Fully Metallic Millimeter-Wave Lens Array Antenna for Wide-Angle Beam Scanning Phased Array

A lens array antenna based on four fully metallic partial Maxwell fish-eye (PMFE) lenses is proposed in this paper. The four PMFE lenses are arranged as a staggered up and down structure in the y-direction. Each PMFE lens is realized by the metallic parallel-plate waveguide (PPW) with periodic metallic nail arrays on the top and bottom plates. Each PMFE lens is fed by the double-ridged waveguide modified from the WR28 standard rectangular waveguide and placed on a straight line, which is more suitable for the linear array arrangement. Four feeding waveguides make up the waveguide feeder array. The mechanical presetting of the feeding array combined with the phased scanning is implemented to realize the wide beam coverage range (BCR). The prototype of the proposed lens array antenna is fabricated. The measured results agree well with the simulated one. The beam scanning range (BSR) of ±65.5° and a 3 dB BCR of ±70.8° are realized with the sidelobe level (SLL) below −8 dB and the maximum gain of 20.3 dBi.