Antenna structures having slot-based parasitic elements
Electronic devices may include radio-frequency transceiver circuitry and antenna structures. The antenna structures may include antenna resonating elements and antenna ground plane structures. An electronic device may have antennas formed from the antenna resonating elements and an antenna ground plane. The antenna ground plane may have slot structures. The slot structures may be configured to form a slot-based parasitic antenna element to minimize coupling between the antennas in a device. The slot-based parasitic antenna element may be located between the antennas in a device. The slots structures from which a parasitic antenna element is formed may include open slots and closed slots. Slots may have one or more arms and one or more bends. Slots may be formed in internal housing members, traces on dielectric carriers, and other conductive structures.
1. An electronic device having a length, a width that is less than the length, and a height that is less than the width, comprising:
a conductive housing having first and second ends;
an antenna ground plane;
a first antenna resonating element that forms a first portion of the conductive housing at the first end and that extends across an entirety of the width of the electronic device;
a second antenna resonating element that forms a second portion of the conductive housing at the second end and that extends across the entirety of the width of the electronic device; and
a slot-based parasitic antenna element formed from slot structures in the antenna ground plane, wherein the first antenna resonating element and the antenna ground plane form a first antenna, the second antenna resonating element and the antenna ground plane form a second antenna, and the slot-based parasitic antenna element is configured to serve as an antenna isolation element to minimize coupling between the first and second antennas.
2. The electronic device defined in claim 1 wherein the slot structures comprise at least one closed slot in the antenna ground plane between the first and second ends.
3. The electronic device defined in claim 2 further comprising an internal metal housing structure that forms at least part of the antenna ground plane, wherein the closed slot is formed in the internal metal housing structure.
4. The electronic device defined in claim 3 wherein the internal metal housing structure comprises at least one planar metal layer in which the closed slot is formed and wherein the electronic device comprises cellular telephone transceiver circuitry coupled to the first and second antennas.
5. The electronic device defined in claim 1 , wherein the first portion of the conductive housing formed from the first antenna resonating element comprises a first external surface of the electronic device and the second portion of the conductive housing formed from the second antenna resonating element comprises a second external surface of the electronic device that opposes the first external surface.
6. The electronic device defined in claim 1 , wherein the first and second antenna resonating elements each extend across an entirety of the height of the electronic device.
7. The electronic device defined in claim 1 , wherein the first portion of the conductive housing that is formed from the first antenna resonating element runs along at least first, second, and third external surfaces of the electronic device.
8. The electronic device defined in claim 7 , wherein the second portion of the conductive housing that is formed from the second antenna resonating element runs along at least the first and second external surfaces and a fourth external surface of the electronic device.
9. The electronic device defined in claim 7 , wherein the first external surface is substantially parallel to the second external surface and the third external surface is substantially perpendicular to the first and second external surfaces.
10. The electronic device defined in claim 7 , wherein the slot structures comprises a first slot in the antenna ground plane between the first and second ends adjacent to the first external surface of the electronic device and a second slot in the antenna ground plane between the first and second ends adjacent to the second external surface of the electronic device.
11. The electronic device defined in claim 1 , where the slot structures comprise a C-shaped closed slot.