Variations of the shorted patch antenna

Many techniques have been explored to reduce the overall size of a microstrip patch conductor in the low microwave frequency spectrum. These include using shorting pins and high dielectric constant material. Perforating or meshing the microstrip patch conductor has also been shown to give reasonable size reductions for a conventional patch antenna without compromising its radiation and impedance performance. We present a perforated shorted printed antenna which uses a shorting post as well as perforation slots that are embedded within the single layer printed antenna to reduce the surface area of the antenna. The antenna is small, with its overall dimensions of 0.13/spl lambda//sub 0//spl times/0.12/spl lambda//sub 0//spl times/0.07/spl lambda//sub 0/ making its size compatible with most portable devices. We also present a variation of the perforated shorted patch that allows multifrequency operation. This new printed antenna consists of a stacked shorted patch geometry, where the lower frequency element is fed by a probe and the upper frequency radiator is electromagnetically coupled to the feed. The lower frequency radiator is a perforated shorted patch. The upper frequency radiator is located below the other element and is in the shape of a shorted ring.