低交叉极化水平的宽带滤波贴片天线

Wideband Filtering Patch Antenna with Low Cross-Polarized Level

提出了一种低交叉极化水平的宽带贴片滤波天线。在层叠式贴片与金属大地之间插入一对1/4波长短路谐振器,天线的通带内可出现3个反射零点,实现了拓展天线工作带宽的效果。在通带的高端出现两个反射零点,提高了天线的高端带外抑制水平。该天线与传统的微带贴片天线相比,具有宽频带、高增益、低交叉水平以及高端频率选择性的优势。为验证理论预期的可实现性,设计了中心频率在3.5 GHz的天线案例。仿真结果表明,该天线的剖面高度为0.1λ0,10 d B匹配带宽为22%,增益为8.4 dBi,交叉极化小于-30 dB。

Awideband filtering patch antenna with low cross-polarized level is proposed. By the insertion of the quarter-wavelength short-circuited resonator between the stacked patches and the ground, three reflection zeros appear in the pass band, which contributes to the enhancement of the bandwidth. The upper out-of-band suppression level is enhanced by the appeared radiation zeros. Compared with the traditional patch antenna, this antenna has the advantages of enhanced bandwidth and realized gain, low cross-polarized level and upper-band frequency selectivity. For verifying the theoretical prediction, one example is designed at 3.5 GHz. The simulated results show that the height of the design is 0.1λ0, the 10-d B matching bandwidth is 22%, the realized gain is 8.4 d Bi and the cross-polarization is below-30 d B.