A signal acquisition system and amplifier resistant to high frequency interference

Abstract

A signal acquisition system and amplifier for resisting high-frequency interference include a signal terminal; a first filter circuit includes a first access point, a second access point, resistors R1, R2, and R3, and capacitors C1, C2, and C3; one end of resistor R1 is connected to the first access point, and the other end is connected to one end of resistor R2, the other end of resistor R2 is connected to the second access point, the end of resistor R1 connected to resistor R2 is also connected to one end of capacitor C3, and the other end of capacitor C3 is grounded; one end of capacitor C1 is connected to the first access point, and the other end is connected to one end of capacitor C2, the other end of capacitor C2 is connected to the second access point, the end of capacitor C1 connected to capacitor C2 is also connected to one end of resistor R3, and the other end of resistor R3 is grounded; the first filter circuit is connected in series with the first access point and the second access point to the signal terminal. Compared with traditional anti-interference filter structures, this invention can achieve better high-frequency interference resistance with a smaller on-chip cost.

Description

Technical Field

[0001] This invention relates to the field of integrated circuit technology, and more specifically to a signal acquisition system and amplifier that resists high-frequency interference. Background Technology

[0002] High-frequency interference is particularly severe in smartphones and wireless IoT devices. When a device transmits data, the antenna can pick up noise in various ways. Meanwhile, diodes in the readout circuit rectify the high-frequency signal, and the envelope of this rectified signal generates noise in the output of the preamplifier. To prevent this proximity effect, system designers must place the preamplifier away from the device antenna and isolate its power supply to mitigate high-frequency interference. This presents a significant challenge to both product miniaturization and system performance improvements.

[0003] As electronic devices continue to add more functions to smaller spaces, the ability to resist high-frequency interference is particularly important when designing preamplifiers. The miniaturization and increasing integration of functions in electronic devices have made high-frequency interference more severe, while the space available for design and use is also decreasing, which poses a great challenge to the high-frequency interference resistance design of devices. Summary of the Invention

[0004] To address the above problems, this invention provides a signal acquisition system and amplifier that resist high-frequency interference, which are described in detail below.

[0005] According to the first aspect, a signal acquisition system resistant to high-frequency interference includes a signal acquisition unit, a preamplifier, and a processing unit;

[0006] The signal acquisition unit is used to acquire signals;

[0007] The preamplifier has multiple signal terminals, including at least one input terminal and at least one output terminal; the preamplifier receives the acquired signal through one of its input terminals, amplifies the acquired signal, and outputs it through one of its output terminals; at least one signal terminal of the preamplifier is connected in series with a composite filter, the composite filter including one or more first filter circuits and one or more second filter circuits;

[0008] The first filtering circuit includes a first access point, a second access point, resistors R1, R2, and R3, and capacitors C1, C2, and C3. One end of resistor R1 is connected to the first access point, and the other end is connected to one end of resistor R2. The other end of resistor R2 is connected to the second access point. The end of resistor R1 connected to resistor R2 is also connected to one end of capacitor C3, and the other end of capacitor C3 is grounded. One end of capacitor C1 is connected to the first access point, and the other end is connected to one end of capacitor C2. The other end of capacitor C2 is connected to the second access point. The end of capacitor C1 connected to capacitor C2 is also connected to one end of resistor R3, and the other end of resistor R3 is grounded. The first filtering circuit is connected in series with the signal terminal of the preamplifier through its first and second access points.

[0009] The second filtering circuit includes a first access point, a second access point, a resistor R, and a capacitor C: one end of the resistor R is connected to the first access point, and the other end is connected to the second access point; one end of the capacitor C is grounded, and the other end is connected to either the first access point or the second access point; the second filtering circuit is connected in series with the signal terminal of the preamplifier through its first access point and second access point.

[0010] The processing unit is used to process the amplified signal.

[0011] According to a second aspect, one embodiment provides a signal acquisition system resistant to high-frequency interference, comprising:

[0012] The signal acquisition unit is used to acquire signals;

[0013] A preamplifier has multiple signal terminals, including at least one input terminal and at least one output terminal. The preamplifier receives a sampled signal through one of its input terminals, amplifies the signal, and outputs it through one of its output terminals. At least one signal terminal of the preamplifier is connected in series with a first filter circuit. The first filter circuit includes a first access point, a second access point, resistors R1, R2, and R3, and capacitors C1, C2, and C3. One end of resistor R1 is connected to the first access point, and the other end is connected to one end of resistor R2. The other end of 2 is connected to the second access point. The end of resistor R1 connected to resistor R2 is also connected to one end of capacitor C3, and the other end of capacitor C3 is grounded. One end of capacitor C1 is connected to the first access point, and the other end is connected to one end of capacitor C2. The other end of capacitor C2 is connected to the second access point. The end of capacitor C1 connected to capacitor C2 is also connected to one end of resistor R3, and the other end of resistor R3 is grounded. The first filter circuit is connected in series with the signal terminal of the preamplifier through the first access point and the second access point.

[0014] The processing unit is used to process the amplified signal.

