On-Chip versus Off-Chip Passives in Radio and Mixed-Signal System-on-Package Design

Optimal total solution for new radio architecture and implementation requires accurate trade-offs for off-chip versus off-chip passives. In this paper, a complete and systematic design methodology for RF blocks in SoP (system-on-package) versus SoC (system-on-chip) is presented. This methodology explores trade-offs between performance and cost when different on-chip or off-chip passives are used. For a better presentation, the method and design techniques are demonstrated through four multi-band/multi-standard radio design examples with various technologies and different circuit topologies. Our study reveals that, in order to obtain cost benefits in RF-SoPs, small RF chips should be merged as larger chips and the integration density of each RF chip should be high enough. Our study also indicates that in a complex chip like a multi-band radio, moving passives off chip could achieve further cost savings and significant performance improvements. These are general conclusions but, our method offers a detailed analysis which can give quantitative measurements of cost savings and performance improvements in off-chip versus off-chip passives in RF SoP design