管理手机中的噪声

摘要： 介绍了影响噪声性能的移动电话手机问题。电源供应布局改善显示以减少噪音的问题。减少噪音低频率下的受雇线性稳压器。功率放大器偏压调节到射频输出上的噪音。低压差稳压器输出噪声被解释。

Maxim > App Notes > BATTERY MANAGEMENT POWER-SUPPLY CIRCUITS

Keywords: cellular telephones, noise, power supply, conducted, radiated, layout, GSM, TDMA Jan 24, 2001

APPLICATION NOTE 668
Managing Noise in Cell-Phone Handsets

Abstract: Presents cellular telephone handset issues impacting noise performance. Power supply layout
improvements are shown to reduce noise problems. Linear regulators are employed to reduce noise at low
frequencies. Power amplifier bias modulates noise on to the RF output. Low dropout regulator output noise is
explained.


To best handle the problem of cell-phone noise, you should apply an understanding of the phone's noise-coupling
mechanisms, noise-sensitive circuit nodes, and noise-generating circuits.




Figure 1. Switch-mode and linear regu