Millimeter-Wave Suspended Silicon-on-Glass Tapered Antenna With Dual-Mode Operation

A highly efficient millimeter-wave (mmW)/Terahertz (THz) dielectric antenna is proposed. The proposed suspended tapered antenna [made of high resistivity silicon (Si)] is fabricated in a new mmW/THz integrated technology platform called silicon-on-glass (SOG). The fabrication process makes the tapered antenna with deep reactive ion etching of the Si layer of the SOG platform, wherein a part of the glass substrate below the antenna tapered section is etched. The glass substrate below the antenna is etched in hydrofluoric acid (HF 49%) before bonding to the Si wafer. The antenna is designed to radiate both E_x-and E_y-polarizations over the frequency band of 110-130 GHz and features additional advantages including highly linear polarization, high-directivity, integrability, and low-cost fabrication. Numerical and experimental results are presented to validate the high-performance proposed antenna. Experiments show gains of 17.5 dBi at 115 GHz and 18.3 dBi at 128 GHz for E_x¹¹ -and E_y¹¹ , -modes excitations, respectively. These two polarizations show measured efficiencies of 94% and 99%, respectively.