104. This advantage of the folded antenna 104 is particularly beneficial when incorporating a high-frequency radio, such as a 2.4 GHz BLE radio, in the hearing device 100. As was discussed previously, the direction of major electric field polarization of a hearing device incorporating a 2.4 GHz radio connected to a conventional dipole antenna is parallel (rather than perpendicular) to the wearer's head, which discourages production of creeping waves needed for ear-to-car communication.

Antenna feeds 114a and 114b electrically couple opposing sides 154 and 156 of the folded antenna 104 to a radio of the electronics 106. In general, the feeds 114a and 114b attach to the folded antenna 104 at locations biased toward the ends 158 and 160, rather than the middle, of the antenna 104. The location of the feeds 114a and 115b can be selected to optimize the input impedance, effective length, radiation efficiency, and other characteristics of the folded antenna 104.

FIG. 2 illustrates additional features of a hearing device 200 incorporating a conformal folded antenna in accordance with various embodiments. In the embodiment shown in FIG. 2, a folded antenna 104 is positioned along the interior surfaces 103 of a shell 102. The top of the shell 102 is removed in FIG. 2 to allow viewing of the interior components of the hearing device 200. FIG. 2 shows a spine 110 positioned within the shell 102 and extending between first and second ends 107 and 109 of the shell 102. The spine 110 supports various electronics 106 of the hearing device 200, and has an end surface 136 that is recessed with respect to the first end 107 of the shell 102. This recess is dimensioned to receive a battery 128 (not shown).

The spine 110 and/or the folded antenna 104 can include a number of struts that extend between the spine 110 and an interior surface 103 of the shell 102. Depending on the location of the struts, some of the struts (e.g., 120 and 122) pass through apertures of the folded antenna 104, while other struts (e.g., 132, 134, 136, 138) extend from an interior surface 103 of the shell 102 above the antenna 104 and terminate at mounting locations at the spine 110. Because the folded antenna 104 is positioned between the shell 102 and the spine 110, the folded antenna 104 can include one or more apertures through which one or more struts (e.g., 120 and 122) can pass. Portions of the struts that pass through the antenna apertures can be electrically insulated from the folded antenna structure.

FIG. 3 illustrates a folded antenna 104 of a hearing device in accordance with various embodiments. The folded antenna 104 shown in FIG. 3 includes first and second opposing sides 154 and 156 and a truncated belly 152 connecting the first and second opposing sides 154 and 156. In the embodiment shown in FIG. 3, the first and second opposing sides 154 and 156 have an axial length that extends beyond an axial length of the belly 152. Portions of the first and second opposing sides 154 and 156 that extend beyond the axial length of the belly 152 can be considered antenna extensions or wings. Feeds 114a and 114b can be electrically connected to the antenna extensions or wings, for example.

FIG. 4 is a cross-sectional view of a folded antenna of a hearing device in accordance with other embodiments. The hearing device 400 shown in FIG. 4 includes a shell 402 comprising a first side 424, an opposing second side 426, a bottom 411, and a removable top 413. The shell 402 has a depth, d, defined between the bottom 411 and the top 413 (when attached). Disposed within the shell 402 is a spine which supports electronics of the hearing device 400, collectively shown as spine/electronics 405. Feeds 418a and 418b electrically connect a folded antenna 410 disposed within the shell 402 with a radio of the spine/electronics 405. The folded antenna 410 is shaped to generally conform to interior surfaces 403 of the shell 402, and encompasses at least part of the spine/electronics 405 of the hearing device 400.

