Loop‐loaded monopole antenna with miniaturization and dual‐band characteristics

Abstract A novel miniaturized dual‐band monopole antenna loaded with two types of loops is presented. The split loop is loaded at the center of the monopole for dual‐band operation and the rectangular loop loaded at the top is for miniaturization. The novel miniaturization technique is used as a self resonant topology. The monopole below its resonant frequency is known to possess a capacitive reactance and the loop below its resonant frequency has an inductive reactance. So an inductive loop is used to match a below‐resonant monopole for miniaturization. As an example of this principle, a miniaturized dual‐band antenna prototype for WLAN applications is designed, fabricated, and tested. Measured results show that the antenna offers higher gains and better efficiencies than the unloaded monopole. The radiation patterns are seen to be unaffected by the presence of the top loaded loop. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:1236–1239, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26784