了解天線規格和操作，第2部分

　　編者注：這兩部系列的第1部分著眼于基本電磁場和天線理論，以及關鍵性能參數。第2部分，檢查一些實際天線的性能特點，包括新的設計。

　　天線可以極大地貢獻到一個系統的性能，但只有當它被給予應有的考慮，在設計過程中的早期。否則，設計者可以運行空間和形成因素的限制，將阻止天線實現其設計的潛力。

　　Also， while it’s critical that designers understand antenna theory and principles， theory can sometimes clash with harsh reality. For example， it should be recognized that specifications on an antenna’s data sheet might not be a clear indicator of its performance in the final product. This is a result of design-specific factors， as well as differing references， methods of test， and presentation formats among antenna suppliers.

　　This article will introduce popular antenna configurations such as the monopole and dipole， and discuss their performance characteristics and how to work with them in the real world. It will also discuss newer antenna designs such as patch and chip antennas， and how they can help designers meet more demanding application requirements.