Corporate-Feed Slotted Waveguide Array Antenna in the 350-GHz Band by Silicon Process

Abstract

A corporate-feed slotted waveguide array antenna with broadband characteristics in terms of gain and reflection in the 350-GHz band is proposed. To improve the etching accuracy of the thin laminated plates with the conventional diffusion bonding process, a new fabrication process has been developed, where the etching accuracy is lower than $\pm 5~\mu \text{m}$ . In this process, the laminated plates are made with silicon wafers and etched by deep reactive ion etcher process. These are gold plated then bonded with the diffusion bonding process. The estimated effective conductivity of the gold plated wafer is $1.6 \times 10^{7}$ S/m. The loss per unit length is 1.1 dB/cm. A $16 \times 16$ element array antenna has been designed and fabricated in the 350-GHz band with the proposed process. The broadband characteristic in terms of the antenna gain is demonstrated for the first time by measurement in this frequency band. The 3-dB down gain bandwidth is 50.8 GHz in simulation and is 44.6 GHz in measurement.