Millimeter-Wave Wide-Angle Beamsteerable Transmission-Type Metasurface Lens Antenna

A low-profile high gain wide-angle beamsteerable metasurface lens (MSL) antenna with transmission-type slotted end loaded cross-dipole as unit cell is proposed for millimeterwave applications. The proposed unit cell is highly insensitive to wider oblique angle of incidence of upto 60 degrees and polarization. The MSL array is constructed using a 25 x 25 matrix of unit cells with an overall size of 7.7 lambda(0) x 7.7 lambda (0) x 0.14 lambda (0). The slot coupled microstrip patch antenna is designed as the feed source placed at a focal distance of 20 mm beneath the MSL resulting in a f/D ratio of 0.24. The mechanically steered beams along 0 degrees, +/- 30 degrees, +/- 45 degrees and +/- 60 degrees are achieved by spatially exciting four distinct MSLs with the feed source. Hence, 3-dB spatial beam coverage of 120 degrees (+/- 60 degrees) is realized with a gain tolerance of 1.9 dB. The maximum gain of 19.5 dBi is achieved in the broadside direction with a gain enhancement of 13.4 dB.