Compact quasi‐self‐complementary antenna for portable UWB applications

Abstract

ABSTRACTA quasi‐self‐complementary (QSC) antenna with microstrip fed and a compact size of 19.7 × 19 mm2 is proposed for portable ultrawideband (UWB) applications. The antenna consists of a half‐elliptical conductor patch with two small half‐circular structures (HCSs) printed on one side of the substrate, and a slot with the complement of the conductor shape cut on the L‐shaped ground plane on the other side of the substrate. Computer simulation is used to design the QSC antenna. Results show that the HCSs can increase the lengths of the current paths on the antenna and hence, increase the operation bandwidth. As a result, for the same operation bandwidth, the size of the antenna can be reduced by 15% using the HCSs. Simulation is used to study the performance of the antenna in terms of S11, radiation pattern, realized gain, and efficiency. For verification of simulation results, the prototype of the antenna is measured using the antenna measurement system, Satimo Starlab system. The effects of the feeding cable used in measurement are also studied using computer simulation. The simulated cable effect on efficiency is evaluated and used to remove the cable effect on the measured result. Then, the simulated and measured efficiencies agree very well. Results show that the antenna has a bandwidth from 3.1 GHz to more than 12 GHz and efficiency of over 60%, making it suitable for portable UWB applications. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:1317–1323, 2014