Near-Field Beam Focusing and Steering Generator Based on 3D Curved Substrate Integrated Waveguide

Traditional planar microwave devices face with some limitations, which will restrict their applications. For example, the generation of a quadratic phase distribution for large near-field focused (NFF) array antennas is difficult because of the limitation of the phase control capability of the traditional beam-forming network. In this paper, a three dimensional (3D) curved substrate integrated waveguide (SIW) transmission line is proposed as a feeding carrier to enhance the amplitude and phase control capability. The longitudinal position of the slotted SIW is employed sufficiently to break the limitation of amplitude and phase control capability. On this basis, the 3D curved SIW can be applied to design the NFF generator that requires high phase control capability. A leaky-wave SIW slot array antenna is designed to slow the sharp change in phase to increase the element density, and compensate focal shift caused by the frequency steering. Finally, the NFF 3D curved SIW slot array antenna is fabricated and measured. It has the ability of wide steer able range with stable height.