The horn antenna is widely used in thetransmission and reception of RF microwave signals. It isusually an assembly of flaring metal waveguide andantenna. Beyond the fundamental knowledge of microwavepropagation it is essential in the design of horn antenna tounderstand the intricacies and design considerations at twoimportant ends: the points of propagating microwaves andpoints of intercepting microwaves. Great care must betaken at the receive ends especially if it involvesastronomical applications where the microwaves to beintercepted are from extra terrestrial sources extremely faraway and hence very weak. This paper highlights the designconsiderations of a horn antenna which are fundamentalprinciples employed in the design of a compact hornantenna that will be suitable for astronomical application at
