A 24-28 GHz Frequency Synthesizer for Millimeter Wave Radar Application

This paper presents the developed $\mathbf{2 4 - 2 8} \mathbf{~ G H z}$ frequency synthesizer for millimeter-wave radar applications, incorporating a phase noise filter (PNF) at the input stage of the phase-frequency detector (PFD) to enhance in-band phase noise suppression. Measurement results show that the PNF effectively reduces phase noise from $-88.6 \mathrm{dBc} / \mathrm{Hz}$ to $-97 \mathrm{dBc} / \mathrm{Hz}$ at a 10 kHz frequency offset with a locking time of less than 68 us.