Question

An antenna has a radiation resistance of $68\Omega$, a load resistance of $10\Omega$, and power gain of $16$. The directive gain of the antenna is

• A. $15$
• B. $16.02$
• C. $17.08$
• D. $18.35$

Answer 1

Answer: (D)

$18.35$

$\eta =\frac{R}{R+R_L}=\frac{68}{68+10}=0.872$
$⟹$ Power gain$=\eta G$
$⟹$ Directive gain, $G=\frac{Powergain}{\eta }=\frac{16}{0.872}=18.35$