Low-Scattering Phased Arrays With Reconfigurable Scattering Patterns Based on Independent Control of Radiation and Scattering

A novel approach for the independent manipulation of the in- band scattering and radiation patterns of phased arrays with high radiation efficiency is proposed. The in- band scattering and radiation mechanism of an array element is analyzed first. It is found that the antenna input impedance may lead to different effects on the antenna scattering and radiation patterns. Taking advantage of this difference, an array element incorporated with a biased p-i-n diode is designed, which has two scattering states with 180 degrees phase differences but a stable radiation state. By controlling the biasing state of the p-i-n diode connected to each element, the scattering pattern of the proposed array can be manipulated dynamically. Meanwhile, the stable radiation pattern of the designed element ensures that the proposed phased array can dynamically radiate a beam scanning to a given direction with high efficiency during the manipulation of scattering patterns. The final designed linear array with p-i-n diodes is able to operate at 2.6-3.4 GHz with a radiation beam scanning up to +/- 45 degrees. Moreover, the reconfigurable scattering beams of the proposed array can point to arbitrary angles within +/- 60 degrees, thus the in-band scattering is significantly reduced in a broad bandwidth. To validate this design, a prototype array is fabricated and measured. Measured results are in good agreement with the simulated results.