| Electromagnetic band gap(EBG) is a special kind of artificial electromagnetic material that is very widely used for antennas and microwave field because of its unique characteristic of band-gap.Based on its surface wave suppression, it has been applied for reducing the mutual coupling between the antennas, improve the proformance of antennas and microwave devices,etc..Its in-phase reflection band also can be used for design low-profile antenna, antenna steath and so on. For its widely application, it is significance to research on the new EBG structure. In this paper, we start from the basic theory of EBG and introduce the equivalent circuit theory of EBG, HFSS simulation method and the measurement methods of EBG band gap.Several kind of miniaturization and multi-band new EBG structures are designed and its application on antenna RCS reduction and improving the axis ratio of circular-polarization antenna array. Specific work is as follows:Firstly, the relationships between the reflection phase band gap and the structure parameters of mush-room EBG are discussed. Based on the theoretical, a miniaturized EBG structure is designed and the results show that the size of EBG structure is reduced 80.2% compared with the mush-room EBG. Then the novel EBG structure of the multi-frequency has been studied by the equivalent circuit model. The three band-gap can be observed in the X polarization and two gaps in the Y polarized.Secondly, we apply the same phase reflection band gap of HIS on the antenna RCS reduction. Research on and validate the basic principles of HIS application on antenna RCS reduction, and discuss the effect of number of HIS structures, loading position on RCS reduction on 10 GHz microstrip antenna. The dual-band microstrip patch antenna array loaded with the novel dual-band HIS is fabricated and tested. The results show that the RCS in both operating bands are reduced by 12 d Bsm at least without degeneration of the radiation performance, such as gain and S11.Lastly, EBG structure can be used for suppress the spread of surface electromagnetic waves for its properties of surface wave bandgap. Circularly polarized microstrip phased array loading with the EBG structure is researched for improving its axial ratio. Within a certain range of the scan angle, the results show that axial ratio has been some improvement for the EBG suppressing the propagation of surface wave. |
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