天线设计1High Frequency Design RFID ANTENNAS From September 2007 High Frequency Electronics Copyright 2007 Summit Technical Media, LLC UHF RFID Antennas for Printer-Encoders― Part 1: System Requirements By Boris Y. Tsirline Zebra Technologies Corporation his series of articles reviews UHF transmission line antennas developed for RFID Printer-Encoders. It explains the basic operating principles of antennas, their effect on the printer’s encoding function as well as how the antennas influence the design of labels with embedded transponders (Smart Labels). The survey of antennas is preceded by the evaluation of antenna-transponder mutual coupling in reactive near-field and by the analysis of the Printer-Encoder environment, which yields four comparison criteria of the antennas’ performance. After ……