Design Trends for 5G-Advanced Devices and Circuits: New Requirements for RF mmWave Front-End Modules

In this paper, we study items of 3GPP Release 18/19 5G-Advanced standardized technical specification and trends toward 6G mobile networks. New communication systems require increased functionalities and extreme performance to provide high data rate, reliability, and low latency services. Consequently, with each generation of mobile devices, radio-frequency (RF) front-end module (FEM) architectures grow more complex to support all these requirements. There is a significant trend to maintain a balance between the increased functionality and the added production cost associated with it. Upcoming 5G-Advanced smartphones incorporate new sensing and interface circuitry to accommodate the new RF bands. It is the first generation of mobile devices to utilize millimeter-wave (mmWave) 25-71 GHz band frequencies, supporting bandwidths of several hundred megahertz MHz. For more bandwidth, 6G is expected to utilize higher frequencies from 94GHz to 3THz. However, circuits for mmWave and THz transmitters/receivers are different from those operating at low frequencies up to 100-200 GHz which are satisfactory with today's semiconductor device technologies. As for communication at frequencies above 300 GHz, new technologies are convergent for supporting circuits. This leads to the great cost of production as well as the process of integration. This paper discusses related requirements, design challenges, and possible solutions. Much of the focus is on strategic system partitioning, design of radio access front ends, and leveraging of innovative semiconductor processes. At the core of these devices are highly integrated RF circuits (ICs), multilayer packages, modules, and mixed-signal printed circuit board (PCB) systems. To accommodate these architectures, more advanced densification and miniaturization as well as technology selection is taking place with electronic systems. It is because more theoretical and practical work into higher frequency circuits and systems is needed to improve existing technologies.