Comparison of RFIC PA Die and Laminate Co-Simulation Methods

Abstract

Package (such as LGA, MCM etc.) with main circuits on Die(s) situated on a substrate and with OMN in the substrate laminate is one of the most popular design styles for RFIC PAs in recent times. In practical design, the overall circuit of the RFIC PA is often designed using ADS Schematic simulation tool. The main circuit is then layout for Die design, and the OMN circuit is layout for laminate design. As the actual parasitics associated with the real RF circuits with high packing dense have significant effects on the RFIC performance, the traditional closed-form circuit models may be no longer valid, and co-simulations of the Die circuit or Die layout EM model and the laminate layout EM model are often considered in order to improve simulation accuracy. There are some generally considered co-simulation methods in practical design, such as Die circuit + Laminate Momentum, Die circuit +Laminate HFSS, Die layout Momentum +Laminate Momentum, Die layout Momentum +Laminate HFSS, Die layout +Laminate ADS Nested Technology, etc. Design engineers might be confused about which co-simulation methods should take for RFIC PA design and development. This paper reviews, compares and discusses the above co-simulation methods in the aspects of algorithms of the simulators, co-simulation modeling method, complexity to build model, run time, and the difference between simulation and measurement results by giving an example of a self-developed RFIC PA operating at 2GHz. It endeavors to draw helpful conclusions for simulation experiences in practical RFIC PA design, and a co-simulation method with Die layout Momentum EM model +Laminate HFSS EM model is recommended based on the software versions used in this work.