一种小型特殊形状圆极化多频谐波天线设计

Design of Circularly Polarized Multi-Frequency Small Antenna with Special Shape

针对现代无线通信系统中紧凑型天线的需求,提出了一种具有二次谐波特性的新型四频天线。首先,该天线采用特殊形状的介质谐振器,并结合了曲折复合右手/左手(composite right/left-hand,CRLH)结构;其次,中间部分采用了一个介电负载,由三个CRLH单元连接而成的。三个CRLH单元相互连接,以120°的角度排列,垂直于微带环贴片。最后,利用微带曲折线通过电感元件实现圆极化,从而改变天线表面的电流分布。此外,在天线上加了一个寄生环来实现二次谐波谐振。实验结果表明,与传统CRLH技术制造的天线相比,该天线的特殊形状提供了圆极化和更加紧凑的尺寸,一次谐波的谐振频率分别为2.25 GHz和2.8 GHz,二次谐波的谐振频率为4.5 GHz和5.6 GHz。

Aiming at the demand of compact antenna in modern wireless communication system,a new type of quad-band antenna with second harmonic characteristics is proposed.Firstly,the antenna adopts a dielectric resonator with a special shape and combines a zigzag composite right/left-hand(CRLH)structure.Secondly,the middle part adopts a dielectric load,which is formed by connecting three CRLH units.Three CRLH units are connected with each other,arranged at an angle of 120 degrees,and perpendicular to the microstrip ring patch.Finally,the microstrip meander line is used to realize circular polarization through inductive elements,thus changing the current distribution on the antenna surface.In addition,a parasitic loop is added to the antenna to realize the second harmonic resonance.Experimental results show that compared with the antenna manufactured by traditional CRLH technology,the special shape of the antenna provides circular polarization and more compact size,and the resonance frequencies of the first harmonic are 2.25 GHz and 2.8 GHz respectively,the resonance frequencies of the second harmonic are 4.5 GHz and 5.6 GHz.