Signal transmission system and signal transmission device

Abstract

The application discloses a signal transmission system and a signal transmission device. The signal transmission system comprises a modulation module, a first differential module, a second differential module, a first isolation module and a demodulation module. The modulation module receives an input signal, modulates the input signal on a first carrier, and outputs a first radio frequency signal. The first differential module is electrically connected with the modulation module, and outputs a first differential signal based on the first radio frequency signal. The first isolation module is electrically connected between the first differential module and the second differential module, and a capacitor in the first isolation module couples the first differential signal to the second differential module. The second differential module outputs a second radio frequency signal based on the first differential signal. The demodulation module is electrically connected with the second differential module, demodulates the second radio frequency signal, and outputs an output signal in proportional relationship with the input signal. Through the above mode, the anti-interference capability can be high, so that the measurement accuracy is improved.

Description

TECHNICAL FIELD

[0001] Embodiments of the present application relate to the technical field of signal transmission, in particular to a signal transmission system and a signal transmission device. BACKGROUND

[0002] In the field of electronics and electrical engineering, it is often necessary to transmit a small frequency voltage signal from a dangerous high-voltage floating primary side to a low-voltage secondary side for measurement and control. A larger common-mode voltage is superimposed on the small voltage signal by an external electromagnetic interference signal. This common-mode voltage is a strong interference source for measuring a small frequency voltage signal, which can result in poor measurement accuracy. CONTENT OF THE INVENTION

[0003] Embodiments of the present application provide a signal transmission system and a signal transmission device, which can have high anti-interference capability to improve measurement accuracy.

[0004] In a first aspect, embodiments of the present application provide a signal transmission system, comprising:

[0005] a modulation module, a first differential module, a second differential module, a first isolation module, and a demodulation module;

[0006] The modulation module is configured to receive an input signal and modulate the input signal on a first carrier to output a first radio frequency signal.

[0007] The first differential module is electrically connected to the modulation module, and the first differential module is configured to output a first differential signal based on the first radio frequency signal.

[0008] The first isolation module is electrically connected between the first differential module and the second differential module, and the first isolation module includes at least one capacitor. The capacitor in the first isolation module is configured to couple the first differential signal to the second differential module.

[0009] The second differential module is configured to output a second radio frequency signal based on the first differential signal.

[0010] The demodulation module is electrically connected to the second differential module, and the demodulation module is configured to demodulate the second radio frequency signal and output an output signal that is in a proportional relationship with the input signal.

[0011] In one or more embodiments, the frequency of the first radio frequency signal is greater than the maximum frequency of the external interference signal.

[0012] In one or more embodiments, the signal transmission system further comprises a carrier generation module, a third differential module, a fourth differential module, and a second isolation module.

[0013] The carrier generating module is configured to generate the first carrier or the second carrier;

[0014] One of the modulation module and the demodulation module is electrically connected to the carrier generating module, and the demodulation module is configured to demodulate the second radio frequency signal based on the second carrier;

[0015] One of the third differential module and the fourth differential module is electrically connected to the carrier generating module, and the third differential module is configured to generate a second differential signal based on the first carrier, or generate the first carrier based on a third differential signal;

[0016] The second isolation module is electrically connected between the third differential module and the fourth differential module, and the second isolation module includes at least one capacitor, and the capacitor in the second isolation module is configured to couple the second differential signal to the fourth differential module, or couple the third differential signal to the third differential module;

[0017] The fourth differential module is configured to output the second carrier based on the second differential signal, or output the third differential signal based on the second carrier.

[0018] In one or more embodiments, the first isolation module includes a first capacitor and a second capacitor, and the second isolation module includes a third capacitor and a fourth capacitor;

[0019] The first capacitor is electrically connected between a first output end of the first differential module and a first input end of the second differential module, and the second capacitor is electrically connected between a second output end of the first differential module and a second input end of the second differential module;

[0020] The third capacitor is electrically connected between a first output end of the third differential module and a first input end of the fourth differential module, and the fourth capacitor is electrically connected between a second output end of the third differential module and a second input end of the fourth differential module, or the third capacitor is electrically connected between a first input end of the third differential module and a first output end of the fourth differential module, and the fourth capacitor is electrically connected between a second input end of the third differential module and a second output end of the fourth differential module.

[0021] In one or more embodiments, the first capacitor, the second capacitor, the third capacitor, and the fourth capacitor are all ceramic capacitors.

