Novel card reader system of passive communication system based on UWB

Abstract

The utility model discloses a novel card reader system of a UWB-based passive communication system. The novel card reader system comprises a master control module and the like. The main control module is connected with the dual-mode communication module, the energy emission module, the beam positioning module, the demodulation module and the energy management module, the energy management module is connected with the energy emission module, and the beam positioning module is connected with the demodulation module. UWB and RFID dual-mode communication is integrated, a shared antenna and Balun circuit architecture is adopted, and compatibility of centimeter-level positioning and low-cost label management is achieved; the energy transmitting module is combined with a pulse generator and a super capacitor for dynamic power supply, energy transmission efficiency is improved, and long-distance tag wakeup is supported; according to the intelligent beam positioning system, an antenna array is driven by an FPGA to realize high-precision beam forming, and multipath suppression is realized in combination with a cascade noise reduction technology; the master control module adopts the collaborative design of an STM chip and a dual-protocol chip, the number of elements is reduced, and the cost is reduced.

Description

Technical Field

[0001] This utility model belongs to the field of novel card reader technology, and relates to a novel card reader system based on a UWB passive communication system. Background Technology

[0002] Traditional RFID systems are mostly based on UHF band electromagnetic backscattering technology, which has limited communication distance and positioning accuracy errors exceeding 1 meter due to signal strength dependence. Furthermore, in dense environments, multi-tag collisions and multipath interference lead to extremely high bit error rates, making it difficult to meet the high-precision, real-time requirements of smart manufacturing, unmanned warehousing, and other scenarios. Although passive tags can operate without batteries through energy harvesting, energy supply efficiency drops sharply under obstructed or long-distance conditions, drastically deteriorating communication stability. In recent years, ultra-wideband (UWB) technology has shown centimeter-level positioning potential due to its sub-nanosecond pulses, high temporal resolution, and strong multipath resistance. However, existing UWB solutions mostly rely on active tags and multi-base station collaboration, resulting in high hardware costs. Research on the integration of backscattering and UWB is still limited by bottlenecks such as low narrowband modulation spectral efficiency and rigid beam control. Some attempts to combine UWB with passive communication fail to achieve reliable communication at the 10-meter level due to insufficient energy harvesting efficiency and poor adaptability to dynamic environments. Therefore, how to overcome the limitations of long-distance communication, high-precision positioning, and dense tag management capabilities of passive UWB systems under low-cost constraints has become a key challenge in the evolution of IoT sensing layer technology. Summary of the Invention

[0003] To address the problems existing in the background technology, this utility model proposes a novel card reader system based on a UWB passive communication system.

[0004] To achieve the above objectives, the technical solution adopted by this utility model is as follows: a novel card reader system based on a UWB passive communication system, comprising: a main control module, a dual-mode communication module, an energy transmission module, a beam positioning module, a demodulation module, and an energy management module;

[0005] The main control module is connected to the dual-mode communication module, the energy transmission module, the beam positioning module, the demodulation module, and the energy management module. The energy management module is connected to the energy transmission module, and the beam positioning module is connected to the demodulation module.

[0006] The main control module includes: an STM control chip, a first protocol chip, a second protocol chip, a memory, and a clock chip;

[0007] The STM control chip is connected to the first protocol chip, the second protocol chip, the memory, and the clock chip, respectively.

[0008] The dual-mode communication module includes: a UWB transceiver, an RFID chip, a dual-mode antenna, and a balun circuit;

[0009] The STM control chip is connected to the UWB transceiver and the RFID chip. The UWB transceiver and the RFID chip are connected to the balun circuit, and the balun circuit is connected to the dual-mode antenna.

[0010] The energy emission module includes: a pulse generator, a power amplifier, a first circulator, and a second circulator;

[0011] The STM control chip is connected to a pulse generator, the pulse generator is connected to a first circulator, the first circulator is connected to a power amplifier, the power amplifier is connected to a second circulator, and the second circulator is connected to a dual-mode antenna.

[0012] The beam positioning module includes: an antenna array, a beam controller, and a programmable gate array;

[0013] The antenna array is connected to the first low-noise amplifier, the first low-noise amplifier is connected to the beam controller, the beam controller is connected to the programmable gate array (PGA), and the PGA is connected to the STM control chip.

[0014] The demodulation module includes: a second low-noise amplifier, a bandpass filter, a demodulator, and an analog-to-digital converter;

[0015] The second circulator is connected to the bandpass filter, the bandpass filter is connected to the second low-noise amplifier, the second low-noise amplifier is connected to the demodulator, the demodulator is connected to the STM control chip and the analog-to-digital converter, and the analog-to-digital converter is connected to the programmable gate array.