The folded antenna 410 shown in FIG. 4 comprises a belly 416 that extends along the bottom 411 of the shell 402 and generally conforms to the shape of the bottom 411. Extending from the belly 416 of the folded antenna 410 are first and second opposing sides 414 and 415. The first and second opposing sides 414 and 415 extend along and generally conform to the shape of first and second sides 424 and 426 of the shell 402. Although not shown in the cross-sectional view of FIG. 4 (and other figures), it is understood that the folded antenna 410 extends axially (e.g., into and out of the page, such as along the z-axis shown in FIG. 1) along a longitudinal axis of shell 402. The folded antenna 410 has an elongated gap 401 defined between opposing first and second sides 414 and 415 of the antenna 410. In the embodiment shown in FIG. 4, the elongated gap 401 faces the top 413 of the shell 402. The first and second opposing sides 414 and 415 of the folded antenna 402 have a height, h, which is about the same as the depth, d, of the shell 402. In some configurations, the first and second opposing sides 414 and 415 have a height, h, which is between about 50% and 100% of the depth, d, of the shell 402 (e.g., >80% or 90% of d).

FIG. 5 illustrates a folded antenna of a hearing device in accordance with some embodiments. The hearing device 500 shown in FIG. 5 includes a shell 402 comprising a first side 424, an opposing second side 426, a bottom 411, and a removable top 413. The shell 402 has a depth, d, defined between the bottom 411 and the top 413 (when attached). Disposed within the shell 402 is a spine which supports electronics of the hearing device 500, collectively shown as spine/electronics 405. Feeds 518a and 518b electrically connect a folded antenna 510 disposed within the shell 402 with a radio of the spine/electronics 405. The folded antenna 510 is shaped to generally conform to interior surfaces 403 of the shell 402, and encompasses at least part of the spine/electronics 405 of the hearing device 500.

The folded antenna 510 shown in FIG. 5 comprises a belly 516 that extends along the bottom 411 of the shell 402 and generally conforms to the shape of the bottom 411. Extending from the belly 516 are first and second opposing sides 514 and 515. The first and second opposing sides 514 and 515 extend along and generally conform to the shape of a limited portion of the first and second sides 424 and 426 of the shell 402. The folded antenna 510 has an elongated gap 401 defined between opposing first and second sides 514 and 515 of the antenna 510. In the embodiment shown in FIG. 5, the elongated gap 501 faces the top 413 of the shell 402. The first and second opposing sides 514 and 515 of the folded antenna 510 have a height, h, which is less than the depth, d, of the shell 402. More particularly, the first and second opposing sides 514 and 515 can have a height, h, which is less than about 50% of the depth, d, of the shell 402 (e.g., between ˜20%-40% of d).

FIG. 6 illustrates a folded antenna of a hearing device in accordance with further embodiments. The hearing device 600 shown in FIG. 6 includes a shell 402 comprising a first side 424, an opposing second side 426, a bottom 411, and a removable top 413. The shell 402 has a depth, d, defined between the bottom 411 and the top 413 (when attached). Disposed within the shell 402 is a spine which supports electronics of the hearing device 600, collectively shown as spine/electronics 405. Feeds 618a and 618b electrically connect a folded antenna 610 disposed within the shell 402 with a radio of the spine/electronics 405. The folded antenna 610 is shaped to generally conform to interior surfaces 403 of the shell 402. According to some embodiments, the folded antenna 610 is configured to encompass at least part of the spine/electronics 405 of the hearing device 600.

The folded antenna 610 shown in FIG. 6 comprises a belly 616 that extends along the bottom 411 of the shell 402 and generally conforms to the shape of the bottom 411. Extending from the belly 616 are first and second opposing sides 614 and 615 that extend along and generally conform to the shape of a limited portion of the first and second sides 424 and 426 of the shell 402. The folded antenna 610 has an elongated gap 601 defined between opposing first and second sides 614 and 615 which, in the embodiment shown in FIG. 6, faces the top 413 of the shell 402. The first and second opposing sides 614 and 615 of the folded antenna 610 have a height, h, which is less than about one-quarter of the depth, d, of the shell 402. More particularly, the first and second opposing sides 614 and 615 can have a height, h, which is less than about 25% of the depth, d, of the shell 402 (e.g., between ˜0%-20% of d).

