is connected to the seventh interface of operational amplifier A1. The sixth interface of operational amplifier A1 is connected between resistor R8 and resistor R5. One end of capacitor C4 is grounded, and the other end is connected to the eighth interface of operational amplifier A1. One end of capacitor C2 is grounded, and the other end is connected to the eighth interface of operational amplifier A1.

[0008] Preferably, the second operational amplifier circuit includes: capacitor C7, operational amplifier A2, capacitor C8, capacitor C1, capacitor C3, resistor R6, and resistor R7.

[0009] One end of capacitor C7 is grounded and the other end is connected to the fourth interface of op-amp A2; one end of capacitor C8 is grounded and the other end is connected to the fourth interface of op-amp A2; one end of capacitor C1 is grounded and the other end is connected to the fourth interface of op-amp A2; one end of capacitor C3 is grounded and the other end is connected to the fourth interface of op-amp A2; resistor R6 is connected to the first and second interfaces of op-amp A2; resistor R7 is connected to the sixth and seventh interfaces of op-amp A2.

[0010] Preferably, the analog predistortion converter circuit includes: transistors D1, D2, D3, D4, D5, D6, D7, D8, resistors R9, R15, R3, R14, R10, R11, R12, and R13;

[0011] Transistors D1, D3, D5, D8, R9, and R15 are connected in series, with R15 grounded; resistors R3, R14, D7, D2, D4, and D6 are connected in series, with D6 grounded; transistor D1 is connected to resistor R3; resistors R10, R11, R12, and R13 are connected in series.

[0012] Preferably, the transistor D1 and resistor R3 of the analog predistortion converter circuit are connected between resistors R1 and R2 of the first operational amplifier circuit; the fifth interface of operational amplifier A1 of the first operational amplifier circuit is connected between resistors R11 and R12 of the analog predistortion converter circuit.

[0013] Preferably, the third interface of op-amp A2 of the second op-amp circuit is connected between transistor D8 and resistor R9 of the analog predistortion converter circuit, the fifth interface of op-amp A2 of the second op-amp circuit is connected between transistor D7 and resistor R14 of the analog predistortion converter circuit, the first interface of op-amp A2 of the second op-amp circuit is connected to resistor R10 of the analog predistortion converter circuit, and the seventh interface of op-amp A2 of the second op-amp circuit is connected to resistor R13 of the analog predistortion converter circuit.

[0014] Compared with the prior art, the technical solution of this utility model has the following advantages / benefits:

[0015] 1. By utilizing the nonlinear characteristics of diodes, an analog voltage with a slope opposite to the nonlinear response of the voltage-controlled oscillator is generated. This cancels out the nonlinearity of the VCO, thereby completing nonlinear correction, improving the accuracy of the echo signal, and reducing spurious echo signal. Attached Figure Description

[0016] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this utility model and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained from these drawings without creative effort.

[0017] Figure 1 This is a circuit diagram of a triangular wave linear frequency modulation analog predistorter according to this utility model.

[0018] Figure 2 This is a simulation diagram of an embodiment of the present invention. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of this utility model clearer, the technical solutions in the embodiments of this utility model are described clearly and completely below. Obviously, the described embodiments are only a part of the embodiments of this utility model, not all of them. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model. Therefore, the detailed description of the embodiments of this utility model provided below is not intended to limit the scope of the claimed utility model, but merely represents selected embodiments of this utility model.

[0020] Example: Figure 1 As shown, a triangular wave linear frequency modulation analog predistorter includes a first operational amplifier circuit, a second operational amplifier circuit, and an analog predistortion conversion circuit; wherein the first operational amplifier circuit is connected to the second operational amplifier circuit through the analog predistortion conversion circuit.

