1-bit Reconfigurable Reflectarray Design with Low Power Consumption Based on Resistance Insensitive Unit Cells

In this article, a 1-bit reconfigurable reflectarray (RRA) based on resistance insensitive unit cells (RIUCs) is proposed for low power consumption RIS applications. By tactfully placing a p-i-n diode at the middle of an H-slotted patch, 1-bit phase quantization is achieved, which is insensitive to the equivalent resistance of the p-i-n diode. The phase difference between ON and OFF states remains 180° ± 20° from 5.09 to 5.62 GHz. The RIUC has stable reflection loss in the scene of high resistance of p-i-n diode in ON state, because the current flowing through the p-i-n diode is very small, comparing to the total current of the RIUC. This property is utilized to reduce the forward biasing current, thus achieving low power consumption. A 16×16 RRA prototype is fabricated. The 2-D beam-scanning performance with a peak gain of 22.10 dBi is realized, corresponding to an aperture efficiency of 24.9%. The measured 1-dB gain bandwidth is 9.16%. An extremely low power consumption of 1.64 mW for the proposed RRA is realized at the cost of less than 0.7 dB gain drop. Moreover, the proposed RIUC is further modified to operate well in the millimeter-wave frequency band.