60-GHz Air Substrate Leaky-Wave Antenna Based on MEMS Micromachining Technology

In this paper, a 60-GHz air substrate leaky-wave antenna based on microelectromechanical system (MEMS) bulk micromachining is proposed. Using penetration dry etching and gold plating processes, the air-filled leaky-wave slots, waveguide, and coupling slot, which are located in the top, middle, and bottom silicon-based layers, respectively, are generated. The three layers are stacked and clamped together using two location pins and five metal screws. The most distinctive feature of the proposed antenna is that the electromagnetic wave cannot see any substrates, except for the air medium, leading to good antenna performance. Good agreement between simulation and measurement demonstrates that the MEMS micromachining process fulfills the millimeter-wave (mm-wave) accuracy. To the best of the authors' knowledge, this is the first time that an air substrate mm-wave antenna is fabricated using the MEMS bulk micromachining technology. The fabricated prototype with a bandwidth of 17.3% and a peak gain of 11.4 dBi is attractive for mm-wave wireless communication applications. Validity of the feasibility provides the possibility to realize the system-in-package solutions.