[0015] In one embodiment, at least one signal terminal of the preamplifier is connected in series with a second filter circuit;

[0016] The second filtering circuit includes a first access point, a second access point, a resistor R, and a capacitor C: one end of the resistor R is connected to the first access point, and the other end is connected to the second access point; one end of the capacitor C is grounded, and the other end is connected to either the first access point or the second access point; the second filtering circuit is connected in series with the signal terminal of the preamplifier through its first and second access points; or,

[0017] The second filtering circuit includes a first access point, a second access point, an inductor L, and a capacitor C: one end of the inductor L is connected to the first access point, and the other end is connected to the second access point; one end of the capacitor C is grounded, and the other end is connected to either the first access point or the second access point; the second filtering circuit is connected in series with the signal terminal of the preamplifier through its first and second access points; or,

[0018] The second filter circuit includes an access point and a capacitor C: one end of the capacitor C is grounded, and the other end is connected to the access point; the second filter circuit is connected in series with the signal terminal of the preamplifier through its access point; or,

[0019] The second filter circuit includes a first access point, a second access point, and a resistor R: one end of the resistor R is connected to the first access point, and the other end is connected to the second access point; the second filter circuit is connected in series with the signal terminal of the preamplifier through its first and second access points; or,

[0020] The second filtering circuit includes a first access point, a second access point, and an inductor L: one end of the inductor L is connected to the first access point, and the other end is connected to the second access point; the second filtering circuit is connected in series with the signal terminal of the preamplifier through its first access point and second access point.

[0021] In one embodiment, the preamplifier has at least one signal terminal connected in series with a first number of first filter circuits and a second number of second filter circuits.

[0022] According to a third aspect, one embodiment provides an amplifier that resists high-frequency interference, comprising:

[0023] At least one input terminal and at least one output terminal;

[0024] An amplifier circuit is used to receive an input signal through the input terminal, amplify the input signal, and output it through the output terminal.

[0025] A first filtering circuit includes a first access point, a second access point, resistors R1, R2, and R3, and capacitors C1, C2, and C3. One end of resistor R1 is connected to the first access point, and the other end is connected to one end of resistor R2. The other end of resistor R2 is connected to the second access point. The end of resistor R1 connected to resistor R2 is also connected to one end of capacitor C3, and the other end of capacitor C3 is grounded. One end of capacitor C1 is connected to the first access point, and the other end is connected to one end of capacitor C2. The other end of capacitor C2 is connected to the second access point. The end of capacitor C1 connected to capacitor C2 is also connected to one end of resistor R3, and the other end of resistor R3 is grounded. The first filtering circuit is connected in series with the signal terminal of the amplifier circuit through the first access point and the second access point.

[0026] In one embodiment, at least one signal terminal is connected in series with a second filter circuit;

[0027] The second filter circuit includes a first access point, a second access point, a resistor R, and a capacitor C: one end of the resistor R is connected to the first access point, and the other end is connected to the second access point; one end of the capacitor C is grounded, and the other end is connected to either the first access point or the second access point; the second filter circuit is connected in series with the signal terminal of the amplifier circuit through its first and second access points; or,

[0028] The second filter circuit includes a first access point, a second access point, an inductor L, and a capacitor C: one end of the inductor L is connected to the first access point, and the other end is connected to the second access point; one end of the capacitor C is grounded, and the other end is connected to either the first access point or the second access point; the second filter circuit is connected in series with the signal terminal of the amplifier circuit through its first and second access points; or,

[0029] The second filter circuit includes an access point and a capacitor C: one end of the capacitor C is grounded, and the other end is connected to the access point; the second filter circuit is connected in series with the signal terminal of the amplifier circuit through its access point; or,

[0030] The second filter circuit includes a first access point, a second access point, and a resistor R: one end of the resistor R is connected to the first access point, and the other end is connected to the second access point; the second filter circuit is connected in series with the signal terminal of the amplifier circuit through its first and second access points; or,

[0031] The second filter circuit includes a first access point, a second access point, and an inductor L: one end of the inductor L is connected to the first access point, and the other end is connected to the second access point; the second filter circuit is connected in series with the signal terminal of the amplifier circuit through its first access point and second access point.

[0032] In one embodiment, at least one signal terminal is simultaneously connected in series with a first number of the first filter circuits and a second number of the second filter circuits.

[0033] In one embodiment, at least one signal terminal is connected in series with a first number of the first filter circuits.

[0034] In one embodiment, the first quantity is an integer of 1 or greater than or equal to 2; the second quantity is an integer of 1 or greater than or equal to 2.

[0035] In one embodiment, each signal terminal is connected in series with the first filter circuit.

[0036] The high-frequency interference-resistant signal acquisition system and amplifier according to the above embodiments can achieve better high-frequency interference resistance performance with a smaller on-chip cost compared to traditional anti-interference filtering structures. Attached Figure Description

[0037] Figure 1 A schematic diagram of a signal acquisition and reading system;

[0038] Figure 2 This is a schematic diagram of a preamplifier;

[0039] Figure 3A schematic diagram of a preamplifier for high-frequency interference suppression;

[0040] Figure 4 This is a schematic diagram of the structure of a signal acquisition system for resisting high-frequency interference according to an embodiment;

[0041] Figure 5 A schematic diagram of a preamplifier having at least one signal terminal connected in series with a first filter circuit, as one embodiment;

[0042] Figure 6 A schematic diagram of a preamplifier having at least one signal terminal connected in series with a first filter circuit, as one embodiment;

[0043] Figure 7 This is a schematic diagram of the structure of a first filter circuit according to an embodiment;

[0044] Figure 8 A schematic diagram of a preamplifier having at least one signal terminal connected in series with a first filter circuit, as one embodiment;

[0045] Figure 9 A schematic diagram of a preamplifier having at least one signal terminal connected in series with a first filter circuit, as one embodiment;

[0046] Figure 10 A schematic diagram of a preamplifier with at least one signal terminal connected in series with a first filter circuit and a second filter circuit, as an embodiment;

[0047] Figure 11 A schematic diagram of a preamplifier with at least one signal terminal connected in series with a first filter circuit and a second filter circuit, as an embodiment;

[0048] Figure 12 This is a schematic diagram of the structure of a second filter circuit according to one embodiment;

[0049] Figure 13 A schematic diagram of a preamplifier with at least one signal terminal connected in series with a first filter circuit and a second filter circuit, as an embodiment;

