Top X Technology Co., Ltd
C&T RF Antennas Inc
RF identification RFID test
Source:Original | Author:C&T RF Antennas Inc | Publish time: 2018-04-17 | 392 Views | Share:

With the reduction of the reader and tag prices and the expansion of the global market, the application of radio frequency identification (RFID) is increasing. The tag can be powered by the reader (passive tag) or it can be powered by the tag's onboard power supply (semiactive tag and active tag). Due to the reduced cost of sub-micro passive CMOS tags, inventory and other applications have rapidly increased. Some assessments indicate that as the price of passive tags continues to fall, almost every product sold will have an RFID tag inside. Due to the importance of passive RFID tags and their unique engineering implementation challenges, this article will focus on passive tag systems.


When receiving the CW signal from the reader, the passive tag rectifies the radio frequency RF (RF) energy to generate a small portion of the energy needed to maintain the tag operation and then changes the antenna's absorption characteristics to modulate the signal and pass it. Backscatter reflects the reader. RFID systems often use simple modulation techniques and coding schemes. However, the simple modulation technique has a low spectral efficiency, and it requires more RF bandwidth for a given data rate. Before modulating, data must be encoded to form a continuous stream of information. There are many types of bit encoding systems available, and each type of encoding has its unique advantages of baseband spectral performance, the complexity of the encoding and decoding, and the difficulty of writing data to the memory under clock-driven conditions. Because of the difficulty in achieving the required accuracy of the timing source on the tag board, as well as the challenging bandwidth requirements and maximized RF energy transmission to supply energy to the tag, passive tags have unique requirements for the coding system used. Finally, some kind of anti-collision protocol is needed so that the reader can read all the tags in its coverage.


RFID Test Overview

Every RFID communication system must pass regulatory requirements and meet the standards used. However, today, system optimization separates winners from losers in this fast-growing industry. This article discusses the testing challenges faced by designers of RFID communication systems: regulatory testing, standards compliance, and optimization.