| Low frequency electromagnetic radiation emission test plays an important role in the analysis of electromagnetic compatibility (EMC) problem, because the wavelength of the electromagnetic wave at the low frequency band is comparable to the length of the cable of equipment under test (EUT), so electromagnetic radiation emission is radiated through the cable of EUT. At the same time so many equipments work at the low frequency, and the electromagnetic interference is very serious between the devices. So it is very important to carry out electromagnetic radiation emission test on the equipments in the low frequency band. However, mutual coupling phenomenon exists between the receiving antenna, EUT and the receiver.The coupling will affect the voltage of the receiving antenna port, which eventually will lead to the large error of the test result and directly affects the precise judgment of the electromagnetic compatibility of EUT.This paper researches the test method of low frequency radiation emission in EMC field, and selects the typical cable-plane structure that is widely used in the EMC test to analyze the test method from two aspects: the full-wave electromagnetic simulation and experimental testing. The main contents of this paper are summarized as follows:Firstly, the test method of the low frequency radiation emission is studied by using the active rod antenna. The electromagnetic simulation and the experimental test analyze the influence of the grounding mode of the rod antenna on the electric field radiation emission test.Secondly, the paper discusses the factors that affect the poor repeatability of the low frequency electric field radiation emission test, which has a propelling effect on the modification of the EMC military test standard.Finally, this paper introduces the pre-estimation method which is called transfer function method and optimized method——multiple segment transfer functions method for low frequency radiation emission field, the optimized method can effectively reduce the testing fee of products under development. In addition, the paper studies the radiation emission of electric field which is based on the standard biconical antenna, and utilizes the full wave simulation and actual test to analyze the influence of the parameters such as the height of the cable from the metal plate and the length of the cable on the radiation emission of the electric field in the low-frequency, which is beneficial to EMC engineer to understand electromagnetic radiation level from electronic equipment, and then make better EMC design. |
PDF Full Text Request