[0050] Figure 14 This is a schematic diagram of the structure of a second filter circuit according to one embodiment;

[0051] Figure 15 A schematic diagram of a preamplifier with at least one signal terminal connected in series with a first filter circuit and a second filter circuit, as an embodiment;

[0052] Figure 16 This is a schematic diagram of the structure of a second filter circuit according to one embodiment;

[0053] Figure 17A schematic diagram of a preamplifier with at least one signal terminal connected in series with a first filter circuit and a second filter circuit, as an embodiment;

[0054] Figure 18 This is a schematic diagram of the structure of a second filter circuit according to one embodiment;

[0055] Figure 19 A schematic diagram of a preamplifier with at least one signal terminal connected in series with a first filter circuit and a second filter circuit, as an embodiment;

[0056] Figure 20 This is a schematic diagram of the structure of a second filter circuit according to one embodiment;

[0057] Figure 21 This is a schematic diagram of the structure of an amplifier that resists high-frequency interference according to one embodiment;

[0058] Figures 22(a), 22(b), and 22(c) are schematic diagrams of the filtering effects of the three filtering structures, respectively.

[0059] Figure 23(a) shows the spectrum of the useful signal and the high-frequency interference signal. Generally speaking, the useful signal and the high-frequency interference signal are in frequency bands that are far apart. Figure 23(b) shows a schematic diagram in which the high-frequency signal intermodulates out of the frequency band of the useful signal due to the presence of interference signal and distortion in the circuit, causing interference to the useful signal. Figure 23(c) shows a schematic diagram in which the high-frequency signal is effectively suppressed after the invention is used, while the useful signal is not affected because of its low frequency. The intermodulation signal generated by the suppressed high-frequency signal is also weakened, thereby achieving the effect of suppressing high-frequency interference. Detailed Implementation

[0060] The present invention will now be described in further detail with reference to specific embodiments and accompanying drawings. Similar elements in different embodiments are referred to by associated similar element reference numerals. In the following embodiments, many details are described to facilitate a better understanding of this application. However, those skilled in the art will readily recognize that some features may be omitted in different situations, or may be replaced by other elements, materials, or methods. In some cases, certain operations related to this application are not shown or described in the specification. This is to avoid obscuring the core parts of this application with excessive description. For those skilled in the art, detailed description of these related operations is not necessary; they can fully understand the related operations based on the description in the specification and general technical knowledge in the art.

[0061] Furthermore, the features, operations, or characteristics described in the specification can be combined in any suitable manner to form various embodiments. At the same time, the steps or actions in the method description can be rearranged or adjusted in a manner obvious to those skilled in the art. Therefore, the various orders in the specification and drawings are only for the clear description of a particular embodiment and do not imply a necessary order, unless otherwise stated that a particular order must be followed.

[0062] The serial numbers assigned to components in this document, such as "first" and "second," are used only to distinguish the described objects and have no sequential or technical meaning. The terms "connection" and "linkage" used in this application, unless otherwise specified, include both direct and indirect connections (linkages).

[0063] A preamplifier is a circuit or electronic device placed between the signal source and the amplifier stage, generally designed to receive weak signals from the signal source. Preamplifiers are typically connected directly to the sensor that detects the signal. A complete sensing system consists of a front-end sensor and a back-end readout circuit, for example... Figure 1 This is one example; in the signal readout circuit, the preamplifier is crucial to the accuracy, signal-to-noise ratio, and linearity of the entire system. Its main functions are: 1) improving the system's signal-to-noise ratio, 2) reducing the relative impact of external interference, and 3) achieving impedance transformation and matching. High-frequency interference is one of the most common external interferences. From the perspective of propagation paths, high-frequency interference may originate from: 1) high-frequency signals propagating through conduction; and 2) high-frequency signals propagating through radiation. From the perspective of propagation sources, high-frequency interference may originate from: 1) high-frequency signals from the same electronic device; and 2) high-frequency signals from different electronic devices. For example, high-frequency radiation generated by on-chip oscillators and signals emitted by wireless communication base stations can both become sources of high-frequency interference.

[0064] Figure 2 This is a schematic diagram of a preamplifier, where PIN1, PIN2, PIN3, and PIN4 are the signal pins of the preamplifier, including input and output pins. High-frequency interference can interfere with the preamplifier through any one or more pins and ultimately be output through the output pins. One solution is to add filter circuits to each pin of the preamplifier to suppress the effects of high-frequency interference, for example... Figure 3 For example, filter circuit F-1 is connected in series with PIN1, filter circuit F-2 is connected in series with PIN2, filter circuit F-3 is connected in series with PIN3, and filter circuit F-4 is connected in series with PIN4.

[0065] To combat high-frequency interference, filter circuits F-1 to F-4 are often implemented using RC low-pass filter circuits. Figure 4As a schematic diagram, point X is connected to the pin of the preamplifier, and point Y can be an on-chip package PAD. Figure 4 The attenuation capability of a resistor-capacitor filter for high-frequency interference signals is closely related to the pole frequency formed by the resistor and capacitor. It only achieves 3dB signal attenuation at the pole frequency w0 = 1 / RC. To achieve better suppression capability, the pole frequency w0 needs to be much smaller than the frequency of the high-frequency interference signal. To meet this system requirement, very large on-chip resistor and capacitor values ​​are often required, or even off-chip resistors and capacitors must be used, which greatly increases the cost of the chip. Furthermore, for some special pins, such as power supply pins which are limited by voltage drop specifications and output pins which are limited by output impedance requirements, the value of the resistor is often limited to several hundred ohms or less. Such small resistor values ​​and the requirements for capacitors make this solution extremely costly to implement.

