A Ku-band low-profile circularly polarized all-metal cavity antenna

In this paper, a Ku-band all-metal cavity circularly polarized antenna with low profile is introduced. By loading three kinds of slots with different shapes on the metal cover plate, good impedance matching (VSWR≤2) is achieved in the working frequency band. The gain of the proposed antenna reaches 8.9dBi, and the axis ratio is less than 2dB, thus achieving good circularly polarized radiation characteristics. It has the characteristics of single material, easy processing, low profile (<0.06λ), stable structure and good heat dissipation, which can have a good application prospect in the high performance antenna system of spaceborne SAR system.