Assigning Excitations for HFSS or HFSS-Transient
Excitations are sources of electromagnetic fields in the design. HFSS has various options to generate incident fields that interact with a structure to produce the total fields. Some of these excitations are local sources residing within the structure such as wave ports and voltage sources, while other excitations such as plane waves are created from local sources away from the structure.The available excitations depend upon the product. They are as follows:

Also see Circuit Elements in HFSS.