Circular polarization slot antenna apparatus capable of being easily miniaturized

摘要

A slot antenna apparatus 10 contains a circuit substrate having a high-frequency circuit arranged therein and a shield case accommodating the circuit substrate. A cross-shaped slot and a feeding pin are formed in an upper plate of the shield case. The cross-shaped slot is composed of first and second slots. The lengths of the slots are different and the slots are perpendicular to each other. The shortest distances from the feeding pin to the first slots are approximately equal. When the power is fed to the upper plate through the feeding pin, the slots are excited to irradiate linearly polarized waves perpendicular to each other, respectively.