Active Beamsteerable Digital Metasurface Lens Antenna for Millimeter-Wave Applications

Abstract

A high-gain phase-graded digital metasurface lens (PG-DMSL) antenna enabled with active beamsteering based on reconfigurable feed source for millimeter-wave applications is proposed. An end loaded cross dipole slotted structure is proposed as a transmission-type unit cell (UC). The designed UC achieves a transmission magnitude better than &#x2013

3 dB with 2-bit phase tuning at 28 GHz. Further, PG-DMSL is devised by arranging four sets of proposed UCs in an array of 25 &#x00D7

25 resulting in an aperture size of 7 &#x03BB

0 &#x00D7

7 &#x03BB

0 and a thickness of 0.23 &#x03BB

0. On switching the states of the 3 PIN diodes, the radiating feed antennas (FAs) kept beneath the designed PG-DMSL at an optimum focal distance of 20 mm can be switched resulting in steered beams along 0&#x00BA

and &#x00B1

30&#x00BA

. The proposed design is experimentally validated showing a measured broadside gain of 19 dBi with an augmented gain of 14.9 dB and a scan loss of 1 dB. IEEE