Researchon Wide Band Antennafor Medical Equipment Electromagnetic Compatibility(EMC) Testing

Electromagnetic Compatibility(EMC)testing for Medical equipment needs test instrument,accessory,antenna and testing chamber,among which antenna attracts many attentions in the EMC research area.Ultra-wide band antenna is high demanded in EMC testing,by using wideband antenna,the testing system can work over a wide frequency band,which make sure that testing can be done in one time,and repeatedly tuning can be avoided.So,wideband antenna can make the testing much more convenient,it is very important to design good performance wide band antenna forEMC testing system.In this thesis,wide band antenna for medical equipment EMC testing is studied.Basic antenna concept and some specifications are firstly introduced,then wide band antenna is induced.To meet the requirements of EMC testing,log-periodic antenna(LPDA)and double-ridged horn antenna(DRHA)are chosen as the design type.In this thesis,an LPDA working at 0.1GHz-1GHz and a DRHA working at 1GHz-8GHz are designed and verified through simulation.For the LPDA,we firstly introduce the working principle,analysis the theoretical model and give the critical parameters.Base on the theory,an original model is constructed in the simulation software,through fine tuning of the critical parameters,guided by the current flow,wide band LPDA can be finally achieved.The VSWR,radiation pattern and realized gain can meet the requirement for EMC testing.For the DRHA,we firstly introduce the basic horn antenna and analysis the aperture-field distribution,radiation pattern through theoretical model.Tofurther enhance the working frequency bandwith,ridged waveguide model in induced.Based on the theoretical analysis,an original DRHA is made in simulation software,some critical parameters is swept,finally good performance DRHA is achieved.The current flow is also given to verify the theory.For both designs,3D electromagnetic software CSTis used to verify and optimize the antenna,through which we get the final demo.The LPDA’s VSWR is less than 2 through the working frequency from 0.1GHz to 1GHz,the DRHA’s VSWR is less than 2 through the working frequency 1GHz to 8GHz.The radiation pattern keeps nearly unchanged,and the gain also meet the requirement for EMC testing.Form the simulation results,it can be concluded that the designs is feasible and have some value for practical medical equipmentEMC testing.