一种新型VHF/UHF双频宽带车载全向天线

摘要

A new dual-band broadband vertically polarized omni-directional vehicular antenna is proposed for VHF/UHF operation.The antenna employs a new design scheme.On the top of the lower arm of a center-fed VHF vehicular dipole,a UHF λ850 MHz/4 coaxial choke sleeve is added.The upper arm is divided into 3 segments joined with 2 λ850 MHz/2 phase-inversed coils and a choke coil is added to the bottom of the antenna.As a result,a new VHF/UHF dual-frequency broadband vertically polarized omni-directional vehicular antenna,combined from a VHF center-fed dipole and a UHF array of 3 elements in series,is achieved.The antenna has good radiation performance over VHF band： 30~225 MHz and UHF band： 800~880 MHz,with antenna gain of 1.5~4.5 dBi over VHF band and more than 6 dBi over UHF band.%提出了一种工作在VHF/UHF频段的双频段宽带垂直极化车载鞭状天线。天线在VHF中馈车载鞭状天线的下辐射体顶端加一个UHF频段8λ40 MHz/4同轴扼流套,将上辐射体分为三段并在段间串接两个λ840 MHz/2倒相线圈,在天线底部加同轴扼流圈,完成了一种VHF中馈鞭状天线与一副UHF三元串联馈电直线阵天线复合的新型VHF/UHF双频段超宽频带垂直极化车载全向天线。该天线在VHF频段（30 MHz~225 MHz）,UHF频段（800 MHz~880 MHz）内均具有良好的辐射特性。增益在VHF频段为1.5~4.5 dB i,在UHF频段大于6 dB i。