A programmable divider with extended division range for 24GHz FMCW frequency synthesizer

As the conventional programmable divider has the division failure problem at the modulus extension boundary, the paper proposed a simple and robust programmable divider structure with extended division range to solve this problem effectively. By adding a reset port and changing the polarities of latches in the 2/3 divider of the last stage, the modified structure performs no division error when switched back and forth at the boundary. The proposed structure is applied in a 24GHz FMCW frequency synthesizer with the division range of 16~63 and is implemented in TSMC 65nm CMOS technology. The post simulation results show that the proposed programmable divider operates properly at the modulus extension boundary and works well in a FMCW frequency synthesizer.