CAD CAD Antenna Designer Feed Networks and Impedance Matching

Question 1

What is the primary purpose of an impedance matching network in an antenna system?

Accepted Answer

To maximize power transfer by minimizing reflections between source and antenna

Answer

To increase the gain of the antenna element

Answer

To reduce the physical size of the antenna

Answer

To improve the radiation pattern directivity

Question 2

What is the standard characteristic impedance of coaxial cable used in most RF antenna systems?

Accepted Answer

50Ω

Answer

75Ω

Answer

100Ω

Answer

25Ω

Question 3

A quarter-wave transformer is used to match a 50Ω source to a 200Ω load. What characteristic impedance must the transformer section have?

Accepted Answer

100Ω

Answer

125Ω

Answer

150Ω

Answer

250Ω

Question 4

What does a VSWR of 1:1 indicate about an antenna system?

Accepted Answer

Perfect impedance match with no reflected power

Answer

Maximum mismatch with all power reflected back to source

Answer

Half the incident power is reflected back to the source

Answer

The antenna is resonant at twice the design frequency

Question 5

What is the primary function of a balun in an antenna feed system?

Accepted Answer

To convert between balanced and unbalanced transmission lines

Answer

To increase the antenna bandwidth

Answer

To boost the transmitted power level

Answer

To provide impedance transformation only

Question 6

What is the reflection coefficient magnitude (|Γ|) when a 50Ω source drives a 100Ω load?

Accepted Answer

0.33

Answer

0.25

Answer

0.50

Answer

0.75

Question 7

Which transmission line type uses two parallel conductors separated by a dielectric and is classified as a balanced line?

Accepted Answer

Twin-lead (parallel wire) line

Answer

Coaxial cable

Answer

Microstrip line

Answer

Rectangular waveguide