L/Ku双频双极化共口径天线设计

Design of L/Ku dual-band dual-polarized subsystemshared-aperture antenna

本文提出了一种新型的用于合成孔径雷达的L/Ku共口径天线单元,L频段单元为双极化的波导背腔十字开槽天线和Ku频段天线为单极化波导缝隙阵列天线。L频段腔体高度通过“倒T”型馈电减小,每一个十字开槽天线均通过一对差分探针馈电。Ku频段缝隙阵列透过同轴探针通过波导功分器馈电。通过L频段2×2阵列和Ku频段嵌套设计的实物加工和测试,实现了阻抗带宽(VSWR<2)分别为22%的L频段双极化天线单元和8.6%的Ku频段单极化波导缝隙阵列。该设计可以应用于大型共口径阵列。

In this paper, new designs of slot elements and a new configuration for array antennas for synthetic aperture radar at L-and Ku-band are proposed. The L-band are cavity-backed crossed slots for dual-polarization, and for Ku-band, waveguide slot arrays for single-polarization are used. The height of the L-band cavity is reduced by adopting an “inverted T” configuration. Each of the crossed slots is fed by a pair of differential probes. The Ku-band slot array is fed by a coax probe although waveguide divider. An initial prototype array comprising 2×2 L-band elements interleaved with Ku-band arrays was fabricated and measured. The impedance bandwidth(VSWR<2) of the antenna are dramatically broadened to 22% at L-band and 8.6% at Ku-band. This element design is applicable for larger shared-aperture arrays.