[0016] The energy management module includes: fuse F1, fuse F2, diode D1, DC-DC converter, charging controller, supercapacitor, transistor Q1, resistor R1, and pulse transformer;

[0017] The external power supply is connected to fuse F1 and the DC-DC converter. Fuse F1 is connected to the positive terminal of diode D1, the negative terminal of diode D1 is connected to the charging controller, the charging controller is connected to the supercapacitor, the supercapacitor is connected to the collector of transistor Q1, the emitter of transistor Q1 is connected to the pulse transformer, the base of transistor Q1 is connected to resistor R1, resistor R1 is connected to the STM control chip, the DC-DC converter is connected to fuse F2, fuse F2 is connected to the main control module through the overvoltage protection circuit, and the pulse transformer is connected to the pulse generator.

[0018] Compared with existing technologies, this utility model has the following advantages: it integrates UWB and RFID dual-mode communication, adopts a shared antenna and balun circuit architecture, and achieves compatibility between centimeter-level positioning and low-cost tag management; the energy transmission module combines a pulse generator and a supercapacitor for dynamic power supply, improving energy transmission efficiency and supporting long-distance tag wake-up; the intelligent beam positioning system achieves high-precision beamforming by driving the antenna array through FPGA, and combines cascaded noise reduction technology to achieve multipath suppression; the main control module adopts a collaborative design of STM chip and dual-protocol chip, reducing the number of components and lowering costs. Attached Figure Description

[0019] Figure 1 This is a general block diagram of a novel card reader system based on a UWB passive communication system according to this utility model;

[0020] Figure 2 This is a system block diagram of the main control module of this utility model;

[0021] Figure 3 This is a system block diagram of the dual-mode communication module of this utility model;

[0022] Figure 4 This is a system block diagram of the energy emission module of this utility model;

[0023] Figure 5 This is a system block diagram of the beam positioning module of this utility model;

[0024] Figure 6 This is a system block diagram of the demodulation module of this utility model;

[0025] Figure 7 This is a block diagram of the energy management module system of this utility model;

[0026] Figure 8 This is a flowchart of a novel card reader system based on a UWB passive communication system. Detailed Implementation

[0027] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0028] like Figures 1-8 As shown, the technical solution adopted by this utility model is as follows: a novel card reader system based on a UWB passive communication system, comprising: a main control module, a dual-mode communication module, an energy transmission module, a beam positioning module, a demodulation module, and an energy management module.

[0029] The main control module is connected to the dual-mode communication module, the energy transmission module, the beam positioning module, the demodulation module, and the energy management module. The energy management module is connected to the energy transmission module, and the beam positioning module is connected to the demodulation module.

[0030] The main control module includes: an STM control chip, a first protocol chip, a second protocol chip, a memory, and a clock chip.

[0031] The STM control chip is connected to the first protocol chip, the second protocol chip, the memory, and the clock chip, respectively.

[0032] In this embodiment, the STM32H743 control chip is used to coordinate and control the operation of the dual-mode communication module, energy transmission module, beam positioning module, demodulation module, and energy management module.

[0033] When a novel UWB-based passive communication reader system starts up, the STM control chip loads firmware from memory to complete the initialization configuration of the dual-mode communication module, energy transmission module, beam positioning module, demodulation module, and energy management module. During operation, the STM control chip's DMA channel simultaneously processes positioning data from the UWB transceiver and tag information from the RFID chip. Based on the precise timestamp provided by the clock chip, time difference of arrival (TDOA) positioning calculations are performed to ensure high positioning accuracy. Simultaneously, periodic wake-up is achieved via RTC interrupts, allowing the system to enter a low-power mode when not in use, reducing power consumption.

[0034] The first protocol chip uses the MAX3421E chip, enabling high-speed data transmission. This chip is responsible for communicating with external USB devices, such as storing location data, configuration files, or performing firmware upgrades. The STM control chip configures and interacts with the first protocol chip via the SPI interface, allowing the system to easily exchange data with other modules and expanding its functionality.

[0035] The second protocol chip uses the MAX3485 chip as a transceiver. This chip is suitable for long-distance, multi-node communication scenarios and has strong anti-interference capabilities. The STM control chip connects to the second protocol chip via a UART interface to send out positioning data and tag information from the system, while simultaneously receiving control commands from other modules, enabling remote monitoring and management of the system.

[0036] The system uses a 16MB SPI Flash memory to store the firmware program, configuration parameters, and real-time acquired positioning data. During system startup, the STM control chip reads the firmware program from the memory for initialization. During system operation, acquired positioning data and tag information are stored in the memory for subsequent analysis and processing. Configuration parameters can also be stored in this memory for easy system maintenance and upgrades.