[0021] The first circuit includes: resistors R1, R2, R8, R4, R5, capacitors C2, C4, C5, C6, and operational amplifier A1;

[0022] One end of resistor R1 is grounded, and the other end is connected to resistor R2. The other end of resistor R2 is connected to the second interface of operational amplifier A1. One end of resistor R4 is grounded, and the other end is connected to the third interface of operational amplifier A1. One end of capacitor C5 is grounded, and the other end is connected to the fourth interface of operational amplifier A1. One end of capacitor C6 is grounded, and the other end is connected to the fourth interface of operational amplifier A1. One end of resistor R8 is grounded, and the other end is connected to resistor R5. The other end of resistor R5 is connected to the seventh interface of operational amplifier A1. The sixth interface of operational amplifier A1 is connected between resistor R8 and resistor R5. One end of capacitor C4 is grounded, and the other end is connected to the eighth interface of operational amplifier A1. One end of capacitor C2 is grounded, and the other end is connected to the eighth interface of operational amplifier A1.

[0023] The second operational amplifier circuit includes: capacitor C7, operational amplifier A2, capacitor C8, capacitor C1, capacitor C3, resistor R6, and resistor R7;

[0024] One end of capacitor C7 is grounded and the other end is connected to the fourth interface of op-amp A2; one end of capacitor C8 is grounded and the other end is connected to the fourth interface of op-amp A2; one end of capacitor C1 is grounded and the other end is connected to the fourth interface of op-amp A2; one end of capacitor C3 is grounded and the other end is connected to the fourth interface of op-amp A2; resistor R6 is connected to the first and second interfaces of op-amp A2; resistor R7 is connected to the sixth and seventh interfaces of op-amp A2.

[0025] The analog predistortion converter circuit includes: transistors D1, D2, D3, D4, D5, D6, D7, and D8; resistors R9, R15, R3, R14, R10, R11, R12, and R13.

[0026] Transistors D1, D3, D5, D8, R9, and R15 are connected in series, with R15 grounded; resistors R3, R14, D7, D2, D4, and D6 are connected in series, with D6 grounded; transistor D1 is connected to resistor R3; resistors R10, R11, R12, and R13 are connected in series.

[0027] The transistor D1 and resistor R3 of the analog predistortion converter circuit are connected between resistors R1 and R2 of the first operational amplifier circuit; the fifth interface of operational amplifier A1 of the first operational amplifier circuit is connected between resistors R11 and R12 of the analog predistortion converter circuit.

[0028] The third interface of op-amp A2 in the second op-amp circuit is connected between transistor D8 and resistor R9 in the analog predistortion converter circuit; the fifth interface of op-amp A2 in the second op-amp circuit is connected between transistor D7 and resistor R14 in the analog predistortion converter circuit; the first interface of op-amp A2 in the second op-amp circuit is connected to resistor R10 in the analog predistortion converter circuit; and the seventh interface of op-amp A2 in the second op-amp circuit is connected to resistor R13 in the analog predistortion converter circuit.

[0029] like Figure 2 As shown, by connecting the triangular wave linear frequency modulation analog predistorter to the oscilloscope, the waveform diagram after eliminating the linear response slope of the voltage-controlled oscillator was obtained.

[0030] Depend on Figure 2It is known that the triangular wave voltage waveform can be adjusted to adapt to different voltage-controlled oscillator nonlinear responses, which can improve the linearity of the circuit and avoid the problem of poor linearity leading to a large amount of spurious signals being introduced into the echo signal, making echo signal processing too difficult, thus improving the signal ranging accuracy.

[0031] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0032] The above are merely preferred embodiments of this utility model. It should be noted that the above preferred embodiments should not be considered as limitations on this utility model, and the scope of protection of this utility model should be determined by the scope defined in the claims. For those skilled in the art, several improvements and modifications can be made without departing from the spirit and scope of this utility model, and these improvements and modifications should also be considered within the scope of protection of this utility model.

Claims

1. A triangular wave chirp analog predistorter characterized by, The first operational amplifier circuit is connected with the second operational amplifier circuit through the analog pre-distortion conversion circuit.

