基于宽带匹配技术的C波段宽带有源微波冷噪声源设计

Design of C-band broadband active cold noise source based on broadband matching technology

针对微波辐射计在同一频段内多通道定标时对稳定宽带低温定标源的需求,结合有源微波冷噪声源的工作原理和宽带匹配技术,提出了一种C波段宽带有源微波冷噪声源的设计方案,并对传统匹配网络结构进行了改进,从而显著地提升了器件的工作带宽,最终使用Avago公司的ATF38143型场效应管设计了一款C波段宽带有源微波冷噪声源。经测试,在常温条件下,该器件在中心频点为6.8 GHz,带宽为1 GHz的范围内输出的最低噪声温度为150.31 K,可应用于多通道C波段微波辐射计的定标工作。同时分析了该器件输出噪声温度受直流偏置电压、环境温度变化的影响,分析结果有助于具体工程应用。

Aiming at the requirement of stable broadband low-temperature calibration source for microwave radiometer multichannel calibration in the same frequency band,by combing the working principle of active microwave cold noise source and broadband matching technology,a design scheme of C-band broadband active microwave cold noise source was proposed,the traditional matching structure was improved,leading to significantly improved operating bandwidth of the device.A broadband active microwave cold noise source was designed using the ATF38143 FET of Avago Company.The test results indicate that under normal temperature condition,the lowest output average noise temperature of the decive is 150.31 K in the range of the center frequency point of 6.8 GHz and the bandwidth of 1 GHz,so it can be applied to the calibration work of multi-channel C-band microwave radiometer.At the same time,the influence of the output noise temperature of the device on DC bias voltage and ambient temperature was analyzed.The analysis results are helpful to the engineering applications.