[0066] Please refer to Figure 4 Some embodiments of this application provide a signal acquisition system that resists high-frequency interference, which may include a signal acquisition unit 10, a preamplifier 20, and a processing unit 30; the signal acquisition unit 10 is used to acquire signals, the preamplifier 20 is used to amplify signals, and the processing unit 30 is used to process the amplified signals.

[0067] In some embodiments, the preamplifier 20 has multiple signal terminals, including at least one input terminal and at least one output terminal; the input terminal is used to receive an input signal, and the output terminal is used to output a signal. In some embodiments, the preamplifier 20 receives a signal acquired by the signal acquisition unit 10 through one of its input terminals, amplifies the acquired signal, and outputs it through one of its output terminals.

[0068] In some embodiments, please refer to Figure 5 The preamplifier 20 has at least one signal terminal connected in series with the first filter circuit F1; it should be noted that... Figure 5 The example shown is of a preamplifier 20 having four signal terminals, one of which is connected in series with the first filter circuit F1; in some embodiments, please refer to Figure 6 and Figure 7The first filter circuit F1 includes a first access point X, a second access point Y, resistors R1, R2, and R3, and capacitors C1, C2, and C3. One end of resistor R1 is connected to the first access point X, and the other end is connected to one end of resistor R2. The other end of resistor R2 is connected to the second access point Y. The end of resistor R1 connected to resistor R2 is also connected to one end of capacitor C3, and the other end of capacitor C3 is grounded. One end of capacitor C1 is connected to the first access point X, and the other end is connected to one end of capacitor C2. The other end of capacitor C2 is connected to the second access point Y. The end of capacitor C1 connected to capacitor C2 is also connected to one end of resistor R3, and the other end of resistor R3 is grounded. The first filter circuit F1 is connected in series with the signal terminal of the preamplifier 20 through the first access point X and the second access point Y.

[0069] The first filter circuit F1 can be regarded as a band-stop filter with high frequency selectivity and high Q value, which can be used to suppress a single frequency point or a very small frequency band. Through the first filter circuit F1, strong suppression of high-frequency interference at a single frequency point can be achieved with very little hardware cost.

[0070] When multiple frequency points need to be eliminated in a targeted manner, multiple first filter units F1 can be connected in series on one signal terminal of the preamplifier 20, or at least two signal terminals can be connected in series with first filter units F1, or these two can be combined, with at least two signal terminals connected in series with first filter units F1, and each signal terminal connected in series with multiple first filter units F1.

[0071] In some embodiments, at least one signal terminal of the preamplifier 20 is connected in series with a first number of first filter circuits F1. In some embodiments, the first number is 1; in some embodiments, the first number is an integer greater than or equal to 2.

[0072] In some embodiments, the preamplifier 20 has multiple signal terminals connected in series with one or more first filter circuits F1.

[0073] In summary, depending on the design requirements, the first filter circuit F1 can be connected in series or not in series for each signal terminal. When the first filter circuit F1 is connected in series, the number of first filter circuits F1 connected in series can also be selected. Figure 8 and Figure 9 Here are two examples.

[0074] Understandably, when there are multiple first filter units F1, especially when multiple first filter units F1 are connected in series on a single signal terminal, these multiple first filter units F1 indicate that it has the following characteristics: Figure 7The circuit structure shown can be varied, but the values ​​of the resistor and capacitor can be different for different first filter units F1, so that the frequency points eliminated by different first filter units F1 are also different.

[0075] Understandably, for some special signal terminals, such as the power supply terminal which is limited by voltage drop specifications, and the output terminal which is limited by output impedance requirements, the value of the resistor in the first filter unit F1 connected in series with the corresponding signal terminal needs to take these specifications into account.

[0076] In some embodiments, please refer to Figure 10 At least one signal terminal of the preamplifier 20 is connected in series with the second filter circuit F2.

[0077] In some embodiments, please refer to Figure 11 and Figure 12 The second filter circuit F2 includes a first access point X, a second access point Y, a resistor R, and a capacitor C: one end of the resistor R is connected to the first access point X, and the other end is connected to the second access point Y; one end of the capacitor C is grounded, and the other end is connected to either the first access point X or the second access point Y; the second filter circuit F2 is connected in series with the signal terminal of the preamplifier 20 through its first access point X and second access point Y.

[0078] In some embodiments, please refer to Figure 13 and Figure 14 The second filter circuit F2 includes a first access point X, a second access point Y, an inductor L, and a capacitor C: one end of the inductor L is connected to the first access point X, and the other end is connected to the second access point Y; one end of the capacitor C is grounded, and the other end is connected to either the first access point X or the second access point Y; the second filter circuit F2 is connected in series with the signal terminal of the preamplifier 20 through its first access point X and its second access point Y.

[0079] In some embodiments, please refer to Figure 15 and Figure 16 The second filter circuit F2 includes an access point X and a capacitor C: one end of the capacitor C is grounded and the other end is connected to the access point X; the second filter circuit F2 is connected in series with the signal terminal of the preamplifier 20 through its access point X.

[0080] In some embodiments, please refer to Figure 17 and Figure 18 The second filter circuit F2 includes a first access point X, a second access point Y, and a resistor R: one end of the resistor R is connected to the first access point X, and the other end is connected to the second access point Y; the second filter circuit F2 is connected in series with the signal terminal of the preamplifier 20 through its first access point X and second access point Y.

[0081] In some embodiments, please refer to Figure 19 and Figure 20The second filter circuit F2 includes a first access point X, a second access point Y, and an inductor L: one end of the inductor L is connected to the first access point X, and the other end is connected to the second access point Y; the second filter circuit F2 is connected in series with the signal terminal of the preamplifier 20 through its first access point X and second access point Y.

