1. 2015-12-24Mobile Communication Lab. (http://mobile pknu.ac.kr)1 Chapter 9. AC Models

2. 2015-12-24Mobile Communication Lab. (http://mobile pknu.ac.kr)2  9-1. Base-Biased Amplifier  Stiff coupling : ( 10 : 1 ) 비율  직류등가 회로  교류등가 회로 ( if X C ≤ 0.1 R ) ① 교류전압원 → 0 ② 교류전류원 → 개방③ C → open ① 직류전압원 → 0 ② 직류전류원 → 개방③ C → short

3. 2015-12-24Mobile Communication Lab. (http://mobile pknu.ac.kr)3 [ Fig 9-1 a ]

4. 2015-12-24Mobile Communication Lab. (http://mobile pknu.ac.kr)4 [ Fig 9-1 b ] ( Base-biased Amp ) V BE ( 下 ) → I B ( 大 ) → I C ( 大 ) → V C ( 小 ) : 위상 천이

5. 2015-12-24Mobile Communication Lab. (http://mobile pknu.ac.kr)5 * Voltage gain

6. 2015-12-24Mobile Communication Lab. (http://mobile pknu.ac.kr)6  9-2. Emitter-Biased Amplifier ( VDB Amp )

7. 2015-12-24Mobile Communication Lab. (http://mobile pknu.ac.kr)7 ( TSEB Amp )

8. 2015-12-24Mobile Communication Lab. (http://mobile pknu.ac.kr)8  9-3. Small-signal Operation * ac emitter current 가 dc emitter current 의 10% 보다 적게  9-4. AC Beta : dc current gain : ac current gain 기호 : I B V B V E · · · 기호 : i b v b v e · · ·

9. 2015-12-24Mobile Communication Lab. (http://mobile pknu.ac.kr)9  9-5. AC resistance of the Emitter diode + - V BE

10. 2015-12-24Mobile Communication Lab. (http://mobile pknu.ac.kr)10 - diode 전류 ex 9-1 ) ① ② ③

11. 2015-12-24Mobile Communication Lab. (http://mobile pknu.ac.kr)11  9-6. Two Tr Models Z in(base) + - v be

12. 2015-12-24Mobile Communication Lab. (http://mobile pknu.ac.kr)12  9-7. Analyzing an Amp. ① Base-Biased Amp.

13. 2015-12-24Mobile Communication Lab. (http://mobile pknu.ac.kr)13 ② VDB Amp.

14. 2015-12-24Mobile Communication Lab. (http://mobile pknu.ac.kr)14 ③ TSEB Amp.

15. 2015-12-24Mobile Communication Lab. (http://mobile pknu.ac.kr)15  9-8. AC Quantities on the Data Sheet Two-port Network i2i2 i1i1 v2v2 v1v1 ++ - - * H parameters v1v1 + - v1v1 + - i1i1 i2i2 h 11 h 22 h 12 v 2 h 21 i 1

16. 2015-12-24Mobile Communication Lab. (http://mobile pknu.ac.kr)16 ( 출력 단락 ) : 입력 임피던스 → h i ( 출력 단락 ) : 전류 이득 → h f ( 입력 개방 ) : 역전압 이득 → h r ( 입력 개방 ) : 출력 어드미턴스 → h o