Ring-shaped Tri-band Defective Ground Reader Antenna for RFID Applications

Abstract

This paper presents the design and simulation analysis of a tri-band monopole antenna with defective ground operating at 3 RFID frequency bands. The antenna is compact with a size of 83mm $\times 55$ mm $\times 3.2$ mm and is designed using FR-4 substrate with a relative permittivity of 4.4. The substrate is sandwiched by the copper monopole at the top with the copper defective ground at the bottom of the structure. The proposed antenna is working at the frequency of 915 MHz, 2.45 GHz, and 5.8 GHz with a gain of 0.51 dBi, 2.09 dBi, and 1.97 dBi, while with bandwidths of 0.19 GHz, 2.39 GHz, and 1.52 GHz, respectively.