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

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160Ω到50Ω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50Ω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。

Based on the rectangular micro-coaxial fabrication technology,a surface micro-machined 10 GHz to 50 GHz ultrawideband 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 160Ωto 50Ω,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 50Ωmicro-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.