Research On Conformal High Power Waveguide Slot Array Technology

With the development of High Power Microwave(HPM) technology, more attention has been progressively paid to the function of HPM antenna as the terminal of HPM system.A lot of different kind HPM antennas have been made, Such as radiant horn,Vlasov antenna,mode-transducting antenna, reflector antenna and plane array. All of these antennas have the same disadvantage, they can not conform to the carrier surfaces.Conventional conformal antenna have been widely used in modern radar and communication systems.Compared to plane array, conformal antenna arrays have special advantages. First of all, because the antenna attaches with aircraft surface,it doesn't affect the performance in acrodynamics, then the conformance antenna arrays such as cylindrically array,sphere array could decrease the mutual couple between radiating units.At least,conformal antennas can compactly fixing.The unit of conventional conformal antenna array usually is microstrip antenna which has lower power-handling capacity, it can not be used as HPM antenna.The waveguide slot array conformal antenna has lots of advantages such as high pulse power capacity,high radiation efficiency,high Gain,low profile and easy conformable to carrier surfaces. so it is the best one of conformal HPM antenna.This paper make a research of HPM cylindrical conformal array of longitudinal slots, and focus on theory equations, power-handle capacity,Gain and efficiency of antennaa and mutual coupling of radiating slots of conformal array. This antenna has been studied from the following aspects in this paper.Firstly, the normalized conductance of a resonant longitudinal shunt slot in the broad wall of a sectorial waveguide has been derived. The three design equations have been researched by the method of active admittance. The second equation has been revised when the exterenal mutual coupling which come from dielectric window and internal mutal coupling which come from higher order mode in sectorial waveguide have been taken into account.Secondly, The HPM plane waveguide slot array antenna have been researched.The designing of power-handling capacity of antenna and suppressing the mutual coupling of waveguide slots have been researched. Based on the research of plane array, The the cylindrically conformal HPM arrays of longitudinal slots of sectorial waveguide is proposed. The normalized resonant conductance versus offset and resonant length of slot are obtained. The structure of HPM conformal array is numerical optimized.The phase compensation is based on Z direction method. The power-handle capacity has been analyzed.The cylinrically conformal HPM array reaches a gain of 24.3dB,a efficiency of 72%, a high power capacity of 2.5GW and a Gain decreasing of 3.3dB when beam shift to 30°?Thirdly, some improvements of the conformal array are proposed. The first one is basing on ridged-sectorial waveguide to expand the low frequency wideband of conformal antenna. The second is alternating-phase feed to waveguide which can improve the gain and wide-angle beam steering capacity of antenna. The third is adding horn cavity to slot which can improve the gain antenna.The last is designing double-layer waveguide array which can improve the high power capacity of dielectric window and extend the bandwidth of antenna. The improved cylinrically conformal HPM array reaches a high power capacity of 2.9GW,a gain of 25.49dB,a efficiency of 95%, and a Gain decreasing of 1.3dB when beam shift to 30°?Finally, A high power capacity experiment of the planar HPM waveguide slot array is made based on a high power MILO microwave system.The experiment result indicate that the waveguide slot array can handle xxGW high power microwave with pulse width of 85ns and frequency of 1.589GHz.