LY THUYET DÚaNG DAY GHEP VA PHAT TRI^N
3.1 Khai ni fm duong day ghep (2]
Khi hai duang day truyen song khong bj che chSn dugc dai g^n nhaụ cong
suat CO the dugc ghep giCra cae dmmg day do su tuong tac giua dien tir truang ciia moi duang daỵ Nhijng duang day nhu the dugc ggi la ducmg da\- ghep. va thumig
la tap hgp ciia 3 duong day dan dicn dugc dat kha gkn nhaụ mac dii co the su dung
them nhieu duong day khac.Hinh 3-1 cho ta thSy nhic^u c^u true khac nhau cua duong day ghep. Cae duong day ghep thuang dugc coi la mode 'H:M. mtidc nay rat dung doi vai cau true duong da> truyen det va gan dung doi voi duang da\ \ i dai be mat. Noi chung mot day cap 3 sgị nhu dugc bieu dien trong Ilinh 3-1. co the CO 2 mode truyen song rieng biet. Tinh nang na\' dugc su dung de lam ho ghep true tiep, bg hybrit va bg Igc. Nhung duang da\' ghep trong Ilinh 3-1. ha\ eac
duong cap 3 sgi nao do co the dugc bieu d'\cn há\ cau Iriic \c trong 1 linh 3-2 Neu gia sir mot duang truyen song loai ILM, thi tro khang dae linh eua cae duang day
ghep CO th6 hoan loan dugc xac djnh lu eac dien dung hieu dung giua duong da\ \a van t6e truyCn song tren duong da>. Nhu ve trong Ilinh 3-2. Ci: la dung khang giua hai ducmg day vcVi su ecS mat ciia mat phang dat. trong khi dcS Cu \a C:: la dung
khang giua cae ducmg day dan vcVi mat phang dat. vd\ su hicn dien cua duong das dan khaẹ N^u duong day dan mach dai eo kich thucVc gicSng nhau \a co khoang each tcVi mat phang dk la nhu nhaụ Thi C,, - C - . Chu y rang \iec dat ICMI la mat
phang dk cho duong da\ thu 3 chi la cho thuan lien chu khcmg eo sir quan tarn dae
biet nao vi trong nhicni irng dung da\ dan na\ la mat phang dat cua mach dien co cau true mach daị