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一、概述在现代无线电通信和雷达技术中,系统灵敏度和选择性一直是设计者的难点或重点。其中的主要限制因素之一就是相位噪声,更一般地说是边带噪声,即相位噪声和AM噪声的组合。相位噪声是指(正弦)频率的短期稳定性。由于相位噪声的存在,引起载波频谱的扩展,其范围可以从偏离载波小于1Hz一直延伸到几兆赫兹(加相位噪声的影响)。频率稳定性是振荡器在整个规定时间范围内产生相同频率的一种量度。如果信号频率存在瞬
I. INTRODUCTION In modem radiocommunication and radar technology, the sensitivity and selectivity of the system have always been the designers’ difficulties or priorities. One of the major limiting factors is phase noise, more generally sideband noise, a combination of phase noise and AM noise. Phase noise is the short-term stability of the (sinusoidal) frequency. Due to the presence of phase noise, the carrier spectrum is caused to spread, ranging from less than 1 Hz away from the carrier up to several megahertz (plus the effect of phase noise). Frequency stability is a measure of how often an oscillator produces the same frequency over the entire specified time frame. If the signal frequency is instantaneous