X-Band Tile-Based Metal-Only Reconstructible Reflectarray With 3-D Printing Support

A tiled-based metal-only reflectarray (RA) using stainless steel unit cells (UCs) is proposed in this letter. The RA aims at providing a low-cost high-gain antenna solution with the agility for customers living in harsh environments such as in the wilderness or under military threatening. The metal-only UCs, each fabricated separately using the laser cutting process with a prescribed reflection phase, are treated as mosaic tiles on a panel supported by a low-loss three-dimensional printing frame. The reflection phase, and hence the main beam direction, of the RA can be reconstructible according to the arrangement of the UCs. For the proof of concept, an RA with a diameter of 16λ
₀
, consisting of 820 UCs, is demonstrated at X-band. The UC comprises four spiral slots whose lengths control the reflection phase. The focal-to-diameter ratio is 0.625. By rearranging the UCs on the panel similar to a jigsaw puzzle, four application scenarios are experimentally verified. The first case has the main beam point in the broadside direction (0°). The other two have an oblique beam of 30° or 45° from the zenith; the final case consists of two main beams pointing broadside (0°) and 30° from the zenith simultaneously. In the broadside case, a peak gain of 29.1 dBi and an aperture efficiency of 35.7% are achieved at 10 GHz, while the 3 dB gain bandwidth is 10.1%. A comparison table is summarized to manifest the uniqueness of the proposed idea.