解决射频功率检测挑战

　　解决射频功率检测挑战

　　大多数射频设备必须监控并控制其射频功率输出，以符合政府的规定，尽量减少射频干扰，并尽量减少电力使用。发射机也这样做有明显的原因：1）最大限度地减少发射功率，增加运行时间和2），以尽量减少功耗。

　　对于接收到的信号路径，射频功率检测也是一个关键的功能。这是需要监测接收到的射频功率调整增益，在RSSI（接收信号强度指示器）是用于控制射频/增益如果通过AGC（自动增益控制）信号链电路为了保持恒定，为后续的模数转换优化信号电平（如果有）和解调。RSSI信号也被用来控制发送信道，从而最大限度地减少发射功率，同时还保持一个可接受的最小误码率（误码率）。由于这些原因，准确的射频功率检测是重要的两个接收器和发射机。

　　Note that this RF power detection differs from RF power measurement， although there is some confusion， ambiguity， and overlap in the terminology. RF power detection is generally used to refer to the measurement of the RF power （usually as a relative value） as represented by a voltage （and current） within an electronic circuit; in contrast， RF power measurement is direct measurement of the power （usually as anabsolute value） of the RF wireless signal in space or air.

　　For the former situation， various ICs and modules are used within a circuit; for the latter， specialized sensors （often based on thermocouples） intercept the impinging RF energy and then convert its heat energy to a voltage corresponding to the RF power. ［Recall that power and energy are intimately related parameters： energy is the time integral of power， while power is the time derivative of energy， the rate at which energy is being received or sourced.］