Errors Analysis of the Digital Generation System for Ultra Wide-Band LFM Signals

Three main digital methods for linear frequency modulated (LFM) waveform generation are compared and analyzed. On the basis of the waveform storage method,a digital generation system scheme for ultra wide-band LFM pulse compression signals is proposed in this paper. The performances of the digital system is investigated in detail including the effects of amplitude quantization bits and the sampling frequency at digital base-band,the non-idealization of the quadrature modulator,spurs involved in the frequency multiplier,and the distortion of intermediate frequency LFM signals in time domain on the performance of output signals. The results are finally proved by computer simulations and therefore provide important theoretical bases and experiential references for parameters selection,performance evaluation,and performance optimization of ultra wide-band systems.