CHAPTER 7
HANDHELD READER ANTENNA AT 5.8 GHz
7.1 INTRODUCTION
Similar to the handheld optical barcode reader, there is a significant market segment for the handheld readers. The examples include the wand for library database management system, apparel tagging and checking of hanging tags, animal tracking, dispatch and inventory control at the manufacturing premises, courier services and deliveries, and so on. The existing systems work in LF and HF band around 132 kHz and 13.56 MHz, respectively, and the handheld readers use a loop antenna (magnetic dipole also called wand as used by magicians) to read the tags. These antennas have omnidirectional patterns to cover maximum reading zone as possible. However, due to the magnetic coupling between the reader and the tag, the distance of the reader is very short, usually less than a few tens of centimeters.
Figure 7.1a shows the configuration of a handheld reader used in the inventory check of books on a library book shelf. As can be seen, the RFID reader consists of a handheld loop antenna and an RFID reader (with battery pack, display, etc.), which are connected by an RF cable for data transmission and reception. The handheld antenna (also called wand) is carried by the hand of a person who ...
