用于全球定位系统终端的小型化四臂螺旋天线

Miniaturized four-armhelical antenna for GPS terminals

设计一种工作在全球定位系统(GPS)L1频段小型化四臂螺旋天线.该天线由弯折的螺旋臂和双层馈电网络组成,与传统的半波长四臂螺旋天线相比,不仅缩短了螺旋臂的长度,而且有效利用了接地面的尺寸,从而在紧凑的空间内仍能保持较高的顶点增益.天线尺寸为20 mm×20 mm×21 mm(0.10λ0×0.10λ0×0.11λ0,λ0为中心频率1.575 GHz时对应的波长).实测结果表明,|S11|≤-10dB的阻抗带宽为2.9%(1.555~1.600 GHz),轴比≤3 dB的圆极化带宽为14%(1.386~1.602 GHz),在L1频段中心频率处的顶点增益达到4.15 dBi.因此,可应用于小型化的全球定位终端设备中.

A miniaturized four-arm helical antenna working in the L1 band of global positioning system(GPS)is designed.The antenna consists of a bent helix arm and a double-layer feeding network.Compared with the traditional half wavelength four arm helix antenna,it not only shortens the length of the helix arm,but also effectively uses the size of the ground,so as to maintain a high vertex gain in a compact space.The antenna size is 20 mm×20 mm×21 mm(0.10λ0×0.10λ0×0.11λ0,λ0 corresponds to the wavelength when the center frequency is 1.575 GHz).The measured results show that the impedance bandwidth of|S11|≤-10dB is 2.9%(from 1.555 to 1.600 GHz),the circular polarization bandwidth of axis ratio≤3 dB is 14%(from 1.386 to 1.602 GHz),and the gain at the center frequency of the L1 band is achieved 4.15 dBi.Therefore,it can be used in miniaturized global positioning terminal equipment.