短波接收机的电磁兼容结构设计

EMC Structural Design of Shortwave Radio Receivers

为保证短波定时仪的正常工作,针对时统设备中短波接收机设计了整机电磁兼容实验;同时针对短波接收机内部2块点频接收板之间存在的干扰问题,设计了短波接收机内部的电磁兼容实验。试验中,通过加装专用的带通滤波器,使天线端子辐射降低了25dB,解决了天线端子发射超标的问题;通过对短波接收机进行电磁屏蔽和接地设计,解决了2块点频接收板之间的干扰问题,消除了15MHz接收机工作时的啸叫现象。实际使用效果和电磁兼容检测结果验证了短波接收机电磁兼容设计的合理性和有效性。

An EMC （Electromagnetic Compatibility） experiment is designed for a shortwave receiver of a timing sys- tem taking into consideration all its units to guarantee normal timing. A particular EMC experiment is further de signed to solve interference between two radio frequency receiving boards in the shortwave receiver. The radiation of the aerial terminal of the shortwave receiver is reduced by 25 dB down to the specified range by adding a special-pur- pose hand-pass filter. The interference hetween the two radio frequency receiving hoards is eliminated through im- provement in electromagnetic shielding and grounding and the squeal of the receiver at 15 MHz during operation is cancelled. The rationality and effectiveness of the EMC design for the shortwave receiver is verified through opera- tion in the field and EMC tests.