Linearly tapered meander line broadband monopole tag antenna with T‐match for Ultra High Frequency Radio Frequency Identification applications

Abstract

In this paper, a compact, broadband linearly tapered meandered monopole tag antenna for UHF-RFID is designed and optimized using particle swarm optimization (PSO) algorithm. An inductive T-match network is utilized for impedance matching with capacitive Higgs-4 chip. The optimization goal of PSO was conjugate matching and in consequence the maximization of read range. Equivalent circuit of the proposed tag antenna is derived using ADS software to validate its impedance characteristics. The performance of the proposed tag in terms of tag power sensitivity, read range, realized gain, and differential radar cross section has been experimentally characterized. To check the tolerance of the designed tag to various object platforms, its read range performance is also verified on objects like wood, fiber, plastic, and so forth. Furthermore, read pattern of the proposed tag has been measured and found to have figure of eight in E-plane and omnidirectional in H-plane. Experimental results reveal that the proposed tag covers 865-867 MHz (ETSI band, Europe) and 902-928 MHz (FCC band, United States) both major RFID bands with a read range of 10 and 12 m, respectively. The proposed tag has 2060 mm3 of volumetric size with maximum measured readable distance of 12 m with EIRP of 3.28 W.