Analysis Of A Non-resonant Slot Antenna Array For High-power Microwave Application

In recent years,many high power microwave(HPM)sources have been successfully applied both in civilian and military fields,which can generate gigawatts of microwave.With the development of HPM technology,the design of antenna is a concern.Particularly,HPM antenna should meet some special requirement due to the feature of HPM,such as high-power handing capacity and compact structure on the premise of ensuring favorable ration.Recently,slotted waveguide antenna has been applied in HPM.This work seeks designs of L-band high-power microwave antennas based on rectangular waveguide slot antennas since they have been proved having high gain and high power capacity.A non-resonant slot antenna is proposed for high-power microwave application,which is a rectangular waveguide with groups of non-resonant closely-spaced slots cut in its broad wall.By this means,more slots can be set in a unit length with lower radiation power in each slot,accordingly higher power capacity and compact longitudinal dimension can be achieved.Furthermore,Ferroelectric phase shifter is studied for highpower microwave in order to expand beam scanning range.The detail contents and innovative work include the followings:1.The basic theory of a non-resonant slot antennaThe L-band high-power microwave antennas based on rectangular waveguide slot antennas has been studied.Higher power capacity can be achieved because more slots can be set in a unit length with lower radiation power in each slot,so the compact longitudinal dimension of the whole antenna is shorter.2.The design and simulation of single and planar array non-resonant slot antennaThe relationship between normalized resistance and the length of slot and broadwall of waveguide is obtained though simulation in proper model.To improve the radiation efficiency,the height of waveguide should be decreased and the normalized resistance rises.With the specially designed input port and output port,the beam direction of the designed antenna is 29.7° away from normal direction in E surface and the gain is 17.9dB.The power capacity of the designed single non-resonant slot antenna is more than 1.6GW.As to the planar array antenna,the influence of different environment of waveguide is revised and the electric field above them is uniformed.The beam direction can be steered almost 39° in the H surface.The simulated gain is more than 23.3 dB and the power capacity is over 6GW.3.Experiment of single non-resonant slot antennaLower power experiment is carried out to verify the feasibility of the single nonresonant slot antenna.The reflection is lower than-20 dB around center frequency.The gain is 16.93 dB at 6.8m away from the antenna and the beam direction is 30°.And the aperture distribution of the near field is similar with simulation.4.Study of ferroelectric phase shifter for high-power microwave applicationFerroelectric phase shifter is studied for high-power microwave in order to expand beam scanning range.The operating principle of the ferroelectric-lens phase-scanning antenna is briefly introduced and several problems are discussed for high-power microwave application.The high-power microwave propagation in ferroelectrics is analyzed by the means of finite difference time domain.180° phaseshift can be achieved in this phase shifter with length of 10 cm and the transmission efficiency is above 90% at L wave band.