零中频接收机及其AGC方法的研究与实现  

Study on and Realization of Zero-IF Receiver and its AGC Algorithm

作　　者：丁丹[1] 刘风亮[2] 

机构地区：[1]装备指挥技术学院光电装备系,北京101416 [2]装备指挥技术学院装备指挥系,北京101416

出　　处：《电讯技术》2010年第6期46-49,共4页Telecommunication Engineering

摘　　要：实现了基于LT5506下变频器和Cyclone IV FPGA的零中频接收机,采用射频、基带一体化架构,尺寸仅为8cm×6cm×1.5cm,重量仅为45g,功耗仅为800mW,满足小型化、低功耗的要求。针对零中频接收机中射频信号检波困难和传统AGC的调节时间受输入信号幅度影响的缺点,由Cyclone IV完成信号检波,增加对数运算环节并改进环路滤波器的结构,配合LT5506中的可变增益放大器仿真并实现固定调节时间的AGC,用8MHz采样时钟对1MHz正弦波进行幅度控制,调节时间恒定为53μs,不受输入信号幅度影响。The zero-IF receiver based on LT5506 and Cyclone W is realized. The framework integrating RF and IF is adopted, and the size is only 8 cm× 6 cm ×1.5 cm, the weight is only 45 g,and the power consumption is only 800 mW. The demand of small size and low power consumption is satisfied. Aiming at the difficulty of amplitude detect for RF signal and the problem that the settling time of traditional Automatic Gain Control（AGC） is affected by the amplitude of input signal, the amplitude detect is accomplished in Cyclone W, logarithm operation is added and the structure of the loop filter is improved, the AGC with fixed settling time is simulated and realized with the cooperation of variable gain amplifier in LT5506, when the amplitude of 1 MHz sine wave is controlled with 8 MHz sampling clock, the settling time remains 53 μs, independent of the amplitude of input signal.

关 键 词：无人机 测控链路 零中频接收机 自动增益控制 调节时间 

分 类 号：TN712.2[电子电信—电路与系统]