Multifrequency Printed Antennas Loaded with Metamaterial Particles

Abstract

This paper provides a review of printed antennas loaded with metamaterial particles. This novel technique allows developing printed antennas with interesting features such as multifrequency (simultaneous operation over two or more frequency bands) and multifunctionality (e. g. radiation pattern diversity). Moreover, compactness is also achieved and the main advantages of conventional printed antennas (light weight, low profile, low cost ...) are maintained. Different types of metamaterial-loaded printed antennas are reviewed: printed dipoles and patch antennas. Several prototypes are designed, manufactured and measured showing good results. Furthermore, simple but accurate equivalent models are proposed. These models allow an easy and quick design of metamaterial-loaded printed antennas. Finally, two interesting applications based on the proposed antennas are reviewed: the patch antennas are used as radiating elements of emerging active RFID systems in the microwave band and the metamaterial-loaded printed dipoles are employed to increase the performance of log-periodic arrays.