Integration of high performance switch with Low Noise Amplifier (LNA) devices results in state of the art performance for 5G Front End Module applications. Here we review switch+ LNA performance metrics and its evolution over the last 10 years and highlight directions for the future.
Over the past few years, CMOS Silicon-oninsulator (SOI) has emerged as the dominant technology for RF switches in RF front end modules for cell phones and WiFi. RF SOI technologies were created from silicon processes originally used for high speed logic applications, but the technology was modified to meet the performance needs of RF switches. The RF SOI technologies have been improved to follow the evolving system requirements for insertion loss, isolation, voltage tolerance, linearity, integration and cost. In this paper, the performance results of the latest generations of RF SOI switch technologies from IBM are reviewed and technology elements that contribute to improved performance are discussed. Future improvements are also discussed.
We present a new device design for 20V application in thin body SOI technology. High breakdown voltage is achieved by forming RX-bound field plates which deplete the drift region of an LDMOS structure using only lateral electric field coupling. A baseline 180nm CMOS SOI process is utilized and RX field plate shapes are designed to result in an essentially uniform longitudinal drift region electric field satisfying the RESURF principal. We studied device scaling and the effect of varying the width and length of the angular RX field plates and their relation to impact ionization rate in both floating body and body-contacted n-channel LDMOS deices. 3D TCAD simulations were used to investigate the effect design parameters on electric field and impact ionization. Unitary 20V rated-LDMOS devices are experimentally demonstrated, verifying a LDMOS option to stacked CMOS for high voltage applications in SOI technology.