Electronic device with rear wall antenna parasitic
An electronic device may be provided with peripheral conductive housing structures, a rear wall, and a vent that includes a conductive cowling. The device may include an antenna having an antenna arm coupled to a positive antenna feed terminal and having a parasitic element. The parasitic element may be formed from a conductive trace that is layered onto the rear wall, that is indirectly fed by the antenna arm, and that overlaps a portion of the conductive cowling. The parasitic element may be shorted to a conductive bracket on the rear wall or may be separated from the bracket by a gap. If desired, the conductive cowling may form some or all of a parasitic element for the antenna. The conductive cowling may be indirectly fed by the conductive trace and/or may include an extension that is indirectly fed by the antenna arm.
1 . An electronic device comprising:
peripheral conductive housing structures;
a display mounted to the peripheral conductive housing structures;
a dielectric cover layer mounted to the peripheral conductive housing structures opposite the display;
a vent aligned with openings in the peripheral conductive housing structures and including a conductive cowling;
an antenna arm coupled to a positive antenna feed terminal; and
a parasitic element that is indirectly fed by the antenna arm, wherein the parasitic element overlaps a portion of the conductive cowling and overlaps a portion of the antenna arm.
2 . The electronic device of claim 1 , wherein the parasitic element is layered onto the dielectric cover layer.
3 . The electronic device of claim 2 , wherein the parasitic element comprises a conductive trace on an interior surface of the dielectric cover layer.
4 . The electronic device of claim 3 , further comprising:
a conductive bracket on the interior surface of the dielectric cover layer.
5 . The electronic device of claim 4 , wherein the conductive trace extends from a first end overlapping the antenna arm to an opposing second end that is coupled to the conductive bracket, the parasitic element comprising the conductive bracket.
6 . The electronic device of claim 4 , wherein the conductive trace extends from a first end overlapping the antenna arm to an opposing second end that is laterally separated from the conductive bracket by a dielectric-filled gap.
7 . The electronic device of claim 1 , further comprising:
a first dielectric substrate, the conductive cowling being layered onto the first dielectric substrate;
a second dielectric substrate, the antenna arm being disposed on at least two sides of the second dielectric substrate;
a flexible printed circuit that includes a signal trace and that has a tail coupled to the peripheral conductive housing structures; and
a conductive spring finger that couples the signal trace to the antenna arm at the positive antenna feed terminal.
8 . The electronic device of claim 1 , wherein the antenna arm comprises a monopole antenna resonating element.
9 . The electronic device of claim 1 , wherein the parasitic element is separated from the antenna arm and the conductive cowling by a dielectric-filled gap, the antenna arm is configured to feed the parasitic element via a first near-field electromagnetic coupling across the dielectric-filled gap, and the parasitic element is configured to indirectly feed the conductive cowling via a second near-field electromagnetic coupling across the dielectric-filled gap.
10 . An electronic device comprising:
peripheral conductive housing structures;
a display mounted to the peripheral conductive housing structures;
a dielectric cover layer mounted to the peripheral conductive housing structures opposite the display;
a conductive trace on an interior surface of the dielectric cover layer;
a conductive bracket on the interior surface of the dielectric cover layer; and
an antenna, wherein the antenna includes
an antenna element coupled to a positive antenna feed terminal, and
a parasitic element that includes the conductive trace and the conductive bracket.
11 . The electronic device of claim 10 , wherein the parasitic element extends from a first end overlapping the antenna element to an opposing second end that is electrically shorted to the conductive bracket.
12 . The electronic device of claim 11 , further comprising:
a conductive chassis coupled to the peripheral conductive housing structures, wherein the conductive chassis is interposed between the display and the dielectric cover layer; and
a dielectric interconnect that couples the conductive bracket to the conductive chassis.
13 . The electronic device of claim 10 , further comprising:
a microphone aligned with holes in the peripheral conductive housing structures, wherein the microphone has a conductive frame that at least partially overlaps the conductive trace.
14 . The electronic device of claim 13 , wherein the antenna further comprises:
an additional parasitic element that includes the conductive frame, the antenna element being configured to indirectly feed the parasitic element via a first near-field electromagnetic coupling, and the parasitic element being configured to indirectly feed the additional parasitic element via a second near-field electromagnetic coupling.
15 . The electronic device of claim 10 , further comprising:
a barometric vent aligned with holes in the peripheral conductive housing structures, wherein the barometric vent has a conductive frame that at least partially overlaps the conductive trace.
16 . The electronic device of claim 4 , further comprising:
a conductive chassis coupled to the peripheral conductive housing structures, wherein the conductive chassis is interposed between the display and the dielectric cover layer; and
a dielectric interconnect that couples the conductive bracket to the conductive chassis.
17 . The electronic device of claim 16 , wherein the conductive trace extends from a first end overlapping the antenna arm to an opposing second end that is coupled to the conductive bracket, the parasitic element comprising the conductive bracket.
18 . An electronic device comprising:
a housing that includes a dielectric cover layer;
a conductive trace on a surface of the dielectric cover layer;
a conductive cowling; and
an antenna that includes an antenna arm, a first parasitic that includes the conductive trace, and a second parasitic that includes the conductive cowling.
19 . The electronic device of claim 18 , wherein the antenna arm is configured to excite the first parasitic and the second parasitic via one or more near-field electromagnetic couplings.
20 . The electronic device of claim 18 , further comprising a vent, wherein the conductive cowling is layered on the vent.