The transmission of HPM-radiation from source to target

This report is the result of a master´s thesis project in microwave engineering which is a part of a Master of Science degree in Engineering physics at Chalmers University of Technology. The report treats microwave propagation from an HPM-generator through a waveguide, antenna to a target. A literature study has been made to investigate how the waveguide, antenna and weather conditions influence the performance of an HPM-weapon. To be able to calculate the strength of the electric field for a certain distance under certain conditions the findings from the literature study have been implemented in a Matlab-program. The conclusions drawn are that weather conditions such as rain and fog have little effect on microwave pulses with frequencies below 10 GHz. The largest loss of energy is when the electric field strength is too high and the air breaks down. To be able to transmit larger effect without breakdown the air in the waveguide/antenna can be replaced with sulphurhexafluoride and/or the pressure of the gas can be increased. Further calculations with the Matlab-program showed that an HPM-weapon has an theoretic effective range of tens of kilometres, which is in the same order as the range of a surface to air missile.