A wide-band PLL-based frequency synthesizer with adaptive dynamics

A wide tuning-range PLL-based frequency synthesizer with constant damping factor (zeta) and natural frequency (omega_n) has been presented in this paper. This synthesizer can be use for UHF and VHF channels. The lock frequency range of the synthesizer can vary from several tens MHz to 1.5 GHz with a 6-MHz channel, and the divide ratio of the frequency divider operates from 5 to 300 precisely. The synthesizer was simulated in 0.18-mum CMOS process with 6-MHz reference frequency and 350~500-KHz tunable bandwidth, under a 1.8-V supply voltage.