Signal source circuit and conducted emission signal source

Abstract

The utility model relates to a signal source circuit and a conducted emission signal source, and the signal source circuit comprises an oscillation circuit which is used for generating an oscillation signal with a set frequency; the signal processing circuit is used for at least amplifying the signal amplitude of the oscillation signal to obtain a comb-shaped signal; the signal processing circuit comprises a first type of phase inverter and a second type of phase inverter, the input end of the first-class inverter is connected with the output end of the oscillating circuit, and the input end of the second-class inverter is connected with the output end of the first-class inverter. Oscillation signals are subjected to primary amplification through the first-class inverter, and the oscillation signals are subjected to secondary amplification through the second-class amplifier, so that signal amplitude amplification is realized, and meanwhile, the circuit structure is simplified. Moreover, the input end of the second type of inverter is connected with the output end of the first type of inverter, so that the oscillation signal returns to an initial state after two times of phase inversion, and the signal can maintain a stable oscillation state.

Description

Technical Field

[0001] This application relates to the field of electromagnetic compatibility testing technology, and in particular to a signal source circuit and a conducted emission signal source. Background Technology

[0002] In the field of electromagnetic compatibility testing, in order to ensure the stability and measurement accuracy of conducted emission test systems, it is necessary to periodically calibrate the conducted emission test systems.

[0003] In related technologies, a signal source is used to connect to the conducted emission test system instead of the product under test. The signal source provides a comb signal to test and verify the conducted emission test system. However, the circuit structure within the current signal source is complex. Utility Model Content

[0004] This application provides a signal source circuit to at least partially solve the above-mentioned technical problems.

[0005] To achieve the above objectives, according to a first aspect of this application, a signal source circuit is provided, comprising:

[0006] An oscillation circuit is used to generate an oscillation signal at a set frequency.

[0007] A signal processing circuit is used to amplify at least the amplitude of the oscillating signal to obtain a comb signal;

[0008] The signal processing circuit includes: a first type of inverter and a second type of inverter;

[0009] The input terminal of the first type of inverter is connected to the output terminal of the oscillator circuit, and the input terminal of the second type of inverter is connected to the output terminal of the first type of inverter.

[0010] Optionally, in some embodiments of this application, the signal processing circuit includes at least two second-type inverters;

[0011] The inputs of at least two Type II inverters are respectively connected to the output of the same Type I inverter, and the outputs of at least two Type II inverters are connected together.

[0012] Optionally, in some embodiments of this application, the first type of inverter and at least two second type of inverters are integrated on the same logic chip.

[0013] Optionally, in some embodiments of this application, the signal processing circuit includes:

[0014] The adjustment unit is used to adjust the rising edge of the amplified oscillation signal;

[0015] One end of the adjustment unit is connected to the output of the second type of inverter.

[0016] Optionally, in some embodiments of this application, the adjustment unit includes:

[0017] The first resistor has one end connected to the output terminal of the second type of inverter.

[0018] Optionally, in some embodiments of this application, the signal processing circuit further includes:

[0019] The second resistor has one end connected to the other end of the adjustment unit, and the other end grounded.

[0020] Optionally, in some embodiments of this application, the signal processing circuit further includes:

[0021] The third resistor has one end connected to the input terminal of the first type inverter and the other end connected to the output terminal of the first type inverter.

[0022] Optionally, in some embodiments of this application, the signal source circuit further includes:

[0023] A voltage regulator circuit is used to provide operating voltage to an oscillation circuit.

[0024] The voltage regulator circuit includes:

[0025] The voltage regulator chip has its output terminal connected to the power input terminal of the oscillation circuit, its input terminal connected to the power supply, and its ground terminal grounded.

[0026] Optionally, in some embodiments of this application, the voltage regulator circuit includes:

[0027] The first filtering unit is connected between the voltage regulator chip and the power supply;

[0028] And / or,

[0029] The second filter unit is connected between the voltage regulator chip and the oscillation circuit.