[0082] When it is necessary to eliminate broadband high-frequency interference, the first filter circuit F1 and the second filter circuit F2 can be connected in series at one or more signal terminals. With this combination, when the frequency of a certain frequency point to be eliminated is high, the resistors and capacitors in the second filter circuit F2, especially the capacitors, can be implemented on the chip at a low cost.

[0083] In some embodiments, at least one signal terminal of the preamplifier 20 is connected in series with a second number of second filter circuits F2. In some embodiments, the second number is 1; in some embodiments, the second number is an integer greater than or equal to 2.

[0084] In some embodiments, the preamplifier 20 has multiple signal terminals connected in series with one or more second filter circuits F2.

[0085] In some embodiments, at least one signal terminal of the preamplifier 20 is connected in series with a first number of first filter circuits F1 and a second number of second filter circuits F2; ​​in some embodiments, the first number is 1; in some embodiments, the first number is an integer greater than or equal to 2; in some embodiments, the second number is 1; in some embodiments, the second number is an integer greater than or equal to 2.

[0086] In some embodiments, at least one signal terminal of the preamplifier 20 is connected in series with both a first filter circuit F1 and a second filter circuit F2.

[0087] In some embodiments, the first filter circuit F1 and the second filter circuit F2 are combined to form a composite filter; in some embodiments, the composite filter includes one or more first filter circuits F1 and one or more second filter circuits F2, and the connection order between the multiple filter circuits included in the composite filter can be freely adjusted according to design requirements.

[0088] Understandably, when there are multiple second filter units F2, especially when multiple second filter units F2 are connected in series on a single signal terminal, these multiple second filter units F2 indicate that they have the following characteristics: Figure 12 , Figure 14 , Figure 16 , Figure 18 or Figure 20 The circuit structure shown can be different for different second filter units F2, but the values ​​of their components, such as resistors and / or capacitors, can be different.

[0089] In some embodiments, at least one signal terminal of the preamplifier 20 is connected in series with both a first filter circuit F1 and a second filter circuit F2. The number of first filter circuits F1 can be one or more, and the number of second filter circuits F2 can be one or more. When there are multiple second filter circuits F2, these multiple second filter circuits F2 can be... Figure 12 , Figure 14 , Figure 16 , Figure 18 or Figure 20 The circuit structure shown, for example, all of these multiple second filter circuits F2 are Figure 12 , Figure 14 , Figure 16 , Figure 18 or Figure 20 In any of the circuit structures shown in the diagram, for example, among these multiple second filter circuits F2, a portion of the second filter circuits F2 can be adopted... Figure 12 , Figure 14 , Figure 16 , Figure 18 or Figure 20 In any of the circuit structures shown in the diagram, the second filter circuit F2 can also be adopted. Figure 12 , Figure 14 , Figure 16 , Figure 18 or Figure 20 In any of the circuit structures shown in the figure, the structures of the second filter circuit F2 in these two parts can be different. For example, one part of the second filter circuit F2 adopts... Figure 12 The circuit structure shown, the other part of the second filter circuit F2 adopts... Figure 14 The circuit structure shown is shown.

[0090] In this text, the signal terminals of the preamplifier 20 are connected in series with a first filter circuit F1. This means that the signal at the signal terminal will be filtered by the first filter circuit F1. For example, when the signal terminal is an input terminal, the signal received at the input terminal will be filtered by the first filter circuit F1 before being input to the preamplifier 20. When the signal terminal is an output terminal, the signal output from the output terminal will be filtered by the first filter circuit F1 before being output to subsequent units such as the processing unit 30. Similarly, the signal terminals of the preamplifier 20 are connected in series with a second filter unit F2. This means that the signal at the signal terminal will be filtered by the second filter unit F2. For example, when the signal terminal is an input terminal, the signal received at the input terminal will be filtered by the second filter unit F2 before being input to the preamplifier 20. When the signal terminal of amplifier 20 is an output terminal, it means that the signal output from the output terminal will be filtered by the second filter unit F2 before being output to a subsequent unit, such as processing unit 30. Similarly, the signal terminal of preamplifier 20 is connected in series with the first filter circuit F1 and the second filter unit F2, which means that the signal on the signal terminal will be filtered by the first filter circuit F1 and the second filter unit F2. For example, when the signal terminal is an input terminal, it means that the signal received at the input terminal will be filtered by the first filter circuit F1 and the second filter unit F2 before being input to preamplifier 20. When the signal terminal is an output terminal, it means that the signal output from the output terminal will be filtered by the first filter circuit F1 and the second filter unit F2 before being output to a subsequent unit, such as processing unit 30.

[0091] Please refer to Figure 21 In some embodiments of this application, an amplifier for resisting high-frequency interference is provided, which may include at least one input terminal and at least one output terminal, and may also include an amplification circuit 21 and a first filter circuit F1; the amplification circuit 21 is used to receive an input signal through the input terminal, amplify the input signal, and output it through the output terminal; it should be noted that, Figure 15 The example shown is an amplifier with four signal terminals, one of which is connected in series with the first filter circuit F1.

[0092] In some embodiments, at least one signal terminal of the amplifier is connected in series with a first number of first filter circuits F1. In some embodiments, the first number is 1; in some embodiments, the first number is an integer greater than or equal to 2.

[0093] In some embodiments, the amplifier has multiple signal terminals connected in series with one or more first filter circuits F1.

[0094] The structure of the first filter circuit F1 can be found in the description above, for example, the description above for... Figure 7 The description will not be repeated here.

[0095] In some embodiments, at least one signal terminal of the amplifier is connected in series with a second filter circuit F2. In some embodiments, at least one signal terminal of the amplifier is connected in series with a second number of second filter circuits F2. In some embodiments, the second number is 1; in some embodiments, the second number is an integer greater than or equal to 2.

