Research On Missile-borne Full Solid Angle Scanning Cylindrical-and-Conical Passive Phased Array Antenna

Phased array antennas have been widely used in radar, telecommunication and microwave imaging systems due to their fast and non-inertial beam scanning with high gain. Usually, the planar phased array antennas only capable of 120° beam scanning, whereas the conformal phased arrays can achieve a wider beam scanning range. For this reason, conformal phased arrays have attracted more and more attention.Homing head is the key equipment for a missile to attack the target accurately. At present, the microwave and millimeter wave missile homing heads are mainly flat and mechanically-controlled. This leads to small scanning range, slow scanning speed,low accuracy and reliability issues. If the phased array is constructed conformal to the conically and cylindrically shaped missile structure, the full solid-angle scanning phased array antenna can be realized. This will not only expand the range of missile attack greatly, but also makes the missile able to send the information back to the control station. Till now, no reports on conically and cylindrically conformal phased arrays with full solid angle scanning capabilities can be found. Therefore, it is worthwhile to address the missile-borne full solid angle scanning phased arrays.In this dissertation, at first, the problems related to radiation field solution and beam coverage of cylindrical and conical conformal arrays have been studied. Based on the rclationship of the direction and the polarization rotation of the element in the cylindrical and conical conformal array, the radiation field solution of cylindrical and conical conformal arrays is achieved. The method of low-elevation beam scanning of the cylindrical and conical conformal array is proposed, then based on this method,the design scheme of full solid angle beam coverage is obtained.Secondly, cylindrically and conically conformed microstrip antenna elements are designed and used to construct cylindrical conformal and conical conformal arrays.These two arrays are able to achieve beam scanning in 30°? ?? 150°, 60° ? ??1200° and 60°? ?? 180°, 60°???120° regions.Afterwards, based on radiation mode of magnetic current on the PEC surface,microstrip Yagi antennas are designed and used to construct cylindrical conformal endfire scanning array, which can achieve the beam scanning in 0° ? ?? 30°, 30° ???150°region. At the same time, based on the project method, an algorithm is deduced to optimize the feeding amplitudes of antenna elements in phased array to obtain better radiation patterns.Finally, the feeding networks for conformal phased array are designed and the whole systems is integrated to form a full solid angle scanning cylindrical-and-conical phased array. A prototype of integrated phased array is fabricated and tested. The measurement results show that the prototype can achieve beam scanning efficiently in 30° ? ?? 180°,60° ??? 120° and 0° ? ??30°, 30° ???150° regions. By arranging several of such arrays along the full perimeter accompanied with switchable feeding configurations, a full solid angle scanning can be achieved.