A bending-insensitive Ku-band SIW microstrip antenna with tilted beam capability

This study proposed a small, tilted beam, frequency bending-insensitive antenna based on the incipient tilted beam angle provided by the microstrip Yagi antenna. A semi-enclosed SIW cavity was added to reduce the size and increase the tilt angle and gain. The antenna size was 0.57 × 0.57 × 0.08 ( $ \mathrm{\lambda }_0^3 $ λ03). Two kinds of processing schemes, PCB processing and 3D printing, were used to fabricate flat and conformal antennas respectively. Simulation and measurement results show that the antenna beam tilt reached 57° and the gain reached 8.05 dB. At the same curvature radius of R = 15 mm, the designed antenna’s frequency deviation was reduced from 2.94% to 0.82% compared with the prototype antenna with the same performance. Compared with other large-size tilted beam antenna elements, the small, bending-insensitive antenna designed in this work provides a solution for configuring a conformal antenna array.