[0037] The clock chip uses the DS3231 chip, providing precise time and date information and an accurate timestamp for the system. Through precise time measurement, the signal propagation time can be accurately calculated, thus improving positioning accuracy. Furthermore, the clock chip can continue operating even when the system is powered off, saving time information to ensure accurate time acquisition upon system restart.

[0038] The main control module, in collaboration with the first and second protocol chips via the STM control chip, achieves timing control, data fusion, and protocol conversion for each module of the system. It dynamically adjusts the energy emission strategy, processes UWB positioning data and RFID tag information in real time, extends battery life through low-power design, and supports both RS485 and USB dual communication interfaces, providing the system with high concurrency processing capabilities and flexible scalability.

[0039] The dual-mode communication module includes: a UWB transceiver, an RFID chip, a dual-mode antenna, and a balun circuit.

[0040] The STM control chip is connected to the UWB transceiver and the RFID chip, respectively. The UWB transceiver and the RFID chip are connected to the balun circuit, and the balun circuit is connected to the dual-mode antenna.

[0041] The UWB transceiver uses the Decawave DW3000 chip, enabling high-speed data transmission and high-precision positioning. The UWB transceiver transmits pulse signals for communication with passive tags. Through synchronous frame detection and ranging algorithms, it achieves bidirectional ranging with the tags, thereby calculating the tag's position. Simultaneously, it receives the backscattered signals from the tags, converts them into digital signals, and transmits them to the STM control chip for processing.

[0042] The RFID chip uses the Impinj Monza 6 chip, which has a certain storage capacity for identifying and managing low-cost passive tags. It transmits tag ID information via Manchester encoding and supports anti-collision algorithms, enabling accurate identification of each tag even when multiple tags are present simultaneously. Working in conjunction with a UWB transceiver, it achieves comprehensive tag management and positioning.

[0043] The dual-mode antenna employs a planar inverted-F antenna, capable of simultaneously covering both the UWB and UHF bands, enabling the transmission and reception of both UWB and RFID signals. Serving as the signal transmission interface for both the UWB transceiver and the RFID chip, it radiates both UWB and RFID signals into space while simultaneously receiving signals reflected back from the tags. Through its integration with a balun circuit, it achieves efficient signal transmission and strong anti-interference capabilities.

[0044] The balun circuit connects the dual-mode antenna, UWB transceiver, and RFID chip, serving as a signal converter and isolation mechanism. The balun circuit converts the differential signal received by the antenna into a single-ended signal, while suppressing common-mode interference and reducing the impact of external interference on the signal, thus improving the stability and reliability of communication.

[0045] The dual-mode communication module integrates UWB and RFID technologies, and through a dual-mode antenna and balun circuit, it achieves compatibility between centimeter-level positioning and low-cost tag management.

[0046] The energy emission module includes: a pulse generator, a power amplifier, a first circulator, and a second circulator.

[0047] The STM control chip is connected to a pulse generator, the pulse generator is connected to a first circulator, the first circulator is connected to a power amplifier, the power amplifier is connected to a second circulator, and the second circulator is connected to a dual-mode antenna.

[0048] The pulse generator generates pulse signals of specific width and frequency according to the control instructions of the STM control chip. These pulse signals are amplified by the power amplifier and then radiated through the circulator and dual-mode antenna to provide power to the passive tag and to communicate with the tag.

[0049] The power amplifier amplifies the pulse signal generated by the pulse generator, increasing its intensity and enabling it to propagate over greater distances. The amplified signal is then transmitted through a circulator to the dual-mode antenna, radiating into space to provide sufficient energy to the passive tag and ensure its proper functioning.

[0050] The first and second circulators have a certain degree of isolation and low insertion loss, enabling unidirectional signal transmission and isolating the transmission and reception paths.

[0051] The first circulator is located between the pulse generator and the power amplifier, isolating the pulse generator from the reverse surge impact of the power amplifier and protecting the pulse generator's safety.

[0052] The second circulator is located between the power amplifier and the dual-mode antenna. It couples the transmitted signal to the dual-mode antenna and guides the backscattered signal from the tag received by the dual-mode antenna to the demodulation module, thus preventing signal reflection from damaging the power amplifier.

[0053] The energy transmission module employs a pulse generator and power amplifier to emit UWB pulses, supporting tag wake-up at a distance of 12 meters. Through a circulator isolation protection circuit, combined with dynamic adjustment of pulse parameters by the main control module, energy transmission efficiency is improved, providing a stable energy supply for passive tags.

