Bandwidth, Gain, and Lowered-Sidelobe Level Improvement of A Circularly Polarized Slotted Waveguide Antenna Array for Ka-Band Applications

This research delivers the performance of a circularly polarized slotted waveguide antenna (CP-SWA) for Ka-band applications. Slotted waveguide antennas are suitable for millimeter wave applications due to their high-power handling, high-stable performance, low transmission loss, and high gain. Furthermore, circular polarization can reduce some effects related to multipath fading, phasing issues, reflectivity, and mismatch polarization. This work applies an arraying method for increasing the performance of the proposed antenna, and it has three CP-SWAs. Based on the simulated results, the proposed antennas have a broadband bandwidth for both the IBW and ARBW, 9.4 GHz and 7.9 GHz, respectively. Next, the proposed CP-SWA antenna array achieves a peak gain of around 11−13 dBic. In addition, arraying methods also have a good impact on lowering the sidelobe level of the antenna. There is an improved sidelobe level of 6-7 dB compared to the single antenna. The proposed CP-SWA antenna array has good characteristics for millimeter-wave applications.