基于加载寄生带的双频天线设计

Design of Dual-band Antenna Based on Parasitic Band Loading

文中提出了一种双频印刷天线设计方法,覆盖2.4 GHz和5.2 GHz频段。该天线通过在偶极子天线振臂旁平行放置寄生单元,降低天线在高频段的输入阻抗(通常输入阻抗远大于50Ω),从而实现良好的阻抗匹配,在主谐振频段外产生新的寄生谐振频点,达到双频段工作的目的。为了验证所提出的天线设计方案,建立了仿真模型,并加工了天线实物。通过仿真分析和实测发现,改变寄生金属单元的位置和尺寸只影响高频段谐振频点,几乎不影响低频段谐振频点,而偶极子天线尺寸的改变只影响低频段谐振频点,不影响高频段谐振频点。文中设计的天线具有双频段相互独立特性,因此天线的两个谐振频段可根据需求独立设计。

In this paper,a simple dual-band printed antenna design is proposed in 2.4 GHz and 5.2 GHz frequency bands.By using a parasitic metal strip placed close to the arms of the printed dipole antenna,a dual-band operation is achieved.The input impedance of the antenna at higher frequency band is decreased(the input impedance is usually more than 50Ω),and the good impedance match is achieved at high frequency band,then a new resonant frequency is generated outside the main resonant frequency.In order to analyze and verify the characteristics of the designed antenna,a prototype of the proposed antenna has been simulated and measured.The results show that the change of position and size for the parasitic metal strip only affects the upper resonant point,and almost has no effect on the lower resonant point.Moreover,the change of size for the dipole antenna only affects the lower resonant point,but almost has no effect on the upper resonant point.Therefore,the two resonant frequencies of antenna can be designed independently according to the requirements.