A Design of LPDA Antenna with Patch Dipoles for Airbone Communication

Ying Liu,Yongwei Li,Yuwen Wang,Ting Yin,P Liu,X Tu

doi:10.1051/matecconf/201711401011

Abstract

This article designs a Log-periodic Dipole Antenna(LPDA) for airborne communication. This antenna replaces traditional dipoles with patch dipoles, the feeder adopt gradual changing structure, its working frequency is from 200MHz to 450MHz.Use HFSS which is the special software for high-frequency electromagnetic to calculate, optimize and simulate. The simulation rsults are in good agreement with the test results. The designed antenna improves its flexibility and reduces profile, it provide a good method for the design of the airborne antenna.

Highlights

LPDA(Log Periodic Antenna) is proposed in 1957,it is a kind of directional antenna[1,2,3,4,5,6],LPDA is a FI(frequency independent)antenna, FI is that the antenna is transformed by a proportional factor τ,the performance of antenna operating requency is equal to antenna operating frequency.LPDA has wider bandwith, which can be designed as 10:1(the ratio of the highest frequency to the lowest frequency),obviously,LPDA belongs to UWB(Ultra Wide Band)antenna[7].The profile of traditional LPDA[8]is relatively high,and its flexibility is not very ideal,but we can replace traditional dipoles with patch dipoles to research airborne antenna.Patch-dipoles LPDA is better to keep correspondence with the wing of aircraft,what’s more,its electrical properties is less affected by the deformation of the wing.so we design a patch-dipoles LPDA applied to airborne antenna
A patched-dipoles LPDA operating at 200MHz-450MHz was designed for a gain of 10dB.the structure of LPDA[9] is affected by the combination of the scaling factor Tau(τ) and spacing factor Sigma(σ)[10],which can be calculated from carrel curves[11], τ corresponding to the best design is 0.95, σ is 0.17. α is 8.411 degree,N(the numbers of dipoles) is 17.From the operating principle of LPDA,we can know that for obtainning higher gain,we must add the number of dipoles,so we add four dipoles,the number of dipoles of LPDA is 21
The input impedence of LPDA is about 80ohm,it is easy to match with coaxial cable which characteristic impedance is 75ohm

Summary

Introduction

LPDA(Log Periodic Antenna) is proposed in 1957,it is a kind of directional antenna[1,2,3,4,5,6],LPDA is a FI(frequency independent)antenna, FI is that the antenna is transformed by a proportional factor τ,the performance of antenna operating requency is equal to antenna operating frequency.LPDA has wider bandwith, which can be designed as 10:1(the ratio of the highest frequency to the lowest frequency),obviously,LPDA belongs to UWB(Ultra Wide Band)antenna[7].The profile of traditional LPDA[8]is relatively high,and its flexibility is not very ideal,but we can replace traditional dipoles with patch dipoles to research airborne antenna.Patch-dipoles LPDA is better to keep correspondence with the wing of aircraft,what’s more,its electrical properties is less affected by the deformation of the wing.so we design a patch-dipoles LPDA applied to airborne antenna

The Design of Patch-dipoles LPDA

The Structure and Results of LPDA In HFSS

The Physical Design of LPDA

Summary