Abstract: In this paper we describe a new approach to what we believe are more reliable, less expensive, and more compact front ends for microwave and millimeter-wave communications. This new approach is based on quasi-optical components, i.e. micorwave and millimeter-wave systems which use some traditionally optical components. Examples of such components are gratings, lenses, Gaussian-beam systems, mirrors and open resonators. In the last decade, it has been suggested that the powers of a very large number of low-power solid-state devices can be combined in free-space using quasi-optical techniques. Usually, such an active device consists of a printed array loaded with diodes or transistors. The active devices feed radiating elements in the array, and the powers of the individual elements are combined coherently in free space.
Keywords: Microvawe communication, quasi-optical components, grid oscilator, antenna, slot antenna, power ampifier.