PDF《V2e-j. .l》

4 lmin angle of reflection coefficient g ? B (4) Reading Z from chart also can get |Γ| & φ φ x r ZL Sheet

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13 (5) φ Z/Zo |Γ|

1 Z Zo = + ?

1 1 Γ Γ Admittance = Y/Y0 = φ Y/Yo -|Γ|

1 On a Smith chart point diametrically opposite Z Z gives Y Y Note Y Y = G + j. Conductance Susceptance On admittance chart r circles g circles & x circles b circles. Note g = G Y and b = B Y o o

0 o o = → →

1 Zo β Sheet

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13 (6) To transform an impedance along a T.L, rotate around the VSWR circle:- Lmin Z(in) BACKWARDS by Lmin/λg takes us to Zin. ZL/Zo ZL Vmin Lmin/λg B l/λg Zo Sheet

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13 (7) Represent a series inductance on a smith chart. 0.5 Read values off the reactance scale 0.20 Therefore, assuming a frequency of say 1GHz the value of series inductance represented on the above Smith Chart is given by:- 2.38nH E

1 * 2π 0.3 *

50 2π N.X L

50 wrt 0.3 0.2 - 0.5 chart Smith from read ) (X Reactance

9 L L = = = ? ? = ? = f Similarly for a series capacitor Sheet

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13 (8) Represent a series capacitance on a smith chart. 1.0 Read values off the reactance scale 0.5 Therefore, assuming a frequency of say 1GHz the value of series capacitance represented on the above Smith Chart is given by:- ohms)

50 (usually factor g normalisin the is N Where 6.36pF

5 .

0 *

50 * E

1 * 2π

1 .N.X 2π

1 C

50 w.r.t 0.5 0.5 - 1.0 chart Smith from read ) (X Reactance

9 C C = = = ? ? = ? = f To represent shunt reactance we need to plot admittance onto the Smith Chart. It is easiest to use a Smith chart with both impedance (usually in black) lines and admittance lines (usually in red) on the same chart. Or you can rotate the Smith chart

180 degrees. Sheet

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13 (9) Represent a shunt inductance on a smith chart. 0.8 Read values off the admittance scale 0.2 Therefore, assuming a frequency of say 1GHz the value of shunt inductance represented on the above Smith Chart is given by:- ( ) ohms)

50 (usually factor on normaisati N 13.26nH

6 .

0 * E

1 * 2π

50 Y * 2π N L

50 w.r.t 0.6mhos 0.2 - 0.8 chart Smith from read ) (Y Admittance

9 L L = = = = ? = ? = f Sheet

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13 (10) Represent a shunt capacitance on a smith chart. 1.0 Read values off the admittance scale 0.2 Therefore, assuming a frequency of say 1GHz the value of shunt inductance represented on the above Smith Chart is given by:- ( ) ohms)

50 (usually factor on normaisati N 2.5pF

50 * E

1 * 2π 0.8 N * 2π Y C

50 w.r.t 0.8mhos 0.2 - 1.0 chart Smith from read ) (Y Admittance

9 C C = = = = ? = ? = f 专注于微波、射频、天线设计人才的培养 易迪拓培训

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