Which of the following is a directional antenna that can be used in point-to-point or point-to-multi-point
WiFi communication systems? (Select TWO).

A.
Backfire

B.
Dipole

C.
Omni

D.
PTZ

E.
Dish

Explanation:
Both the Backfire and the Dish antennae are high gain antenna types that transmit a narrow beam of
signal. It can therefore be used as a point-to-point antenna over short distances, but as point-to-multipoint antenna over longer distances.
Incorrect Answers:
B: A dipole is an omni-directional antenna that is not suitable for point to point WiFi communication
systems.
C: Omni-directional antenna that is not suitable for point to point WiFi communication systems.
D: PTZ antenna found on wireless cameras are dipole antenna, which is not suitable for point to point
WiFi communication systems.

http://en.data-alliance.net/how-to-choose-antenna/
https://en.wikipedia.org/wiki/Short_backfire_antennahttps://www.protectiondepot.com/About-Wireless-Security-Cameras_ep_52-1.html