A 94 GHz Slot Array Fed by a WR10 Interface

Antenna array is an essential part of a terahertz (THz) imaging system. The development of THz antenna is mainly limited by the difficulty in micro-size fabricating and low efficiency caused by non-negligible dielectric and metal losses. This work proposes a structure of PCB-based stripline series-fed slot antenna array for THz high integrity application. To limit energy spreading, standing wave resonating cavity is built by surrounding each transmission channel with metallized vias based on through glass vias (TGV) process. The slots cut the current on the surface of the resonating cavity, thereby generating radiation. A 94GHz slot array prototype is designed and tested, fed by a WR10 interface, with the help of a dumbbell-shaped coupling slot etched on the ground, who functions as a waveguide-stripline transition structure. A metal base and a protective lid are also designed to facilitate testing. The simulation results of this prototype show that the antenna has an efficiency of 78.2%, a gain of 10.7 dB, and a bandwidth of 1.8% (93 GHz ∼94.7 GHz) with |S11| < −10 dB. Due to the dielectric constant and machining error, the measured resonant frequency deviates from the simulated one 3%. Based on this structure, highly integrated sub-terahertz (sub-THz) or THz array with high gain and low loss can be implemented and applied in imaging systems.