A Multilayer Active Microstrip Antenna Array using Silicon Bipolar Monolithic Amplifiers in a Spatial Power Combining Configuration

Recently, a significant amount of research has concentrated on two or three terminal devices in spatial power combining structures. This paper presents a multilayer active microstrip antenna array in a spatial power combining technique by using silicon bipolar monolithic integrated circuits with high reliability. With the advantage of a multilayer structure, the radiation patterns from the antenna side are not affected by the radiation from circuit side, and the patterns are found to agree well with theory. An extra gain of 8.1 dB has been measured in comparison to the passive array, including the feed network loss compensation. This type of array can be built at low cost and, due to the excellent unit-to-unit uniformity of the MAR amplifier, it can be the ideal building block for large microstrip phased array systems. These structures have promising applications in mobile communications, non-invasive medical imaging and other systems where radiating structures are desirable.