Low-THz Dielectric Lens Antenna With Integrated Waveguide Feed

A novel dielectric lens antenna with a broadband integrated waveguide-based feed and an optimized tapered extension is presented for low terahertz frequencies. The antenna consists of an extended hemispherical lens fed by a standard WR-3 rectangular waveguide fitted directly at the bottom of the lens. The antenna has been designed for high-resolution imaging radar systems requiring very wide bandwidth performance and highly directive beams. A novel matching technique based on an air pocket etched off the lens dielectric is employed to obtain broadband antenna operation covering the entire dominant-mode bandwidth of the waveguide. In addition, a new taper shaped lens extension is proposed for the first time and optimized to achieve improved sidelobe level and gain performance. The antenna is compatible with newly developed waveguide-based automotive radar and communications systems. The operating 3 dB gain bandwidth is 30% (230-310 GHz) achieving a maximum of 30 dB measured gain. The measured S11 is well below -14 dB across the WR-3 band.