[0030] According to a second aspect of this application, a conducted emission signal source is provided, comprising:

[0031] Circuit board, including the signal source circuit as described above;

[0032] Signal output interface, used to output comb-shaped signals;

[0033] The signal output interface is electrically connected to the signal processing circuit.

[0034] In the signal source circuit of this application embodiment, the oscillation signal is amplified in one stage by a first-type inverter and in two stages by a second-type amplifier, which simplifies the circuit structure while amplifying the signal amplitude. Furthermore, the input terminal of the second-type inverter is connected to the output terminal of the first-type inverter, so that the oscillation signal returns to its initial state after two phase inversions, enabling the signal to maintain a stable oscillation state.

[0035] Other features and advantages of this application will be described in detail in the following detailed description section. Attached Figure Description

[0036] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0037] To gain a more complete understanding of this application and its beneficial effects, the following description will be provided in conjunction with the accompanying drawings, wherein the same reference numerals in the following description denote the same parts.

[0038] Figure 1 This is a schematic block diagram of the signal source circuit provided in an exemplary embodiment of this application;

[0039] Figure 2 This is a circuit structure diagram of the voltage regulator circuit in the signal source circuit provided in the exemplary embodiment of this application;

[0040] Figure 3 This is a circuit structure diagram of the signal source circuit provided in an exemplary embodiment of this application;

[0041] Figure 4 This is a waveform diagram of the oscillation signal at the input terminal of the first type of inverter and the output terminal of the second type of inverter in the signal source circuit provided in the exemplary embodiment of this application;

[0042] Figure 5 This is a waveform diagram of the oscillation signal at the output terminal of the first type of inverter and the input terminal of the second type of inverter in the signal source circuit provided in the exemplary embodiment of this application;

[0043] Figure 6 These are some of the test results provided in the exemplary embodiments of this application;

[0044] Figure 7 This is a schematic block diagram of the conducted transmission signal source provided in an exemplary embodiment of this application;

[0045] Figure 8This is a block diagram showing the verification connection between the conducted emission signal source and the conducted emission test system provided in an exemplary embodiment of this application.

[0046] Explanation of reference numerals in the attached figures:

[0047] 100. Signal source circuit;

[0048] 110. Oscillating circuit; 111. Active crystal oscillator;

[0049] 120. Signal processing circuit; 120a. Logic chip; 121. Type I inverter; 122. Type II inverter;

[0050] 123. Adjustment unit; R1. First resistor;

[0051] R2 is the second resistor; R3 is the third resistor;

[0052] 130. Voltage regulator circuit; 131. Voltage regulator chip; 132. First filter unit; C1. First capacitor; C2. Second capacitor; 133. Second filter unit; C3. Third capacitor; C4. Fourth capacitor;

[0053] 10. Conducted signal source;

[0054] 10a. Circuit board; 210. Signal output interface; 220. Power supply; 230. Control switch;

[0055] 20. Conducted emission test system; 21. Artificial power network; 22. Measurement receiver. Detailed Implementation

[0056] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the protection scope of this application.

[0057] According to the first aspect of this application, referring to Figure 1 This application provides a signal source circuit 100, including an oscillation circuit 110 and a signal processing circuit 120.

[0058] The oscillation circuit 110 is used to generate an oscillation signal at a set frequency; the signal processing circuit 120 is used to amplify at least the signal amplitude of the oscillation signal to obtain a comb signal.

[0059] The signal processing circuit 120 includes a first type inverter 121 and a second type inverter 122. The input terminal of the first type inverter 121 is connected to the output terminal of the oscillation circuit 110 to receive the oscillation signal output by the oscillation circuit 110; the input terminal of the second type inverter 122 is connected to the output terminal of the first type inverter 121.

