Project: Troubleshooting Radiated Emission of a Satellite Communication System

Time scale: 2 working days

Scope of work: A satellite communication system did not pass the radiated emissions test. Our task was to troubleshoot the problem, identify the issue, and implement a solution to ensure the unit would pass the test.

Troubleshooting Progress:

  • The conclusion drawn is that the significantly high radiated emission issues are attributed to poor grounding in the product design.
  • It has been identified that the ground connections between the DCDC board and the “ground” in the product are not optimal. Additionally, it has been observed that the “ground” itself serves as a separate reference point, distinct from the true grounding structure within the system. This deviation from an ideal grounding configuration likely contributes to the significantly high radiated emission issues encountered.
  • To ensure proper functionality of the common mode capacitors and allow the return of RF current back to the source, it is necessary to ground the filter board. Presently, the case of the filter board is isolated from the system ground, which results in the degradation of the filter’s performance. 
  • To further enhance the radiated emission performance of the system, it is recommended to incorporate ferrite cores with high impedance within the frequency range of 30 to 300 MHz.