LI CM N i LI M U ii DANH MC HNH V. iv MC LC 1 Chng 1. L THUYT CHUNG V ANTEN V ANTEN VI DI 4 1. L thuyt chung v anten. 4 1.1. Gii thiu anten. 4 1.2. Cc tham s c bn ca anten . 5 1.2.1. S bc x sng in t bi mt anten. 5 1.2.2. Gin bc x. 6 1.2.3. Mt cng sut bc x. 9 1.2.4. Cng cng sut bc x. 10 1.2.5. H s nh hng. 11 1.2.6. H s tng ch. 11 1.2.7. Phn cc. 12 1.2.8. Bng thng. 14 1.2.9. Tr khng vo. 14 2. L thuyt chung v anten vi di. 15 2.1. Gii thiu. 15 2.1.1. u im v hn ch ca anten vi di. 16 2.1.2. C ch bc x. 17 2.2. Cc loi anten vi di thng dng. 19 2.2.1. Anten patch vi di (Microstrip Patch Antenna) 19 2.2.2. Anten vi di lng cc (Microstrop Dipole Antenna) 21 2.2.3. Anten khe mch in (Printed Slot Antenna). 21

2.2.4. Anten sng chy vi di (Microstrip Traveling-Wave Antenna). 22 2.3. Cc k thut cp ngun cho anten vi di. 23 2.3.1. ng truyn vi di (Microstrip Feed). 23 2.3.2. Tip in bng cp ng trc (Coaxial Feed). 25 2.3.3. Ghp gn (Proximity Coupled Microstrip Feed). 26 2.3.4. Ghp khe h (Aperture-Coupled Microstrip Feed). 26 2.4. Mng anten vi di. 28 2.4.1. Gii thiu. 28 2.4.2. ng dn song song. 29 Chng 2. TM HIU PHN MM AWR 34 1. Gii thiu phn mm AWR. 34 2. Mi trng thit k AWR. 35 2.1. Cc thnh phn c bn ca AWR. 35 2.2. Cc thao tc c bn trn AWR. 37 2.2.1. Schematic v Netlist trong MWO/AO. 37 2.2.2. S h thng trong VSS. 38 2.2.3. Cu trc EM. 38 2.2.4. To layout vi MWO v AO. 40 2.2.5. To th cho h s o lng ng ra. 43 2.2.6. Biu din m phng. 44 Chng 3. THIT K ANTEN VI DI 50 1. nh hng ca cc thng s n thit k. 50 1.1. Cht nn. 50 1.2. Hnh dng patch. 51 1.3. K thut tip in. 52

2. Thit k,tnh ton thng s. 53 2.1. Patch. 54 2.1.1. Cht nn. 54 2.1.2. Tn s thit k. 54 2.1.3. Mode c bn. 54 2.1.4. T s kch thc. 55 2.1.5. Chiu di patch. 55 2.1.6. Chiu rng patch. 55 2.1.7. Bng thng ca patch. 56 2.1.8. V tr t patch. 57 2.2. Mt phng t. 57 2.3. ng ni vi di. 57 2.3.1. Cht nn. 58 2.3.2. Sng trong ng truyn vi di. 58 2.3.3. rng hiu dng ca ng truyn vi di. 59 2.3.4. Gi tr quasi-static ca tr khng c trng. 60 2.3.5. phn tn trong ng truyn vi di. 60 2.3.6. rng ng truyn vi di. 62 2.4. Khe h v nhnh ct. 63 2.4.1. V tr t khe h. 63 2.4.2. di khe h. 63 2.4.3. rng khe h. 64 2.4.4. Chiu di hiu dng ca nhnh ct. 64 2.4.5. Chiu di nhnh ct. 64 3. Thit k,m phng bng AWR. 65

3.1. M phng trn AWR. 66 3.1.1. Thit lp thng s cho anten. 66 3.1.2. Thit k anten trn AWR. 69 3.2. Kt qu m phng. 74 4. Kt lun v hng pht trin ca ti. 76 TI LIU THAM KHO 78

Truyn thng khng dy v ang pht trin rt nhanh trong nhng nm gn y, theo cc thit b di ng ang tr nn cng ngy cng nh hn. tha mn nhu cu thu nh cc thit b di ng, anten gn trn cc thit b u cui cng phi c thu nh kch thc. Cc anten phng, chng hn nh anten vi di (microstrip antenna) v anten mch in (printed antenna), c cc u im hp dn nh kch thc nh v d gn ln cc thit b u cui, s l la chn tha mn yu cu thit k trn. Cng bi l do ny, k thut thit k anten phng bng rng thu ht rt nhiu s quan tm ca cc nh nghin cu anten. Gn y, c bit l sau nm 2000, nhiu anten phng mi c thit k tha mn cc yu cu v bng thng ca h thng truyn thng di ng t bo hin nay, bao gm GSM (Global System for Mobile communication, 890 960 MHz), DCS (Digital Communication System, 1710 1880 MHz), PCS (Personal Communication System,1850 1990 MHz) v UMTS (Universal Mobile Telecommunication System, 1920 - 2170 MHz), c pht trin v xut bn trong nhiu cc ti liu lin quan.

Anten phng cng rt thch hp i vi ng dng trong cc thit b truyn thng cho h thng mng cc b khng dy (Wireless Local Area Network, WLAN) trong cc di tn 2.4 GHz (2400 2484 MHz) v 5.2 GHz (5150 5350 MHz).Anten vi di vn c bng thng hp nn vic m rng bng thng thng l mt yu cu ht sc quan trng i vi cc ng dng thc t hin nay. Do , vic gim kch thc v m rng bng thng ang l xu hng thit k chnh cho cc ng dng thc t ca anten vi di.

Kha lun tp trung nghin cu v thit k mt anten vi di tuyn tnh hnh ch nht vi k thut tip in thch hp bng phn mm AWR nhm lm r nhng c trng c bn nh c tnh bc x,bng thng tr khng ca anten vi di. Kha lun gm 3 chng :

Chng 1 : L thuyt v anten v anten vi di. Chng 2 : Gii thiu phn mm AWR. Chng 3 : Thit k,m phng anten vi di bng AWR. Phn u trong chng 1 gii thiu v nh ngha anten cng vi cc tham s c bn ca n nh gin bc x,h s nh hng,h s tng chPhn tip theo trnh by s lc v l thuyt anten vi di,u v nhc im cc loi anten vi di v cc k thut tip in thng gp cho chng.

Chng 2 trnh by mt cch tng qut v cch tng quan v phn mm thit k AWR,s lc cch s dng phn mm.

Chng 3 i vo tnh ton,thit k cc tham s cn thit cho mt anten patch vi di tuyn tnh ghp khe h v tin hnh m phng n trn phn mm AWR.Cui chng 3 l phn kt lun v t ra nhng hng pht trin tip theo nhm gip ti hon thin hn.