环形天线设计的rfPIC12F675

Thisapplicationnotedescribesthedesignofasingle-

endedloopantennaforrfPIC12F675transmitters.The

PCBdesignwillcoverall3frequencybandsfrom

290MHzthrough930MHzwithafewcomponent

valuechanges.

ThepreviousMicrochipRFtransmittershadbalanced

outputswhichrequiredtwiceasmanycomponentsto

biasthepoweramplifierandmatchimpedance.The

rfPIC12F675usesfewercomponents,deliversalmost

10dBmoreoutputpowertotheantenna,and

increasesthemaximumfrequencyto930MHz.AN868DesigningLoopAntennasfortherfPIC12F675ThisapplicationnotealsodocumentsthetuningandtestingoftheantennadesigntoavoidamanufacturingAuthor:MyronLoewenstepfortuning.ApictureofthefinishedboardisshownMicrochipTechnologyInc.inFigure1.FormoredetailsonRFregulatorylimitsandcompliancetestingseeApplicationNoteAN242,