The microwave radiactivproperty of snow is studied using self-developed three band microwave radiometers. Experiments were carried out repeatedly from 1986 to 1989 in Northeast China The relation between brightness te...The microwave radiactivproperty of snow is studied using self-developed three band microwave radiometers. Experiments were carried out repeatedly from 1986 to 1989 in Northeast China The relation between brightness temperature and observation angle was obtained with both vertical and horizontal polarizations. The curves corresponding brightness temperature and snow depth were also drawn out for different frequency bands. The results demonstrate the application potential of the multifrequency microwave radiometer in this area.展开更多
为了提高微波光子矢量网络分析仪(MPVNA)进行脉冲测量时的动态范围,提出了一种软件门控方案,该方案利用临时闲置接收通道接收与脉冲激励产生的控制信号同源的脉冲方波,以此生成门控信号。通过这个门控信号对采集到的待测器件脉冲响应进...为了提高微波光子矢量网络分析仪(MPVNA)进行脉冲测量时的动态范围,提出了一种软件门控方案,该方案利用临时闲置接收通道接收与脉冲激励产生的控制信号同源的脉冲方波,以此生成门控信号。通过这个门控信号对采集到的待测器件脉冲响应进行控制,有效提高了信噪比和测量的动态范围。对10 GHz带通滤波器的脉冲散射参数(S参数)进行了测量,实验结果表明:在占空比为1%的脉冲激励下,应用软件门控的测量动态范围相比未应用门控时的提高了约20 d B;门控处理后测得的S11和S22参数曲线也因为信噪比的提升更加光滑和稳定。展开更多
基金The Project supported by National National Science Foundation
文摘The microwave radiactivproperty of snow is studied using self-developed three band microwave radiometers. Experiments were carried out repeatedly from 1986 to 1989 in Northeast China The relation between brightness temperature and observation angle was obtained with both vertical and horizontal polarizations. The curves corresponding brightness temperature and snow depth were also drawn out for different frequency bands. The results demonstrate the application potential of the multifrequency microwave radiometer in this area.
文摘为了提高微波光子矢量网络分析仪(MPVNA)进行脉冲测量时的动态范围,提出了一种软件门控方案,该方案利用临时闲置接收通道接收与脉冲激励产生的控制信号同源的脉冲方波,以此生成门控信号。通过这个门控信号对采集到的待测器件脉冲响应进行控制,有效提高了信噪比和测量的动态范围。对10 GHz带通滤波器的脉冲散射参数(S参数)进行了测量,实验结果表明:在占空比为1%的脉冲激励下,应用软件门控的测量动态范围相比未应用门控时的提高了约20 d B;门控处理后测得的S11和S22参数曲线也因为信噪比的提升更加光滑和稳定。
