Project Wireless - February 2009 - (Page 16) PrOjeCT radiated efficiency of the antenna, as it indicates how much of the antenna’s energy can be transferred to radio waves and how much is lost due to mismatch and radiation losses. especially in small portable or handheld devices, 3-d efficiency is a much better parameter to compare than maximum gain because in actual use the device can be in any orientation. in addition, because in use the maximum gain peak beam can be directed toward the user’s body, the gain is lost due to body attenuation. considerations, along with the mechanical durability and reliability of the antenna component. material selection and mechanical design of both the device and the antenna have direct impact on manufacturability. competent selection leads to cost-effective easy-to-manufacture solutions, especially for very high product volumes. significantly, a bigger antenna does not necessarily correlate with better antenna performance. this is demonstrated by small, ceramic-chip antennas that can outperform much larger antennas when implemented following design guidelines. Contents viewpoint Smart integration design Signal Paths in 3G and Feature / Smart Phone Apps Antennas for Handheld devices mechanIcal layouT one way To deTermIne True anTenna performance IS To look aT ITS ToTal 3d radIaTed effIcIency. | vOLuMe 1 | nuMber 1 the mechanical layout of the device’s design determines the size and type of antenna needed, and the size and type of antenna needed also limits and determines the antenna’s electrical properties. therefore the mechanical design of the device should be considered hand in hand with the selection of the antenna. typical mechanical properties are form factor (external or internal), construction, size, mounting, type of connection, and aesthetic InTernal anTennaS most handheld devices will need an internal antenna, instead of an external one, for purely aesthetic reasons. in fact, more than one antenna will be needed depending on the applications and functions of the device. the typical construction of the internal antennas are stamped metal, pcB, flexible printed circuit (fpc) on plastic carrier, meander line, ltcc, ceramic, quadrifilar, and patch Home Page Product Training Module Online Ordering Suppliers Catalog 16 http://ad.doubleclick.net/clk;211088645;32661511;z?http://www.digikey.com http://ad.doubleclick.net/clk;211088645;32661511;z?http://www.digikey.com http://ad.doubleclick.net/clk;211088750;32661511;w?http://digikey.com/PTM/PTMMaster.page?site=us&lang=en http://ad.doubleclick.net/clk;211088807;32661511;z?http://ordering.digikey.com/ordering/addpart.aspx?site=US&source=search http://ad.doubleclick.net/clk;211088983;32661511;e?http://digikey.com/Suppliers/SupplierIndex.page?site=us&lang=en http://ad.doubleclick.net/clk;211091911;32661511;p?http://dkc1.digikey.com/us/en/pdf/Current.html
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