On The Wideband Miniaturization Antenna And Feed Network

The research works of this paper are made with scientific projects. The design methods of wideband whip missile-borne antenna with matching network and wideband ring direction-finder antenna with equalizing network are discussed in this dissertation. The major works can be divided into three parts: l.The physical prototype of wideband whip missile-borne antenna with matching network is made;2. Wideband ring direction-finder antenna is simulated and designed;3. The physical prototypes of wideband ring antenna with the equalizer in the form of lumped-element and microstrip are manufactured. The main contents could be summarized as follows:Firstly, the project requirements of the missile-borne antenna are illustrated. In order to meet the requirements of miniaturization and easily mounted on missile, considering the characteristic of mechanical and electrical integration, wideband whip missile-borne antennas are designed with the structure of single whip antenna, which is easily embedded into the missile. On the basis of the size of antenna being determined, the matching networks of wideband whip missile-borne antennas are designed by the method of lumped-element matching, which broadens the antenna impedance bandwidth effectively and achieves the broadband requirements. The physical prototypes of three different frequency bands of antennas and matching networks are made and measured. The measured results show that the VSWR of the three different antennas is less than2.5, which can satisfy the project requirements.Secondly, according to the project requirements, three different frequency bands of wideband ring direction-finder antennas are designed by the method of resistance loading. In order to realize the gain stability of antennas in their frequency bands and the requirement of miniaturization, the design methods of the equalizer in the form of lumped-element and microstrip are both employed. The equalizing networks of ring direction-finder antennas are designed. With the simulation of Ansoft HFSS, the physical prototypes of equalizing networks are made and the transmission characteristics and VWSR are measured. The results show that they can satisfy the project requirements.