SIW-based Reflectarray Antennas with Sharp Gain Selectivity and Large Bandwidth

This contribution proposes to couple resonant patches with substrate integrated waveguides (SIW)through various slots to design reflective unit-cells with large bandwidth and very sharp frequency response. Such performance is achieved by appropriately combining the patch and slots resonances, while the required phase delay is obtained by adjusting the SIW length. The proposed cell is planar, easy to manufacture, low-loss, and can operate from micro to millimeter waves. A reflect array based on this unit-cell has been designed and analyzed at 9 GHz, exhibiting a 3 dB bandwidth of 18% and a sharp gain selectivity over 16 dB.