The Study And Design Of Waveguide Slot Array And Wideband Microstrip Antenna

Waveguide slot array and microstrip antenna become the current research hotsbecause of their merits. Waveguide slot array can easily realize the low or very lowside-lobe and therefore it is widely used as missile-guidance head antenna, airborneradar antenna, and so on. At the same time, microstrip antenna with small volume,light weight, low cross section is used widely in wireless communication field.Around these two topics, this paper mainly concentrates on four facets of work:study and design (1) waveguide slot array (2) wideband microstrip antenna (3)wideband microstrip antenna array (4) wideband sum-and-difference network.In the design of waveguide slot array, we discussed the design procedures ofwaveguide standing-wave linear array, waveguide planar array, as well astraveling-wave array, and derived the design equation of each kind of waveguide slotarray and showed the design examples. The computation block based on the FortranLanguage has the universal property, which Can be called by different kinds of array.In addition, the simulation software Ansoft HFSS was used to study resonancecharacteristics of several excitation slots including longitudinal slot, longitudinal slotloaded by pin, and inclination slot. The research results are good reference to thedesign of waveguide slot array.In the design of wideband microstrip antenna, we designed three novel types ofwideband microstirp antenna based on the bandwidth broadening technology: Firstly,from the angle of feed device, the effects of four coplanar waveguide (CPW) feeddevices on the antenna resonant frequency and bandwidth were studied. The feedcharacteristics of coupling slots were analyzed and compared. The conversion ideawas combined with the feed device, fed by which a wideband microstrip antenna witha bandwidth of 28.9% was designed. Secondly, from the angle of special patch shapewith coupled feed technology, we employed the FDTD method to design a Ku-band U slot patch antenna, which had an impedance bandwidth of 50% as well as a gainbandwidth of 33%. By changing the size of U slot and feed slot, the widebandcharacteristics can be converted into dual-frequency characteristics. Finally, using theshorted circuit technology, a short patch antenna with an impedance bandwidth of52% was designed.In the design of microstrip antenna array, we roundly studied the coupling amongthe array elements and proposed a novel wideband feed network based on which an8×8 antenna array and a 2×2 antenna array were designed respectively.In the final part of this paper, we studied a special feed network: thesum-and-difference network. The wideband waveguide sum-and-difference networkand microstrip sum-and-difference network were designed respectively by the use ofwideband phase compensation technology and 0dB coupling technology. And basedon the microwave network principles, an ultra-wideband sum-and-difference networkwas designed by employing the novel power divider and anti-phase balun.