Multifeed Metasurface-Inspired Antenna for D-Band Chip Integration

A multifeed metasurface-inspired antenna with power-combining capability is proposed for D-band chip integration. The antenna consists of three patch layers, including the bottom on-chip patch for power-combining with eight differential feed ports, the middle patch on the substrate board for electromagnetic wave tightly coupling from the chip patch, and the metasurface-inspired patch array on the top of the board for performance enhancement. The characteristic mode analysis (CMAs) is applied to reveal the desired mode behaviors and guide the antenna design. To enhance the antenna efficiency and alleviate the impact of assembly errors, an air-gap layer is applied between the chip and substrate board. Based on this antenna configuration, a new simple package architecture is introduced for chip integration to avoid high-frequency electrical interconnection. In addition, multifeed technology is applied for power combing applications and high-power radiation. To validate the proposed antenna and simplify the experiments, the cascaded T-junctions are applied to provide the eight differential feedings and the on-chip parts are fabricated using the back-end-of-line technology of SiGe BiCMOS process. According to the measurements, the proposed multifeed antenna has good estimated radiation performance, including an operating bandwidth of 22.9% and a peak gain of 7.97 dBi at 135 GHz with an antenna radiation efficiency of 80%. The proposed antenna and package architecture are good candidates for 6G communication and the other subterahertz systems.