Question

You are an antenna engineer and you are asked to design a high directivity/gain antenna for a space-borne communication system operating at 10 GHz. The specifications of the antenna are such that its pattern consists basically of one major lobe and, for simplicity, no minor lobes (if there are any minor lobes they are of such very low intensity and you can assume they are negligible/zero). Also it is desired that the pattern is symmetrical in the azimuthal plane. In order to meet the desired objectives, the main lobe of the pattern should havea half-power beamwidth of 10 degrees. In order to expedite the design, it is assumed that the major lobe of the normalized radiation intensity of the antenna is approximated by 2.9. U (θ , φ)-cos" (6) and it exists only in the upper hemisphere (0 /2,0 ф 2 ). Determine the: (a) Value of n (not necessarily an integer) to meet the specifications of the major lobe. Keep 5 significant figures in your calculations. (b) Exact maximum directivity of the antenna (dimensionless and in dB). (c) Approximate maximum directivity of the antenna based on Kraus' formula (dimension- (d) Approximate maximum directivity of the antenna based on Tai & Pereira's formula less and in dB) (dimensionless and in dB).

Answer 1