Basic Introduction to Yagi-Uda Antenna

Yagi-Uda Antenna is the array of wire antenna, where contains one dipole as the driven element and at least two conductor rods as the parasitic elements.

The antenna with only one parasitic element is called Yagi antenna and have two conditions.

Condition 1: The parasitic element (Reflector)’s electrical length greater than driven element.

Condition 2: The parasitic element (Director)’s electrical length shorter than driven element.

Simplest Yagi-Uda antenna: Driven Element couple with one Reflector and one Director

As ther Director elements increase,

the angle of the Half-power Beamwidth (θ) will be narrower,

the directivity of antenna increase,

and the gain of antenna increase.