Experiment 5 — Coupler Design.

1 Objectives
Upon completion of this study, the student will become familiar with the
following topics:
1. Measuring the basic parameters of couplers.
2. Understanding the role of couplers in a receiver.
2 Prelab Exercise
1. For a 20 dB single section edge coupled line directional coupler, constructed
as a stripline with ground plane, spacing of B =3.2 mm,
dielectric constant of r =4.7, T =0.035 mm, tan δ =0.02, characteristic
impedance of 50 Ω, and center frequency of 1 GHz. Assuming a
lossless component and a perfect termination:
• Write down the S-parameters matrix of the coupler.
• Calculate its Z Oe and Z Oo .
• UseADSLineCalc,setthecomponenttypeto’CPWCPL2’,and
find the dimensions:
W - width of the lines, S - separation of the lines, L -lengthofthe
coupled lines.
2. For a 20 dB single section edge coupled line directional coupler, constructed
as a microstrip, height of substrate hs =1.6 mm, dielectric
constant of r =4.7, T =0.035 mm, tan δ =0.02, characteristic impedance
of 50 Ω, and center frequency of 1 GHz. Assuming a lossless
component and a perfect termination:
• UseADSLineCalc,setthecomponenttypeto’MCLIN’,C_DB =
−20, E_Eff =90 deg,andfind the dimensions:
W - width of the lines, S - separation of the lines, l - length of the coupled
lines (Z Oe and Z Oo remain the same as the previous question).
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