Design and Analysis of a 28GHz 9KV ESD-Protected Distributed Travelling-Wave TRx Switch in 22nm FDSOI

Feilong Zhang,Ned Cahoon,Cheng Li,Mengfu Di,Albert Wang,Chaojiang Li,Zijin Pan

doi:10.1109/jeds.2020.2975598

Abstract

This paper presents design and analysis of a 28GHz broadband single-pole double-throw (SPDT) distributed travelling-wave radio-frequency (RF) switch designed in a foundry 22nm fully-depleted silicon-on-insulator (FDSOI) CMOS technology. The 28GHz SPDT transmitter-receiver (TRx) switch covers the n257 and n258 bands of the fifth-generation (5G) mobile wireless systems. Measurements show compatible switch performance to similar millimeter-wave (mm-wave) RF switches of various topologies designed in compound semiconductor high-electron-mobility transistor (HEMT) and Si bulk CMOS technologies. The SPDT switches achieve the highest reported 9KV ESD protection in measurements. It reveals that the ESD-induced parasitic effects have substantial impacts on mm-wave broadband RF switches. Careful ESD-RFIC co-design is suggested for designing 5G RF switches in above-6GHz bands.

Highlights

RF switches are indispensable components to the RF frontends (RFFE) ICs for smartphone systems
Highend RFFE modules supporting 4G/LTE mobiles typically contain many RF switches, as depicted in Fig. 1, including TRx switches, band switches that are usually integrated into power amplifier modules including duplexers (PAMiD) or low-noise amplifier (LNA) modules, and antenna switches that include coupler to support envelope tracking (ET) for PA and antenna tuner to enlarge frequency covering range
It is strongly suggested that careful ESD-Radio Freq. Integr. Circuits Symp. (RFIC) codesign must be conducted for mm-wave switch designs, regardless whether ESD simulation is performed for the individual ESD protection structures [12]

Summary

INTRODUCTION

RF switches are indispensable components to the RF frontends (RFFE) ICs for smartphone systems. Careful design optimization for the transmission lines is vitally critical to the performance of the distributed travelingwave switches, which was guided by comprehensive EM field simulation in this work. In this design, we choose to use microstrip lines because it consumes less area than coplanar waveguides and is easier to realize.

MEASUREMENT AND ANALYSIS

CONCLUSION