[0022] In one or more embodiments, the signal transmission system further includes at least one of a first high-pass filter and a second high-pass filter, and at least one of a third high-pass filter and a fourth high-pass filter;

[0023] The first high-pass filter is electrically connected between the modulation module and the first differential module, the second high-pass filter is electrically connected between the second differential module and the demodulation module, the third high-pass filter is electrically connected between the modulation module and the third differential module, and the fourth high-pass filter is electrically connected between the fourth differential module and the demodulation module.

[0024] In one or more embodiments, the modulation module comprises a first mixer, and the demodulation module comprises a second mixer and a low-pass filter.

[0025] A first input end of the first mixer inputs the first carrier, a second input end of the first mixer inputs the input signal, and an output end of the first mixer outputs the first radio frequency signal.

[0026] A first input end of the second mixer inputs a second carrier, a second input end of the second mixer inputs the second radio frequency signal, an output end of the second mixer is connected with an input end of the low-pass filter, and an output end of the low-pass filter outputs the output signal.

[0027] In a second aspect, the embodiments of the present application provide a signal transmission device, comprising the signal transmission system as described above.

[0028] In one or more embodiments, the signal transmission device further comprises a first shell, a second shell, a first channel and a second channel.

[0029] The first shell, the second shell, the first channel and the second channel are all hollow structures, and the first channel and the second channel are both arranged between the first shell and the second shell.

[0030] The modulation module, the first differential module, the third differential module, the first high-pass filter and the third high-pass filter in the signal transmission system are all arranged inside the first shell, the demodulation module, the second differential module, the fourth differential module, the second high-pass filter and the fourth high-pass filter in the signal transmission system are all arranged inside the second shell, the first isolation module in the signal transmission system is arranged inside the first channel, and the second isolation module in the signal transmission system is arranged inside the second channel.

[0031] In one or more embodiments, the first channel and the second channel are both made of non-conductive magnetic material.

[0032] The beneficial effects of this application are as follows: The signal transmission system of this application embodiment includes a modulation module, a first differential module, a second differential module, a first isolation module, and a demodulation module. The modulation module is used to receive an input signal and modulate the input signal onto a first carrier wave to output a first radio frequency signal; the first differential module is electrically connected to the modulation module and is used to output a first differential signal based on the first radio frequency signal; the first isolation module is electrically connected between the first differential module and the second differential module, and the first isolation module includes at least one capacitor, which is used to couple the first differential signal to the second differential module; the second differential module is used to output a second radio frequency signal based on the first differential signal; the demodulation module is electrically connected to the second differential module and is used to demodulate the second radio frequency signal and output an output signal proportional to the input signal. Through the above process, on the one hand, by modulating the input signal onto the first carrier wave to output a first radio frequency signal with a higher frequency, it is possible to distinguish the first radio frequency signal from external interference signals based on frequency, and also to ensure that the first radio frequency signal can effectively pass through the capacitor in the first isolation module. Thus, both external interference signals can be eliminated, and high-voltage electrical isolation can be achieved. On the other hand, by implementing a differential process, it is beneficial to improve the anti-electromagnetic interference capability. In summary, the signal transmission system provided in this application embodiment has a high anti-interference capability, which is beneficial to improving the accuracy of measurement. Attached Figure Description

[0033] One or more embodiments are illustrated by way of example with reference to the accompanying drawings, which are not intended to limit the embodiments, and elements having the same reference numerals in the drawings are designated as similar elements.

[0034] Figure 1 This is a schematic diagram of the signal transmission system provided in the embodiments of this application. Figure 1 ;

[0035] Figure 2 This is a schematic diagram of the signal transmission system provided in the embodiments of this application. Figure 2 ;

[0036] Figure 3 This is a schematic diagram of the signal transmission system provided in the embodiments of this application. Figure 3 ;

[0037] Figure 4 This is a schematic diagram of the signal transmission system provided in the embodiments of this application. Figure 4 ;

[0038] Figure 5 This is a schematic diagram of the circuit structure of each differential module provided in the embodiments of this application;

[0039] Figure 5is a schematic diagram of a signal transmission system provided by an embodiment of the present application Figure 6 ;

[0040] Figure 6 is a schematic diagram of a signal transmission system provided by an embodiment of the present application Figure 7 ;

[0041] Figure 7 is a structural schematic diagram of a first shell, a second shell, a first channel and a second channel provided by an embodiment of the present application. DETAILED DESCRIPTION

[0042] In order to make the objectives, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and in detail below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are some but not all of the embodiments of the present application. It should be understood that the specific embodiments described herein are only used to explain the present application and should not be used to limit the present application.

