Linear LTC5566双路可编增益下变换混频器解决方案

Linear公司的LTC5566是双路可编程增益下变换混频器,每路采用有源混频器和15.5dB增益控制范围的数字IF VGA,每路的IF增益通过SPI每步可编0.5dB,35dBm输出IP3,工作电压3.3V,主要用在4G和5G MIMO接收器,分集接收机,分布式天线系统(DAS),网络测试/监视设备,软件定以无线电(SDR).本文介绍了LTC5566主要特性,框图,测试电路和应用电路,以及演示板DC2460A主要特性,电路图和材料清单.

The LTCR5566 dual programmable gain downconvertingmixer is ideal for diversity and MIMO receivers that requireprecise gain setting. Each channel incorporates an activemixer and a digital IF VGA with 15.5dB gain control range.The IF gain of each channel is programmed in 0.5dB stepsthrough the SPI.

Programmable RF input tuning via the SPI or parallelcontrol lines makes the device attractive for widebandradio applications. Furthermore, a reduced power modeis available, programmed through the SPI.

Integrated RF transformers provide single-ended 50Ω inputs.The differential LO input is designed for single-endedor differential drive. The differential IF output simplifiesthe interface to differential IF filters and amplifiers. Themixers are optimized for use up to 5GHz but may be usedup to 6GHz with degraded performance.

LTC5566主要特性:

nn12dB Power Conversion Gain

nn35dBm Output IP3

nn15.5dB Range IF DVGA in 0.5dB Steps

nnProgrammable RF Input Tuning

nnReduced Power Mode

nn3.3V Single Supply

nnSimple SPI for Fast Development

nn–40°C to 105°C Operation (TC)

nnVery Small Solution Size

nn32-Lead (5mm × 5mm) QFN Package

LTC5566应用:

nn4G and 5G MIMO Receivers

nnDiversity Receivers

nnDistributed Antenna Systems (DAS)

nnNetwork Test/Monitoring Equipment

nnSoftware-Defined Radios

图1.LTC5566框图

图2.LTC5566测试电路图:100欧姆匹配差分IF输出

图2.LTC5566应用电路图:双路MIMO接收器,可编增益,每步0.5dB