[0060] It is understandable that the performance parameters (such as input impedance, output impedance, amplification factor and bandwidth) of the first type inverter 121 and the second type inverter 122 can be the same or different to meet different signal processing requirements.

[0061] The above technical solution uses a first-stage inverter 121 to amplify the oscillation signal and a second-stage amplifier to amplify the oscillation signal, thus simplifying the circuit structure while amplifying the signal amplitude.

[0062] Furthermore, the input terminal of the second type inverter 122 is connected to the output terminal of the first type inverter 121, so that the oscillation signal returns to its initial state after two phase inversions, enabling the signal to maintain a stable oscillation state. For example, the waveforms at the input terminal of the first type inverter 121 and the output terminal of the second type inverter 122 are as follows: Figure 4 As shown, the waveforms at the output of the first type inverter 121 and the input of the second type inverter 122 are as follows: Figure 5 As shown.

[0063] In some specific implementations, the oscillation circuit 110 includes an active crystal oscillator 111 (oscillator). The active crystal oscillator 111 has high precision and good frequency stability, with an accuracy of up to 0.1 ppm.

[0064] Specifically, refer to Figure 1 Pin 1 of the active crystal oscillator 111 is unused, pin 2 of the active crystal oscillator 111 is grounded, pin 3 of the active crystal oscillator 111 is connected to the input terminal of the first type inverter 121, and pin 4 of the active crystal oscillator 111 is connected to the operating voltage U1.

[0065] In one example of this application, the operating frequency of the active crystal oscillator 111 is 10MHz. More specifically, the oscillation signal output by the active crystal oscillator 111 is a standard square wave signal.

[0066] In one example of this application, the active crystal oscillator 111 can also have its own temperature control.

[0067] In one example of this application, the active crystal oscillator 111 adopts a dual in-line package (DIP), which has high reliability.

[0068] In some embodiments of this application, reference is made to Figure 1The signal processing circuit 120 includes at least two second-type inverters 122. The input terminals of the at least two second-type inverters 122 are respectively connected to the output terminal of the same first-type inverter 121, and the output terminals of the at least two second-type inverters 122 are connected together.

[0069] It can be understood that at least two Type II inverters 122 are connected in parallel to the output of the same Type I inverter 121, and the more Type II inverters 122 connected in parallel, the larger the amplitude of the combined oscillation signal output by these parallel Type II inverters 122. More specifically, the amplitude of the combined oscillation signal output by the parallel Type II inverters 122 is directly proportional to the number of parallel Type II inverters 122. The number of Type II inverters 122 can be selected according to the signal amplification requirements.

[0070] In one embodiment of this application, the amplifier circuit may include only one first-type inverter 121, which is connected to at least two second-type inverters 122.

[0071] In another embodiment of this application, at least two first-type inverters 121 may be provided in the amplifier circuit, each first-type inverter 121 is connected to at least two second-type inverters 122, and the output terminals of all second-type inverters 122 are connected to output an amplified signal.

[0072] In some embodiments of this application, reference is made to Figure 3 The first type inverter 121 and at least two second type inverters 122 are integrated into the same logic chip 120a. This approach reduces the overall size of the first type inverter 121 and the second type inverter 122, while further reducing circuit complexity and improving reliability.

[0073] It is understood that the amplifier circuit of this application includes at least one logic chip 120a, and of course, more logic chips 120a can be selected according to the signal method requirements.

[0074] In one example of this application, the logic chip 120a includes one first-type inverter 121 and five second-type inverters 122; the input and output terminals of the first-type inverter 121 and each of the second-type inverters 122 respectively constitute the pins of the logic chip 120a. More specifically, the logic chip 120a in this application adopts a 74HC04D hexadecimal logic chip 120a.

[0075] In some embodiments of this application, reference is made to Figure 1The signal processing circuit 120 includes an adjustment unit 123. The adjustment unit 123 is used to adjust the rising edge of the amplified oscillation signal (e.g., a square wave signal); one end of the adjustment unit 123 is connected to the output terminal of the second type inverter 122, and the other end is connected to the signal output interface 210.

