High Sensitivity Test Broadband Level Control System Emc Design

The most important performance of broadband test system is the sensitivity. And the complicate electromagnetic environment in the broadband level control system would have an impact on the test system's sensitivity. So it is very meaningful to design broadband EMC equipment for the sensitive equipment.The main content of this thesis is to design a broadband anti-interference level control system. The aim is to design an equipment to keep the programmable attenuator having an 0.1dB step attenuation in the complicate electromagnetic environment of -60dBm level when the programmable attenuator is working at the level of -120dBm.This system contents a programmable attenuator and a 10 dB attenuator . In the course of design, the suitable assembly is chosen and tested. Since the system works at very low level, it needs to design some EMC experiments to test some sensitive parts of the system. If the equipment's ability of anti-interference is not enough, then position of equipment would be adjusted and electromagnetic shielding, absorbing material would be used to design the equipments'anti-interfere.The electromagnetic disturbance's level of every system assembles are analyzed to confirm whether it is interfered. Then it takes some EMC measurements. After taking the EMC measurements, the system is tested at some frequencies. The result is that this design is reasonable; test system meets predetermined requirements and has the very strong use value.