通信应用微分电路设计技术

　　通信应用微分电路设计技术

　　在通信系统设计的主要挑战之一是成功捕获信号具有足够的保真度。严格的标准规范要求适当的接口拓扑选择。部署蜂窝电话的通信标准，如码分多址（CDMA）和宽带CDMA，需要高动态范围，高输入线性度和低噪声，以避免阻断剂的影响，信号失真，和灵敏度退化。在过去，完全差分信号链的性能优势是捏造的单端选项，由于实际应用问题。然而，集成RF电路技术和可扩展的高性能差分RF积木的最新进展允许差分架构，以适用于高性能接收机设计。

　　A single-ended signal is unbalanced by definition and is measured by the difference between the signal of interest and a constant reference point， normally ground， which serves as the return path for the signal. A problem can be encountered if an error source is introduced to the single-ended signal. Since the ground reference will be unaffected by the injected error， the error is carried forward through the signal. In a single-ended configuration， any variation introduced to the desired signal will be problematic to remove without involving overly complex cancellation techniques. For this reason， single-ended or unbalanced signals are more prone to noise and interference， such as electro-magnetic coupled interference. Also， as will be shown later， unbalanced configurations have higher distortion than balanced circuits.