了解天线规格和操作

    　本文是由两部分组成的系列的第1部分。它将介绍设计师天线的理论，规格，天线设计的趋势，以及现实世界的天线的例子。第2部分，将深入探讨最新的天线设计，以及如何指定和应用它们。

　　天线可能是最受忽视的RF设计的一部分，但范围，性能和合法性的RF链路是非常依赖于它。无论如何，天线的选择往往是直到设计结束时，在该点的最佳天线性能可能无法实现的空间内提供。

　　在这一点上的选择可能要经过多个设计或最终接受的降解性能。这两个选项是可取的，但与各种类型的天线的理论和行为的基本理解，可以避免的情况下，一个设计师可以得到更接近最佳的RF性能。

　　To that end， Part 1 of this two-part series focuses on the basic electromagnetic field principles of antennas. It then illustrates these principles with two styles of antennas that are often used in low-power handheld products： dipoles and monopole whips. These types cover a wide range of available antennas and are among the most common to be implemented incorrectly. （For more on antenna selection， see the TechZone article， “Antenna Selection Depends on Many Factors”。）

　　Part 2 of the series looks at dipole and monopole antennas in more detail， while also discussing some antenna design trends that are being driven by the needs of today‘s wearable， handheld， and compact devices. These newer antennas include chip antennas such as theJohanson Technology 2450AT18B100E， 2.4 GHz to 2.5 GHz chip RF antenna， and patch antennas such as the Antenova SRF2W012-100 DROMUS， flexible dual-band Wi-Fi antenna. It will also discuss antennas fabricated as part of the pc board itself.