[0096] The description of the second filter circuit F2 can be found in the description above, for example, the description above for... Figure 12 , Figure 14 , Figure 16 , Figure 18 or Figure 20 The description will not be repeated here.

[0097] Understandably, when there are multiple first filter units F1, especially when multiple first filter units F1 are connected in series on a single signal terminal, these multiple first filter units F1 indicate that it has the following characteristics: Figure 7 The circuit structure shown can be varied, but the values ​​of the resistor and capacitor can be different for different first filter units F1, so that the frequency points eliminated by different first filter units F1 are also different.

[0098] Understandably, when there are multiple second filter units F2, especially when multiple second filter units F2 are connected in series on a single signal terminal, these multiple second filter units F2 indicate that they have the following characteristics: Figure 12 , Figure 14 , Figure 16 , Figure 18 or Figure 20 The circuit structure shown can be different for different second filter units F2, but the values ​​of their components, such as resistors and / or capacitors, can be different.

[0099] In some embodiments, the amplifier has at least one signal terminal connected in series with a first number of first filter circuits F1 and a second number of second filter circuits F2; ​​in some embodiments, the first number is 1; in some embodiments, the first number is an integer greater than or equal to 2; in some embodiments, the second number is 1; in some embodiments, the second number is an integer greater than or equal to 2.

[0100] In some embodiments, at least one signal terminal of the amplifier is connected in series with both a first filter circuit F1 and a second filter circuit F2. The number of first filter circuits F1 can be one or more, and the number of second filter circuits F2 can be one or more. When there are multiple second filter circuits F2, these multiple second filter circuits F2 can be... Figure 12 , Figure 14 , Figure 16 , Figure 18 or Figure 20The circuit structure shown, for example, all of these multiple second filter circuits F2 are Figure 12 , Figure 14 , Figure 16 , Figure 18 or Figure 20 In any of the circuit structures shown in the diagram, for example, among these multiple second filter circuits F2, a portion of the second filter circuits F2 can be adopted... Figure 12 , Figure 14 , Figure 16 , Figure 18 or Figure 20 In any of the circuit structures shown in the diagram, the second filter circuit F2 can also be adopted. Figure 12 , Figure 14 , Figure 16 , Figure 18 or Figure 20 In any of the circuit structures shown in the figure, the structures of the second filter circuit F2 in these two parts can be different. For example, one part of the second filter circuit F2 adopts... Figure 12 The circuit structure shown, the other part of the second filter circuit F2 adopts... Figure 14 The circuit structure shown is shown.

[0101] In this text, the signal terminal of the amplifier is connected in series with a first filter circuit F1. This means that the signal at the signal terminal will be filtered by the first filter circuit F1. For example, when the signal terminal is the input terminal, the signal received at the input terminal will be filtered by the first filter circuit F1 before being input to the amplifier circuit 21. When the signal terminal is the output terminal, the signal output at the output terminal will be filtered by the first filter circuit F1 before being output to the subsequent unit. Similarly, the signal terminal of the amplifier is connected in series with a second filter unit F2. This means that the signal at the signal terminal will be filtered by the second filter unit F2. For example, when the signal terminal is the input terminal, the signal received at the input terminal will be filtered by the second filter unit F2 before being input to the amplifier circuit 21. For amplifier circuit 21, when the signal terminal is the output terminal, it means that the signal output from the output terminal will be filtered by the second filter unit F2 before being output to the subsequent unit. Similarly, when the signal terminal of the amplifier is connected in series with the first filter circuit F1 and the second filter unit F2, it means that the signal at the signal terminal will be filtered by the first filter circuit F1 and the second filter unit F2. For example, when the signal terminal is the input terminal, it means that the signal received at the input terminal will be filtered by the first filter circuit F1 and the second filter unit F2 before being input to amplifier circuit 21. When the signal terminal is the output terminal, it means that the signal output from the output terminal will be filtered by the first filter circuit F1 and the second filter unit F2 before being output to the subsequent unit.

[0102] Please refer to Figure 22(a), which shows the filtering effect of a traditional RC filter; please refer to Figure 22(b), which shows the filtering effect of two first filter circuits F1 connected in series at the signal terminals; and please refer to Figure 22(c), which shows the filtering effect of one first filter circuit F1 and one second filter circuit F2 connected in series at the signal terminals. It can be seen that when multiple frequency points need to be specifically eliminated, multiple first filter circuits F1 can be connected in series at one or more signal terminals; when broadband high-frequency interference needs to be eliminated, first filter circuits F1 and second filter circuits F2 can be used simultaneously at one or more signal terminals. If one of the frequency points is high, the components in the second filter circuit F2 can be implemented on a chip at a lower cost.

[0103] To illustrate the advantages of this invention in single-frequency point high-frequency suppression applications, Table 1 lists the results using traditional RC filtering and... Figure 7 The first filter circuit F1 shown illustrates the total resistance and capacitance values ​​required for two different structures to achieve a high-frequency suppression of 104dB at 0.85GHz, provided the low-frequency impedance of the filter structure is less than 90Ω. In the first filter circuit F1, resistors R1, R2, and R3 are 45 ohms, 45 ohms, and 22.5 ohms, respectively, and capacitors C1, C2, and C3 are 4 picofarads, 4 picofarads, and 8 picofarads, respectively. As can be seen from the data in Table 1, in common integrated circuit processes, the area of ​​the resistors used in the two structures is negligible compared to the area of ​​the capacitors, while the required capacitor area differs by approximately 25 times.

