Application of superheterodyne FM reception in measurement of blade tip clearance 超外差调频接收技术在叶尖间隙测量中的应用
The design of a frontend circuit in the shortwave noise spectrum monitoring system is made by utilizing superheterodyne reception and direct digtal synthesis techniques. 利用超外差式接收和直接数字合成(DDS)技术设计了高频地波雷达频谱监测系统的前端电路。
For the former, through combining the superheterodyne method and the quadrature mixing frequency method, the wideband reception and mirror frequency suppression can be implemented by Secondary frequency conversion technology. 对于前者,主要阐述如何将超外差技术和正交混频结合起来,利用二次变频实现宽带接收和镜频抑制;对于后者,主要介绍带通采样定理和基于多相均匀滤波器组的数字信道化方法。