单工无线呼叫系统分发射和接收两大部分。发射部分采用锁相环式频率合成器技术， MC145152和MC12022芯片组成锁相环，将载波频率精确锁定在35MHz，输出载波的稳定度达到4×10-5，准确度达到3×10-5，由变容二极管V149和集成压控振荡器芯片MC1648实现对载波的调频调制；末级功放选用三极管2SC1970，使其工作在丙类放大状态，提高了放大器的效率，输出功率达到设计要求。接收部分以超大规模AM/FM立体声收音集成芯片CXA1238S为主体，灵敏度、镜像抑制、信噪比等各项性能指标均达

Phase Locked Loops (PLL) Introduction to PLL The concept of Phase Locked Loops (PLL) first emerged in the early 1930’s.But the technology was not developed as it now, the cost factor for developing this technology was very high. Since the adva

Beken BK1085 64-125MHz FM stereo transmitter datasheet with register map and example schematic