FIG. 7 is a cross-sectional view of a portion of a hearing device that includes a folded antenna in accordance with various embodiments. For purposes of illustration, FIG. 7 shows a portion of the hearing device 400 shown in FIG. 4, but can apply to other embodiments, such as those shown in FIGS. 5 and 6. FIG. 7 shows a second side 415 of a folded antenna 410 situated adjacent to a second side 426 of the hearing device's shell 402. An electrical insulator 419 (e.g., dielectric material) is disposed between the second side 415 of the folded antenna 410 and the spine/electronics 405 situated within the interior of the shell. In some embodiments, the insulator 419 can be a coating or layered material applied directly to the antenna surface. In other embodiments, the insulator 419 can be a separate electrically insulating structure. Suitable insulator materials 419 include polyester, polyetherimide, polyimide, polytetrafluoroethylene (PTFE), silicone, tape, paper, and air, for example.

FIG. 8 illustrates a folded antenna of a hearing device in accordance with various embodiments. The hearing device 800 shown in FIG. 8 includes a shell 402 comprising a first side 424, an opposing second side 426, a bottom 411, and a removable top 413. The shell 402 has a depth, d, defined between the bottom 411 and the top 413 (when attached). Disposed within the shell 402 is a spine which supports electronics of the hearing device 800, collectively shown as spine/electronics 405. Feeds 818a and 818b electrically connect a folded antenna 810 disposed within the shell 402 with a radio of the spine/electronics 405. The folded antenna 810 is shaped to generally conform to interior surfaces 403 of the shell 402, and encompasses at least part of the spine/electronics 405 of the hearing device 800.

The folded antenna 810 shown in FIG. 8 comprises a belly 816 that extends along the top 413 of the shell 402 and generally conforms to the shape of the top 413. Extending from the belly 816 of the folded antenna 810 are first and second opposing sides 814 and 815 that extend along and generally conform to the shape of first and second sides 424 and 426 of the shell 402. The folded antenna 810 has an elongated gap 801 defined between opposing first and second sides 814 and 815 which, in the embodiment of FIG. 8, faces the bottom 411 of the shell 402. The first and second opposing sides 814 and 815 of the folded antenna 802 have a height, h, which is about the same as the depth, d, of the shell 402. In some configurations, the first and second opposing sides 814 and 815 have a height, h, which is between about 50% and 100% of the depth, d, of the shell 402 (e.g., >80% or 90% of d).

FIG. 9 illustrates a folded antenna of a hearing device in accordance with some embodiments. The hearing device 900 shown in FIG. 9 includes a shell 402 comprising a first side 424, an opposing second side 426, a bottom 411, and a removable top 413. The shell 402 has a depth, d, defined between the bottom 411 and the top 413 (when attached). Disposed within the shell 402 is a spine which supports electronics of the hearing device 900, collectively shown as spine/electronics 405. Feeds 918a and 918b electrically connect a folded antenna 910 disposed within the shell 402 with a radio of the spine/electronics 405. The folded antenna 910 is shaped to generally conform to interior surfaces 403 of the shell 402, and encompasses at least part of the spine/electronics 405 of the hearing device 900.

The folded antenna 910 shown in FIG. 9 comprises a belly 916 that extends along the top 413 of the shell 402 and generally conforms to the shape of the top 413. Extending from the belly 916 of the folded antenna 910 are first and second opposing sides 914 and 915 which extend along and generally conform to the shape of a limited portion of the first and second sides 424 and 426 of the shell 402. The folded antenna 910 has an elongated gap 901 defined between opposing first and second sides 914 and 915 which, in the embodiment shown in FIG. 9, faces the bottom 411 of the shell 402. The first and second opposing sides 914 and 915 of the folded antenna 902 have a height, h, which is less than the depth, d, of the shell 402. More particularly, the first and second opposing sides 914 and 915 can have a height, h, which is less than about 50% of the depth, d, of the shell 402 (e.g., between ˜20%-40% of d).