[0104] structure Total resistance value Total capacitance High frequency suppression Traditional RC filter 90Ω 405pF 104dB First filter circuit F1 112.5Ω 16pF 104dB

[0105] Table 1

[0106] To illustrate the advantages of this invention in single-frequency point high-frequency suppression applications, Table 2 lists the results using traditional RC filtering and... Figure 15 The filter structure shown is formed by the first filter circuit F1 and the second filter circuit F2. These two different structures require a total resistance and total capacitance value to achieve a high-frequency suppression of 104dB at 0.85GHz while satisfying a low-frequency impedance of less than 90Ω. In the first filter circuit F1, resistors R1, R2, and R3 are 45 ohms, 45 ohms, and 22.5 ohms, respectively, and capacitors C1, C2, and C3 are 4 picofarads, 4 picofarads, and 8 picofarads, respectively. In the second filter circuit F2, capacitor C is 49 picofarads. As can be seen from the data in Table 2, in common integrated circuit processes, the area of ​​the resistors used in both structures is negligible compared to the area of ​​the capacitors, while the required capacitor area differs by approximately six times.

[0107] structure Total resistance value Total capacitance High frequency suppression Traditional RC Filter 90Ω 405pF 104dB Figure 15 The structure shown Approximately 110Ω 65pF 104dB

[0108] Table 2

[0109] Comparative analysis reveals that, for both single-frequency high-frequency suppression and broadband high-frequency suppression, the filtering structure mentioned in this invention has significant performance and cost advantages over conventional RC filters. Based on this, the signal acquisition system and amplifier designed to resist high-frequency interference can achieve a significant improvement in high-frequency interference resistance with a smaller hardware cost compared to traditional systems and amplifiers.

[0110] Figures 23(a) to 23(c) The effects of the present invention are shown more intuitively; Figure 23(a) shows the spectrum of the useful signal and the high-frequency interference signal. Generally speaking, the useful signal and the high-frequency interference signal are in a frequency band that is far apart; Figure 23(b) shows that due to the presence of interference signals and distortion in the circuit, the high-frequency signal intermodulates out the interference signal in the frequency band of the useful signal, causing interference to the useful signal; Figure 23(c) shows that after using the present invention, the high-frequency signal is effectively suppressed, while the useful signal is not affected because of its low frequency. The intermodulation signal generated by the suppressed high-frequency signal is also weakened, thereby achieving the effect of suppressing high-frequency interference.

[0111] This document describes various exemplary embodiments with reference to them. However, those skilled in the art will recognize that changes and modifications can be made to the exemplary embodiments without departing from the scope of this document. For example, various operational steps and components for performing operational steps can be implemented in different ways depending on the specific application or considering any number of cost functions associated with the operation of the system (e.g., one or more steps can be deleted, modified, or combined with other steps).

[0112] While the principles herein have been illustrated in various embodiments, numerous modifications to the structure, arrangement, proportions, elements, materials, and components, particularly suited to specific environmental and operational requirements, may be used without departing from the principles and scope of this disclosure. These modifications and other alterations or alterations will be included within the scope of this document.

[0113] The foregoing specific descriptions have been described with reference to various embodiments. However, those skilled in the art will recognize that various modifications and changes can be made without departing from the scope of this disclosure. Therefore, considerations for this disclosure are to be illustrative rather than restrictive, and all such modifications are to be included within its scope. Similarly, advantages, other advantages, and solutions to problems with respect to various embodiments have been described above. However, benefits, advantages, solutions to problems, and any elements that produce these, or make them more explicit, should not be construed as critical, essential, or necessary. The term “comprising” and any other variations thereof as used herein are non-exclusive inclusion, meaning that a process, method, article, or apparatus that includes a list of elements includes not only those elements but also other elements not expressly listed or not part of the process, method, system, article, or apparatus. Furthermore, the term “coupled” and any other variations thereof as used herein refer to physical connections, electrical connections, magnetic connections, optical connections, communication connections, functional connections, and / or any other connections.

[0114] Those skilled in the art will recognize that many changes can be made to the details of the above embodiments without departing from the basic principles of the invention. Therefore, the scope of the invention should be determined only by the claims.

Claims

1. A signal acquisition system resistant to high-frequency interference, characterized in that, Includes a signal acquisition unit, a preamplifier, and a processing unit; The signal acquisition unit is used to acquire signals; The preamplifier has multiple signal terminals, including at least one input terminal and at least one output terminal; the preamplifier receives the acquired signal through one of its input terminals, amplifies the acquired signal, and outputs it through one of its output terminals; at least one signal terminal of the preamplifier is connected in series with a composite filter, the composite filter including one or more first filter circuits and one or more second filter circuits; The first filtering circuit includes a first access point, a second access point, resistors R1, R2, and R3, and capacitors C1, C2, and C3. One end of resistor R1 is connected to the first access point, and the other end is connected to one end of resistor R2. The other end of resistor R2 is connected to the second access point. The end of resistor R1 connected to resistor R2 is also connected to one end of capacitor C3, and the other end of capacitor C3 is grounded. One end of capacitor C1 is connected to the first access point, and the other end is connected to one end of capacitor C2. The other end of capacitor C2 is connected to the second access point. The end of capacitor C1 connected to capacitor C2 is also connected to one end of resistor R3, and the other end of resistor R3 is grounded. The first filtering circuit is connected in series with the signal terminal of the preamplifier through its first and second access points. The second filtering circuit includes a first access point, a second access point, a resistor R, and a capacitor C: one end of the resistor R is connected to the first access point, and the other end is connected to the second access point; one end of the capacitor C is grounded, and the other end is connected to either the first access point or the second access point; the second filtering circuit is connected in series with the signal terminal of the preamplifier through its first access point and second access point. The processing unit is used to process the amplified signal.

