Abstract
A penta-band folded antenna for mobile phone applications is presented.The antenna is comprised of two modified inverted-L monopole radiators with a short grounded transmission line for impedance matching and includes a ground plane printed on FR-4 substrate. The radiators are bonded onto a plastic carrier whose dimensions are 50 x 15 x 4 mm3. The antenna is designed and optimized to generate two separate bands, ranging from (i) 870 to 1010 MHz and (ii) 1710 to 2490 MHz with return loss for both better than 7.5 dB. Thus, the antenna covers five bands useful for mobile phone applications, namely, Global System for Mobile Communications/Digital Communication System/Personal Communication Services/Universal Mobile Telecommunications System/Bluetooth. The design strategy was such that the two separate widebands of interest can be controlled relatively independently. Design considerations for the constructed prototype are discussed. The effects of the ground plane, the mobile phone housing and the human hand on the return loss, and the efficiency of the proposed antenna are also investigated. It is found that the hand grip on the mobile phone has a significant effect on the performance of the antenna, especially its efficiency. (C) 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:3440, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27274