Antenna shortcourse

The following are several types of wire antennas except

• Horn

• Dipole

• Loop

• Monopole

An antenna with dimensions of 0.25λ, working at a frequency of 3GHz, what are the dimensions of the antenna?

• A.      2.5 cm

• A.      25 cm

• A.      10 cm

• A.      100 cm

Choose one of the advantages of wireless communication compared to wired communication…

• At a very long distances, wireless communication has less free space loss than cable loss

• Wireless communication is free from Doppler effect on moving users

• Communication Cables experience multipath resulting in signal degradation

• Multipath in wireless communication protects signals from intersymbol interference (ISI) compared to wired communication which only uses one path.

The radiation pattern of a good antenna is measured in the region ...

• Farfield

• Middle Field

• Reactive Near Field

• Radiative Near Field

The following are some of the things that affect the efficiency of an antenna except

• Power of the antenna

• Material of the antenna

• Dielectric component of antenna

• Antenna impedance

The effective aperture will reach its optimum value if the antenna…

• In the matching impedance condition

• Has losses due to conductive components

• Has losses due to dielectric component

• Antenna efficiency reach 200%

If a conductor element without feed is near the antenna, what are the possibilities?

• The conductor component undergoes scattering aperture principle

• An impedance matching is required due to the antenna input impedance has changed

• A resonant short circuit that change the antenna radiation pattern will occur

• All answer are true

An antenna with an impedance of 50 Ohms, how much is the VSWR value if connected to a 50 Ohms transmission line?

• 1.46

• 0

• 1

• unlimited

The following things happen to electromagnetic waves while inside the propagation channel:

• Reflection

• All answer are true

• Diffraction

• Scattering

The following is the purpose of doing an array on an antenna except...

• Improve antenna gain

• Improve antenna matching impedance

• Better directed radiation pattern

• Improve the received power on the receiver side