Table 2.

Absolute versus relative parameterization: Basic properties.

Feature	Parameterization
	Absolute	Relative
Parameter space and geometry constraints	Box constraints and (usually) linear constraints on antenna dimensions	Only lower and upper parameter bounds (box constraints)
Handling antenna dimensions	Direct: one-to-one correspondence between parameters and antenna dimensions	Indirect: some dimensions calculated using relative and absolute parameters
Solving optimization tasks
Pros	Direct account for antenna dimensions (suitable for size reduction tasks)	Reduced number of geometry constraints
Cons	Potentially complex geometry of a feasible region (may lead to additional challenges when handling electrical and field characteristics)	Indirect relationship between design variables and antenna geometry (may not be suitable for size reduction tasks)