Use of Layout
•“Artwork” is used to define the size and shape of solder connects for components like capacitors, diodes, RF chips, etc.
•The dimensions of solder pads (where you actually connect your circuit) are specified on data sheets.  They are also available in the ADS “library” for many standard elements.
•The size of pads add length to your lines, so you will need to include them in your simulation for most accurate results.  This means you need to figure out their size before you simulate the circuit, so you will do some back-and-forth between layout and simulation.