[0043] It should be noted that when an element is described as being “connected” to another element, it can be directly connected to the other element or one or more intermediate elements can be present therebetween.

[0044] In addition, the technical features involved in each of the embodiments of the present application described below can be combined with each other as long as they do not conflict with each other.

[0045] Please refer to Figure 8 , Figure 1 is a schematic diagram of a signal transmission system provided by an embodiment of the present application. As shown in Figure 1 , the signal transmission system 100 includes a modulation module 101, a first differential module 102, a first isolation module 103, a second differential module 104 and a demodulation module 105.

[0046] The first differential module 102 is electrically connected to the modulation module 101, the first isolation module 103 is electrically connected between the first differential module 102 and the second differential module 104, and the demodulation module 105 is electrically connected to the second differential module 104.

[0047] Specifically, the modulation module 101 is configured to receive an input signal VIN and modulate the input signal VIN on a first carrier LO1 to output a first radio frequency signal RF1. The first differential module 102 is configured to output a first differential signal based on the first radio frequency signal RF1. The first isolation module 103 includes at least one capacitor, and the capacitor in the first isolation module 103 is configured to couple the first differential signal to a second differential module 104. The second differential module 104 is configured to output a second radio frequency signal RF2 based on the first differential signal. The demodulation module 105 is configured to demodulate the second radio frequency signal RF2 and output an output signal VOUT proportional to the input signal VIN.

[0048] In this embodiment, by modulating the input signal VIN on the first carrier LO1, a first radio frequency signal RF1 with a higher frequency can be output.

[0049] On the one hand, the first radio frequency signal RF1 can be distinguished from an interference signal based on frequency. In some embodiments, the frequency of the first radio frequency signal RF1 is greater than the maximum frequency of the external interference signal. For example, the frequency of the external interference signal (usually an electromagnetic interference signal) is usually within 1 GHz, the bandwidth of the input signal is DC to 500 MHz, and the frequency of the first carrier LO1 is 2 GHz. Therefore, the frequency range of the first radio frequency signal RF1 is 2 GHz ± 0.5 GHz, i.e. 1.5 GHz to 2.5 GHz. It can be seen that the frequency range of the first radio frequency signal RF1 is greater than 1 GHz, and the first radio frequency signal RF1 can be easily distinguished from the external interference signal based on frequency. Then, subsequent filtering based on frequency can achieve the elimination of the external interference signal, which is beneficial to improve the anti-interference ability.

[0050] On the other hand, since the frequency of the first radio frequency signal RF1 is high, the first radio frequency signal RF1 can be effectively coupled to the second differential module 104 through the capacitor in the first isolation module 103, and a capacitor with a small capacity can be used at this time. The frequency of the high-voltage alternating current borne by the first isolation module 103 is usually much lower than 2 KHz. At this time, the capacitive reactance of the capacitor in the first isolation module 103 is large, which constitutes a kind of factual high-voltage electrical isolation barrier, and can withstand very high voltage (such as 2000V alternating voltage). For example, in some embodiments, the capacitance of the capacitor is configured to be 10 PF. When the frequency of the first radio frequency signal RF1 is 2 GHz, the capacitive reactance of the capacitor is 8Ω (small capacitive reactance), and the first radio frequency signal RF1 can pass through easily. However, for the high-voltage alternating current with a frequency of 2 KHz, the capacitive reactance of the capacitor is 8MΩ (large capacitive reactance), which constitutes a high-voltage electrical isolation barrier, thereby achieving high-voltage electrical isolation, which is beneficial to realize safe and reliable communication and signal transmission between different parts of the signal transmission system 100, while ensuring the stability and anti-interference ability of the signal transmission system 100.

[0051] In addition, the embodiment also provides a differential process to couple the external interference signal to the two signal lines at the same time. Since only the voltage difference between the two signals is concerned, the external interference signal (such as common mode noise) can be completely eliminated. This means that even if there are strong electromagnetic field changes in the environment of the signal transmission system 100, as long as the influence on the two signal lines is similar, the final calculated difference will not be affected by these noises. It can be seen that the embodiment also has high anti-electromagnetic interference capability.

