A receiver for portable low frequency communication

Abstract

The utility model discloses a receiver for portable low frequency communication belongs to communication circuit technical field. Small aperture multi -pole sub antenna array is connected with multichannel cross matching low noise amplifier LNA network, multichannel cross matching low noise amplifier LNA network is connected with band pass filter module, secondary amplification module, low noise power module and MCU control module respectively, and band pass filter module is connected with secondary amplification module, and secondary amplification module is connected with AD conversion module and low noise power module respectively, and AD conversion module is connected with low noise power module and MCU control module respectively. The utility model aims at guaranteeing high sensitivity and low noise coefficient, and realizing the portability and practicality of low frequency communication equipment completely.

Description

Technical Field

[0001] This utility model belongs to the field of communication circuit technology, and specifically relates to a receiver for portable low-frequency communication. Background Technology

[0002] Low-frequency communication (typically referring to frequencies below 300kHz) possesses irreplaceable value in specific application scenarios due to its outstanding advantages such as low propagation loss, strong diffraction capability, and good penetration, including fields like underground engineering communication, underwater vehicle navigation, long-range wireless sensing, and emergency rescue communication. However, realizing portable low-frequency communication devices has always faced a core technical bottleneck: the physical size of the antenna. According to basic antenna principles, the efficiency of traditional resonant antennas is closely related to their physical size and electrical wavelength, especially in the low-frequency band, where wavelengths can reach hundreds of meters or even kilometers. If a conventional half-wavelength antenna design is used, the antenna size will be enormous, completely failing to meet the portable application requirements such as individual soldier carrying and mobile field operations.

[0003] To reduce antenna size, existing technologies typically employ methods such as loading (e.g., adding inductors) or using non-resonant modes. However, these methods often come at the cost of significantly sacrificing antenna radiation efficiency and receiver sensitivity. This leads to a sharp deterioration in the receiver's signal-to-noise ratio, a substantial decrease in communication distance and quality, and limited practical value of the reduced-size device. On the other hand, at the receiver design level, existing portable devices mostly use a single antenna coupled with a high-gain amplification link. While this approach is simple in structure, it is highly susceptible to environmental electromagnetic interference, and the noise matching of its front-end low-noise amplifier (LNA) is often difficult to optimize over a wide bandwidth, further limiting its performance in weak low-frequency signal detection scenarios.

[0004] Furthermore, attempting to improve the signal-to-noise ratio through spatial signal processing using small-aperture antenna array technology introduces new challenges. The consistency between antenna elements and amplifier channels within the array is crucial. Even minute performance mismatches can cause signal cancellation during signal synthesis, particularly differential processing, introducing additional noise and preventing the realization of the theoretical array gain advantage. Therefore, the lack of a highly consistent, finely tuned, low-noise receiving front-end that can match high-performance small-aperture antenna arrays has become a key issue restricting the development of portable low-frequency communication technology. Utility Model Content

[0005] This invention provides a receiver for portable low-frequency communication, aiming to achieve both high sensitivity and low noise figure while fully realizing the portability and practicality of low-frequency communication equipment.

[0006] This utility model is achieved through the following technical solution: A receiver for portable low-frequency communication includes a small-aperture multipole antenna array, a multi-channel cross-matched low-noise amplifier (LNA) network, a bandpass filter module, a secondary amplifier module, an RF filter module, a low-noise power supply module, an AD conversion module, and an MCU control module. The small-aperture multipole antenna array is connected to a multi-channel cross-matched low-noise amplifier (LNA) network. The multi-channel cross-matched LNA network is connected to a bandpass filter module, a secondary amplifier module, a low-noise power supply module, and an MCU control module. The bandpass filter module is connected to the secondary amplifier module. The secondary amplifier module is connected to an AD conversion module and a low-noise power supply module. The AD conversion module is connected to the low-noise power supply module and the MCU control module.

[0007] Furthermore, the small-aperture multipole antenna array transmits signals to a multi-channel cross-matched low-noise amplifier (LNA) network. The LNA network receives signals from the secondary amplification module, the low-noise power supply module, and the MCU control module. The LNA network also transmits signals to a bandpass filter module, which in turn transmits signals to the secondary amplification module. The secondary amplification module also receives signals from the low-noise power supply module. Furthermore, the secondary amplification module transmits signals to an AD conversion module, which in turn receives signals from the low-noise power supply module and the MCU control module. Finally, the low-noise power supply module also transmits signals to the MCU control module.

[0008] Furthermore, the small aperture multipole antenna array is arranged in a cross shape, and from left to right on the X-axis, it consists of element 1-A, element 1-B, element 2-A, and element 2-B. On the Y-axis, from top to bottom, they are primitive 4-A, primitive 4-B, primitive 3-A, and primitive 3-B.

[0009] Furthermore, the multi-channel cross-matched low-noise amplifier (LNA) network includes chips U5 and U6. Terminal 3 of chip U5 is connected to one end of capacitor C8 and the output terminal CH1_+IN of the small aperture multipole antenna array, respectively. Terminal 8 of chip U5 is connected to terminal 21 of chip U13A in the MCU control module. Terminal 1 of chip U5 is connected to terminal 22 of chip U13A of the MCU control module. Terminal 2 of chip U5 is connected to terminal 25 of chip U13A of the MCU control module. Terminal 7 of chip U5 is connected to one end of capacitor C1, one end of capacitor C2, and the +5V0 operating voltage terminal, respectively. The other end of capacitor C1 is connected to the other end of capacitor C2 and then grounded. Terminal 4 of chip U5 is connected to the output terminal of operational amplifier U2A and one end of capacitor C33 in the bandpass filter module. Terminal 5 of chip U5 is connected to terminal 2 of operational amplifier U2A, and terminal 6 of chip U5 is connected to terminal 3 of operational amplifier U2A and then grounded. Terminal 3 of chip U6 is connected to one end of capacitor C11 and the output terminal CH2_+IN of the small aperture multipole antenna array. Terminal 8 of chip U6 is connected to terminal 28 of chip U13A of the MCU control module. Terminal 1 of chip U6 is connected to terminal 27 of chip U13A of the MCU control module. Terminal 2 of chip U6 is connected to terminal 25 of chip U13A of the MCU control module. Terminal 7 of chip U6 is connected to one end of capacitor C16, one end of capacitor C20, and the +5V0 operating voltage terminal. The other end of capacitor C16 is connected to the other end of capacitor C20 and then grounded. Terminal 4 of chip U6 is connected to the output of operational amplifier U2B and one end of capacitor C14 in the bandpass filter module. Terminal 5 of chip U6 is connected to terminal 6 of operational amplifier U2B, and terminal 6 of chip U6 is grounded after being connected to terminal 5 of operational amplifier U2B. The other end of capacitor C8 is connected to the other end of capacitor C11 and then grounded.

