Advanced System-on-Chip (SoC) Electron Cyclotron Emission Imaging (ECEI) Arrays for DIII-D

The Electron Cyclotron Emission Imaging (ECEI) System on the DIII-D tokamak has been upgraded with a 20-element System-on-Chip (SoC) E-band (72-80 GHz) imaging receiver array for 2-D T_e measurements. The SoC technique integrates different functional components together into a single chip, including a low noise preamplifier, a balanced mixer, IF amplifier and a local oscillator multiplier circuit. Mounted into a shielded receiver module with a machined horn antenna, system noise temperatures were reduced from ~55,000 K to ~5,000 K while simultaneously increasing isolation and reducing inter-element crosstalk. This E-band array of SoC-based receiver modules will be joined in late 2018 by a companion 20-element SoC-based W-band (75-110 GHz) array being developed for wider coverage on DIII-D, spanning from the core region (rho ~ [-0.2, 0.4]) to the pedestal region (rho ~ [0.85,0.99]).