一种新型宽频带近场测试系统双极化探头设计

摘要

A novel dual-polarized feed operating in 18~40 GHz for near-field measurement system is proposed. The quadruple-ridge horn is designed as the radiation part. A method of adding an isolated plane between the feeding ridges is applied to realize the low cross-polarization property of the feed in the wide frequency band. The measurement data shows that the cross-polarization is below -40 dB in the direction of the main radiation in the frequency band,and the radiation pattern is symmetrical. This feed has the properties of small size,low cross-polarization,wide bandwidth,and simple feeding characters. The validity and the efficiency are approved by the simulation,manufacture,and measurement. The proposed method can be applied for wide-band near-field measurement system.%　　设计了一个工作在18~40 GHz的双极化近场测试系统探头。探头采用四脊喇叭形式,为改善脊喇叭交叉极化特性,提出了在两脊馈电间加隔板的形式,使其在较宽的频带内具有较低的交叉极化。测试结果表明：该探头在18~40 GHz频带内在主辐射方向上交叉极化低于-40 dB,且方向图具有良好的对称性。该探头具有口面小、交叉极化低、频带宽、馈电简单的优点,适用于近场测试系统中使用。通过模型设计、加工、实测验证了该方法的正确性及有效性,此方法可以用于宽频带近场测试系统中。