[0010] Furthermore, the bandpass filter module includes capacitor C33 and capacitor C14. The other end of capacitor C33 is connected to one end of capacitor L4. The other end of capacitor L4 is connected to one end of capacitor L6, one end of capacitor C3, and one end of capacitor C13. The other end of capacitor L6 is grounded. The other end of capacitor C13 is grounded. The other end of capacitor C3 is connected to one end of capacitor L5. The other end of capacitor L5 is connected to one end of capacitor L7, one end of capacitor C10, one end of resistor R7 in the secondary amplifier module, and terminal 3 of operational amplifier U10A in the secondary amplifier module. The other end of capacitor C14 is connected to one end of capacitor L8. The other end of capacitor L8 is connected to one end of capacitor L10, one end of capacitor C15, and one end of capacitor C37. The other end of capacitor L10 is grounded. The other end of capacitor C37 is grounded. The other end of capacitor C15 is connected to one end of capacitor L9. The other end of capacitor L9 is connected to one end of capacitor L11, one end of capacitor C35, one end of resistor R9 in the secondary amplifier module, and terminal 5 of operational amplifier U10B in the secondary amplifier module.

[0011] Furthermore, the secondary amplification module includes operational amplifier U10A and operational amplifier U10B. Terminal 2 of operational amplifier U10A is connected to one end of resistor R13, one end of resistor R12, and one end of capacitor C19, respectively. The other end of resistor R3 is grounded, and the other end of resistor R12 is connected to the other end of capacitor C19, terminal 1 of operational amplifier U10A, and one end of capacitor C7 of the analog acquisition signal module, respectively. Terminal 6 of the operational amplifier U10B is connected to one end of resistor R12, one end of resistor R14, and one end of capacitor C38. The other end of resistor R12 is grounded. The other end of resistor R14 is connected to the other end of capacitor C38, terminal 7 of operational amplifier U10B, and one end of capacitor C12 of the analog acquisition signal module. The other end of resistor R17 is connected to the other end of resistor R19 and then grounded.

[0012] Furthermore, the analog acquisition signal module includes capacitor C7 and capacitor C12. The other end of capacitor C7 is connected to one end of resistor R4. The other end of resistor R4 is connected to one end of resistor R1 and terminal 2 of operational amplifier U3A. Terminal 3 of operational amplifier U3A is connected to one end of resistor R8, one end of resistor R6 and one end of capacitor C10. The other end of resistor R6 is connected to the +5V0 operating voltage terminal. The other end of resistor R8 and the other end of capacitor C10 are connected to ground. The other end of capacitor C12 is connected to one end of resistor R11. The other end of resistor R11 is connected to one end of resistor R10 and terminal 6 of operational amplifier U3B. Terminal 5 of operational amplifier U3B is connected to one end of resistor R15, one end of resistor R16 and one end of capacitor C15. The other end of resistor R15 is connected to the +5V0 operating voltage terminal. The other end of resistor R16 is connected to the other end of capacitor C15 and then grounded. Terminal 1 of operational amplifier U3A is connected to the other end of resistor R1 and one end of resistor R5, respectively. Terminal 1 of operational amplifier U3B is connected to the other end of resistor R10 and one end of resistor R13, respectively. The other end of resistor R5 is connected to one end of Zener diode DR1 and terminal 3 of chip U4. Terminal 10 of chip U4 is connected to one end of capacitor C6, one end of capacitor C4, terminal 2 of chip U4, and the operating voltage +1V8. The other end of capacitor C6 is grounded, the other end of capacitor C4 is grounded, and terminal 1 of chip U4 is connected to one end of capacitor C5 and REF4096. The other end of capacitor C5 is grounded. The other end of resistor R13 is connected to one end of Zener diode DR2 and terminal 3 of chip U7. Terminal 10 of chip U7 is connected to one end of capacitor C17, one end of capacitor C19, terminal 2 of chip U7, and the operating voltage +1V8. The other end of capacitor C17 is grounded, the other end of capacitor C19 is grounded, and terminal 1 of chip U7 is connected to one end of capacitor C18 and REF4096. The other end of capacitor C18 is grounded. The other end of the Zener diode DR1 is connected to the other end of the Zener diode DR2, terminal 4 of chip U4, and terminal 4 of chip U7, respectively. Terminal 5 of chip U4 and terminal 5 of chip U7 are connected to ground. Terminal 6 of chip U4 is connected to terminal 18 of chip U13A, terminal 8 of chip U4 is connected to terminal 19 of chip U13A, terminal 7 of chip U4 is connected to terminal 33 of chip U13A, and terminal 9 of chip U4 is connected to terminal 32 of chip U13A. Terminal 6 of chip U4 is connected to terminal 14 of chip U13A and resistor R45 and then grounded. Terminal 8 of chip U7 is connected to terminal 15 of chip U13A. Terminal 7 of chip U7 is connected to terminal 16 of chip U13A. Terminal 9 of chip U7 is connected to terminal 17 of chip U13A.

