spectrum purity meaning in English

光谱纯度
频谱纯度

3 . with comprehensive improvement of transponder including structural adjustment to lna ; optimization of ( phase locked loop ) pll filter ; structural adjustment to the transmitter and phase error adjustment to the intermediate frequency demodulation circuit , we have successfully enhanced sensitivity , expanded dynamic range , increased transmitting power and improved the spectrum purity ; decreased capture time for pll ; improved the signal quality after demodulation ; reduced its volume and power consumption . 4
3 、对通信机的全面改进，包括lna结构的调整、锁相环环路滤波器的优化、发射部分结构的调整以及中频解调电路的相差调整，提高了系统的接收灵敏度、改善了本振的频谱纯度、减少了锁相环的锁定时间、使中频解调后的信号质量大为提高，同时还减少了体积、节约了系统的功耗。