FIG. 10 illustrates a folded antenna of a hearing device in accordance with other embodiments. The hearing device 1000 shown in FIG. 10 includes a shell 402 comprising a first side 424, an opposing second side 426, a bottom 411, and a removable top 413. The shell 402 has a depth, d, defined between the bottom 411 and the top 413 (when attached). Disposed within the shell 402 is a spine which supports electronics of the hearing device 1000, collectively shown as spine/electronics 405. Feeds 1018a and 1018b electrically connect a folded antenna 1010 disposed within the shell 402 with a radio of the spine/electronics 405. The folded antenna 1010 is shaped to generally conform to interior surfaces 403 of the shell 402. In some embodiments, the folded antenna 1010 is configured to encompass at least part of the spine/electronics 405 of the hearing device 1000.

The folded antenna 1010 shown in FIG. 10 comprises a belly 1016 that extends along the top 413 of the shell 402 and generally conforms to the shape of the top 413. Extending from the belly 1016 of the folded antenna 1010 are first and second opposing sides 1014 and 1015 that extend along and generally conform to the shape of a limited portion of the first and second sides 424 and 426 of the shell 402. The folded antenna 1010 has an elongated gap 1001 defined between opposing first and second sides 1014 and 1015 which, in the embodiment shown in FIG. 10, faces the bottom 411 of the shell 402. The first and second opposing sides 1014 and 1015 of the folded antenna 1010 have a height, h, which is less than about one-third or one-quarter of the depth, d, of the shell 402. For example, the first and second opposing sides 1014 and 1015 can have a height, h, which is less than about 25% of the depth, d, of the shell 402 (e.g., between ˜0%-20% of d). It is noted that the embodiments shown in FIGS. 8-10 can incorporate an insulating coating or layer on or adjacent the folded antenna in a manner described previously with reference to FIG. 7.

FIG. 11 illustrates a hearing device incorporating a conformal folded antenna in accordance with various embodiments. In the embodiment shown in FIG. 11, the hearing device 1100 includes many of the structural and electrical components shown in FIG. 4. The embodiment of FIG. 11 differs from that of FIG. 4 in terms of the antenna implementation. In the embodiment shown in FIG. 11, the folded antenna 1110 is attached to the exterior surface 407 of the shell 402. The folded antenna 1110 has a shape that generally conforms to the exterior surface 407 of the shell 402, and can be attached thereto with an adhesive or other type of bonding. In some embodiments, the folded antenna 1110 shown in FIG. 11 and other figures can be formed as a laser direct structuring (LDS) component on the shell 402 (e.g., formed on the exterior surface 407 in FIG. 11). A protective coating (not shown in FIG. 11, but see FIG. 14) can be applied to the exterior surface of the folded antenna 1100.

The hearing device 1100 shown in FIG. 11 includes a shell 402 comprising a first side 424, an opposing second side 426, a bottom 411, and a removable top 413. The shell 402 has a depth, d, defined between the bottom 411 and the top 413 (when attached). Disposed within the shell 402 is a spine which supports electronics of the hearing device 1100, collectively shown as spine/electronics 405. Feeds 1118a and 1118b extend through the opposing sides 424 and 426 and electrically connect a folded antenna 1110 disposed within the shell 402 with a radio of the spine/electronics 405. Sealing material can be used to seal the apertures in the opposing sides 424 and 426 through which the feeds 1118a and 1118b pass. As previously discussed, the folded antenna 1110 is shaped to generally conform to exterior surfaces 407 of the shell 402, and encompasses at least part of the spine/electronics 405 of the hearing device 1100.

The folded antenna 1110 shown in FIG. 11 comprises a belly 1116 that extends along the bottom 411 of the shell 402 and generally conforms to the shape of the bottom 411. Extending from the belly 1116 are first and second opposing sides 1114 and 1115, which extend along and generally conform to the shape of first and second sides 424 and 426 of the shell 402. The folded antenna 1110 has an elongated gap 1101 defined between the opposing first and second sides 1114 and 1115. In the embodiment shown in FIG. 11, the elongated gap 1101 faces the top 413 of the shell 402. The first and second opposing sides 1114 and 1115 of the folded antenna 1102 have a height, h, which is about the same as or slightly greater than the depth, d, of the shell 402. In some configurations, the first and second opposing sides 1114 and 1115 have a height, h, which is between about 50% and 100% of the depth, d, of the shell 402 (e.g., >80% or 90% of d).

