Santa Barbara.

s the operating frequency of semiconductor solid-state devices increases into the millimeter-wave region, the size of the devices and their power han-dling capability are reduced. In order to provide the advantages of a solid-state technology for moderate power levels at millimeter-wave fre-quencies, solid-state components must be combined. Spatial power combining provides enhanced RF effi-ciency by coupling the components to beams or modes in free space rather than via transmission lines in corpo-rate combining structures. Recent in-48 December 2000ISSN 1527-3342/00/$10.00©2000 IEE