Active Planar Van Atta Array Reflector with Switchable Retroreflection

The Van Atta reflector can re-radiate back towards the incident direction by inverting the phase gradient naturally induced by an external incident wave, therefore it has found many applications in the field of monostatic radar cross section (RCS) enhancement. Here, we present a planar Van Atta array reflector with switchable reflection mode between retro-reflection and normal reflection by changing bias voltages to the positive-intrinsic-negative (PIN) diodes on the antenna. The retrodirective angle range of the switchable reflector is -60° to 60°, and the operating frequency is 4.75 GHz. The ON and OFF states of the PIN diodes corresponding to retro-reflection and specular reflection, respectively, hence achieving a difference of monostatic RCS in two states, which may have potential applications in RCS control and wireless communication technologies.