An Overview on Monopulse Microstrip Antenna Design Evolution

Abstract

A monopulse radar system functions to detect targeted objects by using Sum and Difference signals from the reflected signals. The use of parabolic type antennas in conventional radar systems has disadvantages in terms of space, mass, and manufacturing costs. Therefore, microstrip antennas have been proposed because they are flat, lightweight, and cheaper to fabricate. Multiple devices used to produce the important sum and difference signals i.e., hybrid junctions, directional coupler, comparator, and other related methods are studied in this paper. This is due to each of them has their own advantages and limitations. Monopulse microstrip antenna also can be designed in single and multiple layers. Single layer antenna structure is smaller in size and low cost. However, the downside of this structure is having low bandwidth. On the other hand, the multi-layer structure has a higher bandwidth compared to single layer. Nevertheless, at the same time it is thicker in size, difficult to integrate as well as requires more expensive manufacturing costs. It is found that the combination of a single layered antenna structure design and hybrid coupler has the potential to provide better advantages in terms of simplicity, space and cost.