[0013] Furthermore, the MCU control module includes a chip U13A. Terminal 5 of the chip U13A is connected to one end of capacitor C67 and terminal 3 of crystal oscillator Y1. The other end of capacitor C67 is connected to terminal 2 of crystal oscillator Y1 and then grounded. Terminal 4 of crystal oscillator Y1 is connected to one end of capacitor C73 and one end of capacitor C72. The other end of capacitor C73 is connected to the other end of capacitor C72 and then grounded. Terminal 44 of the chip U13A is connected to one end of resistor R46 and one end of resistor R47. The other ends of resistors R46 and R47 are both grounded. Terminal 7 of the chip U13A is connected to one end of resistor R48 and one end of capacitor C68, respectively. The other end of capacitor C68 is grounded, and the other end of resistor R48 is connected to VDD3V3.

[0014] Furthermore, the low-noise power supply module includes chip U8. Terminal 12 of chip U8 is connected to terminal 2 of chip U8, one end of capacitor C23, one end of capacitor C24, and terminal 2 of chip U11. The other end of capacitor C23 is grounded, and the other end of capacitor C24 is grounded. Terminal 3 of chip U8 is connected to the +5V0 operating voltage terminal via series resistor R17. Terminal 6 of chip U8 is connected to ground via series capacitor C26. Terminal 14 of chip U8 is connected to ground via series capacitor C27. Terminal 11 of chip U8 is connected to... One end of capacitor C21 is connected to one end of capacitor C22. The other end of capacitor C21 is connected to the other end of capacitor C22, terminal 8 of chip U8, and one end of inductor L1. The other end of inductor L1 is connected to terminal 7 of chip U8, one end of capacitor C25, and one end of capacitor L2. The other end of inductor L2 is connected to the +5V0 operating voltage terminal, the -5V0 operating voltage terminal, and one end of resistor R18. The other end of resistor R18 is connected to one end of LED D1. The other end of LED D1 is grounded. Terminal 4 of chip U8 is connected to one end of resistor R19. The other end of resistor R19 is connected to one end of resistor R20 and terminal 5 of chip U8. The other end of resistor R19 is grounded. Terminals 9 and 10 of chip U8 are both grounded.

[0015] Furthermore, the low-noise power supply module also includes a chip U11. Terminal 2 of chip U11 is connected to one end of resistor R34, one end of capacitor C56, one end of capacitor C55, one end of capacitor C54, one end of diode D3, and one end of fuse F1. The other end of resistor R34 is connected to terminal 1 of chip U11. The other ends of capacitors C56, C55, and C54 are grounded, and the other end of diode D3 is grounded. The other end of fuse F1 is connected to terminal 1 of the power input. Terminal 2 of chip U11 is grounded. Terminals 3 and 9 of chip U11 are connected to ground. Terminal 5 of chip U11 is connected to terminal 4 of chip U11, one end of resistor R35, one end of capacitor C52, one end of capacitor C57, one end of capacitor C58, the +5V0 terminal, and the +6V terminal. The other end of capacitor C52 is connected to one end of resistor R36, the other end of resistor R35, and terminal 6 of chip U11. The other end of resistor R36 is grounded. The other end of capacitor C58 is grounded. The other end of capacitor C57 is grounded.

[0016] The beneficial effects of this utility model are: This invention achieves effective detection of low-frequency signals with a size much smaller than half a wavelength by employing small-aperture multipole antenna array technology, laying the foundation for the development of portable low-frequency communication devices.

[0017] To address the high requirements for cell consistency in the array of this invention, a multi-channel cross-matching LNA network was designed. A high-precision programmable feedback resistor network controlled by an MCU was used to achieve precise fine-tuning of the gain of each channel, ensuring the synthesis quality of the array signal.

[0018] This invention also introduces a secondary amplification module, which further improves the signal-to-noise ratio of the received signal and enhances the reliability and practicality of the whole device in practical applications. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the frame structure of this utility model.

[0020] Figure 2 This is a schematic diagram of the small-aperture multipole antenna array of this utility model.

[0021] Figure 3 This is the circuit diagram of the multi-channel cross-matched low-noise amplifier (LNA) network of this utility model.

[0022] Figure 4 This is a circuit diagram of the bandpass filter module of this utility model, where (a) is the circuit diagram of the CH1 signal channel and (b) is the circuit diagram of the CH2 signal channel.

[0023] Figure 5 This is the circuit diagram of the secondary amplification module of this utility model.

[0024] Figure 6 This is a circuit diagram of the analog signal acquisition module of this utility model.

[0025] Figure 7 This is a circuit diagram of the MCU control module of this utility model, where (a) is the circuit diagram of chip U13A and (b) is the circuit diagram of chip U13B.

[0026] Figure 8 This is a circuit diagram of the low-noise power supply module of this utility model, wherein (a) is the circuit diagram of chip U8, (b) is the circuit diagram of chip U9, (c) is the circuit diagram of chip U11, and (d) is the circuit diagram of chip U3C.

[0027] Figure 9 This is the circuit diagram of the ADC reference power supply of this utility model.

[0028] Figure 10 This is the circuit diagram of the STM32 power supply module of this utility model. Detailed Implementation

[0029] In the following description, specific details such as particular system architectures and techniques are set forth for illustrative purposes and not for limitation, in order to provide a thorough understanding of the embodiments of this application. However, those skilled in the art will understand that this application may also be implemented in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, apparatuses, circuits, and methods are omitted so as not to obscure the description of this application with unnecessary detail.

[0030] It should be understood that, when used in this specification and the appended claims, the term "comprising" indicates the presence of the described features, integrals, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or collections thereof.

[0031] It should also be understood that the terminology used in this application specification is for the purpose of describing particular embodiments only and is not intended to limit the application. As used in this application specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.

