Topic: Electromagnetics
For broadside antenna array, the largest possible spacing between the antenna elements without any grating lobes is
- A. $\lambda/2$
- B. $\lambda$
- C. $2\lambda$
- D. none of the above
Answer: B. $\lambda$
Explanation: In general, as the element spacing is increased, the main lobe beam width is decreased. However, grating lobes (maxima in direction other than the main lobe direction) are introduced when the array element spacing is greater than or equal to one wavelength. Thus, $\lambda$ represents the spacing boundary.