Radio Frequency Identification (RFID) is a non-contact automatic identification technology that relies on radio frequency communication to identify objects. It can function in various harsh environments and quickly recognize multiple high-speed moving objects through attached tags. Due to its fast and efficient identification, RFID has gained widespread attention from major manufacturers. It holds great potential in fields such as warehousing and logistics, product anti-counterfeiting, distribution, and maintenance tracking. This article explores the fundamental principles of RFID technology and discusses its applications in supply chain management, security, and mobile tracking. While RFID offers many advantages, it still faces challenges that require further research and development. In recent years, RFID technology has become a mainstream solution for fast item identification. Unlike traditional barcode systems, RFID does not require close proximity between the reader and the tag, allowing long-range recognition via radio signals. RFID tags can store and transmit information such as manufacturer details, product type, and environmental data without relying on linear barcodes. Additionally, RFID systems can automatically detect tags from different angles, significantly improving recognition accuracy compared to barcodes. Although RFID has shown significant advantages since its inception, its high cost initially limited its commercial use. However, with advancements in the electronics industry and the miniaturization of devices, the cost of RFID systems has gradually decreased, making them more competitive with traditional labels. In large retail environments, RFID’s ability to manage inventory and track products is unmatched by conventional methods. RFID is a non-contact automatic identification system that uses RF signals to identify objects through inductive or electromagnetic coupling. Tags are essential components of RFID technology, containing transponders that send specific signals to readers. Most RFID tags have an ID number, such as a SKU code, which allows the reader to retrieve related data from a database. Some tags also include readable and writable memory for storing additional information about the tagged object. The basic working principle of RFID is illustrated in Figure 1. RFID tags are generally divided into active and passive types based on their power source. Active tags have their own battery, allowing them to transmit stronger signals and operate over longer distances. Passive tags, on the other hand, draw energy from the reader’s electromagnetic field. Similarly, readers can be active or passive depending on the type of tag they are reading. 1.1 Active Tags Active RFID tags have an internal power source, such as a battery, enabling them to be both readable and writable. Their built-in power allows them to send stronger signals, resulting in longer read and write ranges. However, this also makes them larger and more expensive. As a result, active tags are typically used for long-range identification of large items like aircraft or vehicles. Low-power active tags are usually slightly bigger than a pair of playing cards. These tags can remain in sleep mode when not within range and can continuously broadcast signals when active. Active tags can operate at higher frequencies, such as 455MHz, 2.45GHz, and 5.8GHz, depending on the required identification distance and memory capacity. At these frequencies, readers can operate within a range of 20 to 100 meters. 1.2 Passive Tags Passive RFID tags do not have an internal power source and instead receive energy from the reader’s electromagnetic field. When a tag enters the reader’s range, it detects changes in the electromagnetic field through its antenna, generating an induced current. This current is stored in an integrated capacitor, and once enough charge is accumulated, the tag can send a modulated signal containing its ID back to the reader. Since passive tags lack a power source, their performance is generally lower than that of active tags. In the U.S., a typical passive tag costs around 20 cents. With advances in microelectronics, these tags are becoming smaller and cheaper. Their affordability makes them widely used across many industries. In addition to being low-cost, passive tags are also very compact. However, current antenna technology limits how small they can be made. Larger tags tend to have a greater read range. Most passive tags currently have only about 2K of memory, which restricts their ability to store complex or detailed information. This limitation affects their application scope. As RFID technology continues to evolve, tags will likely be able to store more information, opening up new possibilities for use. The communication between passive tags and readers typically involves high or low-frequency modulation. In low-frequency modes (below 100MHz), the tag’s capacitor is matched with an inductor coil, and the signal strength varies according to the tag’s ID. This change is then radiated outward. The speed of the change depends on the modulation frequency. In high-frequency modes (above 100MHz), the tag uses backscattering to transmit signals, adjusting its antenna impedance based on internal circuitry. When the impedance changes, the antenna sends out an RF signal that the reader can detect and decode. Passive tags commonly operate at frequencies like 128kHz, 13.6MHz, 915MHz, and 2.45GHz, with read ranges varying from a few centimeters to several meters. The choice of operating frequency is influenced by environmental conditions, transmission medium, and required identification distance. 2. RFID Applications Over the past few years, as RFID technology has matured, its application areas have expanded significantly, leading to substantial impacts across various industries. The most common uses include supply chain management, security, and the tracking of valuable assets and individuals. 2.1 Supply Chain Management Most laptop power adapters are suitable for 100 to 240 VAC (50 / 60Hz). Basically, most of the notebook computers are external power supply, with a power cord and host connection, so you can reduce the size and weight of the host, only a very small number of models built-in power supply in the host. In the power adapter has a nameplate, marked above the power, input and output voltage and current and other indicators, with particular attention to the input voltage range, which is the so-called "travel power adapter", if the city voltage is only 110V of the country , This feature is very useful, and some parallel notebook is only sold in the country of origin, there is no such compatible voltage design, or even only a single input voltage of 110V, 220V in China under the voltage plug will burn. 5W Medical Adapter,Blood Cell Switch Power Supply,IVD medical device power supply,Ivd medical power switch adapter Shenzhen Longxc Power Supply Co., Ltd , https://www.longxcpower.com