原标题：Linear LTC5583双路6GHz RMS功率检测方案

　　Linear公司的LTC5583是匹配的双路6GHz RMS功率检测器,能测量两路AC信号,动态范围从-59dBm 到4dBm,频率范围从40MHz 到6GHz,整个温度范围精度为±0.5dB,两路的匹配输出小于1.25dB,快速响应时间,上升时间140ns,主要用在VSWR监视器,MIMO发送功率控制,基站功率放大器控制,发送和接收增益控制以及RF仪表.本文介绍了LTC5583主要特性,方框图, 单端输入配置和差分输入配置测试电路图以及单端输入配置图和差分输入配置图.

　　LTC5583 - Matched Dual-Channel 6GHz RMS Power Detector

　　The LTC5583 is a dual-channel RMS power detector, capable of measuring two AC signals with wide dynamic range, from –59dBm to 4dBm, depending on frequency.

　　Each AC signal’s power in decibel-scaled value is precisely converted to a DC voltage on a linear scale, independent of the crest factor of the input signal waveforms. The LTC5583 is suitable for precision power measurement and level control for a variety of RF standards, including LTE, EDGE, W-CDMA, CDMA2000, TD-SCDMA, and WiMAX.

　　Good channel-to-channel isolation is necessary for operating the dual channels simultaneously. For applications where the two input signals are at the same frequency (e.g. measuring VSWR), the LTC5583 provides 40dB isolation at 2.14GHz even with single-ended inputs. No baluns are needed. When the two input signals are at different frequencies, the isolation can be as high as 50dB. The isolation can be improved to >55dB with differential inputs.

　　The power difference of the two input signals is provided at a difference output pin. Each channel also has a fast envelope detector, which tracks the RF input signal’s envelope and outputs a voltage directly proportional to the signal’s instantaneous power. The envelope detectors can be disabled to reduce power consumption.

　　LTC5583主要特性:

　　Frequency Range: 40MHz to 6GHz

　　Linear Dynamic Range: Up to 60dB

　　±0.5dB (Typ) Accuracy Over Temperature

　　40dB Channel-to-Channel Isolation at 2GHz Even with Single-Ended RF Inputs

　　Matched Dual-Channel Outputs: <1.25dB (Typ)

　　Single-Ended RF Inputs—No Transformer Required

　　Accurate RMS Power Measurement of High Crest

　　Factor Modulated Waveforms

　　Difference Output Provides VSWR Measurement

　　Fast Envelope Detector Outputs

　　Fast Response Time: 140ns Rise Time

　　Small 4mm 4mm QFN24 Package

　　LTC5583应用:

　　VSWR Monitor

　　MIMO Transmit Power Control

　　Basestation PA Control

　　Transmit and Receive Gain Control

　　RF Instrumentation

　　图1.LTC5583方框图

　　图2.LTC5583测试电路图:40MHz-3GHz,单端输入配置

　　图3.LTC5583测试电路图:2GHz-6GHz,差分输入配置

　　图4.LTC5583单端输入配置图

　　图5.LTC5583差分输入配置图