IC-725A短波电台本振频率的高稳定度改进  

High Stability Improvement of Local Oscillation Frequency of IC-725A HF Transmitter-Receiver

作　　者：葛勤革 张曙霞[2] 蒋宇中[2] 张涛涛[2] 

机构地区：[1]海军司令部信息化部,北京100841 [2]海军工程大学电子工程学院,武汉430033

出　　处：《舰船电子工程》2014年第4期63-66,共4页Ship Electronic Engineering

摘　　要：在短波信道探测中,收发系统的本振频差对多普勒频移的测量至关重要。针对短波信道探测系统中IC-725A短波电台原有本振频偏较大的问题,采用锁相环(PLL)频率合成技术,利用铷时钟提供基准参考频率,对IC-725A短波电台的本振信号源进行高稳定度改进。给出PLL中鉴相器(PD)、环路低通滤波器(LF)的设计方案,并用电路实现。研究并给出一种在不影响电台总体性能的情况下将PLL输出的高稳定度本振信号注入到电台中的方法。实验测试结果表明,改造后两部IC-725A短波电台的本振信号的频差在10-4 Hz数量级,完全能满足短波信道探测对电台本振频率精度的要求。The local oscillation frequency difference between transmitter and receiver is of great importance to the meas- urement of Doppler shift in high frequency（HF） channel sounding. The original local oscillation frequency offset of IC-725A HF transmitter-receiver is too big to measure Doppler shift. Therefore, a method is proposed to improve the stability of local oscillation frequency of IC-725A, which is based on phase-locked-loop（PLL） frequency synthesizing technology. And the ru- bidium clock is used as norm reference frequency source. The design schemes of phase discriminator（PD） and loop low-pass fiher（LF） are provided, which is implemented by circuit. The injection approach of the high stability local oscillation signal output by PLL into IC-725A is given, by which the performance of IC-725A is totally not influenced. The result of test ex- periment shows that the local oscillation frequency difference of two improved IC-725A is at the magnitude of 10.4 Hz, which means that it satisfies the local oscillation frequency precision requirement of HF channel sounding.

关 键 词：短波 信道探测 本振频率 锁相环 鉴相器 

分 类 号：TN742[电子电信—电路与系统]