A Nineteen-Beam Steering Pattern Reconfigurable Antenna Based on Quarter-Mode Substrate Integrated Waveguide

A pattern reconfigurable quarter-mode substrate integrated waveguide (QMSIW) antenna with a low profile is proposed in this communication. First, a slot is etched on a QMSIW cavity as a radiating element. Two cavity modes including a quarter mode (QM) and an eighth mode are utilized to obtain the enhanced bandwidth. Then, four quarters sharing the same edge metalized vias are placed in a back-to-back configuration. In this way, the antenna structure is very simple and compact. By choosing the corresponding feed port and phase, nineteen-beam steering including four single-fed tilted beams in total space quadrants (5.8 dBi,
$\theta _{\mathbf {max}} = 20^{\circ }$
), eight multifed tilted beams in total space quadrants (6.4 dBi,
$\theta _{\mathbf {max}} = 30^{\circ }$
), four double beams, one semidoughnut beam (3.9 dBi), one toroidal beam (1.1 dBi), and one axial beam (7.7 dBi) can be obtained. The antenna can operate at 2.5 GHz with a height of 1.5 mm (
$\lambda _{\mathbf {0}}$
/83).