[0032] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0033] Many specific details are set forth in the following description in order to provide a full understanding of this application. However, this application may also be implemented in other ways different from those described herein. Those skilled in the art can make similar extensions without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0034] Implementation This embodiment provides a receiver for portable low-frequency communication. The receiver includes a small-aperture multipole antenna array, a multi-channel cross-matched low-noise amplifier (LNA) network, a bandpass filter module, a secondary amplifier module, an RF filter module, a low-noise power supply module, an AD conversion module, and an MCU control module. The small-aperture multipole antenna array is connected to a multi-channel cross-matched low-noise amplifier (LNA) network. The multi-channel cross-matched LNA network is connected to a bandpass filter module, a secondary amplifier module, a low-noise power supply module, and an MCU control module. The bandpass filter module is connected to the secondary amplifier module. The secondary amplifier module is connected to an AD conversion module and a low-noise power supply module. The AD conversion module is connected to the low-noise power supply module and the MCU control module.

[0035] Furthermore, the small-aperture multipole antenna array transmits signals to a multi-channel cross-matched low-noise amplifier (LNA) network. The LNA network receives signals from the secondary amplification module, the low-noise power supply module, and the MCU control module. The LNA network also transmits signals to a bandpass filter module, which in turn transmits signals to the secondary amplification module. The secondary amplification module also receives signals from the low-noise power supply module. Furthermore, the secondary amplification module transmits signals to an AD conversion module, which in turn receives signals from the low-noise power supply module and the MCU control module. Finally, the low-noise power supply module also transmits signals to the MCU control module.

[0036] Furthermore, such as Figure 2 As shown, the receiver includes a small aperture multipole antenna array, a multi-channel cross-matched low-noise amplifier (LNA) network, a bandpass filter module, a secondary amplifier module, an RF filter module, a low-noise power supply module, an AD conversion module, and an MCU control module. The small-aperture multipole antenna array is connected to a multi-channel cross-matched low-noise amplifier (LNA) network. The multi-channel cross-matched LNA network is connected to a bandpass filter module, a secondary amplifier module, a low-noise power supply module, and an MCU control module. The bandpass filter module is connected to the secondary amplifier module. The secondary amplifier module is connected to an AD conversion module and a low-noise power supply module. The AD conversion module is connected to the low-noise power supply module and the MCU control module.

[0037] Furthermore, the small-aperture multipole antenna array transmits signals to a multi-channel cross-matched low-noise amplifier (LNA) network. The LNA network receives signals from the secondary amplification module, the low-noise power supply module, and the MCU control module. The LNA network also transmits signals to a bandpass filter module, which in turn transmits signals to the secondary amplification module. The secondary amplification module also receives signals from the low-noise power supply module. Furthermore, the secondary amplification module transmits signals to an AD conversion module, which in turn receives signals from the low-noise power supply module and the MCU control module. Finally, the low-noise power supply module also transmits signals to the MCU control module.

[0038] Furthermore, such as Figure 2 As shown, the small aperture multipole antenna array is arranged in a cross shape, and from left to right on the X-axis, they are element 1-A, element 1-B, element 2-A and element 2-B. On the Y-axis, from top to bottom, they are primitive 4-A, primitive 4-B, primitive 3-A, and primitive 3-B.

[0039] Furthermore, such as Figure 3 As shown, the multi-channel cross-matched low-noise amplifier (LNA) network includes chip U5 and chip U6. Terminal 3 of chip U5 is connected to one end of capacitor C8 and the output terminal CH1_+IN of the small aperture multipole antenna array. Terminal 8 of chip U5 is connected to terminal 21 of chip U13A in the MCU control module. Terminal 1 of chip U5 is connected to terminal 22 of chip U13A of the MCU control module. Terminal 2 of chip U5 is connected to terminal 25 of chip U13A of the MCU control module. Terminal 7 of chip U5 is connected to one end of capacitor C1, one end of capacitor C2, and the +5V0 operating voltage terminal, respectively. The other end of capacitor C1 is connected to the other end of capacitor C2 and then grounded. Terminal 4 of chip U5 is connected to the output terminal of operational amplifier U2A and one end of capacitor C33 in the bandpass filter module. Terminal 5 of chip U5 is connected to terminal 2 of operational amplifier U2A, and terminal 6 of chip U5 is connected to terminal 3 of operational amplifier U2A and then grounded. Terminal 3 of chip U6 is connected to one end of capacitor C11 and the output terminal CH2_+IN of the small aperture multipole antenna array. Terminal 8 of chip U6 is connected to terminal 28 of chip U13A of the MCU control module. Terminal 1 of chip U6 is connected to terminal 27 of chip U13A of the MCU control module. Terminal 2 of chip U6 is connected to terminal 25 of chip U13A of the MCU control module. Terminal 7 of chip U6 is connected to one end of capacitor C16, one end of capacitor C20, and the +5V0 operating voltage terminal, respectively. The other end of capacitor C16 is connected to the other end of capacitor C20 and then grounded. Terminal 4 of chip U6 is connected to the output of operational amplifier U2B and one end of capacitor C14 in the bandpass filter module. Terminal 5 of chip U6 is connected to terminal 6 of operational amplifier U2B, and terminal 6 of chip U6 is grounded after being connected to terminal 5 of operational amplifier U2B. The other end of capacitor C8 is connected to the other end of capacitor C11 and then grounded.

[0040] Furthermore, such as Figure 4 As shown, the bandpass filter module includes capacitor C33 and capacitor C14. The other end of capacitor C33 is connected to one end of capacitor L4. The other end of capacitor L4 is connected to one end of capacitor L6, one end of capacitor C3, and one end of capacitor C13. The other end of capacitor L6 is grounded. The other end of capacitor C13 is grounded. The other end of capacitor C3 is connected to one end of capacitor L5. The other end of capacitor L5 is connected to one end of capacitor L7, one end of capacitor C10, one end of resistor R7 in the secondary amplifier module, and terminal 3 of operational amplifier U10A in the secondary amplifier module. The other end of capacitor C14 is connected to one end of capacitor L8. The other end of capacitor L8 is connected to one end of capacitor L10, one end of capacitor C15, and one end of capacitor C37. The other end of capacitor L10 is grounded. The other end of capacitor C37 is grounded. The other end of capacitor C15 is connected to one end of capacitor L9. The other end of capacitor L9 is connected to one end of capacitor L11, one end of capacitor C35, one end of resistor R9 in the secondary amplifier module, and terminal 5 of operational amplifier U10B in the secondary amplifier module.