[0076] This scheme uses adjustment unit 123 to adjust the rising edge of the amplified oscillation signal, thereby generating a pulse with narrow time-domain pulse width, steep leading and trailing edges, and high amplitude. After Fourier transform, a comb-like spectrum rich in high-frequency components is formed in the frequency domain. For example, a comb signal can be generated in the frequency range of 10MHz to 1000MHz to meet the verification requirements of the conducted emission test system 20. As an example, Figure 6 The test results only show the performance from 30MHz to 200MHz, and the results show that the stability is high.

[0077] In one example of this application, the adjustment unit 123 can adjust the rise time, so that the rise time of the oscillation signal is slowed down.

[0078] In some embodiments of this application, reference is made to Figure 1 and Figure 3 The adjustment unit 123 includes a first resistor R1. One end of the first resistor R1 is connected to the output terminal of the second type inverter 122, and the other end is connected to the signal output interface 210. By adjusting the rising edge of the oscillation signal through the first resistor R1, a wider spectrum is generated, resulting in better measurement performance.

[0079] In some other embodiments of this application, the adjustment unit 123 may employ an RC filter to adjust the rising edge speed of the oscillation signal.

[0080] In some embodiments of this application, reference is made to Figure 1 and Figure 3 The signal processing circuit 120 also includes a second resistor R2. The second resistor R2 is used for shunt protection to ground. One end of the second resistor R2 is connected to the other end of the adjustment unit 123, and the other end of the second resistor R2 is grounded.

[0081] In some specific implementations, one end of the second resistor R2 is connected to the first resistor R1, and the other end of the second resistor R2 is grounded.

[0082] In one example of this application, the resistance of the second resistor R2 is greater than the resistance of the first resistor R1.

[0083] In some embodiments of this application, reference is made to Figure 1 and Figure 3 The signal processing circuit 120 also includes a third resistor R3.

[0084] The third resistor R3 is used to suppress the coupling between the first type of inverter 121 and the oscillation circuit 110; one end of the third resistor R3 is connected to the input terminal of the first type of inverter 121, and the other end of the third resistor R3 is connected to the output terminal of the first type of inverter 121. By setting the third resistor R3, unnecessary coupling between the first type of inverter 121 and the active crystal oscillator can be prevented or weakened.

[0085] In some embodiments of this application, reference is made to Figures 1 to 3 The signal source circuit 100 also includes a voltage regulator circuit 130. The voltage regulator circuit 130 is used to provide the operating voltage U1 to the oscillation circuit 110.

[0086] The voltage regulator circuit 130 includes a voltage regulator chip 131. The output terminal 'a' of the voltage regulator chip 131 is connected to the power input terminal of the oscillation circuit 110, the input terminal of the voltage regulator chip 131 is connected to the power supply 220, and the ground terminal of the voltage regulator chip 131 is grounded. The voltage regulator chip 131 stabilizes the power supply voltage provided by the power supply 220 to the operating voltage required by the oscillation circuit 110.

[0087] It should be noted that the model of the voltage regulator chip 131 can be selected according to the actual operating voltage and power supply voltage. In one example of this application, the power supply voltage VCC provided by the power supply 220 is 7.4V, while the operating voltage U1 is 5V. Accordingly, the model of the voltage regulator chip 131 can be AS1117S50.

[0088] In some embodiments of this application, reference is made to Figure 2 and Figure 3 The voltage regulator circuit 130 includes a first filter unit 132. The first filter unit 132 is connected between the voltage regulator chip 131 and the power supply 220. By setting the first filter unit 132, noise on the side of the power supply 220 can be filtered out to avoid affecting the normal operation of the voltage regulator chip 131.

