Antenna And Radome Design Of Conical Conformal Phased Array

Conformal phased array(CPA) is a new form antenna array, which combines the advantages of conformal antenna and phased array antenna. It has a broad prospect with the application of the aircraft. Radome is not only an important part in radar system, but also can be used as the carrier for conformal antenna. In this paper, the structure of conical conformal phased array antenna-radome is designed and analyzed in consideration of the influence of the radome. The main contents of this paper are summarized as follows:Firstly, the antenna element of CPA working in Ku band is designed and tested. Considering the demand of wide beam and easy installation microstrip patch antenna and bow-tie slot antenna are chosen. Microstrip patch antenna is consisted of square patch and media agency. Simulation result shows that the impedance bandwidth with the port isolation less than-10 d B reaches 0.9GHz. The half power beam width of E-plane and H-plane separately reaches 92.8°and 81.7°.To achieve single-side radiation, the bow-tie slot antenna is added metal back chamber. The simulation result illustrates that the impedance bandwidth with the port isolation less than-10 d B reaches 1.56 GHz. The half power beam width of E-plane and H-plane separately reaches 53.4°and 53.5°. On this basis, the above antennas are made and tested. The testing results are in good agreement with the simulated.Secondly, the conical radome with A-sandwich structure is designed. The microwave transmittance of radome is firstly analyzed by equivalent transmission line theory. On this basis, the conical radome is analyzed to meet the target of 3d B beam width variations and sighting error by PO physical optics. Finally, the radome structure and material is determined and the simulation result meets the engineering indicators.Thirdly, the mathematic model and mutual coupling of conformal antenna array(CAA) are analyzed. First, for any surface conformal array, the method of vector pattern superposition is used to solve its far-field characteristics. Then, the mutual coupling coefficient of antenna elements are solved through active element patterns. In addition, the overall structure of conical conformal phased array antenna-radome is made up and verifies the above method. Finally, a simplified algorithm based on active element patterns is proposed.Fourthly, the low side lobe pattern synthesis for conical conformal phased array antenna-radome structure is presented. Firstly, the single polarization pattern is synthesized by Taylor line source synthesis method and aperture projection method(APM). Besides, mutual coupling calibration is used to improve the pattern characteristic. Lastly, through using dual-polarized antenna element, the pattern shape and polarization form are designed together for conical conformal phased array antenna-radome structure to improve polarization purity.