FIG. 12 illustrates a hearing device incorporating a conformal folded antenna in accordance with various embodiments. The hearing device 1200 shown in FIG. 12 includes a shell 402 comprising a first side 424, an opposing second side 426, a bottom 411, and a removable top 413. The shell 402 has a depth, d, defined between the bottom 411 and the top 413 (when attached). Disposed within the shell 402 is a spine which supports electronics of the hearing device 1200, collectively shown as spine/electronics 405. Feeds 1218a and 1218b extend through the opposing sides 424 and 426 and electrically connect a folded antenna 1210 disposed within the shell 402 with a radio of the spine/electronics 405. Sealing material can be used to seal the apertures in the opposing sides 424 and 426 through which the feeds 1218a and 1218b pass. The folded antenna 1210 is shaped to generally conform to exterior surfaces 407 of the shell 402, and encompasses at least part of the spine/electronics 405 of the hearing device 1200.

The folded antenna 1210 shown in FIG. 12 comprises a belly 1216 that extends along the bottom 411 of the shell 402 and generally conforms to the shape of the bottom 411. Extending from the belly 1216 of the folded antenna 1210 are first and second opposing sides 1214 and 1215, which extend along and generally conform to the shape of a limited portion of the first and second sides 424 and 426 of the shell 402. The folded antenna 1210 has an elongated gap 1201 defined between the opposing first and second sides 1214 and 1215. In the embodiment shown in FIG. 12, the elongated gap 1201 faces the top 413 of the shell 402. The first and second opposing sides 1214 and 1215 of the folded antenna 1210 have a height, h, which is less than the depth, d, of the shell 402. More particularly, the first and second opposing sides 1214 and 1215 can have a height, h, which is less than about 50% of the depth, d, of the shell 402 (e.g., between ˜20%-40% of d).

FIG. 13 illustrates a hearing device incorporating a conformal folded antenna in accordance with some embodiments. The hearing device 1300 shown in FIG. 13 includes a shell 402 comprising a first side 424, an opposing second side 426, a bottom 411, and a removable top 413. The shell 402 has a depth, d, defined between the bottom 411 and the top 413 (when attached). Disposed within the shell 402 is a spine which supports electronics of the hearing device 1300, collectively shown as spine/electronics 405. Feeds 1318a and 1318b extend through the opposing sides 424 and 426 and electrically connect a folded antenna 1310 disposed within the shell 402 with a radio of the spine/electronics 405. Scaling material can be used to seal the apertures in the opposing sides 424 and 426 through which the feeds 1318a and 1318b pass. The folded antenna 1310 is shaped to generally conform to exterior surfaces 407 of the shell 402. In some embodiments, the folded antenna 1300 is configured to encompass at least part of the spine/electronics 405 of the hearing device 1300.

The folded antenna 1310 shown in FIG. 13 comprises a belly 1316 that extends along the bottom 411 of the shell 402 and generally conforms to the shape of the bottom 411. Extending from the belly 1316 of the folded antenna 1310 are first and second opposing sides 1314 and 1315 that extend along and generally conform to the shape of a limited portion of the first and second sides 424 and 426 of the shell 402. The folded antenna 1310 has an elongated gap 1301 defined between opposing first and second sides 1314 and 1315 which, in the embodiment shown in FIG. 13, faces the top 413 of the shell 402. The first and second opposing sides 1314 and 1315 of the folded antenna 1302 have a height, h, which is less than about one-third or one-quarter of the depth, d, of the shell 402. For example, the first and second opposing sides 1314 and 1315 can have a height, h, which is less than about 25% of the depth, d, of the shell 402 (e.g., between ˜0%-20% of d).