[0089] In some embodiments of this application, reference is made to Figure 2 and Figure 3 The first filter unit 132 includes a first capacitor C1 and a second capacitor C2. One end of the first capacitor C1 is connected to the input terminal of the voltage regulator chip 131, and the other end of the first capacitor C1 is grounded; one end of the second capacitor C2 is connected to the input terminal of the voltage regulator chip 131, and the other end of the second capacitor C2 is grounded.

[0090] It is understandable that the first capacitor C1 and the second capacitor C2 have different capacitance values, which can effectively handle signals of different frequencies and ensure the stability of the voltage at the input terminal of the voltage regulator chip 131.

[0091] In some specific implementations, the capacitance of the first capacitor C1 is greater than the capacitance of the second capacitor C2. Specifically, the first capacitor C1 filters out low-frequency noise, while the second capacitor C2 filters out high-frequency noise.

[0092] In one example of this application, the first capacitor C1 is an electrolytic capacitor, and the second capacitor C2 is a regular capacitor (i.e., a fixed capacitor).

[0093] In some embodiments of this application, reference is made to Figure 2 and Figure 3 The voltage regulator circuit 130 includes a second filter unit 133. The second filter unit 133 is connected between the voltage regulator chip 131 and the oscillation circuit 110. By setting the second filter unit 133, the self-oscillation that may occur in the voltage regulator chip 131 can be suppressed, and the voltage fluctuations caused by the oscillation circuit 110 can be filtered out, thus ensuring the stability of the operating voltage output by the voltage regulator chip 131.

[0094] In some embodiments of this application, reference is made to Figure 2 and Figure 3 The second filter unit 133 includes a third capacitor C3 and a fourth capacitor C4. One end of the third capacitor C3 is connected to the output terminal of the voltage regulator chip 131, and the other end of the third capacitor C3 is grounded; one end of the fourth capacitor C4 is connected to the output terminal of the voltage regulator chip 131, and the other end of the fourth capacitor C4 is grounded.

[0095] It is understandable that the third capacitor C3 and the fourth capacitor C4 have different capacitance values, which can effectively handle signals of different frequencies and ensure the stability of the operating voltage output by the voltage regulator chip 131.

[0096] In some specific implementations, the capacitance of the third capacitor C3 is greater than that of the fourth capacitor C4. Specifically, the third capacitor C3 filters out low-frequency noise, while the fourth capacitor C4 filters out high-frequency noise.

[0097] In one example of this application, the third capacitor C3 is an electrolytic capacitor, and the fourth capacitor C4 is a regular capacitor (i.e., a fixed capacitor).

[0098] According to the second aspect of this application, referring to Figure 7 A conducted emission signal source 10 is provided, which includes a circuit board 10a and a signal output interface 210. The circuit board 10a includes the signal source circuit 100 as described above. The signal output interface 210 is used to output a comb signal and is electrically connected to a signal processing circuit 120.

[0099] By adopting the above signal source circuit 100, a stable comb signal is obtained. At the same time, due to the simplification of the circuit structure, the size of the circuit board 10a is reduced, thereby reducing the size of the conducted emission signal source 10, making it convenient to carry and use, and helping to meet the periodic calibration requirements of the conducted emission test system 20.

[0100] In some specific implementations, the signal output interface 210 uses a solder head to SMA connector cable and an SMA male to banana head plug cable to output signals to the conducted emission test system 20.

[0101] In some embodiments of this application, reference is made to Figure 7 The conducted signal source 10 also includes a power supply 220. The power supply 220 is electrically connected to the circuit board 10a to supply power to the circuit board 10a. Specifically, the power supply 220 can be a battery or a power supply circuit.

[0102] In some embodiments of this application, the conducted transmission signal source 10 further includes a power socket (not shown), which is used to connect the power supply 220 to an external power source to supply power to the power supply 220. For example, the power socket is used to charge a battery.

