I-modulator yesigaba iyisekhethi lapho isigaba segagasi lesithwali silawulwa isignali emodulayo.Kunezinhlobo ezimbili zokuguquguquka kwesigaba se-sine wave: ukuguquguquka kwesigaba esiqondile kanye nokuguquguquka kwesigaba okungaqondile.Umgomo wokuguquguquka kwesigaba esiqondile uwukusebenzisa isignali yokumodela ukuze uguqule ngokuqondile imingcele yeluphu ezwakalayo, ukuze isignali yenkampani yenethiwekhi ngeluphu enomsindo ikhiqize ukushintsha kwesigaba futhi yakhe igagasi lokushintshwa kwesigaba;Indlela yokuguqulwa kwesigaba esingaqondile iqala ngokushintsha i-amplitude yegagasi eliguquliwe, bese iguqula ukuguqulwa kwe-amplitude ibe ukuguqulwa kwesigaba, ukuze kuzuzwe ukuguquguquka kwesigaba.Le ndlela yasungulwa ngu-Armstrong ngo-1933, ebizwa ngokuthi i-Armstrong modulation method
Isishintshi sesigaba se-microwave esilawulwa nge-elekthronikhi iyinethiwekhi enezimbobo ezimbili esetshenziselwa ukunikeza umehluko wesigaba phakathi kokuphumayo nokokufaka okungalawulwa isignali yokulawula (ngokuvamile i-DC bias voltage).Inani lokushintsha kwesigaba lingahluka ngokuqhubekayo ngesignali yokulawula noma ngevelu ehlukanisiwe enqunywe kusengaphambili.Abizwa ngokuthi ama-analog phase shifters kanye nama-digital phase shifters ngokulandelanayo.I-modulator yesigaba iyimodula yokhiye wokushintsha kwesigaba kanambambili kusistimu yokuxhumana ye-microwave, esebenzisa igagasi lesikwele eliqhubekayo ukuze lilinganise isignali yenkampani yenethiwekhi.I-Sine wave phase modulation ingahlukaniswa ibe ukuguquguquka kwesigaba esiqondile kanye nokuguquguquka kwesigaba okungaqondile.Ngokusebenzisa ubudlelwano bokuthi i-sine wave amplitude I-engeli iyingxenye yemvamisa esheshayo, igagasi eliguquliwe lingaguqulwa libe yigagasi eliguquliwe lesigaba (noma okuphambene nalokho).Isekethe ye-modulator yesigaba esivame ukusetshenziswa kakhulu yi-varactor diode phase modulator.Isifunda se-modulation yesigaba esingaqondile siyinkimbinkimbi kunesekhethi ye-modulation yesigaba esiqondile.Isimiso saso siwukuthi umzila owodwa wesiginali yenkampani yenethiwekhi ugudluzwa yi-shifter yesigaba esingu-90 ° futhi ingena kumojula ye-amplitude elinganiselwe ukuze icindezele ukuguquguquka kwe-amplitude yesiphathi.Ngemuva kokunciphisa okufanele, isignali etholiwe yengezwa komunye umzila wesithwali ukuze kukhishwe isignali ye-amplitude-modulating.Lo mjikelezo ubonakala ngokuzinza kwemvamisa ephezulu, kodwa ukushintshwa kwesigaba akukwazi ukuba kukhulu kakhulu (ngokuvamile ngaphansi kuka-15°) noma ukuhlanekezela okukhulu.I-modulator yesigaba esilula ivame ukusetshenziswa kuma-transmitters omsakazo we-FM.
