一种新颖的跳频振荡器

A New Type of Hopping Oscillaror

摘要本文综合考虑到频率合成技术及单端口体波谐振器HBAR的特点提出了一种基于一阶非线性PLL的锁相频率合成方案。文中对这种跳频方案的原理、性能特点作了详细论述、并通过实验、从不同角度对本方案进行了说明、同时对整机的各项指标作了详尽测试:在HBAR无载Q_N值为4000的情况下,该多模跳频振荡源的捷变范围为770MHz—840MHz、捷变时间小于20μS。杂散分量低于—60dB、二次谐波分量低于—34dB。离散捷变频率点为16点,构成闭环跳频系统后,对开环VCO的短稳改善了三个量级:从1.3×10^(-5)/ms到1.6×10^(-8)/ms及9.56×^(-7)/s到1.69×!0^(-9)/s,尤为重要的是该多模跳频振荡源达到此性能所需的硬件量很小,因此在对体积要求苛刻的场合、此种跳频方案具有极强的竞争力。

Through considering both the frequency synthesis technique and the single port HBAR features,a plan based of the first order nonlinear PLL is designed. A practical frequency hopping oscillator is designed and its theory is discussed in detail. This plan also is demonstrated with experiments from different aspects. In thes frequency hoopping system, the agile bandwidth is from TTO MHz to 840 MHz with agile time less than 20μs,spurious lower than—60dB and the second harmonic lower than-34dB. The frequency stability of the closed—Loop VCO is improved three orders ,i.e from 1.3×10^(-5)ms to 1.6×10^(-8)/ms and from 9.56×10^(-7)/s to 1.69×10^(-9)/s. It is worth mention that the hardware of the single port HBAR Oscillator to achieve such characteristocs is very small. When there is severe demands for small volume,almost no frequency synthesis technique can compete with the single port HBAR frequency hopping oscillation.