A Novel Dual-Band Millimeter Reflector Antenna with High Gain and Ultra-Low Side-lobe Level

In this paper, a novel offset reflector antenna which ensures that W band and Ka band operate simultaneously with high gains and ultra low Side Lobe Level (SLL) is designed and fabricated. The W band is horizontal polarization while the Ka band is vertical polarization, then two independent feed horns and a surface formed by period horizontal metal grids are adopted to separate the two wave bands through polarization orthogonality. The surface reflect the W-band electromagnetic wave while the Ka band propagate, thus the surface acted as a sub reflector of dual reflector antenna for W band and Ka band still works with a classical single offset reflector. In order to obtain the ultra low SLL and high gain, an appropriate aperture electric-field distribution containing amplitude and phase between antenna efficiency and SLL is achieved by the distinctive antenna structure and their optimized dimension. The designing principle is presented and the simulated and measured results are compared with each other.