3 views

The beamwidth-between-first null of uniform linear array of $\mathrm{N}$ equally-spaced (element spacing $=d$ ), equally-excited antennas is determined by

1. $\mathrm{N}$ alone and not by $d$
2. $d$ alone and not by $\mathrm{N}$
3. the ratio, $(\mathrm{N} / d)$
4. the product, $(\mathrm{N} d)$