The Conical Antenna Analysis And Radar Lure Erbium Applications

Broad-band antenna with omnidirectional radiation is one of the modern communication techniques. With the development of electronic techniques and the accelerate growth of wideband wireless equipment, broad-band antenna with omnidirectional radiation becomes one of the most important brances on antenna research fields. The origins of this article is to design Bait System for a radar, so an independent bait antenna is needed. Besides some special requirements, broad-band and omnidirection techniques are the vital requirements. As for linear antenna, there are many means to achieve broad-band. Biconical antenna and its typical varietyæ¢'onical antenna over finite plane are chosen in this article to complete .Because they are well known as an easy to build broad-band and to get omnidirectional radiation, the key part among which is the conical antenna over finite plane.The whole article has five chapters. Chapter one is preface, including research background and working arrangement. The development of antenna today, the basic characteristic of antenna and the means for linear antenna to achieve broad-band are discussed in research background. In chapter two , an independent bait antenna for radar system is designed. According to the technique requirement, three typies of antenna as quadrafilar helix antenna > V-dipole and conical antenna over finite plane are analyzed and compared. Conical antenna over finite plane is chosen for its most fitful performance. Finally the detail structure of the bait antenna is calculated and drawn. Chapter three is the problem of radiation and reception of electromagnetic waves associated with a spherically capped biconical antenna having unequal cone angles ^and 92. Both cones that comprise a bicone are excited symmetrically at the apices by a voltage source. The characteristics as directivity > pattern and impedance are shown in equations and graphs. With the principle of equal-length finite cone, unequal-length finite cone are discussed about pattern. Finite-Difference Time-Domain(FDTD) method represents the time-dependent Maxwell's differentialequations by a set of difference equations that can be solved numerically using a digital computer. The method is easily adapted to complex geometries, so simplified theoretical models are not required. For above reasons, in chapter four Finite-Difference Time-Domain(FDTD) method is used to analyse the real structure of the designed conical antenna in chapter two. The computer results are compared with the results of Ansoft HFSS-a professional High frequency structure simulator and the result of measurement, most of which are shown to be in good agreement. Chapter five is the conclusion of whole article.