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BI TP TRUYN SNG V ANTEN

1. Mt my pht c cng sut 3 W, anten pht c h s khuch i l 30 dBi. c ly 40

km t mt anten thu c din tch hiu dng l 3,5 m2, hiu sut lm vic 100%. Tnhcng sut sng mang nhn c anten thu.

2. Xc nh cng sut my pht cn thit thc hin tuyn thng tin c cc iu kin: c

ly thng tin 50 km, tn s cng tc 2GHz, h s khuych i ca anten thu v anten phtl 30 dBi, cng sut anten thu nhn c l 10-6W.

3. Mt my pht c cng sut 50 W. Biu din cng sut my pht sang n v dBm v

dBW?

4. Cng sut bi 9 c cp cho anten v hng lm vic vi sng mang c tn s 900MHz, tm cng sut thu (tnh theo dBm) ti im cch anten pht mt khong 10 km. Gis anten thu c h s khuch i l 2 v sng truyn trong khng gian t do.

5. Tnh tn hao khi truyn sng trong khng gian t do (theo dn v dB) bit c ly truyn

sng 50 km, tn s cng tc 2 GHz, vi anten v hng.

6. Xc nh mt cng sut ti im cch anten 30 km ca mt anten c cng sut bc x5 W v h s khuch i ca anten l 40 dBi.

7. Cho ng truyn c cc thng s sau: Cng sut bc x 15 W, bc sng cng tc 35

cm, h s khuch i ca anten pht l 100, cao ca anten pht v anten thu ln lt l

80 m v 20 m, c ly ng truyn l 10 km. Vi R = 0,91 v = 1800 khi sng phn cc

ngang v R = 0,68; = 1800 khi sng phn cc ng. Xc nh h s suy gim?

8. Mt anten pht c t cao 49m v anten thu c t cao 25m. Khong cchtm nhn thng ca hai anten ny l gi tr no di y?

9. Mt anten pht c t cao 30m v anten thu c t cao 15m. Khong cch

tm nhn thng ca hai anten ny l gi tr no di y?

10. Anten pht v tuyn truyn hnh t cao 64m. Tnh cao ca anten thu ti mtim t cch xa i pht mt khong 50 km c th thu c tn hiu.

11. Xc nh h s khuch i (theo dBi) ca anten c h s hng tnh l 40 v hiu sutlm vic 60%.

12. Xc nh cng sut bc x ng hng tng ng (theo dBW v dBm) ca mt anten

c h s hng tnh 43 dBi, hiu sut 70% v cng sut u vo anten l 5 W.

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13.Mt anten c in tr bc x 20 , in tr tn hao 0,5 v h s hng tnh l 200.

Xc nh hiu sut ca anten v h s khuch i.

14.Mt anten c cng sut bc x 65W, cng sut tn hao 5W v h s hng tnh l 500.

Xc nh hiu sut ca anten v h s khuch i.

15. Mt chn t i xng c chiu di ton b 50 cm, cng tc tn s 300 MHz. Xc nhchiu di hiu dng ca n?

16. in tr bc x ca chn t vng dt c gi tr bng bao nhiu?

17. Mt anten gng parabol c h s khuch i l 50 dBi, hiu sut lm vic 60%. Tnhgc na cng sut.

18. Mt anten c gc na cng sut bng 20. Xc nh h s khuch i khi bit hiu sutlm vic ca anten l 55%.

19.Mt anten pht c h s khuch i l 40 dBi, anten c cng sut pht l bao nhiu

anten thu gng parabol c ng knh ming gng 0,9 m; hiu sut lm vic 0,55 tcch anten pht 50 km nhn c cng sut 70 dBW. Gi thit sng truyn trong khnggian t do.

20. Anten gng parabol c h s khuch il 40 dBi, hiu sut lm vic 60%, lm vic titn s 4GHz.Tnh ng knh ming gng.

21. Mt anten pht c h s khuch il 30 dBi, cng sut pht ca anten l 5W. c ly 50km t mt anten thu gng parabol c ng knh ming gng 1,5m. Tnh cng sutanten thu nhn c.

22. Mt anten gng parabol c h s khuch i l 30 dBi, hiu sut lm vic 60%. Tnhgc na cng sut.

23. Mt anten c gc na cng sut bng 1,20. Xc nh h s khuch i khi bit hiu sutlm vic ca anten l 55%.