TAILIEUCHUNG - Sổ tay RFID (P2)

Differentiation Features of RFID Systems Fundamental Differentiation Features RFID systems exist in countless variants, produced by an almost equally high number of manufacturers. If we are to maintain an overview of RFID systems we must seek out features that can be used to differentiate one RFID system from another (Figure ). RFID systems operate according to one of two basic procedures: full duplex (FDX)/ half duplex (HDX) systems, and sequential systems (SEQ). In full and half duplex systems the transponder’s response is broadcast when the reader’s RF field is switched on | RFID Handbook Fundamentals and Applications in Contactless Smart Cards and Identification Second Edition Klaus Finkenzeller 2 Copyright 2003 John Wiley Sons Ltd. ISBN 0-470-84402-7 Differentiation Features of RFID Systems Fundamental Differentiation Features RFID systems exist in countless variants produced by an almost equally high number of manufacturers. If we are to maintain an overview of RFID systems we must seek out features that can be used to differentiate one RFID system from another Figure . RFID systems operate according to one of two basic procedures full duplex FDX half duplex HDX systems and sequential systems SEQ . In full and half duplex systems the transponder s response is broadcast when the reader s RF field is switched on. Because the transponder s signal to the receiver antenna can be extremely weak in comparison with the signal from the reader itself appropriate transmission procedures must be employed to differentiate the transponder s signal from that of the reader. In practice data transfer from transponder to reader takes place using load modulation load modulation using a subcarrier but also sub harmonics of the reader s transmission frequency. In contrast sequential procedures employ a system whereby the field from the reader is switched off briefly at regular intervals. These gaps are recognised by the transponder and used for sending data from the transponder to the reader. The disadvantage of the sequential procedure is the loss of power to the transponder during the break in transmission which must be smoothed out by the provision of sufficient auxiliary capacitors or batteries. The data capacities of RFID transponders normally range from a few bytes to several kilobytes. So-called 1-bit transponders represent the exception to this rule. A data quantity of exactly 1-bit is just enough to signal two states to the reader transponder in the field or no transponder in the field . However this is perfectly adequate to fulfil .

TỪ KHÓA LIÊN QUAN
TAILIEUCHUNG - Chia sẻ tài liệu không giới hạn
Địa chỉ : 444 Hoang Hoa Tham, Hanoi, Viet Nam
Website : tailieuchung.com
Email : tailieuchung20@gmail.com
Tailieuchung.com là thư viện tài liệu trực tuyến, nơi chia sẽ trao đổi hàng triệu tài liệu như luận văn đồ án, sách, giáo trình, đề thi.
Chúng tôi không chịu trách nhiệm liên quan đến các vấn đề bản quyền nội dung tài liệu được thành viên tự nguyện đăng tải lên, nếu phát hiện thấy tài liệu xấu hoặc tài liệu có bản quyền xin hãy email cho chúng tôi.
Đã phát hiện trình chặn quảng cáo AdBlock
Trang web này phụ thuộc vào doanh thu từ số lần hiển thị quảng cáo để tồn tại. Vui lòng tắt trình chặn quảng cáo của bạn hoặc tạm dừng tính năng chặn quảng cáo cho trang web này.