[0041] Furthermore, such as Figure 5 As shown, the secondary amplification module includes operational amplifier U10A and operational amplifier U10B. Terminal 2 of operational amplifier U10A is connected to one end of resistor R13, one end of resistor R12, and one end of capacitor C19, respectively. The other end of resistor R3 is grounded. The other end of resistor R12 is connected to the other end of capacitor C19, terminal 1 of operational amplifier U10A, and one end of capacitor C7 of the analog acquisition signal module, respectively. Terminal 6 of the operational amplifier U10B is connected to one end of resistor R12, one end of resistor R14, and one end of capacitor C38. The other end of resistor R12 is grounded. The other end of resistor R14 is connected to the other end of capacitor C38, terminal 7 of operational amplifier U10B, and one end of capacitor C12 of the analog acquisition signal module. The other end of resistor R17 is connected to the other end of resistor R19 and then grounded.

[0042] Furthermore, such as Figure 6 As shown, the analog signal acquisition module includes capacitor C7 and capacitor C12. The other end of capacitor C7 is connected to one end of resistor R4. The other end of resistor R4 is connected to one end of resistor R1 and terminal 2 of operational amplifier U3A. Terminal 3 of operational amplifier U3A is connected to one end of resistor R8, one end of resistor R6 and one end of capacitor C10. The other end of resistor R6 is connected to the +5V0 operating voltage terminal. The other end of resistor R8 and the other end of capacitor C10 are connected to ground. The other end of capacitor C12 is connected to one end of resistor R11. The other end of resistor R11 is connected to one end of resistor R10 and terminal 6 of operational amplifier U3B. Terminal 5 of operational amplifier U3B is connected to one end of resistor R15, one end of resistor R16 and one end of capacitor C15. The other end of resistor R15 is connected to the +5V0 operating voltage terminal. The other end of resistor R16 is connected to the other end of capacitor C15 and then grounded. Terminal 1 of operational amplifier U3A is connected to the other end of resistor R1 and one end of resistor R5, respectively. Terminal 1 of operational amplifier U3B is connected to the other end of resistor R10 and one end of resistor R13, respectively. The other end of resistor R5 is connected to one end of Zener diode DR1 and terminal 3 of chip U4. Terminal 10 of chip U4 is connected to one end of capacitor C6, one end of capacitor C4, terminal 2 of chip U4, and the operating voltage +1V8. The other end of capacitor C6 is grounded, the other end of capacitor C4 is grounded, and terminal 1 of chip U4 is connected to one end of capacitor C5 and REF4096. The other end of capacitor C5 is grounded. The other end of resistor R13 is connected to one end of Zener diode DR2 and terminal 3 of chip U7. Terminal 10 of chip U7 is connected to one end of capacitor C17, one end of capacitor C19, terminal 2 of chip U7, and the operating voltage +1V8. The other end of capacitor C17 is grounded, the other end of capacitor C19 is grounded, and terminal 1 of chip U7 is connected to one end of capacitor C18 and REF4096. The other end of capacitor C18 is grounded. The other end of the Zener diode DR1 is connected to the other end of the Zener diode DR2, terminal 4 of chip U4, and terminal 4 of chip U7, respectively. Terminal 5 of chip U4 and terminal 5 of chip U7 are connected to ground. Terminal 6 of chip U4 is connected to terminal 18 of chip U13A, terminal 8 of chip U4 is connected to terminal 19 of chip U13A, terminal 7 of chip U4 is connected to terminal 33 of chip U13A, and terminal 9 of chip U4 is connected to terminal 32 of chip U13A. Terminal 6 of chip U4 is connected to terminal 14 of chip U13A and resistor R45 and then grounded. Terminal 8 of chip U7 is connected to terminal 15 of chip U13A. Terminal 7 of chip U7 is connected to terminal 16 of chip U13A. Terminal 9 of chip U7 is connected to terminal 17 of chip U13A.

[0043] Furthermore, such as Figure 7 As shown, the MCU control module includes a chip U13A. Terminal 5 of the chip U13A is connected to one end of capacitor C67 and terminal 3 of crystal oscillator Y1. The other end of capacitor C67 is connected to terminal 2 of crystal oscillator Y1 and then grounded. Terminal 4 of crystal oscillator Y1 is connected to one end of capacitor C73 and one end of capacitor C72. The other end of capacitor C73 is connected to the other end of capacitor C72 and then grounded. Terminal 44 of the chip U13A is connected to one end of resistor R46 and one end of resistor R47. The other ends of resistors R46 and R47 are both grounded. Terminal 7 of the chip U13A is connected to one end of resistor R48 and one end of capacitor C68, respectively. The other end of capacitor C68 is grounded, and the other end of resistor R48 is connected to VDD3V3.

[0044] Furthermore, such as Figure 8As shown, the low-noise power supply module includes chip U8. Terminal 12 of chip U8 is connected to terminal 2 of chip U8, one end of capacitor C23, one end of capacitor C24, and terminal 2 of chip U11. The other end of capacitor C23 is grounded, and the other end of capacitor C24 is grounded. Terminal 3 of chip U8 is connected to the +5V0 operating voltage terminal via series resistor R17. Terminal 6 of chip U8 is connected to ground via series capacitor C26. Terminal 14 of chip U8 is connected to ground via series capacitor C27. Terminal 11 of chip U8 is connected to... One end of capacitor C21 is connected to one end of capacitor C22. The other end of capacitor C21 is connected to the other end of capacitor C22, terminal 8 of chip U8, and one end of inductor L1. The other end of inductor L1 is connected to terminal 7 of chip U8, one end of capacitor C25, and one end of capacitor L2. The other end of inductor L2 is connected to the +5V0 operating voltage terminal, the -5V0 operating voltage terminal, and one end of resistor R18. The other end of resistor R18 is connected to one end of light-emitting diode D1. The other end of light-emitting diode D1 is grounded. Terminal 4 of chip U8 is connected to one end of resistor R19. The other end of resistor R19 is connected to one end of resistor R20 and terminal 5 of chip U8. The other end of resistor R19 is grounded. Terminals 9 and 10 of chip U8 are both grounded.