2. A triangular wave chirp analog predistorter according to claim 1, characterized in that, The first operational amplifier circuit comprises resistance R1, resistance R2, resistance R8, resistance R4, resistance R5, capacitor C2, capacitor C4, capacitor C5, capacitor C6 and operational amplifier A1. One end of the resistance R1 is grounded, and the other end is connected with the resistance R2, and the other end of the resistance R2 is connected with the second interface of the operational amplifier A1; one end of the resistance R4 is grounded, and the other end is connected with the third interface of the operational amplifier A1; one end of the capacitor C5 is grounded, and the other end is connected with the fourth interface of the operational amplifier A1; one end of the capacitor C6 is grounded, and the other end is connected with the fourth interface of the operational amplifier A1; one end of the resistance R8 is grounded, and the other end is connected with the resistance R5; the other end of the resistance R5 is connected with the seventh interface of the operational amplifier A1; the sixth interface of the operational amplifier A1 is connected between the resistance R8 and the resistance R5; one end of the capacitor C4 is grounded, and the other end is connected with the eighth interface of the operational amplifier A1; one end of the capacitor C2 is grounded, and the other end is connected with the eighth interface of the operational amplifier A1.

3. A triangular wave chirp analog predistorter according to claim 2, wherein, The second operational amplifier circuit comprises capacitor C7, operational amplifier A2, capacitor C8, capacitor C1, capacitor C3, resistance R6 and resistance R7. One end of the capacitor C7 is grounded, and the other end is connected with the fourth interface of the operational amplifier A2; one end of the capacitor C8 is grounded, and the other end is connected with the fourth interface of the operational amplifier A2; one end of the capacitor C1 is grounded, and the other end is connected with the fourth interface of the operational amplifier A2; one end of the capacitor C3 is grounded, and the other end is connected with the fourth interface of the operational amplifier A2; the resistance R6 is connected with the first and second interfaces of the operational amplifier A2; the resistance R7 is connected with the sixth and seventh interfaces of the operational amplifier A2.

4. A triangular wave chirp analog predistorter according to claim 3, wherein, The analog pre-distortion conversion circuit comprises triode D1, triode D2, triode D3, triode D4, triode D5, triode D6, triode D7, triode D8, resistance R9, resistance R15, resistance R3, resistance R14, resistance R10, resistance R11, resistance R12 and resistance R13. The triode D1, the triode D3, the triode D5, the triode D8, the resistance R9 and the resistance R15 are connected in series, and the resistance R15 is grounded; the resistance R3, the resistance R14, the triode D7, the triode D2, the triode D4 and the triode D6 are connected in series, and the triode D6 is grounded; the triode D1 is connected with the resistance R3; the resistance R10, the resistance R11, the resistance R12 and the resistance R13 are connected in series.

5. A triangular wave chirp analog predistorter according to claim 4, wherein, The triode D1 and the resistance R3 of the analog pre-distortion conversion circuit are connected between the resistance R1 and the resistance R2 of the first operational amplifier circuit; the fifth interface of the operational amplifier A1 of the first operational amplifier circuit is connected between the resistance R11 and the resistance R12 of the analog pre-distortion conversion circuit.

6. A triangular wave chirp analog predistorter according to claim 5, wherein, The third interface of the operational amplifier A2 of the second operational amplifier circuit is connected between the triode D8 and the resistor R9 of the analog pre-distortion conversion circuit, and the fifth interface of the operational amplifier A2 of the second operational amplifier circuit is connected between the triode D7 and the resistor R14 of the analog pre-distortion conversion circuit; the first interface of the operational amplifier A2 of the second operational amplifier circuit is connected to the resistor R10 of the analog pre-distortion conversion circuit, and the seventh interface of the operational amplifier A2 of the second operational amplifier circuit is connected to the resistor R13 of the analog pre-distortion conversion circuit.

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