US Patent 7427957 Patch antenna

A patch antenna for achieving a vertically-polarized radiation pattern is described. The patch antenna includes a closed-curve slot within which a signal feed point is located. Parasitic slots are disposed outside or inside the closed-curve slot. In one embodiment, the closed-curve slot is a ring slot and the parasitic slots are arc slots having a common center point with the ring slot. The antenna may further include a lower patch capable of producing a different radiation pattern with different polarization and at a different frequency band, to result in a dual-band antenna. The dual-band antenna may operate in the 5.9 GHz DSRC and 1.575 GHz GPS bands.