[0045] Furthermore, such as Figure 8 As shown, the low-noise power supply module also includes a chip U11. Terminal 2 of chip U11 is connected to one end of resistor R34, one end of capacitor C56, one end of capacitor C55, one end of capacitor C54, one end of diode D3, and one end of fuse F1. The other end of resistor R34 is connected to terminal 1 of chip U11. The other ends of capacitors C56, C55, and C54 are grounded, and the other end of diode D3 is grounded. The other end of fuse F1 is connected to terminal 1 of the power input. Terminal 2 is grounded. Terminals 3 and 9 of chip U11 are connected to ground. Terminal 5 of chip U11 is connected to terminal 4 of chip U11, one end of resistor R35, one end of capacitor C52, one end of capacitor C57, one end of capacitor C58, the +5V0 terminal, and the +6V terminal. The other end of capacitor C52 is connected to one end of resistor R36, the other end of resistor R35, and terminal 6 of chip U11. The other end of resistor R36 is grounded. The other end of capacitor C58 and the other end of capacitor C57 are grounded.

[0046] In summary, this invention, through the coordinated operation of a multipole antenna array and a high-consistency signal processing link, significantly reduces the antenna size while maintaining receiver sensitivity, thus solving the problem of traditional low-frequency communication equipment being difficult to port due to its excessively long wavelength. Impedance matching, low-noise amplification, and filtering are employed between modules to effectively suppress noise and improve the signal-to-noise ratio, making reliable detection and demodulation of low-frequency signals possible on a miniaturized platform.

[0047] This invention utilizes a multipole structure for its antenna array, achieving a small-aperture array through the finite-difference approximation principle. The spacing between its antenna elements is significantly smaller than the traditional half-wavelength dimension, enabling effective detection of low-frequency signals within a limited space. The design employs four groups of planar elements, each containing two antennas, for a total of eight antenna elements. This structure extracts the target signal and suppresses common-mode interference through differential signal processing, thus maintaining effective response to low-frequency signals while reducing the overall size. The significance of this design lies in solving the problem of the bulky size of traditional low-frequency antennas due to excessively long wavelengths, providing crucial antenna technology support for the realization of portable low-frequency communication systems.

[0048] This utility model's multi-channel cross-matching LNA network module consists of eight independent low-noise amplifiers (LNAs) sharing a high-precision feedback resistor network. The gain of each channel is precisely controlled by an MCU. Its core function is to match the input impedance between the antenna elements and the LNAs to achieve the lowest noise figure and highest system sensitivity. Since small-aperture multipole antennas use differential output, the consistency between elements significantly affects system performance. Therefore, this module uses a programmable feedback resistor network to adjust the gain of each LNA, adapting it to the actual response characteristics of different antenna elements, thereby achieving optimal noise matching during signal synthesis. This design not only improves the system's signal detection capability but also provides crucial amplification and matching support for the practical application of small-aperture antennas in low-frequency communication.

[0049] This utility model's bandpass filter module adopts a passive LC resonant circuit structure, forming a bandpass filter network through cascading a second-order low-pass filter and a second-order high-pass filter. Its main function is to select the frequency of the LNA output signal, filtering out out-of-band noise and interference, thereby improving the signal-to-noise ratio. Since the preceding LNA has already achieved impedance matching and outputs a low-impedance signal, this module eliminates the need for complex matching circuits, simplifying the design and reducing system power consumption. This filter module is of great significance in low-frequency communication systems, effectively improving the quality of the received signal and providing a cleaner analog signal foundation for subsequent signal processing.

[0050] This invention's secondary amplifier module is based on linear voltage regulator (LDO) technology, achieving voltage conversion and stabilization from a 24V DC input to multiple outputs of 5V and 3.3V. Its core design objective is to suppress power supply noise and prevent high-frequency interference introduced by the switching power supply from affecting the high-sensitivity circuitry of the receiver front end. By employing an LDO voltage regulator, this module significantly reduces power supply ripple and noise while providing a stable operating voltage, ensuring the system's performance stability during low-frequency small-signal detection. This low-noise power supply plays a crucial role in improving the overall signal-to-noise ratio and ensuring reliable operation of the system in complex electromagnetic environments.

[0051] This invention's MCU control module, based on an ARM Cortex-M architecture microcontroller, features multi-channel control and low power consumption. It primarily manages the programmable feedback resistor network. Before use, the feedback resistor parameters for each LNA channel can be configured via a host computer. The MCU stores and outputs these settings, thus precisely controlling the gain of each channel. Furthermore, the MCU coordinates the AD conversion module, converting the amplified and filtered high signal-to-noise ratio analog signal into a digital signal, which is then transmitted to the data acquisition system for subsequent demodulation and processing. This module enables configurable system parameters and automated control, significantly improving the device's flexibility and environmental adaptability.

[0052] The AD conversion module of this invention is responsible for converting the high-quality analog signal processed as described above into a digital signal to facilitate subsequent digital signal processing and demodulation. This module operates under the coordination of the MCU and employs a high-resolution analog-to-digital converter to ensure high conversion accuracy and dynamic range even in the low-frequency signal range. Through this module, the system can reliably acquire low-frequency communication signals, providing the necessary digital signal interface for establishing a complete communication link.

