1-bit Phase Reconfigurable Unit Cell for X-band Intelligent Reflective Surface

In this study, a 1-bit phase reconfigurable unit cell (UC) is proposed for an X-band intelligent reflective surface (IRS). The UC is designed by integrating a PIN diode into a slotted copper patch. The maximum phase shift occurs at the design frequency of 9.5 <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\text{GHz}$</tex> and the phase difference varies within <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$180^{\circ}\pm 20^{\circ}$</tex> from 9 to 10 GHz in the X-band. A 16 <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\times 16$</tex> IRS is designed and simulated using the proposed UC to verify gain and beam steering performance. The IRS has a gain of <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$20.5 \text{dBi}$</tex> at <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\theta=0^{\circ}$</tex>. At <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\theta=\pm 40^{\circ}$</tex> the gain is <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$18.6 \ \text{dB}\mathbf{i}$</tex> which validates good beam steering performance.