  This work presents mm-Wave and sub-THz chip-to-package transitions for
communications systems. To date, reported transitions either have high loss,
typically 3 to 4 dB, or require high cost packages to support very fine bump
pitches and low loss materials. We analyze the impact of transitions on a high
frequency, wide bandwidth communication system and present the design of a
chip-to-package transition in two different commercial packaging technologies.
The proposed transitions achieve <1 dB loss in both technologies, validating
the design methodology.