Claims

1. A receiver for portable low-frequency communication, characterized in that, The receiver includes a small aperture multipole antenna array, a multi-channel cross-matched low-noise amplifier (LNA) network, a bandpass filter module, a secondary amplifier module, an RF filter module, a low-noise power supply module, an AD conversion module, and an MCU control module. The small-aperture multipole antenna array is connected to a multi-channel cross-matched low-noise amplifier (LNA) network. The multi-channel cross-matched LNA network is connected to a bandpass filter module, a secondary amplifier module, a low-noise power supply module, and an MCU control module. The bandpass filter module is connected to the secondary amplifier module. The secondary amplifier module is connected to an AD conversion module and a low-noise power supply module. The AD conversion module is connected to the low-noise power supply module and the MCU control module.

2. The receiver for portable low-frequency communication according to claim 1, characterized in that, The small-aperture multipole antenna array transmits signals to a multi-channel cross-matched low-noise amplifier (LNA) network. The LNA network receives signals from the secondary amplification module, the low-noise power supply module, and the MCU control module. The LNA network also transmits signals to a bandpass filter module, which in turn transmits signals to the secondary amplification module. The secondary amplification module receives signals from the low-noise power supply module and transmits signals to an analog-to-digital (A / D) converter module. The A / D converter module also receives signals from the low-noise power supply module and the MCU control module, and the low-noise power supply module also transmits signals to the MCU control module.

3. The receiver for portable low-frequency communication according to claim 1, characterized in that, The small aperture multipole antenna array is arranged in a cross shape, and from left to right on the X-axis are element 1-A, element 1-B, element 2-A and element 2-B; On the Y-axis, from top to bottom, they are primitive 4-A, primitive 4-B, primitive 3-A, and primitive 3-B.

4. A receiver for portable low-frequency communication according to claim 1, characterized in that, The multi-channel cross-matched low-noise amplifier (LNA) network includes chips U5 and U6. Terminal 3 of chip U5 is connected to one end of capacitor C8 and the output terminal CH1_+IN of the small aperture multipole antenna array. Terminal 8 of chip U5 is connected to terminal 21 of chip U13A in the MCU control module. Terminal 1 of chip U5 is connected to terminal 22 of chip U13A of the MCU control module. Terminal 2 of chip U5 is connected to terminal 25 of chip U13A of the MCU control module. Terminal 7 of chip U5 is connected to one end of capacitor C1, one end of capacitor C2, and the +5V0 operating voltage terminal, respectively. The other end of capacitor C1 is connected to the other end of capacitor C2 and then grounded. Terminal 4 of chip U5 is connected to the output terminal of operational amplifier U2A and one end of capacitor C33 in the bandpass filter module. Terminal 5 of chip U5 is connected to terminal 2 of operational amplifier U2A, and terminal 6 of chip U5 is connected to terminal 3 of operational amplifier U2A and then grounded. Terminal 3 of chip U6 is connected to one end of capacitor C11 and the output terminal CH2_+IN of the small aperture multipole antenna array. Terminal 8 of chip U6 is connected to terminal 28 of chip U13A of the MCU control module. Terminal 1 of chip U6 is connected to terminal 27 of chip U13A of the MCU control module. Terminal 2 of chip U6 is connected to terminal 25 of chip U13A of the MCU control module. Terminal 7 of chip U6 is connected to one end of capacitor C16, one end of capacitor C20, and the +5V0 operating voltage terminal. The other end of capacitor C16 is connected to the other end of capacitor C20 and then grounded. Terminal 4 of chip U6 is connected to the output terminal of operational amplifier U2B and one end of capacitor C14 of the bandpass filter module. Terminal 5 of chip U6 is connected to terminal 6 of operational amplifier U2B, and terminal 6 of chip U6 is grounded after being connected to terminal 5 of operational amplifier U2B. The other end of capacitor C8 is connected to the other end of capacitor C11 and then grounded.

5. A receiver for portable low-frequency communication according to claim 4, characterized in that, The bandpass filter module includes capacitor C33 and capacitor C14. The other end of capacitor C33 is connected to one end of capacitor L4. The other end of capacitor L4 is connected to one end of capacitor L6, one end of capacitor C3, and one end of capacitor C13. The other end of capacitor L6 is grounded. The other end of capacitor C13 is grounded. The other end of capacitor C3 is connected to one end of capacitor L5. The other end of capacitor L5 is connected to one end of capacitor L7, one end of capacitor C10, one end of resistor R7 in the secondary amplifier module, and terminal 3 of operational amplifier U10A in the secondary amplifier module. The other end of capacitor C14 is connected to one end of capacitor L8. The other end of capacitor L8 is connected to one end of capacitor L10, one end of capacitor C15, and one end of capacitor C37. The other end of capacitor L10 is grounded. The other end of capacitor C37 is grounded. The other end of capacitor C15 is connected to one end of capacitor L9. The other end of capacitor L9 is connected to one end of capacitor L11, one end of capacitor C35, one end of resistor R9 in the secondary amplifier module, and terminal 5 of operational amplifier U10B in the secondary amplifier module.

6. A receiver for portable low-frequency communication according to claim 5, characterized in that, The secondary amplification module includes operational amplifiers U10A and U10B. Terminal 2 of operational amplifier U10A is connected to one end of resistor R13, one end of resistor R12, and one end of capacitor C19, respectively. The other end of resistor R3 is grounded. The other end of resistor R12 is connected to the other end of capacitor C19, terminal 1 of operational amplifier U10A, and one end of capacitor C7 of the analog acquisition signal module, respectively. Terminal 6 of the operational amplifier U10B is connected to one end of resistor R12, one end of resistor R14, and one end of capacitor C38. The other end of resistor R12 is grounded. The other end of resistor R14 is connected to the other end of capacitor C38, terminal 7 of operational amplifier U10B, and one end of capacitor C12 of the analog acquisition signal module. The other end of resistor R17 is connected to the other end of resistor R19 and then grounded.

