| Due to that the conformal array has characteristic of low profile, which does not affect the aerodynamics of aircraft and suit for wide angle scan, it is more and more widely applied on the high speed carrier. However, the conformal array also has some problems. For example, the micro-strip antenna is always assembled as an array element whose operation band is narrow. Moreover, the micro-strip antenna does not always have enough beamwidth, whereas broad beamwidth is needed when scanning in wide angle. When the conformal array is mounted on complex carrier, the conventional plane array analysis and synthesis theories are not suitable. Based on the Finite Difference Time Domain(FDTD)method, the low profile broadband micro-strip antenna and the low profile broad beamwidth micro-strip antenna technologies are studied in this thesis. The cylindrical conformal line and loop arrays and complex conformal array on column- sphere carrier synthesis methods are also studied. The main contents are as follows:First of all, theories of FDTD are introduced in detail. The types and setup of the excitation source are discussed. The methods of transform in radiation fields from near field to far field in the frequency domain and in the time domain are presented when FDTD is applied to analyze the characteristics of far field.Secondly, some experiments for conformal antenna have been studied to analysis the effects which result from carrier. Based on the FDTD, the low profile broadband micro-strip antenna technology and the low profile broad beamwidth micro-strip antenna are analyzed and designed.Thirdly, the analysis and synthesis theories of cylindrical conformal line and loop arrays are studied. The method of INSGA-II is applied for synthesizing of the hemisphere carrier conformal array and the column- sphere carrier complex conformal array. And the measured array pattern is given.Finally, the effects of the array tolerance, mismatch and phase errors on the array is also analyzed. |
PDF Full Text Request