Cellular Handset Antenna Efficiency Measurement Using the Wheeler Cap

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Cellular Handset Antenna Efficiency Measurement Using the Wheeler Cap
【文件名】:06217@52RD_Cellular Handset Antenna Efficiency Measurement Using the Wheeler Cap.pdf
【格　式】:pdf
【大　小】:117K
【简　介】:SKYWORKS
【目　录】:In the design of wireless portable devices, the variability of antenna efficiency can have a great effect on overall system performance. RF engineers must make frequent and critical design tradeoffs to improve sensitivity by fractions of a decibel. However, poor antenna efficiency can easily cause a degradation of several decibels. A GSM system might easily pass testing in which a cable connection to the antenna port is used but lose significant efficiency by its antenna in the field. This White Paper describes the importance of antenna efficiency and provides a measurement technique that can be used to quantify it. Antenna “efficiency” is different than antenna “gain.” Antenna efficiency quantifies the resistive loss of the antenna in terms of the proportion of power that is actually radiated versus the power that is first delivered to it. Antenna gain, however, is a directional quantity that refers to the signal strength that can be derived from an antenna relative to a reference dipole.