Study Of Substrate Integrated Waveguide Multi-Beam Array Antenna

As a technique to improve the rate of commnucation, the capacity of communication channel, and maximize the use of spectrum resources, the multi-beam technology has been widely used. However, with rapid development of microwave circuit and micro-electronic technique, it has become increasingly difficult to achieve the requirements of simplification, lightweight and integration for the traditional forms of multi-beam antenna. With millimeter waves and the band of THz being increasingly focused, the normal plane circuit such as microstrip, CPW, and stripline can not meet the antenna performance because of high loss. So it is necessary to find a suitable way to achieve the multi-beam antenna. It was quickly noticed that the new technology of substrate integrated waveguide(SIW), which has been proposed in recent years, is a better way to solve the above problems. Therefore, this paper mainly focuses on the multi-beam antenna with SIW technology.The basic theory and analysis method of SIW technology are present at the beginning of the paper. Meanwhile, the transition structure between SIW and plane circuit is studied, to achieve the connection of the two-part. Then based on the basic theory and design methods, a co-planar transition structure of gradient line is achieved. To obtain the specific direction of multi-beam by changing the amplitude and phase of input signal, the basic theory and analysis methods of SIW phase shifter are studied, and the 450 and 800 phase shifter are designed as examples. Finally, based on the slot array theory, a SIW slot array antenna has been designed.Secondly, in order to achieve multi-beam function, the most classic form of beamforming network, the Rotman lens, is introduced and the geometrical optics method is presented. Then, based on SIW technology, the SIW Rotman lens is designed and its modeling and simulation results are presented in the paper.At the final part of the paper, a muti-beam antenna is constituted by integrating the SIW Rotman lens, SIW phase-shift and SIW slot array antenna on a substrate. Then the final structure of the antenna and its results are presented, and the relationship between the antenna structure and its performance are also discussed. Simulations show that the antenna can achieve VSWR?2, gain ?15d B, sidelobe ?-10 d B and 7 beams of the beam scanning between ±25°.