[0052] In summary, in the signal transmission system 100 provided by the embodiment of the present application, the input signal VIN is modulated on the first carrier LO1 to eliminate the interference signal, a capacitor is arranged to achieve high voltage electrical isolation, and a differential process is arranged to improve the anti-electromagnetic interference capability. Therefore, the signal transmission system 100 has high anti-interference capability, which is beneficial to improve the measurement accuracy.

[0053] In some embodiments, as shown in Figure 1 The signal transmission system 100 further includes a carrier generation module 106, a third differential module 107, a fourth differential module 108, and a second isolation module 109. The demodulation module 105 is electrically connected to the carrier generation module 106, the third differential module 107 is electrically connected to the modulation module 101, the fourth differential module 108 is electrically connected to the carrier generation module 106, and the second isolation module 109 is electrically connected between the third differential module 107 and the fourth differential module 108.

[0054] Specifically, the carrier generation module 106 is configured to generate a second carrier LO2. The demodulation module 105 is configured to demodulate a second radio frequency signal RF2 based on the second carrier LO2. The fourth differential module 108 is configured to output a third differential signal based on the second carrier LO2. The second isolation module 109 includes at least one capacitor, and the capacitor in the second isolation module 109 is configured to couple the third differential signal to the third differential module 107. The third differential module 107 is configured to generate the first carrier LO1 based on the third differential signal.

[0055] In this embodiment, by making the first carrier LO1 input to the modulation module 101 and the second carrier LO2 input to the demodulation module 105 have the same source, the synchronous detection function can be realized, which is beneficial to improve the stability of the signal transmission system 100 and reduce noise.

[0056] It should be noted that, as Figure 2The hardware structure of the signal transmission system 100 shown is only an example, and the signal transmission system 100 can have more or fewer components than those shown in the figure, can combine two or more components, or can have a different component configuration, and various components shown in the figure can be implemented in hardware, software, or a combination of hardware and software including one or more signal processing and / or application specific integrated circuits.

[0057] For example, as Figure 2 shown, Figure 3 Another connection mode of the carrier generation module 106, the third differential module 107, the fourth differential module 108, and the second isolation module 109 is exemplarily shown.

[0058] The modulation module 101 is electrically connected to the carrier generation module 106, one of the third differential module 107 and the fourth differential module 108 is electrically connected to the carrier generation module 106, and the second isolation module 109 is electrically connected between the third differential module 107 and the fourth differential module 108, and the second isolation module 109 includes at least one capacitor.

[0059] Specifically, the carrier generation module 106 is configured to generate a first carrier LO1. The third differential module 107 is configured to generate a second differential signal based on the first carrier LO1. The capacitor in the second isolation module 109 is configured to couple the second differential signal to the fourth differential module 108. The fourth differential module 108 is configured to output a second carrier LO2 based on the second differential signal. The demodulation module 101 is configured to demodulate the second radio frequency signal RF2 based on the second carrier LO2.

[0060] In some embodiments, as Figure 3 shown, the first isolation module 103 includes a first capacitor C1 and a second capacitor C2, and the second isolation module 109 includes a third capacitor C3 and a fourth capacitor C4.

[0061] The first capacitor C1 is electrically connected between the first output end of the first differential module 102 and the first input end of the second differential module 104, and the second capacitor C2 is electrically connected between the second output end of the first differential module 102 and the second input end of the second differential module 104. The third capacitor C3 is electrically connected between the first input end of the third differential module 107 and the first output end of the fourth differential module 108, and the fourth capacitor C4 is electrically connected between the second input end of the third differential module 107 and the second output end of the fourth differential module 108. It can be understood that this embodiment corresponds to the composition block diagram shown in Figure 4 .

[0062] For Figure 2In the block diagram shown, the connection relationship between the first capacitor C1 and the second capacitor C2 remains unchanged. The third capacitor C3 is electrically connected between the first output terminal of the third differential module 107 and the first input terminal of the fourth differential module 108, and the fourth capacitor C4 is electrically connected between the second output terminal of the third differential module 107 and the second input terminal of the fourth differential module 108.

[0063] It is understood that in this embodiment, the first differential module 102 and the fourth differential module 108 are both modules that convert single-ended input to differential output (that is, modules that convert a single-ended signal (a single signal relative to ground) into a differential signal (a pair of signals with the same amplitude but opposite phase)), and the second differential module 104 and the third differential module 107 are modules that convert differential input to single-ended output (that is, modules that convert differential signals into single-ended signals). And for... Figure 3 In terms of the block diagram shown, the first differential module 102 and the third differential module 107 are both modules that convert single-ended input to differential output, while the second differential module 104 and the fourth differential module 108 are modules that convert differential input to single-ended output.

