Design on UHF Hopping Synthesizer Based on ADF4193
Wang Ying-dong · Radio Engineering · 2010
Frequency synthesizer chip ADF4193 has such characteristics as fractional-N divider and fast lock.The charge pump current is increased while switching frequency to enlarge the loop bandwidth,thus shortening the loop lock time.The stability of the loop is ensured by adjusting the component parameter via the programmable switch.ADF4193 is the core circuit in UHF hopping synthesizer.The loop parameters are simulated with ADIsimPLL.Low noise operational amplifier is used as voltage amplifier to widen the tune voltage range of VCO.The spurious suppression is greatly improved by adjusting the loop bandwidth and the PCB layout.The experimental results are presented in the end.