中频70M，30M带宽LFM信号，采样率为102.4M，，数字下变频后，还进行了三倍抽取，最后还得到I，Q两路信号 -IF 70M, 30M bandwidth LFM signal, the sampling rate 102.4M, under digital variable frequency after also carried out three times extracted, and finally also received the I and Q signals