Definition ofunifyingdecouplingefficiencyofdifferentarrayantennas— Case studyofdensefocalplanearrayfeedforparabolicreflector

摘要

This paperemphasizestheimportanceofrecognizingthemajorroleplayedbymutualcouplingeffectsinarrayantennas, especially fordensearrayswithelementspacingwithinhalfawavelength.Forarrayoperationintransmitmode,backward wavesemanatebothfromelementportsthatareexcitedbyforwardwaves,andfromnon-excitedports.Thisoveralland excitation-dependentmismatchishereincharacterizedintermsofadecouplingefficiency.Itisshownhowthisdecoupling efficiencyreducestothewell-knownimpedancemismatchfactorforaconventionalphase-steeredarray(allelementsex- cited), andtotheembeddedelementefficiency(onlyoneelementexcited)usedtocharacterizemultipleinputandmultiple output (MIMO)arrays.Generally,thisdecouplingefficiencycanbeusedtocharacterizethecombinedeffectofmismatchand coupling foranyexcitationofanarray,forinstance,theAirypatternexcitationoffocalplanearray(FPA)feedsforreflectors, as showcasedhere.Theabovementionedformsofdecouplingefficienciesareevaluatedanddiscussedforanexamplearray of idealizedrectangularapertureswithspecialemphasisontheAiryexcitation. -2009 ElsevierGmbH.Allrightsreserved