一、前言雷达、通讯和制导等军用武器系统的最佳应用取决于对它所要工作的电磁环境的了解。如果使瞬时带宽足够窄以便提高频率精度,就可能漏失许多脉冲或频率捷变信号;所以实验室里的扫频振荡器式频谱分析器不能满足这种侦察设备的要求。必须采用一种系统,既有宽瞬时带宽,又有好的频率分辨率。布喇格小室 I. Preface The best application of military weapon systems such as radar, communications and guidance depends on an understanding of the electromagnetic environment in which it is to work. If the instantaneous bandwidth is made narrow enough to improve the frequency accuracy, many pulses or frequency-agile signals may be missed; therefore, a swept-spectrum oscillator analyzer in the laboratory does not meet the requirements for such reconnaissance equipment. A system must be used that has both wide instantaneous bandwidth and good frequency resolution. Bragg chamber