### Wireless Communication Network Lab

```實驗十三

Wireless Communication Network Lab.

[email protected]
http://wcnlab.niu.edu.tw

Wireless Communication Network Lab.
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EE of NIU
Chih-Cheng Tseng
2

Wireless Communication Network Lab.
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•

•

•

EE of NIU
Chih-Cheng Tseng
3

Wireless Communication Network Lab.

EE of NIU
Chih-Cheng Tseng
4

Wireless Communication Network Lab.
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EE of NIU
Chih-Cheng Tseng
5

Wireless Communication Network Lab.
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CVSD調變：將類比輸入信號轉成NRZ形式之數位信號。

CVSD解調：將NRZ之數位信號復回成類比信號輸出。
EE of NIU
Chih-Cheng Tseng
6

Wireless Communication Network Lab.
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+ 12 V
0 .1u
1
7 80 5
3
+5V O u t
2
2
In
3
1 00 k
1k
8
+
_
7
LM311
Ou t
1
4
- 12 V

EE of NIU
Chih-Cheng Tseng
7

Wireless Communication Network Lab.
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EE of NIU
Chih-Cheng Tseng
8

Wireless Communication Network Lab.
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LM311是個集極、射極均為開路的比較器，其

• 當V2>V3時，Q off，即 pin 7 與 pin 1 之間呈斷路關

• 當V2<V3時，Q 飽和，故 pin 7 與 pin 1 之間只有約
0.2 V 的壓降，可看成短路。
EE of NIU
Chih-Cheng Tseng
9

Wireless Communication Network Lab.
7
V2
2
Q
V3
3
1

EE of NIU
Chih-Cheng Tseng
10

Wireless Communication Network Lab.
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• 當Vi>0時，Q open，Vo≈5 V( 註 )
• 當Vi<0時，Q short，Vo≈0 V
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RL
 5V
【註】當輸出端接上負戴RL時，V0 
1k  RL
，必須RL>>1 KΩ才能使Vo維持在 5 V。
EE of NIU
Chih-Cheng Tseng
11

Wireless Communication Network Lab.
+5V
+
12 V
1k
7
Vo
2
Vi
Q
1 00 k
3
1

EE of NIU
Chih-Cheng Tseng
12

Wireless Communication Network Lab.
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pin 2所並接之100 KΩ 電阻 之主要用途為提供pin 2一

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V，此電壓除供比較器使用外，尚可供其它實驗中的
TTL IC做為直流電源使用。
EE of NIU
Chih-Cheng Tseng
13

Wireless Communication Network Lab.
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EE of NIU
Chih-Cheng Tseng
14

Wireless Communication Network Lab.
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EE of NIU
Chih-Cheng Tseng
15

Wireless Communication Network Lab.
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EE of NIU
Chih-Cheng Tseng
16

Wireless Communication Network Lab.

EE of NIU
Chih-Cheng Tseng
17
```