Which answer is correct for this Antenna and Wave Propagation homework problem?

[Dhruv]

Homework Statement

I have attached the photo of the problem below.

Homework Equations

The Attempt at a Solution

According to me answer should be (a) but book is giving answer as (d).

 

[berkeman]

Homework Statement

I have attached the photo of the problem below.

Homework Equations

The Attempt at a Solution

According to me answer should be (a) but book is giving answer as (d).

What do they mean by "omnidirectional" here? Like a spherical radiation pattern? Or omnidirectional in the plane that is perpendicular to a dipole antenna?

I also agree that d is a strange answer, but knowing what they mean by omnidirectional may help...

 

[Dhruv]

L

What do they mean by "omnidirectional" here? Like a spherical radiation pattern? Or omnidirectional in the plane that is perpendicular to a dipole antenna?

I also agree that d is a strange answer, but knowing what they mean by omnidirectional may help...

Like a spherical radiation pattern.

 

[Dhruv]

What do they mean by "omnidirectional" here? Like a spherical radiation pattern? Or omnidirectional in the plane that is perpendicular to a dipole antenna?

I also agree that d is a strange answer, but knowing what they mean by omnidirectional may help...

I should calculate the array factor correct ? And then from there I should calculate angle for maxima ?

 

[Dhruv]

Help please .