Multi-range-resolution radar using sideband spectrum energy

A radar range resolution is generally determined by its transmitted pulse width and is thus a constant parameter unrelated to the detection range. However, a method has been proposed for greatly improving a radar range resolution by using signal-processing techniques to reduce the received pulse width at the expense of a high target signal-to-noise ratio. In this method, an autocorrelation output is first obtained from a time-series representation of the received signal, and this autocorrelation output is then processed using a least-squares error-shaping filter. This creates a corresponding increase in the bandwidth of the principal frequency spectrum, thereby improving the range resolution. The relationship between this spectral distribution and the range side-lobes in cases where the transmitted signal is a simple pulse or a plain phase-modulated wave is investigated. The interference cancelling effect achieved when a radar based on the proposed scheme receives interference is also investigated