Flip-Chip Aperture Coupled D-Band Active Radiator Tiles in 22-nm CMOS FDSOI

Abstract

A ${2} {\times } {2}$ D-band active radiator tile is designed in 22-nm CMOS fully depleted silicon on insulator (FDSOI). The tile uses commercial materials, fabrication, and assembly techniques while relaxing printed circuit board (PCB) requirements by eliminating D-band routing. This is accomplished by fully integrating the D-band signal generation, amplification, phase shifting, and antenna coupling structures onto the chip. The phase shifting is accomplished without requiring I/Q generation using the on-chip frequency multipliers. The on-chip power amplifiers (PAs) directly excite off-chip patch antennas via aperture coupling from the chip to the PCB, avoiding the need for costly transitions off-chip. The tile is aligned and assembled with the antenna using flip-chip bonding, which also provides all the low-frequency interconnects for the chip. A ${2} {\times } {4}$ array using two of the tiles, demonstrating the scalability of the system, achieves a narrow inter-chip element spacing of $0.6{\lambda }$ at 140 GHz, a peak effective isotropic radiated power (EIRP) of +23.5 dBm, and a scan range of ±40° while dissipating 77 mW per element.