Project Wireless - February 2009 - (Page 14) PrOjeCT operaTIng Frequency operating frequency is determined by the type of application. for example, Wi-fi 802.11 b/g, ZigBee, and Bluetooth use the same 2.4-ghz ism band that has a bandwidth of about 80 mhz (2.4 to 2.48 ghz). a commercial gps system uses the l1 1.575-ghz band with a bandwidth of 2 mhz (1,575.42 mhz ±1 mhz). a gsm system uses the 850/1,900-mhz band or the 900/1,800-mhz band, depending on the region of the world. 3g systems use a variety of bands, depending on region. for example, the european Wcdma system uses the 2.1-ghz band. Quad- or penta-band cellular band antennas are often used for worldwide roaming and interoperability as they combine 4-band gsm and W-cdma 2100 to receive and transmit signals in all cellular bands. other applications include Wimax, uWB, ism900, ism5/5.8ghz, dvB-h, mediaflo, dect, rfid, vhf, uhf, am, and fm. multiantenna systems, such as diversity and multi in multi out (mimo), are used in applications where enhanced data rates are needed. With multiple antennas, it is crucial to design and characterize the whole antenna system including antenna-to-antenna isolation and correlation coefficient testing. Contents viewpoint Smart integration design Signal Paths in 3G and Feature / Smart Phone Apps Antennas for Handheld devices an InTernal, mulTIhybrId, cellular penTa-band anTenna IS TypIcally uSed for worldwIde roamIng and InTeroperabIlITy. Home Page Product Training Module Online Ordering Suppliers Catalog | vOLuMe 1 | nuMber 1 (vsWr), polarization, directivity, sideand back-lobe levels, front-to-back ratio, radiating patterns, impedance, and power rating. the materials selected and the actual radiator rf design also determine the antenna’s final electrical performance. the materials used need to have low loss (tan ∂) and good conductivity. gaIn and eFFIcIency the maximum gain, average gain, and efficiency determine the range and performance of the antenna. the higher these numbers, the better the range and 14 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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