14
Active Antennas in Substrate Integrated Waveguide (SIW) Technology
14.1 Introduction
In this chapter, the substrate integrated waveguide (SIW) technology is adopted in the development of active low-profile antennas featuring a cavity-backed configuration; this topology consists of a traditional planar antenna where the radiating element is connected to a cavity. In the framework of modern wireless systems, these antenna structures have been extensively studied and implemented, as they offer many advantages, like increased efficiency performance thanks to the suppression of the unwanted surface-wave modes and better heat-dissipation capabilities due to the presence of an adequate metal surface. These features are particularly favourable in large array configurations handling high power levels and make these structures really suitable for wireless sensor networks and space communication applications.
In fact, low-profile antennas find an interesting field of application in the realization of reconfigurable phased-array configurations. Generally, this kind of designs requires compact, active antennas as unit elements, in order to avoid grating lobes when scanning the beam and to minimize spurious radiation. When active antenna elements are used, coupled oscillator arrays ...
