LO_phase_noise and its effect ...

LO_phase_noiseanditseffectonRecerverPerformanceTech-noteTheCommunicationsEdgeAuthor:C.JohnGrebenkemperLocalOscillatorPhaseNoiseanditsEffectonReceiverPerformanceAllsuperheterodynereceiversuseoneormorelocaloscillatorstoconvertaninputfrequencytoanintermediatefrequencybeforethesignalisdemodulated.Intheidealreceiver,thesefrequencyconversionswouldnotdistorttheinputsignal,andallinformationonthesignalcouldberecovered.Inareal-worldreceiver,boththemixerusedforconvertingthesignal’sfrequencyandthelocaloscillatorwilldistortthesignalandlimitthereceiver’sabilitytorecoverthemodulationonasignal.Mixerdegradations,suchasundesiredmixingproducts,canbeminimizedbyproperdesignintherestofthereceiver.Thelocaloscillatordegradations,whichare