i- A 3-element uniform linear array with inter-element spacing of λ/2 is operated as a broadside array ,find the directions of null radiation , find the direction and the relative level of the side lobe .
ii- if the peak radiation is to rotate by 30 degrees off the broadside direction , what should be the current phasing ?
iii- design a non-uniform linear array to have the pattern :
E = [(sin(3Ψ/2))/(sin(Ψ/2))]2
where Ψ=πcosφ , and φ is measured from the array line , namely find the number of elements , the element spacing , and the current amplitudes , also what is the relative side lobe level ?