EM.Picasso® is a versatile planar structure simulator for modeling and design of printed antennas, planar microwave circuits, and layered periodic structures. EM.Picasso's simulation engine is based on a 2.5-D full-wave Method of Moments (MoM) formulation that provides the ultimate modeling accuracy and computational speed for open-boundary multilayer structures. It can handle planar structures with arbitrary numbers of metal layouts, slot traces, vertical interconnects and lumped elements interspersed among different substrate layers. You can use EM.Picasso to model large finite-sized antenna arrays as well as infinite periodic structures such as frequency selective surfaces.
Since its introduction in 2002, EM.Picasso has been successfully used by numerous users around the globe in industry, academia and government. The new EM.Picasso 2013 has been totally reconstructed based on our integrated EM.Cube software foundation. This integration has introduced far more powerful CAD utilities, greater geometrical variety, and a vast array of capabilities like parametric sweep, [[optimization]], data visualization and post-processing computations. The new foundation also facilitates import and export of many popular CAD formats and provides a seamless interface with our other simulation tools.
== A Planar Method Of Moments Primer ==
When a periodic structure is excited using a gap or probe source, it acts like an infinite periodic phased array. All the periodic replicas of the unit cell structure are excited. You can even impose a phase progression across the infinite array to steer its beam. You can do this from the property dialog of the gap or probe source. At the bottom of the '''Gap Source Dialog''' or '''Probe Source Dialog''', there is a section titled '''Periodic Beam Scan Angles'''. You can enter desired values for '''Theta''' and '''Phi''' beam scan angles in degrees. The corresponding phase progressions are calculated and applied to the periodic Green's functions:
:<math>\Psi_x = -\frac{2\pi S_x}{\lambda_0} \sin\theta \cos\phi</math> :<math>\Psi_y = -\frac{2\pi S_y}{\lambda_0} \sin\theta \sin\phi</math><!--[[File:PMOM101.png]]-->
Note that you have to define a finite-sized array factor in the Radiation Pattern dialog. You do this in the '''Impose Array Factor''' section of this dialog. In the case of a periodic structure, when you define a new far field item in the Navigation Tree, the values of '''Element Spacing''' along the X and Y directions are automatically set equal to the value of '''Periodic Lattice Spacing''' along those directions. You have to set the '''Number of Elements''' along the X and Y directions, which are both equal to one initially, representing a single radiator. If you forget to define an array factor, the radiation pattern of the unit cell structure will be displayed, which does not show beam scanning.