对具有金属地的微带定向天线，低剖面设计面临着工作频带窄的难题。采用蘑菇形EBG结构代替微带定向天线的常规金属地，利用EBG地对特定频率电磁波的同相反射特性，在保持天线工作频带条件下，缩减天线微带基板的厚度，实现低剖面设计。以一只工作频点为5.8 GHz的2×2微带阵列天线为例，该阵列天线的辐射单元采用分形结构以进一步提升天线带宽。仿真计算和实际测试表明：该微带阵列天线在采用低剖面设计后，微带基板厚度由原1.0 mm降至0.25 mm，而天线的定向辐射方向图、增益和工作带宽基本保持不变。%The low profile design of microstrip directional antenna with metal ground is facing the challenge of narrow working frequency band. In this paper,mushroom-like electromagnetic band-gap (EBG) structure is used to replace the conventional metal ground in microstrip directional antenna. EBG ground could perform same phase reflection when it responds to specific fre-quency electromagnetic waves. Therefore,a low profile design achieved by employing the EBG ground and reducing the thick-ness of the antenna’s micro-band base plate while maintaining the working frequency band. A 2×2 microstrip array antenna with working frequency point of 5.8 GHz is taken as an example in this paper. The fractural structure is used for radiative unit of this array antenna to further widen its bandwidth. Both simulating calculation and the test results show that,with the low profile de-sign for the microstrip array antenna,the thickness of the microstrip base plate can be reduced from 1.0 mm to 0.25 mm while the directional radiation pattern,gain and working bandwidth almost keep the original state.
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