在窄脉冲调制下相位噪声测量的定标过程中,通过采用PRF滤波器提取主谱线技术,对主载频差拍频率的波形进行了还原,使定标过程较之传统方法简便快捷。在脉冲调制状态下的锁相环路设计中,采用PRF滤波器消除PRF谱线,避免锁相环路难以锁定或者偏锁,另外通过提高环路增益等方法解决由于窄脉冲调制造成的环路锁定能力降低。应用以上技术的脉冲调制波相位噪声现场测量装置分别以不同的环路带宽对不同占空比下的脉冲调制波源的相位噪声进行了测量,证明了上述方法的可行性。

In narrow pulse modulation, the method that the beat shape depart from carrier frequency is reverted by PRFfilter to get main spectrum line during the calibration of phase noise measurement, comparing with traditional way is simple and fast. The PRF filter is used to remove PRF lines and the loop gain is increased to solve the problem which is hard to lock because of decrease of power in loop design in pulse modulation. The pulsed wave at different duty cycle is measured using phase noise measurement systems at different loop bandwidth. The results prove these methods are useful .