Leaky-Wave Coding Metasurface Antenna for Manipulating Far-Field and Near-Field Radiation

This paper presents a leaky-wave coding metasurface antenna that can be used for manipulating far-field beam and near-field radiation with a fixed frequency. Pin diodes on each slot are used to control the opening and closing of the slots. Due to the propagation of the TE10 mode in the waveguide, there exists an opposite phase of 180° by reversing the offset direction of the slots. The FPGA-controlled diodes enable 1-bit coded control with amplitude states of 0 and 1, as well as phase states of 0° and 180°. The beam can achieve far-field scanning from −40° to +40°, with a maximum gain of 15.8 dBi and gain fluctuations within 2.5 dBi at 9.6 GHz. For the near-field case, beam focusing has been achieved at
$z_{\theta}=12\lambda_0$
, and the movement of the focal point has also been realized. The developed antenna utilizes fewer diodes, offering lower cost and flexible programming capabilities. These results indicate that the developed antenna has promising prospects in areas such as beam scanning and beam shaping.