Design Of X - Band One - Dimensional Single Pulse Polarization Radar Antenna System

Mono-pulse radar antenna system is the preferred form for precise tracking. It has a high tracking accuracy, fast tracking speed, strong anti-interference ability and so on. In this paper, I design a one-dimensional mono-pulse variable polarization radar antenna system, based on Hengda company’s projects. The system is divided into the following three main working parts:the reflector antenna, one-dimensional mono-pulse feed system and circularly polarized antenna cover.(1) we use a offset parabolic antenna to achieve the technical requirements of low sidelobe, fan beam. The advantage of the antenna is to eliminate the feed block of the reflected waves, so the antenna gain is increased, reducing sidelobe; while the feed is placed outside the field of action to eliminate the effect of surface waves on the feed of reflection.(2) one-dimensional mono-pulse feed system, which consists of two pyramidal horn antenna and a E-farfield folding magic T components. Pyramidal horn antenna design basis is to take the opening angle of the parabolic antenna equal to-10dB beamwidth of the horn to achieve optimal irradiation. E-farfield folding magic magic T is the balance arm along the E-farfield bending, by adjusting the size of the metal vertebrae to achieve optimum performance magic T’s.(3) circularly polarized antenna cover, to achieve a mono-pulse becomes polarized antenna function. Which is periodically loaded on both sides of the gate metal fold microstrip dielectric plate, fold size adjustment means may be implemented to gate a linearly polarized wave into a circularly polarized wave in a certain bandwidth. This circularly polarized wave generation method with a low manufacturing cost, small space structure, stable performance and easy installation.For the above system components, based on the traditional theory, combined with modern electromagnetic calculation software design of the components, and processing measured. The simulation and measurement show that: the system is within a specified bandwidth for a VSWR<2, Gain≥32dB, SLLe≤25dB, the depth value of zero＜-30dB, and the sum differential conflict≤4.88dB. but also to achieve the antenna can work in linear polarization and circular polarization, the Axial Ratio<4dB.