MHMIC technology applied to active integrated antennas

An active integrated antenna may be defined as a radiating element on which the current distribution along the structure may be altered in a controlled manner. The ability to control the current distribution along its structure is the unique feature of this class of antennas and gives it its primary advantage. With this ability, radiation characteristics such as pattern shape, axial ratio, and gain may all be controlled. An antenna configuration with integrated active devices has been developed [1]. The resultant topology is a microstrip transmission line configuration with cascade distributed amplifiers. This active antenna has been designed, modelled, fabricated, and its radiation characteristics measured. The above capabilities of controlling the radiation characteristics have been verified. The prototype active antenna utilized three packaged amplifiers and a microstrip transmission line on a Duroid substrate (ε
r
=2.94) (Figure 1). To facilitate the fabrication of active integrated antennas, the application of Miniature Hybrid Microwave Integrated Circuit (MHMIC) technology was investigated.