Radiation and coupling studies of finite-size dual polarized vivaldi arrays using a domain decomposition FEM

Increasing functionality demands along with tightened constraints on RF-front-end size, weight and cost, has shifted architectures from multi-system to single yet multifunctional system designs. One of the significant challenges of such systems lays on the design of multifunctional radiators. UWB antenna apertures (arrays) can meet the demands of such designs because they offer large bandwidth, gain and scan volume and can be easily reconfigured by dynamically partitioning the aperture and controlling the element or sub-array excitation. Among others, dual-polarized tapered slot (Vivaldi) arrays are very attractive candidates because they offer large bandwidths (4:1 and upwards), scan volume (typical 50deg-elevation) and polarization diversity. The design of such arrays has been traditionally done using ldquoperiodic cellrdquo (infinite array) approximations in conjunction with full-wave (FEM or BEM) solvers, because large computational savings in terms of meshing and solution are achieved [1]. Infinite array approximation, although very successful for large arrays, it ignores truncation effects, that can have prominent affects at the lower bands of UWB antennas. Moreover, in a multifunctional aperture setting, periodic cell solutions can not be used to predict important design merits such as inter or intra array or sub-array coupling. Presently, the study of such affects has been done either using experiments [4] or supercomputer simulations using traditional full-wave methods eg. FEM, BEM and FDTD [2] The purpose of this paper is to firstly study the radiation behavior of isolated finite arrays under various excitations by quantifying truncations effects, and secondly to quantify inter-array coupling effects. Simulations will be done on commodity workstations via a rigorous yet efficient domain decomposition finite element (DD-FEM) method proposed in [3].