[0064] Figure 3 An exemplary circuit structure diagram of each differential module (including the first differential module 102, the second differential module 104, the third differential module 107, and the fourth differential module 108) is shown. For example, Figure 5 As shown in sections (a1), (a2), (a3), and (a4), each differential module consists of multiple inductors. The left side of each differential module represents a single-ended signal, and the right side represents a differential signal. (This is combined with...) Figure 5 For example, when the left side of each differential module is the input terminal and the right side is the output terminal, then the first differential module 102 and the fourth differential module 108 can be... Figure 4 Any one of parts (a1), (a2), (a3), and (a4) in the diagram; when the left side of each differential module is the output and the right side is the input, then the second differential module 104 and the third differential module 107 can be... Figure 5 Any one of parts (a1), (a2), (a3), and (a4) in the diagram. The specific circuit principle is common knowledge in this field and will not be elaborated here. It is understood that in the field of electronic technology, differential signals and single-ended signals can also be called balanced signals and unbalanced signals, respectively. The specifics are within the scope of what those skilled in the art can easily understand and will not be elaborated here.

[0065] In some embodiments, the first capacitor C1, the second capacitor C2, the third capacitor C3 and the fourth capacitor C4 are all ceramic capacitors. Thus, the first capacitor C1, the second capacitor C2, the third capacitor C3 and the fourth capacitor C4 have small capacitance values, and the first radio frequency signal SF1 can pass through effectively. For high-voltage alternating current with a low frequency, the first capacitor C1, the second capacitor C2, the third capacitor C3 and the fourth capacitor C4 form a high-voltage electrical isolation barrier, and thus can withstand a very high voltage.

[0066] It should be noted that the first capacitor C1, the second capacitor C2, the third capacitor C3 and the fourth capacitor C4 are only exemplarily shown in the embodiments of the present application, and other implementation manners can also be used in other embodiments, such as capacitors formed by two pcb boards, and the embodiments of the present application do not make specific limitations, as long as the capacitance values are small.

[0067] In some embodiments, as shown in Figure 5 The signal transmission system 100 further includes at least one of the first high-pass filter 110 and the second high-pass filter 111 (in this embodiment, the signal transmission system 100 simultaneously includes the first high-pass filter 110 and the second high-pass filter 111 as an example), and at least one of the third high-pass filter 112 and the fourth high-pass filter 113 (in this embodiment, the signal transmission system 100 simultaneously includes the third high-pass filter 112 and the fourth high-pass filter 113 as an example).

[0068] The first high-pass filter 110 is electrically connected between the modulation module 101 and the first differential module 102, the second high-pass filter 111 is electrically connected between the second differential module 104 and the demodulation module 105, the third high-pass filter 112 is electrically connected between the modulation module 101 and the third differential module 107, and the fourth high-pass filter 113 is electrically connected between the fourth differential module 108 and the demodulation module 105.

[0069] Specifically, as described in the above embodiments, by modulating the input signal VIN on the first carrier LO1, the first radio frequency signal RF1 with a high frequency can be output. At this time, the frequency of the first radio frequency signal RF1 is higher than the frequency of the external interference signal, and thus the cut-off frequency of the first high-pass filter 110 is set to be higher than the frequency of the external interference signal and lower than the frequency of the first radio frequency signal RF1, so that the external interference signal can be filtered out and the first radio frequency signal RF1 is retained. Secondly, by setting the second high-pass filter 111, the external interference signal can be filtered out again, so that the second radio frequency signal RF2 and the first radio frequency signal RF1 are the same signal, which is beneficial to improve the accuracy.

[0070] Similarly, since the frequency of the second carrier LO2 is usually set to be higher than the frequency of the external interference signal, the external interference signal can be filtered out and the second carrier LO2 can be retained by setting the cutoff frequency of the fourth high-pass filter 113 to be higher than the frequency of the external interference signal and lower than the frequency of the second carrier LO2. Further, the external interference signal can be filtered out again by setting the third high-pass filter 112, so that the second carrier LO2 is the same as the first carrier LO1, which is beneficial to improve the accuracy.

[0071] In some embodiments, as shown in Figure 6 The modulation module 101 includes a first mixer M1, and the demodulation module 114 includes a second mixer M2 and a low-pass filter M3.

