EHF3701 Assignment 01 Answers Year 2025

High Frequency Electronics

Assignment 1 Answers

Year 2025




0027 63 985 5033

,
,
, QUESTION 1

Given:

o characteristic impedence 𝑍0 = 50Ω
o distance between ground planes 𝑏 = 0.32𝑐𝑚
o dielectric constant 𝜀𝑟 = 2.2
o frequency, 𝑓 = 10𝐺𝐻𝑧
o conductor thickness 𝑡 = 0.01𝑚𝑚
o conductor resistance 𝜌 = 0.026Ω
o loss tangent tan 𝛿 = 0.01
o speed of light 𝑐 = 3 × 108 𝑚/𝑠



1.1.1 Using the approximate formula for a symmetric stripline impedence

60 4𝑏
𝑍0 = 𝑙𝑛 ( )
√𝜀𝑟 𝜋𝜔

4𝑏 𝑍0 √𝜀𝑟
ln ( )=
𝜋𝜔 60

4𝑏 𝑍0 √𝜀𝑟
= 𝑒 60
𝜋𝜔

4𝑏
𝜔= 𝑍0 √𝜀𝑟
𝜋𝑒 60

4𝑏
𝜔= 𝑍0 √𝜀𝑟
𝜋𝑒 60

4 × 0.32
𝜔=
50×√2.2
𝜋×𝑒 60


𝜔 = 0.1184𝑐𝑚



1.1.2 Dielectric attenuation

𝜋𝑓√𝜀𝑟 tan 𝛿
𝛼𝑑 =
𝑐

𝜋 × 1010 × √2.2 × 0.01
𝛼𝑑 = × 8.686 𝑑𝐵/𝑚
3 × 108

𝛼𝑑 = 13.5 𝑑𝐵/𝑚