Extending CW radar unambiguous detection range using a Modified Frank Code
Dong‐Jin Yeom, P.E. Pace · 2018
A number theoretic transform of the Frank polyphase modulation is introduced in order to significantly extend the unambiguous detection range of CW polyphase modulation radar beyond a single code period using N coprime moduli and their residues. The Modified Frank Code (MFC) allows the coverage of a large unambiguous range while minimizing the correlation lengths necessary to achieve the required compression gain for target detection. We present 3 different formulations of the MFC each having their unique characteristics. We show that the third formulation (MFC-III), retains a perfect periodic autocorrelation property with zero sidelobes similar to the original Frank modulation.