[0072] The first input end of the first mixer M1 inputs the first carrier LO1, the second input end of the first mixer M1 inputs the input signal VIN, and the output end of the first mixer M1 outputs the first radio frequency signal RF1. The first input end of the second mixer M2 inputs the second carrier LO2, the second input end of the second mixer M2 inputs the second radio frequency signal RF2, the output end of the second mixer M2 is connected with the output end of the low-pass filter M3, and the output end of the low-pass filter M3 outputs the output signal VOUT.

[0073] Specifically, the first carrier LO1 is the local oscillator signal of the first mixer M1, and the first radio frequency signal RF1 output by the first mixer M1 contains two frequencies: f0+f1 and f0-f1, where f0 is the frequency of the first carrier LO1, and f1 is the frequency of the input signal VIN. Then, the second carrier LO2 is the local oscillator signal of the second mixer M2, and the signal output by the second mixer M2 contains two signal components: one is twice the frequency f0 of the first carrier LO1, i.e., 2f0; and the other is the frequency f1 of the input signal VIN. Then, by configuring the cutoff frequency of the low-pass filter M3 to be greater than the frequency f1 and less than 2f0, 2f0 can be filtered out, and only the signal with the frequency f1 is left, i.e., the input signal VIN is restored from the second radio frequency signal RF2, and the signal transmission process is realized.

[0074] The signal transmission device provided in the embodiments of the present application includes the signal transmission system 100 in any of the embodiments of the present application.

[0075] In some embodiments, as shown in Figure 7 Figure 8 The signal transmission device further includes a first housing 200, a second housing 300, a first channel 400, and a second channel 500.

[0076] The first shell 200, the second shell 300, the first channel 400 and the second channel 500 are hollow structures, and the first channel 400 and the second channel 500 are arranged between the first shell 200 and the second shell 300.

[0077] Specifically, the modulation module 101, the first differential module 102, the third differential module 107, the first high-pass filter 110 and the third high-pass filter 112 in the signal transmission system 100 are arranged inside the first shell 200, the demodulation module 114, the second differential module 104, the fourth differential module 108, the second high-pass filter 111 and the fourth high-pass filter 113 in the signal transmission system 100 are arranged inside the second shell 300, the first isolation module 103 in the signal transmission system 100 is arranged inside the first channel 400, and the second isolation module 109 in the signal transmission system 100 is arranged inside the second channel 500.

[0078] All circuits of the modulation module 101, the first differential module 102, the third differential module 107, the first high-pass filter 110 and the third high-pass filter 112 are enclosed inside the first shell 200 (i.e. the hollow part of the first shell 200); all circuits of the demodulation module 114, the second differential module 104, the fourth differential module 108, the second high-pass filter 111 and the fourth high-pass filter 113 are enclosed inside the second shell 300 (i.e. the hollow part of the second shell 300). In some embodiments, the first shell 200 and the second shell 300 are made of conductive material, so that external interference signals (such as external electromagnetic interference) can be shielded outside.

[0079] In some embodiments, the first channel 400 and the second channel 500 are made of non-conductive magnetic material. In some embodiments, the non-conductive magnetic material is nickel-zinc ferrite material. The specific shape of the first channel 400 and the second channel 500 can be set based on the actual application scenario, and the embodiments themselves do not make specific limitations, for example, in some embodiments, the first channel 400 and the second channel 500 are tubular channels. In some embodiments, the first shell 200, the second shell 300, the first channel 400 and the second channel 500 are integrally formed structures. Thus, the two ends of the first channel 400 and the second channel 500 are tightly and seamlessly combined with the first shell 200 and the second shell 300, so that external interference signals (such as external electromagnetic interference) cannot enter the signal transmission system 100 through the gaps.

[0080] The above only describes the embodiments of the present application, and does not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation based on the content of the specification and drawings, or direct or indirect application in other related technical fields, is also included in the patent protection scope of the present application.

[0081] The above examples are only used to illustrate the technical solutions of the present application, and are not intended to limit the present application; the technical features in the above examples or different examples can also be combined, and the steps can be implemented in any order. Those skilled in the art should understand that the technical solutions recorded in the foregoing examples can still be modified, or some technical features can be replaced by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the examples of the present application.