2. A signal acquisition system resistant to high-frequency interference, characterized in that, include: The signal acquisition unit is used to acquire signals; A preamplifier has multiple signal terminals, including at least one input terminal and at least one output terminal. The preamplifier receives a sampled signal through one of its input terminals, amplifies the signal, and outputs it through one of its output terminals. At least one signal terminal of the preamplifier is connected in series with a first filter circuit. The first filter circuit includes a first access point, a second access point, resistors R1, R2, and R3, and capacitors C1, C2, and C3. One end of resistor R1 is connected to the first access point, and the other end is connected to one end of resistor R2. The other end of 2 is connected to the second access point. The end of resistor R1 connected to resistor R2 is also connected to one end of capacitor C3, and the other end of capacitor C3 is grounded. One end of capacitor C1 is connected to the first access point, and the other end is connected to one end of capacitor C2. The other end of capacitor C2 is connected to the second access point. The end of capacitor C1 connected to capacitor C2 is also connected to one end of resistor R3, and the other end of resistor R3 is grounded. The first filter circuit is connected in series with the signal terminal of the preamplifier through the first access point and the second access point. The processing unit is used to process the amplified signal.

3. The signal acquisition system as described in claim 2, characterized in that, The preamplifier has at least one signal terminal connected in series with a second filter circuit. The second filtering circuit includes a first access point, a second access point, a resistor R, and a capacitor C: one end of the resistor R is connected to the first access point, and the other end is connected to the second access point; one end of the capacitor C is grounded, and the other end is connected to either the first access point or the second access point; the second filtering circuit is connected in series with the signal terminal of the preamplifier through its first and second access points; or, The second filtering circuit includes a first access point, a second access point, an inductor L, and a capacitor C: one end of the inductor L is connected to the first access point, and the other end is connected to the second access point; one end of the capacitor C is grounded, and the other end is connected to either the first access point or the second access point; the second filtering circuit is connected in series with the signal terminal of the preamplifier through its first and second access points; or, The second filter circuit includes an access point and a capacitor C: one end of the capacitor C is grounded, and the other end is connected to the access point; the second filter circuit is connected in series with the signal terminal of the preamplifier through its access point; or, The second filter circuit includes a first access point, a second access point, and a resistor R: one end of the resistor R is connected to the first access point, and the other end is connected to the second access point; the second filter circuit is connected in series with the signal terminal of the preamplifier through its first and second access points; or, The second filtering circuit includes a first access point, a second access point, and an inductor L: one end of the inductor L is connected to the first access point, and the other end is connected to the second access point; the second filtering circuit is connected in series with the signal terminal of the preamplifier through its first access point and second access point.

4. The signal acquisition system as described in claim 3, characterized in that, The preamplifier has at least one signal terminal connected in series with a first number of first filter circuits and a second number of second filter circuits.

5. An amplifier that resists high-frequency interference, characterized in that, include: At least one input terminal and at least one output terminal; An amplifier circuit is used to receive an input signal through the input terminal, amplify the input signal, and output it through the output terminal. A first filtering circuit includes a first access point, a second access point, resistors R1, R2, and R3, and capacitors C1, C2, and C3. One end of resistor R1 is connected to the first access point, and the other end is connected to one end of resistor R2. The other end of resistor R2 is connected to the second access point. The end of resistor R1 connected to resistor R2 is also connected to one end of capacitor C3, and the other end of capacitor C3 is grounded. One end of capacitor C1 is connected to the first access point, and the other end is connected to one end of capacitor C2. The other end of capacitor C2 is connected to the second access point. The end of capacitor C1 connected to capacitor C2 is also connected to one end of resistor R3, and the other end of resistor R3 is grounded. The first filtering circuit is connected in series with the signal terminal of the amplifier circuit through the first access point and the second access point.

6. The amplifier as claimed in claim 5, characterized in that, At least one signal terminal is connected in series with a second filter circuit; The second filter circuit includes a first access point, a second access point, a resistor R, and a capacitor C: one end of the resistor R is connected to the first access point, and the other end is connected to the second access point; one end of the capacitor C is grounded, and the other end is connected to either the first access point or the second access point; the second filter circuit is connected in series with the signal terminal of the amplifier circuit through its first and second access points; or, The second filter circuit includes a first access point, a second access point, an inductor L, and a capacitor C: one end of the inductor L is connected to the first access point, and the other end is connected to the second access point; one end of the capacitor C is grounded, and the other end is connected to either the first access point or the second access point; the second filter circuit is connected in series with the signal terminal of the amplifier circuit through its first and second access points; or, The second filter circuit includes an access point and a capacitor C: one end of the capacitor C is grounded, and the other end is connected to the access point; the second filter circuit is connected in series with the signal terminal of the amplifier circuit through its access point; or, The second filter circuit includes a first access point, a second access point, and a resistor R: one end of the resistor R is connected to the first access point, and the other end is connected to the second access point; the second filter circuit is connected in series with the signal terminal of the amplifier circuit through its first and second access points; or, The second filter circuit includes a first access point, a second access point, and an inductor L: one end of the inductor L is connected to the first access point, and the other end is connected to the second access point; the second filter circuit is connected in series with the signal terminal of the amplifier circuit through its first access point and second access point.

7. The amplifier as claimed in claim 6, characterized in that, At least one signal terminal is connected in series with a first number of the first filter circuits and a second number of the second filter circuits.

8. The amplifier as claimed in claim 5, characterized in that, At least one signal terminal is connected in series with a first number of the first filter circuits.

9. The amplifier as claimed in claim 7 or 8, characterized in that, The first quantity is an integer of 1 or greater than or equal to 2; the second quantity is an integer of 1 or greater than or equal to 2.

10. The amplifier as claimed in claim 5, characterized in that, The first filter circuit is connected in series at each signal terminal.

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