RFID (Radio Frequency Identification) is a non-contact automatic identification technology that allows the automatic recognition of objects and the retrieval of related data through radio frequency signals. This system can operate in various harsh environments without the need for manual intervention. An RFID system typically consists of two main components: the reader and the electronic tag. The electronic tag stores data, and when it enters the effective range of the reader, communication occurs based on a specific protocol. RFID technology can identify high-speed moving objects and multiple tags simultaneously, making operations fast and efficient. Short-range RF products are resistant to harsh conditions like oil and dust, making them suitable for replacing barcodes in environments such as factory assembly lines. Long-range RF products, often used in transportation, can recognize objects from several tens of meters away, such as for vehicle identification or automatic toll collection [6]. Additionally, due to its difficulty in being counterfeited or tampered with, RFID offers strong security features. Its applications are widespread, including animal tracking, access control, parking management, production automation, and material handling. Governments and international organizations are actively working on developing RFID standards, but there is currently no complete global or domestic standard. Major RFID specifications include the EPC standard in the U.S. and Europe, the UID standard in Japan, and the ISO 18000 series.
RFID tags come in various types and classifications. Based on power supply, they can be categorized into active and passive tags. In terms of carrier frequency, they are divided into low frequency (134.2 kHz), high frequency (13.56 MHz), ultra-high frequency (433 MHz and 915 MHz), and microwave tags (2.45 GHz and above) [6]. While individual RFID technologies have matured, practical applications in logistics and manufacturing still face challenges such as cost, signal interference, improved recognition rates, information security, privacy protection, and standardization.
The basic RFID system includes RFID tags, readers, and application support software. The CC2430 chip supports a powerful integrated development environment, offering industry-standard IAR IDE for interactive debugging. It is widely recognized by embedded systems and operates at 2.4 GHz. Fabricated using a 0.18μm CMOS process, the chip consumes 27 mA during operation and less than 27 mA or 25 mA in receive and transmit modes, respectively. Available in a 7 mm × 7 mm QLP package with 48 pins, all pins are categorized into I/O ports, power lines, and control lines [5]. The chip’s sleep mode and quick transition to active mode make it ideal for long battery life applications, especially in RFID systems. This article uses TI’s CC2430 as the core component to design active RFID tags, which can be powered by a button battery with low power consumption. Minimal peripheral circuits are required, and high-frequency components are integrated within the chip, ensuring stable performance and resistance to external interference. It is well-suited for applications requiring low power consumption and high performance.
2. Label Hardware Design
2.1 Hardware Circuit Structure
A typical active RFID tag includes an antenna, radio frequency module, control module, memory, wake-up circuit, and battery module, as shown in the figure. The radio frequency module handles the modulation and demodulation of signals between the tag and the reader. The controller executes commands from the reader, while the memory stores tag information and microcontroller programs. The radio frequency module comprises a transmitter and receiver. The transmitter includes a modulator, power amplifier, band-pass filter, mixer, and local oscillator, while the receiver consists of a low-noise amplifier, band-pass filter, demodulator, and waveform shaping. The TI CC2430 integrates the entire wireless communication system, requiring only a few peripheral circuits to form a wireless module, reducing costs and simplifying the label design. The chip is manufactured using a 0.18μm CMOS process, with a current consumption of 27 mA during operation and less than 27 mA or 25 mA in receive and transmit modes. It comes in a 7 mm × 7 mm QLP package with 48 pins, and all pins are categorized into I/O ports, power lines, and control lines. The sleep mode and ultra-fast transition to active mode make it ideal for long-lasting battery applications, especially in RFID systems. This design matches the output to a 50-ohm microstrip patch antenna, and surface-mount components are used in PCB design to simplify complexity and reduce size. The entire PCB measures 10 cm × 5 cm, meeting the requirement for miniaturized label design. The circuit diagram of the tag is shown in Figure 2.
2.2 Low Power Design of Labels
For active tags, since they are battery-powered, their operational life is limited, so energy efficiency and low power consumption are crucial. This helps conserve battery energy and extend the tag's working life. The CC2430 chip, produced using a 0.18μm CMOS process, consumes 27 mA during operation, with less than 27 mA or 25 mA in receive and transmit modes, respectively. By incorporating a control program during the design phase, the tag can enter the working state only within the reader's range, maximizing energy savings.
2.3 Reader Design
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