The Research Of Compact And Multi-band EBG

Due to its unique property, EBG structures have attracted much interest of many scholarsand also have been widely applied in microwave field, especially in the antenna field.However, with the development of integrated circuit and FDM (frequency divisionmultiplexing[6]) technology, EBG structures should be improved towards the direction forcompactness, multi-frequency, and broadband to meet the requirements of the currentdevelopment. This paper proposes a compact EBG structure，a dual-band planar EBGstructure and a tri-band EBG structure with theoretical analysis and practice certification,respectively. The main content can be summarized as follows:1. This paper proposes a compact EBG structure by adding the “C” slot on the patch of theELV-EBG (the edge-located via mushroom-type EBG[43]) structure. The“C”slot can hinderthe surface current in the EBG structure, which results in a longer current path and a lowerresonant frequency. Results show that the resonant frequency is reduced by2.5GHzcompared to the ELV-EBG structure with the same size. Thus, a30.8%size reduction isachieved by adding the “C”slot on the patch of ELV-EBG structure. Then the proposed EBGelements are inserted in an antenna array to reduce the mutual coupling. After adding thedesigned EBG structure in the antenna array, the isolation between antennas is increased andthe performance of impedance matching of the antenna element is improved.2. The tri-band EBG structure is designed in this paper by introducing slots on the patch ofthe mushroom-like EBG structure. In the simulation, it is found that the three differentstop-bands can be adjusted by changing the size of the geometrical parameters of the slots.Therefore, the stop-bands of the tri-band EBG structure are independently tunable.3. Based on conventional planar HIS structure, the resonance frequency is obviouslyreduced by adding four “Z”slots on the patch of the HIS structure. Then an embed patch isintroduced inside the substrate in the proposed HIS structure, which forms a multilayerstructure and the resonance frequency of the proposed HIS structure is reduced further.