Antenna system for metallized devices
An embedded antenna system is described for use with metallized enclosures and housings used with wireless communication devices. One or multiple radiators are coupled to a metal cover, with ground points established on the metal cover to improve radiation efficiency and control the frequency response of the antenna system. Dynamic tuning methods are described wherein detuning of the antenna system for sources such as body-loading are compensated at adjusting impedance properties of the combination of radiator and metallized cover.
1. An antenna system for a device having a metal housing, the antenna system comprising:
an antenna element configured to couple to and excite current on the metal housing;
an antenna tuning module, the antenna tuning module comprising a switch having a plurality of ports, wherein each port connects a different connection point of a plurality of connection points on the metal housing to a ground reference via a transmission line, wherein the antenna tuning module is coupled to one or more processors configured to perform operations, the operations comprising:
determining a tuning state for the device;
configuring the antenna tuning module to couple a different connection point to the ground reference based at least in part on the tuning state for the device.
2. The antenna system of claim 1 , wherein the tuning state comprising one or more of no body loading; hand loading of the device; or head loading of the device.
3. The antenna system of claim 1 , wherein the antenna tuning module further comprising a tunable reactance configured to adjust a reactance provided to a feed port of the antenna element.
4. The antenna system of claim 1 , wherein the antenna tuning module further comprises a tunable reactance configured to be coupled between one of the different connections points and the ground reference.
5. The antenna system of claim 1 , wherein the antenna tuning module further comprises a control port configured to control a variable reactance associated with at least one of the different connection points.
6. The antenna system of claim 1 , wherein the metal housing is a metal cover associated with the device.
7. The antenna system of claim 1 , further comprising a second antenna element and a second antenna tuning module, the second tuning module configured to actively tune the second antenna element.
8. The antenna system of claim 7 , wherein the second antenna tuning module is configured to selectively couple at least one of the plurality of connection points to the ground reference.
9. The antenna system of claim 1 , further comprising at least one coupling layer positioned between the antenna element and the metal housing.
10. The antenna system of claim 9 , wherein one or more connection points on the coupling layer are selectively coupled to the ground reference.
11. The antenna system of claim 9 , wherein the at least one coupling layer comprises a plurality of coupling layers.
12. The antenna system of claim 9 , wherein the antenna system further comprises one or more parasitic elements between the ground reference and the metal housing.