摘要
为了实现地面数字电视700MHz频率迁移的目标,确保广州广播电视台转播中央电视节目的安全播出,并提高原发射机的利用率,本文提出了广播电视发射台700MHz频率迁移发射机改造方案的设计思路与实现方式。此次技术改造关注三个关键环节:一是激励器的调试,二是Doherty功率放大器的改频和带宽扩宽改造,三是数字滤波器的重调。其中,Doherty功放本身具有的窄带特性构成了改造的难点。本文创新地提出了Doherty功放模块的改频和带宽扩宽改造方案,最终成功完成了700MHz频率迁移的任务。
To realize the task of frequency migration of 700 MHz for digital terrestrial television(DTT),ensure the safe broadcasting of CCTV programs relayed by Guangzhou Radio and Television Station,and improve the utilization rate of the original transmitter,combined with the actual situation of the original transmitter,this article proposes the design concept and implementation method of 700MHz frequency migration transmitter transformation plan for broadcasting and television transmission station.This technological transformation focuses on three key aspects.The first is the driver debugging.The second is the frequency conversion and bandwidth widening of Doherty power amplifier.The third is the digital filter.The difficulty lies in the narrow-band characteristic of Doherty amplifier.An innovative scheme of frequency conversion and bandwidth widening for Doherty power amplifier module is proposed,and the task of 700MHz frequency migration is completed.
作者
肖幸伟
Xiao Xingwei(Guangzhou Radio and Television Station,Guangdong 510010,China)
出处
《广播与电视技术》
2023年第12期16-21,共6页
Radio & TV Broadcast Engineering