[0054] The beam positioning module includes: antenna array, beam controller, and programmable gate array.

[0055] The antenna array is connected to the first low-noise amplifier, the first low-noise amplifier is connected to the beam controller, the beam controller is connected to the programmable gate array (PGA), and the PGA is connected to the STM control chip.

[0056] Antenna arrays enable directional beam transmission and reception, improving signal gain and interference immunity. By adjusting the phase and amplitude of each antenna through a beam controller, a directional beam is formed, concentrating energy in a specific direction to improve tag positioning accuracy and signal strength. Simultaneously, signals reflected back from the tags are received and transmitted to a low-noise amplifier for processing.

[0057] The beam controller receives phase compensation values ​​from the programmable gate array (PGA) and adjusts the shifters in each channel to change the signal phase of each antenna in the antenna array, thereby achieving beamforming and directionality. Working in conjunction with the antenna array, it improves the system's resistance to multipath interference and positioning accuracy.

[0058] The programmable gate array (PGA) calculates the phase compensation value of each antenna in real time based on the signal received by the antenna array, and sends it to the beam controller via the LVDS interface to achieve adaptive beam adjustment. Simultaneously, it calculates the time difference of arrival of signals received by multiple antennas and outputs the tag's coordinates, providing the system with high-precision positioning information.

[0059] The beamforming module, based on an antenna array and a beam controller driven by a programmable gate array, achieves high-precision beamforming and enhances signal gain. Through real-time algorithms and multipath compensation, it maintains high positioning accuracy even in dense metal environments and supports high refresh rates.

[0060] The demodulation module includes: a second low-noise amplifier, a bandpass filter, a demodulator, and an analog-to-digital converter.

[0061] The second circulator is connected to the bandpass filter, the bandpass filter is connected to the second low-noise amplifier, the second low-noise amplifier is connected to the demodulator, the demodulator is connected to the STM control chip and the analog-to-digital converter, and the analog-to-digital converter is connected to the programmable gate array.

[0062] The second low-noise amplifier amplifies the weak signal received by the antenna, bringing it to a level that the demodulator can process. Since signals are subject to various interferences and attenuation during transmission, the second low-noise amplifier can increase signal strength while maintaining a low noise level, providing good signal quality for subsequent demodulation processing.

[0063] The bandpass filter filters the signal amplified by the second low-noise amplifier, removing out-of-band noise and interference signals to ensure that only UWB signals can enter the demodulator, thereby improving the accuracy and reliability of demodulation.

[0064] The demodulator demodulates the filtered signal, converting the UWB pulse signal into a baseband digital signal. The demodulated digital signal is then transmitted to an analog-to-digital converter for further digitization, while simultaneously communicating with the STM control chip to feed the demodulation result back to the main control module.

[0065] The analog-to-digital converter samples and digitizes the analog signal output from the demodulator, converting it into a 12-bit digital signal. Sampling at a high sampling rate ensures accurate capture of the signal's characteristics. The digitized signal is then transmitted to a programmable gate array for further processing.

[0066] The demodulation module demodulates weak signals through a cascaded low-noise amplifier and bandpass filter. An analog-to-digital converter and a programmable gate array work together to digitize the signal and perform baseband processing, feeding back the tag's backscattered data to the main control module to assist in positioning and communication protocol parsing.

[0067] The energy management module includes: fuse F1, fuse F2, diode D1, DC-DC converter, charging controller, supercapacitor, transistor Q1, resistor R1, and pulse transformer.

[0068] The external power supply is connected to fuse F1 and the DC-DC converter. Fuse F1 is connected to the positive terminal of diode D1, the negative terminal of diode D1 is connected to the charging controller, the charging controller is connected to the supercapacitor, the supercapacitor is connected to the collector of transistor Q1, the emitter of transistor Q1 is connected to the pulse transformer, the base of transistor Q1 is connected to resistor R1, resistor R1 is connected to the STM control chip, the DC-DC converter is connected to fuse F2, fuse F2 is connected to the STM control chip through an overvoltage protection circuit, and the pulse transformer is connected to the pulse generator.

[0069] Supercapacitors can rapidly store and release energy, providing instantaneous high current to the system. During the charging phase, energy is obtained from an external power source and stored through a charging controller. During the discharging phase, when the pulse generator requires high-power pulses, the supercapacitor can rapidly release energy to provide sufficient current to the pulse generator, ensuring the normal transmission of the pulse signal. Simultaneously, supercapacitors can also recover energy coupled by the pulse transformer, improving energy utilization efficiency.

