Справочник Пользователя для Intel 820E

180  

Design 

Guide 

Ω

Ω

Ω

Ω

G

G

4.5 mils

2.1 mils

6 mils

18 mils

10 mils

S

a) Microstrip cross section for 28-

Ω  

trace

b) Stripline cross section for 28-

Ω 

trace

G

G

5 mils

1.2 mils

5 mils

13.5 mils

6 mils

S

7 mils

1.2 mils

1.2 mils

x-section_28trace

 

Note:  Do not forget ground floods and stitching. 

3D field solvers, such as those by HP, Ansoft, Sonnet, and Polar, are most accurate when calculating the 
impedance. Z calculators based on equations (zcalc) also are fairly accurate. The differences are listed in 
the following table. 

H  4.5 4.5 4.2 4.8 4.5 4.5 

W 18 18 18 18 17 19 

W1  18.1 18.1 18.1 18.1 17.1 19.1 

T  1.4 2.8 1.4 1.4 1.4 1.4 

ε

r  4.5 4.5 4.5 4.5 4.5 4.5 

Z0 

(3D) 

29.0 28.4 27.6 30.4 30.2 27.9 

Z0 

(zcalc) 

29.1 28.7 27.7 30.4 30.2 28.0