[0103] In some embodiments of this application, reference is made to Figure 7 The conducted signal source 10 also includes a control switch 230. The control switch 230 is electrically connected between the power supply 220 and the circuit board 10a, and is used to control the power supply 220 to supply power to the circuit board 10a.

[0104] In some embodiments of this application, the conducted emission signal source 10 further includes a device housing (not shown). The circuit board 10a, power supply 220, and control switch 230 are mounted on the device housing, which provides structural support and protection.

[0105] This application exemplarily describes the working process of the conducted emission signal source 10 calibrating the conducted emission test system 20:

[0106] The verification work will be carried out in a shielded room, referring to... Figure 8 The high and low ends of the conducted emission signal source 10 are connected to the positive AN+ and negative AN- terminals of the artificial power network 21, respectively. The conducted emission signal source 10 generates a comb-shaped signal and sends it to the artificial power network 21. Simultaneously, an RF cable is connected to the measurement port M of the artificial power network 21 to send the picked-up comb-shaped signal to the measurement receiver 22, thereby realizing the testing and verification of the conducted emission test system 20. As an example, Figure 6 The test results were only shown for frequencies from 30MHz to 200MHz.

[0107] In the description of this application, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more features. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0108] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0109] The embodiments, implementation methods, and related technical features of this application can be combined and substituted for each other without conflict.

[0110] The above are merely preferred embodiments of this application and are not intended to limit this application in any way. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of this application without departing from the scope of the technical solution of this application shall still fall within the scope of the technical solution of this application.

Claims

1. A signal source circuit, characterized in that, include: An oscillation circuit is used to generate an oscillation signal at a set frequency. A signal processing circuit is used to amplify at least the signal amplitude of the oscillating signal to obtain a comb signal; The signal processing circuit includes: a first type of inverter and a second type of inverter; The input terminal of the first type of inverter is connected to the output terminal of the oscillation circuit, and the input terminal of the second type of inverter is connected to the output terminal of the first type of inverter.

2. The signal source circuit according to claim 1, characterized in that, The signal processing circuit includes at least two inverters of the second type; The inputs of at least two second-type inverters are respectively connected to the output of the same first-type inverter, and the outputs of at least two second-type inverters are connected together.

3. The signal source circuit according to claim 1, characterized in that, The first type of inverter and at least two of the second type of inverter are integrated into the same logic chip.

4. The signal source circuit according to claim 1, characterized in that, The signal processing circuit includes: An adjustment unit is used to adjust the rising edge of the amplified oscillation signal; One end of the adjustment unit is connected to the output of the second type of inverter.

5. The signal source circuit according to claim 4, characterized in that, The adjustment unit includes: The first resistor has one end connected to the output terminal of the second type of inverter.

6. The signal source circuit according to claim 4, characterized in that, The signal processing circuit further includes: A second resistor, one end of which is connected to the other end of the adjustment unit, and the other end of which is grounded.

7. The signal source circuit according to any one of claims 1 to 6, characterized in that, The signal processing circuit further includes: A third resistor, one end of which is connected to the input terminal of the first type of inverter, and the other end of which is connected to the output terminal of the first type of inverter.

8. The signal source circuit according to any one of claims 1 to 6, characterized in that, The signal source circuit also includes: A voltage regulator circuit is used to provide operating voltage to the oscillation circuit; The voltage regulator circuit includes: A voltage regulator chip is provided, with its output terminal connected to the power input terminal of the oscillation circuit, its input terminal connected to the power supply, and its ground terminal grounded.

9. The signal source circuit according to claim 8, characterized in that, The voltage regulator circuit includes: The first filtering unit is connected between the voltage regulator chip and the power supply. And / or, The second filtering unit is connected between the voltage regulator chip and the oscillation circuit.

10. A conducted signal source, characterized in that, include: The circuit board includes the signal source circuit as described in any one of claims 1 to 9; Signal output interface, used to output comb-shaped signals; The signal output interface is electrically connected to the signal processing circuit.

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