7. A receiver for portable low-frequency communication according to claim 6, characterized in that, The analog signal acquisition module includes capacitor C7 and capacitor C12. The other end of capacitor C7 is connected to one end of resistor R4. The other end of resistor R4 is connected to one end of resistor R1 and terminal 2 of operational amplifier U3A. Terminal 3 of operational amplifier U3A is connected to one end of resistor R8, one end of resistor R6 and one end of capacitor C10. The other end of resistor R6 is connected to the +5V0 operating voltage terminal. The other end of resistor R8 and the other end of capacitor C10 are connected to ground. The other end of capacitor C12 is connected to one end of resistor R11. The other end of resistor R11 is connected to one end of resistor R10 and terminal 6 of operational amplifier U3B. Terminal 5 of operational amplifier U3B is connected to one end of resistor R15, one end of resistor R16 and one end of capacitor C15. The other end of resistor R15 is connected to the +5V0 operating voltage terminal. The other end of resistor R16 is connected to the other end of capacitor C15 and then grounded. Terminal 1 of operational amplifier U3A is connected to the other end of resistor R1 and one end of resistor R5, respectively. Terminal 1 of operational amplifier U3B is connected to the other end of resistor R10 and one end of resistor R13, respectively. The other end of resistor R5 is connected to one end of Zener diode DR1 and terminal 3 of chip U4. Terminal 10 of chip U4 is connected to one end of capacitor C6, one end of capacitor C4, terminal 2 of chip U4, and the operating voltage +1V8. The other end of capacitor C6 is grounded, the other end of capacitor C4 is grounded, and terminal 1 of chip U4 is connected to one end of capacitor C5 and REF4096. The other end of capacitor C5 is grounded. The other end of resistor R13 is connected to one end of Zener diode DR2 and terminal 3 of chip U7. Terminal 10 of chip U7 is connected to one end of capacitor C17, one end of capacitor C19, terminal 2 of chip U7, and the operating voltage +1V8. The other end of capacitor C17 is grounded, the other end of capacitor C19 is grounded, and terminal 1 of chip U7 is connected to one end of capacitor C18 and REF4096. The other end of capacitor C18 is grounded. The other end of the Zener diode DR1 is connected to the other end of the Zener diode DR2, terminal 4 of chip U4, and terminal 4 of chip U7, respectively. Terminal 5 of chip U4 and terminal 5 of chip U7 are connected to ground. Terminal 6 of chip U4 is connected to terminal 18 of chip U13A, terminal 8 of chip U4 is connected to terminal 19 of chip U13A, terminal 7 of chip U4 is connected to terminal 33 of chip U13A, and terminal 9 of chip U4 is connected to terminal 32 of chip U13A. Terminal 6 of chip U4 is connected to terminal 14 of chip U13A and resistor R45 and then grounded. Terminal 8 of chip U7 is connected to terminal 15 of chip U13A. Terminal 7 of chip U7 is connected to terminal 16 of chip U13A. Terminal 9 of chip U7 is connected to terminal 17 of chip U13A.

8. A receiver for portable low-frequency communication according to claim 7, characterized in that, The MCU control module includes a chip U13A. Terminal 5 of the chip U13A is connected to one end of capacitor C67 and terminal 3 of crystal oscillator Y1. The other end of capacitor C67 is connected to terminal 2 of crystal oscillator Y1 and then grounded. Terminal 4 of crystal oscillator Y1 is connected to one end of capacitor C73 and one end of capacitor C72. The other end of capacitor C73 is connected to the other end of capacitor C72 and then grounded. Terminal 44 of the chip U13A is connected to one end of resistor R46 and one end of resistor R47. The other ends of resistors R46 and R47 are both grounded. Terminal 7 of the chip U13A is connected to one end of resistor R48 and one end of capacitor C68, respectively. The other end of capacitor C68 is grounded, and the other end of resistor R48 is connected to VDD3V3.

9. A receiver for portable low-frequency communication according to claim 8, characterized in that, The low-noise power supply module includes chip U8. Terminal 12 of chip U8 is connected to terminal 2 of chip U8, one end of capacitor C23, one end of capacitor C24, and terminal 2 of chip U11. The other end of capacitor C23 and capacitor C24 are grounded. Terminal 3 of chip U8 is connected to the +5V0 operating voltage terminal via series resistor R17. Terminal 6 of chip U8 is connected to ground via series capacitor C26. Terminal 14 of chip U8 is connected to ground via series capacitor C27. Terminal 11 of chip U8 is connected to capacitor U11... One end of C21 is connected to one end of capacitor C22. The other end of capacitor C21 is connected to the other end of capacitor C22, terminal 8 of chip U8, and one end of inductor L1. The other end of inductor L1 is connected to terminal 7 of chip U8, one end of capacitor C25, and one end of capacitor L2. The other end of inductor L2 is connected to the +5V0 operating voltage terminal, the -5V0 operating voltage terminal, and one end of resistor R18. The other end of resistor R18 is connected to one end of LED D1. The other end of LED D1 is grounded. Terminal 4 of chip U8 is connected to one end of resistor R19. The other end of resistor R19 is connected to one end of resistor R20 and terminal 5 of chip U8. The other end of resistor R19 is grounded. Terminals 9 and 10 of chip U8 are both grounded.

10. A receiver for portable low-frequency communication according to claim 9, characterized in that, The low-noise power supply module also includes a chip U11. Terminal 2 of chip U11 is connected to one end of resistor R34, one end of capacitor C56, one end of capacitor C55, one end of capacitor C54, one end of diode D3, and one end of fuse F1. The other end of resistor R34 is connected to terminal 1 of chip U11. The other ends of capacitors C56, C55, and C54 are grounded, and the other end of diode D3 is grounded. The other end of fuse F1 is connected to terminal 1 of the power input. Terminal 1 is grounded. Terminals 3 and 9 of chip U11 are connected to ground. Terminal 5 of chip U11 is connected to terminal 4 of chip U11, one end of resistor R35, one end of capacitor C52, one end of capacitor C57, one end of capacitor C58, the +5V0 terminal, and the +6V terminal. The other end of capacitor C52 is connected to one end of resistor R36, the other end of resistor R35, and terminal 6 of chip U11. The other end of resistor R36 is grounded. The other end of capacitor C58 and the other end of capacitor C57 are grounded.

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