Sidelobes and attenuation in the backplane in antenna array

i am doing a project with 4 element colinear dipole array. i am seeing lots of sidelobes and much attenuation in the backplane. does anyone know why this is?

Hey,
Nice to see you. I also had same problem when I was measuring the antenna pattern for my 4 element Bi-conical dipole array in the Anechoic chamber. I mounted those dipole elements on a big ground plane and i experienced attenuation on back lobe.


I guess the geometry of ground plane plays important role in the pattern attenuation.The side lobes may be generated due to reflections from edges.Make sure to measure exactly the dimensions of your ground plane LxB in terms of wavelengths,that may be one of the culprit. Some other issues are the metal clamps used for mounting the board. Also the mechanical inconsistency in design may cause some pattern shaping.Let me know if this helps you

Best of Luck.