Multi-beam Lens Imaging Antenna Research

The increasing demand for technology in anti-terrorism, aircraft landing, remote sensing and radio astronomical fields have stimulated a renewed interested in the research of the passive milliliter-wave imaging in the world. The focal plane imaging technology has the advantage of real-time imaging and it's possible to be developed as well as human eyes. So it has more attractions and perspective. As a sensor of the passive imaging system, the performance of the focal plane array antenna is especially important. The paper is mainly focus on the research of the focal plane array lens antenna.Compared with dual-reflector dielectric lens antennas can eliminate the blockage problem and simplify the mechanically design. Lens antennas are more compact, easily to be design and construct. They also offer greater design flexibility to meet various stringent requirements. The main mission of this paper is to design a focal plane lens multi-beam antenna to meet the system demand.Up to now, there are lots of commercial software packages, such as HFSS, CST, FEKO et al. They apply different methods and are very convenient for solving complicated electromagnetic problems. And they can provide very accurate results. But because of the limitation of computational resources, they are always challenging to apply to calculating the objects with large electromagnetic size. Compared with FEM (Finite element method) MOM (Moment method) and FDTD (Finite difference time domain method), GO (Geometric optic) is more property to solve the electromagnetic large object. A better way to use the software is to combine these tools with some other analytical method. In this paper, HFSS combined with ray tracing will be applied to solve arbitrary feeds and large dielectric lens antennas.There are many types of horns and they are easy to be designed. By comparison, we choose the pyramidal horn as the feed. To achieve the large field of view, the 3dB intersection of adjacent beams and uniform beams, many lenses are compared and the convex-convex dielectric lens was chose. Moreover the properties of the focal flat, slope and curve plane are discussed. In the end, an accomplished multi-beam lens antenna model and the method to design multi-beam dielectric lens antenna are given.