To efficiently determine the plasma electron density fluctuations using the MIR diagnostic technique, a 55 ~ 75 GHz 65 nm-CMOS transmitter has been developed where four separate IF signals are up-converted, amplified, and then combined to generate an 8-tone RF output; a broadband 90 nm-CMOS receiver has also been constructed, which achieves 40 dB gain with 17 dB single sideband noise figure. The circuits and their corresponding modules will soon be deployed on the DIII-D and NSTX-U fusion devices. A 110 ~ 140 GHz 65 nm-CMOS receiver has also been designed, which is suitable for measuring the deep-core temperature fluctuations in the DIII-D tokamak using the ECEI diagnostic system. In addition to RF-LNA/balun, mixer, and IF amplifier, the LO balun/tripler and driving amplifier are now included in this highly integrated circuit chip. The compact transmitter and receiver modules can be easily built in mass with relatively low cost, which facilitates the array implementation and maintenance.