Q. Low is the G/T ratio of an antenna, higher is its efficiency.

_________ antennas consist of a regular arrangement of antenna elements with a feed network

A rectangular horn antenna has an aperture area of 3λ × 2λ. Then the maximum directivity that can be achieved by this rectangular horn antenna is:

If the beam width of an antenna in two orthogonal planes are 300 and 600. Then the directivity of the antenna is:

_________ has a constant power spectral density.

The noise temperature of an antenna is given by the expression: