1. 2010 mid-term examination (100)
Microwave Engineering
Date: October 20, 2010.
Z − Z0
Z = 50Ω, f = 5.3 [GHz], Γ = L
1. Consider a coaxial line with 0 Z L + Z 0 (80)
1)Calculate the reflection coefficient, Γ in terms of the magnitude (in dB) and
phase when resistors, R = 23 [Ω] and R = 374 [Ω] are attached. (10) Hint:)
Γ(dB) = 20 log10 Γ
2)Calculate the reflected and transmitted powers for problem 1) when
Pi = 1 [mW ] . Hint:) PR =| Γ | 2 Pi , PT = (1− | Γ | 2 ) Pi (20)
3)Calculate the VSWR (Voltage Standing Wave Ratio) for problem 1). Hint:)
1+ Γ
VSWR =
1 − Γ (10)
4)Calculate the reflection coefficient, Γ in terms of the magnitude and phase
when an inductor, L = 3[ nH ] is attached. Hint:) Z L = jωL (20)
5)Calculate the transmitted power to the inductor in problem 4) when
Pi = 1 [mW ] . (10)
6)Calculate the VSWR (Voltage Standing Wave Ratio) for problem 4). (10)
2. 2. Compare the voltage in circuit theory and the voltage wave in transmission line
theory (10)