ABSTRACT
This chapter describes the principles of design for interrogator antennas. It describes the basic principles used in the design of antennas for interrogators operating in the high-frequency (HF) and low-frequency (LF) bands. Antennas for interrogators operating in the HF and LF ranges are designed for parameters such as maximum read distance for transponders, transponder read rate, as well as regulations such as the maximum field allowed in some specific conditions. The majority of antennas used in HF and LF interrogators are variations of the coil antenna that generates a magnetic field. The chapter considers the auxiliary elements such as tuning indicators, multiplexers, and preamplifiers used with those antennas in order to improve the overall performance of the system. It also describes the basic principles used in the design of antennas in interrogators operating in the ultra-high-frequency band. The chapter shows different examples of commercially available antennas for interrogators.
