摘要
频率合成芯片ADF4193具有小数分频和快速锁定特性。换频时通过增加电荷泵电流以扩大环路带宽,缩短了环路的锁定时间,并采用可编程开关调整环路元件参数来确保环路稳定。UHF跳频频率合成器以ADF4193为核心电路实现设计,采用ADIsimPLL软件仿真环路参数,利用低噪声运算放大器构成的电压放大器来扩大VCO的调谐电压范围,通过调整环路带宽及设计合理的PCB布局来抑制杂散,给出了实测结果。
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.
出处
《无线电工程》
2010年第2期44-47,共4页
Radio Engineering
