US Patent 7928914 Multi-frequency conductive-strip antenna system

To address the above-mentioned need an antenna (100) is provided having a conductive-strip radiating element (102) supported above a substrate (206) via three legs (201-203). The point where the substrate contacts the three legs form two antenna ports and a ground utilized for feeding the RF signal, tuning the antenna, and grounding. More particularly, a first leg (201) of the radiating element is used solely as a tuning port, while a second leg (202) is grounded, and a third leg (203) is utilized solely as a feed port. The tuning port is substantially maximally distal to the feed port on the substrate. Reactive loads are provided at the tuning port to effectively tune the central operating frequency of the antenna.