Research And Design Of Waveguide Slob Antenna Based On The Metamaterials Structure

In the past ten-odd years, with the increasing demand for radar anti-jamming and the development of pulse Doppler visual radar, the antenna should have low or very low side lobe side performance, which makes the waveguide slot array antenna been the preferred form of antenna to meet the requirements. Waveguide slot array antenna has become the preferred new form of radar antenna, which is widely used in radar and communications fields. While left-handed materials with new characteristics has became the research focus today. SRR is one of the realization of the left-handed material.In this thesis, based on analysis and design of the traditional broadside slot array antenna, the new waveguide slot array antenna is studied whose slots are replaced by left-handed material structure. The major work done can be summarized as follows:First, the characteristics of waveguide broadside slot array antenna and the method of design are analyzed. The twenty elements waveguide slot array antenna is synthesized using Chebyshev method.Secondly, the slot of waveguide slot array antenna above is replaced by the SRR(Split-Ring Resonator) forming the LHM(Left-Handed Material) in the new array. The rectangular SSRR, rectangular SRR, the circular SSRR and the circular SRR waveguide array are simulated fourteen different types in total.In this paper, ANSOFT HFSS electromagnetic simulation software is used to simulate the two waveguide slot array antennas. The results show that the maximum radiation direction for the new slot array is±45°with the radiation funnel-shaped pattern, which is different from maximum radiation direction along normal of the traditional waveguide broadside slot array. The maximum radiation direction of the uniform linear array compromised of LHM structure changes to the array line direction (end fire array) or perpendicular to the array line (side fire array), as the position of the split changes. Because of the absence of the classical theory calculated formula, the coupling cannot be estimated and calculated, the input impedance fluctuate a little, and the VSWR is a little great. The resonance characteristic of the SRR makes the bandwidth narrow.