The radar system

A beat signal is generated by transmitting a frequency-modulated signal of a triangular-wave shape to a target and by receiving the signal reflected from the target. The beat signal is sampled and multiplied by a window function. When a discrete frequency spectrum is to be determined, a first window function having a gentle amplitude attenuation from the center of a sampling section to the two ends is applied to a low range (or a short-distance range) of the frequency spectrum, and a second window function having a steep amplitude attenuation from the center of the sampling section to the twoends is applied to a high range (or a long-distance range) of the frequency spectrum.