研究正、负线性调频信号的特性，给出其时域、频域图像，以及频率随时间变化曲线。对于初学雷达信号处理者学习LFM信号有帮助。-Study the positive and negative chirp signal characteristics, given the time domain, frequency domain images, as well as the frequency versus time. It s helpful for beginners who study Rada