超宽带矩形微同轴平面对数周期天线

Ultra-wideband rectangular micro-coaxial planar log-periodic antenna

摘要:

在宽带电子系统轻量化的需求下，基于MEMS矩形微同轴技术设计了10 GHz~50 GHz的超宽带平面对数周期天线。天线采用三节矩形微同轴阻抗变换实现160 Ω到50 Ω的宽频带阻抗匹配，并通过矩形微同轴转共面波导进行馈电。为展现微同轴的馈电优势，验证设计的微同轴平面对数周期天线性能，制备了50 Ω矩形微同轴传输线和天线实物并进行了测试。实测结果表明，在10 GHz~50 GHz频段内，矩形微同轴传输线传输损耗＜0.22 dB/cm，两根间隔0.15 mm的矩形微同轴传输线间隔离度＞60 dB。天线实测反射系数＜-8 dB，增益＞4 dBi，增益波动＜1.6 dB。

Abstract:

Based on the rectangular micro-coaxial fabrication technology, a surface micro-machined 10 GHz to 50 GHz ultra-wideband planar log-periodic antenna is designed under the requirement of lightweight for the wideband electronic system in this paper. To match the nominal antenna impedance of 160 Ω to 50 Ω, a three-step impedance transformer is designed. Besides, a rectangular micro-coaxial line to CPW transition is used to feed the antenna. To display the advantages of the micro-coaxial feeding line and demonstrate the performances of the designed antenna, some 50 Ω micro-coaxial lines and the above log-periodic antenna have been fabricated and measured. The measured results show that, through the whole frequency band, the micro-coax lines have insertion loss as low as 0.22 dB/cm, and high isolation of 60 dB for the neighboring coaxial lines at a distance of 0.15 mm. The designed antenna has return loss as low as -8 dB, and antenna gain above 4 dBi with gain variation less than 1.6 dB.