Compact printed antenna

Abstract

A compact printed antenna includes a substrate and a printed circuit on the substrate. The printed circuit includes a ground metal, a helical metal, a short circuit leg and a feeding leg. The ground metal has a feeding structure. The helical metal includes a plurality of conductive apertures to connect a plurality of metal strips to form a flat helical structure. The helical metal is parallel with the ground metal and has a short circuit end and an open circuit end to form an open circuit-short circuit structure. The short circuit end connects the ground metal through the short circuit leg. The feeding leg is extended outwards from a selected location on the helical metal to further connect a matching circuit. By providing the compact printed antenna, the flat helical structure of the helical metal can be shrunk in size, an inductance to allow the antenna making desired adjustment for the input impedance can be generated, and the adjustment freedom upon coupled impedance for the antenna can be increased.

Dependencies are inferred from the claim text.