差分馈电双极化四波束方向图可重构天线

提出了一种平面差分馈电双极化四波束方向图可重构天线. 该天线由两个相互正交的偶极子和四个带PIN二极管的寄生单元构成，有两个差分馈电端口，通过短截微带线给两个相互正交的偶极子馈电. 两个偶极子正交摆放、异面垂直，与寄生单元蚀刻在同一基板上，整体结构简单. 切换PIN二极管的不同状态得到四个波束的方向图可重构和两种方式的极化可重构. 实验表明，?10 dB阻抗带宽为8.9%，覆盖3.27～3.58 GHz频段，平均增益为5.6 dBi，前后比约为10 dB，平均辐射效率为68%. 该天线结构紧凑、成本低、易加工.

Differentially-fed dual-polarization four beam pattern reconfigurable antenna

A planar differentially-fed dual-polarization four beam pattern reconfigurable antenna is proposed in this paper. It is composed of two orthogonal dual-dipole elements and four parasitic elements embedded with four PIN diodes. The two dual-dipole elements are overlapped and 90° rotational symmetrical, making the overall structure very compact. Dual-dipole elements are excited differentially through short microstrip feeding lines. All dipoles and parasitic elements are etched on the same substrate, resulting in a full planar structure. Four beam pattern reconfigurability and dual-polarization reconfigurability are realized by switching the combinations of PIN diodes states. The antenna obtains a ?10 dB impedance bandwidth of 8.9% covering from 3.27 to 3.58 GHz, an average gain of 5.6 dBi, an FBR about 10 dB, and average radiation efficiency of 68% in the measurement. The proposed antenna has compact structure, low cost and easy processing.