Tilted-Beam Solar Antenna for Hybrid Energy Harvesting System

A tilted-beam antenna array integrated with solar cells is proposed in this letter. In each unit, four rectangular crystalline silicon solar cells are arranged as superstrate on the top of a slot antenna. By changing the relative position of the superstrate and feeding structure, two modes of the antenna can be observed with tilted beams. A power divider is employed, and the two modes are combined which leads to a dual-beam at +30° and −30° simultaneously. A 1 × 3 antenna array is proposed and fabricated, and the measured fractional bandwidth is 20.8%, with a low profile of 0.025<italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">λ</i><sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> and a peak gain of 13.2 dBi. The experiment of the solar cell is also carried out to verify the effectiveness of the design. The proposed antenna array has the advantages of wideband, high gain, low profile and tilted beam, which makes it suitable for the hybrid energy harvesting system.