Page 139 - Complete Wireless Design
P. 139
Amplifier Design
138 Chapter Three
Figure 3.39 Pi matching network after combining components.
Follow this procedure to match two unequal and pure resistances, as shown
in the example of Fig. 3.40.
1. Decide on the loaded Q (in this case 15), and the frequency (in this case 1.5
GHz).
2
2
2. Find the “R” value by “R” R (Q 1); “R” 12 (15 1); “R” 2712
SMALL
ohms. R is the smaller value of the two resistances, whether it is R or
SMALL S
R .
L
3. Find X QR 15 12 180 ohms.
S1 S
4. Find X “R”/Q 2712/15 181 ohms.
P1
5. Find:
"R"
2712
Q 1 1 6.76
2 R 58
L
6. Find:
"R" 2712
X 401 ohms
P2 Q 6.76
2
7. Find:
X Q R 6.76 58 392 ohms
S2 2 L
8. X and X are combined by:
P1 P2
X X 181 401
P2
P1
X 125 ohms
TOTAL X X 181 401
P1 P2
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