FD-SOI Enabled mmWave Telecommunication Applications and System Architectures

Abstract

Due to ever increasing data traffic and the continued demand for high data rate on both fixed and mobile communication, future telecommunication radio access network will adopt mmWave frequencies. The use of phased array antenna system for directed and steerable beamforming will enable mmWave radio interface to have lower transmit power per antenna element than that in sub 6GHz cellular user equipment (UE) and access points. In addition to beamforming, mmWave system also needs to be close to the antenna array with minimum chip-to-chip interconnect to reduce loss and increased power efficiency driving SOC integration for mmWave frontend and transceiver. Both lower transmit power and drive for SOC integration makes mmWave capable Silicon technologies (Partially and Fully depleted SOI, SiGe & bulk CMOS) In this talk, different beamforming architecture options of mmWave telecommunication system will be highlighted along with key FOM's and chip partitioning covering both UE and base stations. Two key challenges of mmWave phased array system are the power efficiency of Transmitters and thermal power budget of the overall system. Hence, differentiation among silicon technologies will be based on Max. Power Output (Psat), power efficiency (PAE) at operating point of power amplifiers and losses between antenna and Transmitter/Receiver. The beamforming architectures and partitioning of chips will be determined by the EIRP, frequency band and amount of DC power dissipated in the system. There's a trade-off between area scaling of SOC and thermal power density to be dissipated. The challenge will be more severe as we will move to higher mmWave frequencies (> 60GH) as the array dimension will shrink, the beamforming SOC areas have to be scaled to be accommodated close to antenna elements. High thermal density needs to be addressed by improved power efficiency of the Silicon technology, improved thermal impedance of the package. As an example of Silicon implementation for mmWave beamforming radio, we'll provide examples of Fully Depleted SOI (FDSOI) based mmWave beamforming systems to show how FDSOI can address different system level challenges and enable SOC integration at high overall power efficiency. The intrinsic technology FOM's that impact the mmWave performance of different components and overall system will be discussed with examples based on measured silicon data. Roadmap of FDSOI technology generations to address the power and performance challenges of mmWave systems with ever increasing frequencies will be highlighted. The talk will conclude with comparisons among different silicon technologies for mmWave telecommunication systems and highlighting merits and demerits of different system architectures that can be addressed by combination of different Silicon technologies in comparison with FDSOI based implementations.