SP 5.4-1 soln - KU ITTCjstiles/723/handouts/SP 5.4-1 soln.pdf · 4/4/2008 SP 5.4-1 soln 1/2 Jim...

2
4/4/2008 SP 5.4-1 soln 1/2 Jim Stiles The Univ. of Kansas Dept. of EECS Special Problem 5.4-1 A matching network has been constructed to match a complex load to a transmission line with characteristic impedance 0 50 Z = Ω . The design frequency of this matching network is 0 10 f MHz = . Note that this matching network is not specifically one of the standard designs that we studied. The capacitor has a capacitance of value: 9 10 2 C farads π = Determine the complex admittance L Y of the load. Solution First, combine the capacitor and L Y to form an new load with admittance L Y : 0 50 Z = Ω 01 100 Z = Ω L Y 4 λ 0 in Γ = C

Transcript of SP 5.4-1 soln - KU ITTCjstiles/723/handouts/SP 5.4-1 soln.pdf · 4/4/2008 SP 5.4-1 soln 1/2 Jim...

Page 1: SP 5.4-1 soln - KU ITTCjstiles/723/handouts/SP 5.4-1 soln.pdf · 4/4/2008 SP 5.4-1 soln 1/2 Jim Stiles The Univ. of Kansas Dept. of EECS Special Problem 5.4-1 A matching network has

4/4/2008 SP 5.4-1 soln 1/2

Jim Stiles The Univ. of Kansas Dept. of EECS

Special Problem 5.4-1 A matching network has been constructed to match a complex load to a transmission line with characteristic impedance 0 50Z = Ω . The design frequency of this matching network is 0 10f MHz= . Note that this matching network is not specifically one of the standard designs that we studied. The capacitor has a capacitance of value:

9102

C faradsπ

=

Determine the complex admittance LY of the load. Solution First, combine the capacitor and LY to form an new load with admittance LY ′ :

0 50Z = Ω 01 100Z = Ω LY

0inΓ = C

Page 2: SP 5.4-1 soln - KU ITTCjstiles/723/handouts/SP 5.4-1 soln.pdf · 4/4/2008 SP 5.4-1 soln 1/2 Jim Stiles The Univ. of Kansas Dept. of EECS Special Problem 5.4-1 A matching network has

4/4/2008 SP 5.4-1 soln 2/2

Jim Stiles The Univ. of Kansas Dept. of EECS

where:

( )0

97 102 10

20.01

L L

L

L

Y j C Y

j Y

j Y

ω

ππ

′ = +

⎛ ⎞= +⎜ ⎟

⎝ ⎠= +

Now, in order for 0inΓ = , we know that (because of the 4

λ

transformer):

201 0

20 01

L LZ ZZ YZ Z

′ ′= ⇒ =

And so if matched:

( )0

2201

50 0 005100L

ZY .Z

′ = = =

Therefore:

0.005 0.01 0.005 0.01L L LY j Y Y j⇒ = −′ = = +

0 50Z = Ω 01 100Z = Ω 0L LY j C Yω′ = +