Wideband Transmit-Reflect-Array With Tilted Beams Considering Beam Squint Effect

This paper presents a modified multi-frequency phase synthesis approach to design the wideband transmit-reflect-array (TRA) with tilted beams considering the beam squint effect. Unlike the conventional phase synthesis approach, the effectiveness of the method is improved by introducing the pre-deviated beam direction at optimized frequency point to mitigate the beam squint, thus achieving a wideband flat gain. To verify this design approach, a wideband TRA with asymmetric beams is designed, fabricated, and measured. The measured results agree well with the simulated results, achieving a 1-dB gain bandwidth of 40.2% (33.7%) and a peak aperture efficiency of 43.7% (35.3%) in transmission (reflection) mode.