Abstract: Frequency modulation continuous wave (FMCW) fuze has the advantages of low probability of intercept and high ranging accuracy. The traditional harmonic detection algorithm used for FMCW fuze has the inherent error, which is inversely proportional to the frequency offset. And the computing amount of FFT method used for the short range frequency modulated radar is huge, and the hardware is not easy to implement in low cost application. A new algorithm based on the derivative ratio is proposed to reduce the error without increasing the frequency offset. Furthermore, owing to the severe requirement related to the volume and cost of traditional fuze, the new method has the advantage of small amount of computation and high real-time performance, which makes it more implementable in low-cost hardware such as the single chip microcomputer (SCM).

Key words: ordnance science and technology, fuze, frequency modulation continuous wave, range error