Coupling structures for electronic device housings

1. A housing for an electronic device, comprising:

a first antenna defining:

a first portion of an exterior surface of the housing; and

an interlock feature;

a housing member defining a second portion of the exterior surface of the housing and set off from the first antenna by a first gap;

a first molded element positioned at least partially within the first gap;

a second molded element positioned at least partially within the first gap and defining a third portion of the exterior surface of the housing, the second molded element mechanically engaged with the interlock feature of the first antenna;

a second antenna set off from the housing member by a second gap, the second antenna defining a fourth portion of the exterior surface of the housing;

a third molded element positioned at least partially within the second gap; and

a fourth molded element positioned at least partially within the second gap and defining a fifth portion of the exterior surface of the housing.

2. The housing of claim 1 , wherein:

the interlock feature is a blind recess extending into the first antenna; and

the second molded element at least partially fills the blind recess to mechanically engage the second molded element to the first antenna.

3. The housing of claim 1 , wherein:

the interlock feature is a first interlock feature;

the housing member defines a second interlock feature; and

the first molded element is mechanically engaged with the second interlock feature.

4. The housing of claim 2 , wherein:

the first molded element further defines a textured surface; and

the second molded element is mechanically engaged with the textured surface, thereby retaining the first molded element to the second molded element.

5. The housing of claim 1 , wherein:

the first antenna is formed from a first metal;

the housing member is formed from a second metal; and

the first antenna is electrically isolated from the housing member by the first and second molded elements.

6. The housing of claim 4 , wherein:

the first molded element is formed from a first polymer; and

the second molded element is formed from a second polymer that is different from the first polymer.

7. The housing of claim 1 , wherein:

the housing is configured to receive a display;

the housing defines a set of side surfaces that surround the display; and

the first, second, and third portions of the exterior surface of the housing each define at least a portion of a side surface of the set of side surfaces.

8. A housing for an electronic device, comprising:

a first housing member having a first interlock feature and defining a first portion of a peripheral wall extending around a periphery of the housing, the first housing member configured to operate as a first antenna;

a second housing member having a second interlock feature and defining a second portion of the peripheral wall;

a first molded element positioned between the first housing member and the second housing member and mechanically engaged with the second interlock feature;

a second molded element positioned between the first housing member and the second housing member and defining a third portion of the peripheral wall, the second molded element mechanically engaged with the first interlock feature;

a third housing member having a third interlock feature and defining a fourth portion of the peripheral wall, the third housing member configured to operate as a second antenna;

a third molded element positioned between the second housing member and the third housing member; and

a fourth molded element positioned between the second housing member and the third housing member and defining a fifth portion of the peripheral wall, the second molded element mechanically engaged with the third interlock feature.

9. The housing of claim 8 , wherein:

the first interlock feature includes a recess formed in the first housing member; and

the second molded element at least partially fills the recess.

10. The housing of claim 8 , wherein:

the first molded element includes a third interlock feature; and

the second molded element is mechanically engaged with the third interlock feature.

11. The housing of claim 8 , wherein:

the first molded element defines a textured surface; and

the second molded element is mechanically engaged with the textured surface of the first molded element.

12. The housing of claim 11 , wherein the textured surface comprises one or more of:

a group of micro-sized pores in the first molded element; or

a group of nano-sized pores in the first molded element.

13. The housing of claim 11 , wherein:

the first molded element comprises a fiber-reinforced polymer; and

the second molded element is substantially free of fibers.

14. A portable electronic device comprising:

a transparent member defining a front surface of the portable electronic device;

a display positioned under the transparent member; and

a housing surrounding the display and comprising;

a first housing member configured to operate as a first antenna of the portable electronic device and defining a first portion of an exterior side surface of the housing and an interlock feature;

a second housing member defining a second portion of the exterior side surface;

a first joint structure at least partially between the first and second housing members and mechanically retaining the first housing member to the second housing member, the first joint structure comprising:

a first molded element comprising a first polymer material; and

a second molded element comprising a second polymer material different from the first polymer material and mechanically engaged with the interlock feature of the first housing member;

a third housing member configured to operate as a second antenna of the portable electronic device and defining a third portion of the exterior side surface of the housing; and

a second joint structure between the second and third housing members mechanically engaging the third housing member to the second housing member.

15. The portable electronic device of claim 14 , wherein the second molded element defines a fourth portion of the exterior side surface of the housing.

16. The portable electronic device of claim 14 , wherein:

the portable electronic device further comprises a radio circuit within the housing; and

the first housing member is electrically coupled to the radio circuit.

17. The portable electronic device of claim 14 , wherein the joint structure electrically isolates the first housing member from the second housing member.

18. The portable electronic device of claim 14 , wherein the first molded element has a higher yield strength than the second molded element.

19. The portable electronic device of claim 14 , wherein:

the interlock feature comprises a plurality of grooves; and

the second molded element engages the plurality of grooves.

20. The housing of claim 1 , wherein:

the interlock feature comprises a plurality of grooves; and

portions of the second molded element extend into the plurality of grooves.