[0070] The DC-DC converter steps down the external 12V power supply to 5V, providing a stable operating voltage for other modules in the system. This ensures that other modules in the system can operate normally under a stable power supply environment, improving the system's stability and reliability.

[0071] The charging controller manages the charging process of the supercapacitor. In the initial stage of charging, a constant current charging method is used to rapidly charge the supercapacitor with a current of 1A. When the supercapacitor's voltage approaches 2.7V, it automatically switches to a constant voltage charging method to ensure that the supercapacitor is not overcharged, thus protecting its safety and lifespan.

[0072] Fuse F1 and F2 provide overcurrent protection for the 12V and 5V power supplies, respectively, preventing damage to other components due to short circuits or overloads. Transistor Q1 is switched on or off via a control signal from the STM control chip, controlling the discharge of the supercapacitor. When the pulse generator needs to operate, the STM control chip turns on transistor Q1, supplying power to the pulse generator from the supercapacitor. When not needed, transistor Q1 is turned off, stopping the supercapacitor's discharge and achieving efficient energy management.

[0073] The energy management module uses a combination of supercapacitors and DC-DC converters to support multiple power sources. Intelligent charging and discharging control and protection circuits ensure system safety, and dynamic power consumption management strategies further reduce energy consumption.

[0074] The core function of the overvoltage protection circuit is to provide power conversion and multiple protections for the STM control chip through a combination of fuses, current-limiting resistors, step-down chips and TVS diodes, preventing overcurrent, overvoltage and surge impacts.

[0075] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A new reader system for a UWB-based passive communication system, characterized in that, It comprises a main control module, a dual-mode communication module, an energy emission module, a beam positioning module, a demodulation module and an energy management module. The main control module is connected with the dual-mode communication module, the energy emission module, the beam positioning module, the demodulation module and the energy management module respectively.

2. A new card reader system for a UWB-based passive communication system according to claim 1, characterized in that, The main control module comprises an STM control chip, a first protocol chip, a second protocol chip, a memory and a clock chip. The STM control chip is connected with the first protocol chip, the second protocol chip, the memory and the clock chip respectively.

3. A new card reader system for a UWB-based passive communication system according to claim 2, characterized in that, The dual-mode communication module comprises a UWB transceiver, an RFID chip, a dual-mode antenna and a balun circuit. The STM control chip is connected with the UWB transceiver and the RFID chip, the UWB transceiver and the RFID chip are connected with the balun circuit, and the balun circuit is connected with the dual-mode antenna.

4. The new card reader system of a UWB-based passive communication system according to claim 3, characterized in that, The energy emission module comprises a pulse generator, a power amplifier, a first circulator and a second circulator. The STM control chip is connected with the pulse generator, the pulse generator is connected with the first circulator, the first circulator is connected with the power amplifier, the power amplifier is connected with the second circulator, and the second circulator is connected with the dual-mode antenna.

5. The new card reader system of a UWB-based passive communication system according to claim 2, characterized in that, The beam positioning module comprises an antenna array, a beam controller and a programmable gate array. The antenna array is connected with a first low-noise amplifier, the first low-noise amplifier is connected with the beam controller, the beam controller is connected with the programmable gate array, and the programmable gate array is connected with the STM control chip.

6. The new card reader system of a UWB-based passive communication system according to claim 5, characterized in that, The demodulation module comprises a second low-noise amplifier, a band-pass filter, a demodulator and an analog-to-digital converter. The second circulator is connected with the band-pass filter, the band-pass filter is connected with the second low-noise amplifier, the second low-noise amplifier is connected with the demodulator, the demodulator is connected with the STM control chip and the analog-to-digital converter respectively, and the analog-to-digital converter is connected with the programmable gate array.

7. The new card reader system of a UWB-based passive communication system according to claim 4, characterized in that, The energy management module comprises a fuse F1, a fuse F2, a diode D1, a DC-DC converter, a charging controller, a super capacitor, a transistor Q1, a resistor R1 and a pulse transformer. An external power supply is connected with the fuse F1 and the DC-DC converter, the positive electrode of the fuse F1 is connected with the diode D1, the negative electrode of the diode D1 is connected with the charging controller, the charging controller is connected with the super capacitor, the super capacitor is connected with the collector of the transistor Q1, the emitter of the transistor Q1 is connected with the pulse transformer, the base of the transistor Q1 is connected with the resistor R1, the resistor R1 is connected with the STM control chip, the DC-DC converter is connected with the fuse F2, the fuse F2 is connected with the STM control chip through an overvoltage protection circuit, and the pulse transformer is connected with the pulse generator.

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