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In this article, an inkjet-printed inverted-F antenna suitable for a watch-type wireless communication device is presented. The antenna and covering the 2.4 WLAN band (2.4-2.484 GHz) has thickness (2 mm 3 ) and size (40 Â 25 mm 2 ). The performance of the printed antenna is experimentally studied and compared with a reference antenna made of Rogers copper laminate. The effect of inkjet-printed layer thickness on the antenna performance is presented. In addition, the impact of the user's hand proximity on the antenna performance is studied experimentally. The results showed that the total antenna efficiency increases by 13% and 27% with an increase of 1.5 lm in printed layer thickness and a user's hand to antenna distance of 12.5 mm, respectively. The shape of the radiation pattern of the antenna is distorted due to the proximity of the user's hand.

Miniaturized electromagnetic band‐gap (EBG) structures suitable for hand‐held devices at 1.575 and 2.4 GHz frequency bands are presented. To miniaturize the structures, a ceramic substrate with relative permittivity of 82 is used to obtain a period of the order of 2.6–3.5 mm. Simulation results are presented for slotted‐patch and two‐dimensional (2‐D) fork EBGs at 1.575 GHz. Measured results are presented for spiral EBG at 2.4 GHz. Measured data with good isolation and radiation properties validates the concept of proposed EBG structures. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 2508–2513, 2007; Published online in Wiley InterScience (www.interscience.wiley.com) DOI 10.1002/mop.22761

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