User's Manual
GuardianManual001‐5006‐000Rev0 22|Page
Therequiredantennaimpedanceis50ohms.Toreducepotentialradiointerference,theantennatypeanditsgain
shouldbechosentoensuretheeffectiveisotropicradiatedpower(EIRP)isnotmorethanrequiredforsuccessful
communication.
SeeTable1.7foralistoftestedantennarecommendations.TheseantennasareFCC
approvedforusewiththe
Guardian.Similarantennatypesfromothermanufacturersareequallyacceptable.Itisimportanttofollowthe
manufacturer’srecommendedinstallationproceduresandinstructionswhenmountinganyantenna.
2.5.2 OMNIDIRECTIONALANTENNA
Ingeneral,anomnidirectionalantennashouldbeusedatamasterstationandRelayPoints.Thisallowsequal
coveragetoalloftheremotelocations.OmnidirectionalantennasaredesignedtoradiatetheRFsignalina360‐
degreepatternaroundtheantenna.Shortrangeantennassuchasfoldeddipoles
andgroundindependentwhips
areusedtoradiatethesignalinaballshapedpatternwhilehighgainomniantennas,suchasacollinearantenna,
compresstheRFradiationsphereintothehorizontalplanetoprovidearelativelyflatdiscshapedpatternthat
travelsfurtherbecausemoreoftheenergy
isradiatedinthehorizontalplane.
2.5.3 YAGIANTENNA
Atremotelocations(notusedasaRelayPoint),adirectionalYagiisgenerallyrecommendedtominimize
interferencetoandfromotherusers.
2.5.4 VERTICALDIPOLES
Verticaldipolesareveryoftenmountedinpairs,orsometimesgroupsof3or4,toachieveevencoverageandto
increasegain.Theverticalcollinearantennausuallyconsistsofseveralelementsstackedoneabovetheotherto
achievesimilarresults.
Figure2.4‐AntennaTypes
Omni(VerticalCollinear) Yagi VerticalDipole