All-Metal Circularly Polarized Slotted Waveguide Antenna Using a High-Order Mode Feeding Cavity

An all-metal circularly polarized slotted waveguide antenna is demonstrated in this work. Compared with the traditional circularly polarized waveguide antenna adopting waveguide power division network, slotted waveguide and polarization converter, the proposed antenna is only composed of a high-order mode feeding cavity and several radiation waveguides etched with T-shaped slots, resulting in low profile height while maintaining good performance. Our antenna is operating near 19GHz, and the −10dB S
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bandwidth is from 18.36GHz to 19.66GHz, while the 3dB axial ratio bandwidth is from 18.85GHz to 19.17GHz.