AWR Application Notes

AWR Software for the Design of MIMO and Phased Array Antenna Systems 3 www.cadence.com/go/awr These requirements showcase some of the application-specific metrics that drive range, frequency, antenna size, and gain. They represent the starting point for the system designer, who also will weigh cost and delivery concerns and available semiconductor and integration technologies when considering possible architectures and defining individual component performance targets. The AWR VSS software provides system designers with the capabilities needed to convert these requirements into hardware specifications and work out the initial design details. Starting with the phased array configuration, the AWR VSS software is able to represent thousands of antenna elements with a single model, enabling the antenna design team to quickly produce radiation patterns with basic array properties such as number of elements, element spacing, individual element gain or radiation pattern (imported measured or simulated antenna data), array configuration, and gain taper. The model, shown in Figure 1, allows designers to specify the array's physical configuration based on various standard lattice and circular geometries, as well as custom geometries. Figure 1: Single phased array elements can model large scale (thousands of elements) arrays The array behavior is easily defined through a parameter dialog box or a data file containing configuration parameters such as gain and phase offset, theta/phi angles of incidence, number of elements in both X/Y locations (length units or lambda- based), spacing, and signal frequency. This model greatly simplifies early exploration of large-scale phased array configura- tions and individual antenna performance requirements versus the old method of implementing such a model using basic individual blocks, where array sizes were generally limited to several hundred elements, each modeled as a single input/single output block. Figure 2 shows a portion of the AWR VSS parameter dialog box used to quickly define an antenna-array architecture using standard or custom geometries. The lattice option allows configuration of the phased array in a lattice pattern using the number of elements along the X and Y axes, NX and NY, element spacing along these axes, dx and dy, and gamma, the angle between these axes. Setting gamma to 90° results in a rectangular lattice, while setting it to 60° creates a triangular lattice. Figure 2: Phased array parameter dialog box Any positive value for gamma may be used to configure the lattice, while the circular option enables configuration of circular phased arrays with one or more concentric circles. The number of elements in each concentric circle and the radius of each circle can be defined as vectors by variables NC and R. Examples of lattice and circular array configurations are shown in Figure 3. Figure 3: Standard AWR VSS array geometries — lattice (left), circular (right)

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