Ka band microstrip antenna arrays with high efficiency

Microstrip antennas possess attractive features such as low profile, light weight, small volume and low production cost. In addition, the benefit of a compact low cost feed network is attained by integrating the microstrip feed structure with the radiating elements on the same substrate. However, losses in the microstrip feed network form a significant limit to the achievable gain in microstrip antenna arrays. Losses are the major disadvantage of mm-wave microstrip antenna arrays. This paper presents the design of mm-wave microstrip antenna arrays with high efficiency. Methods to minimize losses in the microstrip antenna array feed network are described. A planar multiport network modeling approach is employed to compute losses in the microstrip antenna feed network. Design considerations, computational results and measured results of 64 and 256 elements patch arrays with high efficiency at mm waves are presented.