A 1-Bit Programmable Reflectarray Antenna for Muti-Beam Scanning

This paper presents a 1-bit programmable reflect array antenna which is capable to realize multi-beam scanning over a wide angle. The element is a cross-shaped patch structure with a diode placed in the middle gap, which is simple and practical in large-angle beam scanning. The 1-bit phase resolution is achieved by controlling the diode on and off. In addition, the element loss is lower than 0.9 dB, and a phase shift of
$180^{\circ}\pm 20^{\circ}$
is achieved from 5.27 to 6.47 GHz, with a relative bandwidth of 20.4%. The DC bias line is designed without influencing the reflection performance of the element. Then a 20*20 programmable reflectarray antenna is formed using the above elements, and the diode state above the array is dynamically adjusted. Both single-beam and dual-beam scanning angle ranges of
$\pm 60^{\circ}$
can be achieved at 5.8 GHz.