Topic: Radar and Navigation
In a monostatic radar, if the antenna aperture is doubled, then the radar range will
- A. reduce by a factor of 2
- B. increase by a factor of 2
- C. reduce by a factor of $\sqrt{2}$
- D. increase by a factor of $\sqrt{2}$
Answer: D. increase by a factor of $\sqrt{2}$
Explanation: $R_{\text{max}} = \left(\frac{P_{t}G\sigma A_{e}}{(4\pi)^{2}S_{\text{min}}}\right)^{1/4}$.
Assuming antenna aperture here relates to the cross-sectional area derived from diameter D, where $A_{e} = \frac{\pi D^{2}}{4}$.
So, $R_{\text{max}} = \left(\frac{P_{t}G\sigma \pi D^{2}}{4(4\pi^{2})S_{\text{min}}}\right)^{1/4}$.
Thus, $R_{\text{max}} \propto (D^{2})^{1/4} \propto D^{1/2}$.
If the antenna aperture (diameter D) is doubled, the radar range will be increased by a factor of $\sqrt{2}$.