Claims

1. A signal transmission system, characterized by, The signal transmission system comprises a modulation module, a first differential module, a second differential module, a first isolation module and a demodulation module. The modulation module is configured to receive an input signal and modulate the input signal on a first carrier to output a first radio frequency signal. The first differential module is electrically connected to the modulation module, and the first differential module is configured to output a first differential signal based on the first radio frequency signal. The first isolation module is electrically connected between the first differential module and the second differential module, and the first isolation module comprises at least one capacitor, and the capacitor in the first isolation module is configured to couple the first differential signal to the second differential module. The second differential module is configured to output a second radio frequency signal based on the first differential signal. The demodulation module is electrically connected to the second differential module, and the demodulation module is configured to demodulate the second radio frequency signal and output an output signal proportional to the input signal. The frequency of the first radio frequency signal is greater than the maximum frequency of an external interference signal.

2. The signal transmission system of claim 1, wherein, The signal transmission system further comprises a carrier generation module, a third differential module, a fourth differential module and a second isolation module.

3. The signal transmission system according to claim 1 or 2, characterized in that, The carrier generation module is configured to generate the first carrier or a second carrier. One of the modulation module and the demodulation module is electrically connected to the carrier generation module, and the demodulation module is configured to demodulate the second radio frequency signal based on the second carrier. One of the third differential module and the fourth differential module is electrically connected to the carrier generation module, and the third differential module is configured to generate a second differential signal based on the first carrier or generate the first carrier based on a third differential signal. The second isolation module is electrically connected between the third differential module and the fourth differential module, and the second isolation module comprises at least one capacitor, and the capacitor in the second isolation module is configured to couple the second differential signal to the fourth differential module or couple the third differential signal to the third differential module. The fourth differential module is configured to output the second carrier based on the second differential signal or output the third differential signal based on the second carrier. The first isolation module comprises a first capacitor and a second capacitor, and the second isolation module comprises a third capacitor and a fourth capacitor.

4. The signal transmission system of claim 3, wherein The first capacitor is electrically connected between a first output end of the first differential module and a first input end of the second differential module, and the second capacitor is electrically connected between a second output end of the first differential module and a second input end of the second differential module. The third capacitor is electrically connected between a first output end of the third differential module and a first input end of the fourth differential module, and the fourth capacitor is electrically connected between a second output end of the third differential module and a second input end of the fourth differential module, or the third capacitor is electrically connected between a first input end of the third differential module and a first output end of the fourth differential module, and the fourth capacitor is electrically connected between a second input end of the third differential module and a second output end of the fourth differential module. ​ 5. The signal transmission system of claim 4, wherein, The first capacitor, the second capacitor, the third capacitor and the fourth capacitor are ceramic capacitors.

6. The signal transmission system of claim 3, wherein, The signal transmission system further comprises at least one of a first high-pass filter and a second high-pass filter, and at least one of a third high-pass filter and a fourth high-pass filter. The first high-pass filter is electrically connected between the modulation module and the first differential module, the second high-pass filter is electrically connected between the second differential module and the demodulation module, the third high-pass filter is electrically connected between the modulation module and the third differential module, and the fourth high-pass filter is electrically connected between the fourth differential module and the demodulation module.

7. The signal transmission system of claim 1, wherein, The modulation module comprises a first mixer, and the demodulation module comprises a second mixer and a low-pass filter. A first input end of the first mixer inputs the first carrier, a second input end of the first mixer inputs the input signal, and an output end of the first mixer outputs the first radio frequency signal. A first input end of the second mixer inputs a second carrier, a second input end of the second mixer inputs the second radio frequency signal, an output end of the second mixer is connected with an input end of the low-pass filter, and an output end of the low-pass filter outputs the output signal.

8. A signal transmission device, characterized by comprising: The signal transmission system comprises the signal transmission device.

9. The signal transmission device of claim 8, wherein, The signal transmission device further comprises a first shell, a second shell, a first channel and a second channel. The first shell, the second shell, the first channel and the second channel are hollow structures, and the first channel and the second channel are arranged between the first shell and the second shell. The modulation module, the first differential module, the third differential module, the first high-pass filter and the third high-pass filter in the signal transmission system are arranged in the first shell, the demodulation module, the second differential module, the fourth differential module, the second high-pass filter and the fourth high-pass filter in the signal transmission system are arranged in the second shell, the first isolation module in the signal transmission system is arranged in the first channel, and the second isolation module in the signal transmission system is arranged in the second channel.

10. The signal transmission device of claim 9, wherein, The first channel and the second channel are made of non-conductive magnetic material.

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