Question

The gain of a certain lossless antenna is 20 dB. The capture area of the antenna required to produce this gain when operating at 10 GHz frequency is _____$\times {10}^{-3}{m}^2.$

Answer 1

$\text{Here,}f=10\text{GHz,}G=20dB=100$

$\because G=\frac{4\pi }{{\lambda }^2}\times A_c$

$100=\frac{4\pi }{{\left(\frac{3\times {10}^8}{10\times {10}^9}\right)}^2}\times A_c$

$\text{or}{A}_c=\frac{100\times 9\times {10}^{16}}{4\pi \times 100\times {10}^{18}}=7.162\times {10}^{-3}{m}^2$