FIG. 14 is a cross-sectional view of a portion of a hearing device that includes a folded antenna in accordance with various embodiments. For purposes of illustration, FIG. 14 shows a portion of the hearing device 1100 shown in FIG. 11, but can apply to other embodiments, such as those shown in FIGS. 12 and 13. FIG. 14 shows the spine/electronics 405 of the hearing device 1100 situated adjacent the second side 426 of the shell 402. FIG. 14 also shows a second side 1115 of a folded antenna 1110 situated adjacent the second side 426 of the shell 402. In some embodiments, and as shown in FIG. 14, the folded antenna 1110 can optionally incorporate a metal mesh or grid 1117 within an aperture of each side (e.g., first and second sides 1114 and 1115) of the folded antenna 1100. A protective material 1119 is disposed on the exterior surface of the second side 1115 (and the first side 1114) of the folded antenna 1110. The protective material 1119 can be a coating or one or more layers of protective material. Suitable materials 1119 can include those listed above with reference to FIG. 7, with the understanding that aesthetics are important since the protective material 1119 would be visible.

FIG. 15 illustrates a folded antenna of a hearing device in accordance with various embodiments. The hearing device 1500 shown in FIG. 15 includes a shell 402 comprising a first side 424, an opposing second side 426, a bottom 411, and a removable top 413. The shell 402 has a depth, d, defined between the bottom 411 and the top 413 (when attached). Disposed within the shell 402 is a spine which supports electronics of the hearing device 1500, collectively shown as spine/electronics 405. Feeds 1518a and 1518b extend through the opposing sides 424 and 426 and electrically connect a folded antenna 1510 disposed on the exterior of the shell 402 with a radio of the spine/electronics 405. Sealing material can be used to seal the apertures in the opposing sides 424 and 426 through which the feeds 1518a and 1518b pass. The folded antenna 1510 is shaped to generally conform to exterior surfaces 407 of the shell 402, and encompasses at least part of the spine/electronics 405 of the hearing device 1500.

The folded antenna 1510 shown in FIG. 15 comprises a belly 1516 that extends along the top 413 of the shell 402 and generally conforms to the shape of the top 413. Extending from the belly 1516 of the folded antenna 1510 are first and second opposing sides 1514 and 1515 that extend along and generally conform to the shape of first and second sides 424 and 426 of the shell 402. The folded antenna 1510 has an elongated gap 1501 defined between opposing first and second sides 1514 and 1515 which, in the embodiment of FIG. 15, faces the bottom 411 of the shell 402. The first and second opposing sides 1514 and 1515 of the folded antenna 1510 have a height, h, which is about the same as the depth, d, of the shell 402 (e.g., +/−10%). In some configurations, the first and second opposing sides 1514 and 1515 have a height, h, which is between about 50% and 100% of the depth, d, of the shell 402 (e.g., >80% or 90% of d).

FIG. 16 illustrates a folded antenna of a hearing device in accordance with some embodiments. The hearing device 1600 shown in FIG. 16 includes a shell 402 comprising a first side 424, an opposing second side 426, a bottom 411, and a removable top 413. The shell 402 has a depth, d, defined between the bottom 411 and the top 413 (when attached). Disposed within the shell 402 is a spine which supports electronics of the hearing device 1600, collectively shown as spine/electronics 405. Feeds 1618a and 1618b extend through the opposing sides 424 and 426 and electrically connect a folded antenna 1610 disposed on the exterior of the shell 402 with a radio of the spine/electronics 405. Sealing material can be used to seal the apertures in the opposing sides 424 and 426 through which the feeds 1618a and 1618b pass. The folded antenna 1610 is shaped to generally conform to exterior surfaces 407 of the shell 402, and encompasses at least part of the spine/electronics 405 of the hearing device 1600.

The folded antenna 1610 shown in FIG. 16 comprises a belly 1616 that extends along the top 413 of the shell 402 and generally conforms to the shape of the top 413. Extending from the belly 1616 of the folded antenna 1610 are first and second opposing sides 1614 and 1615 which extend along and generally conform to the shape of a limited portion of the first and second sides 424 and 426 of the shell 402. The folded antenna 1610 has an elongated gap 1601 defined between opposing first and second sides 1614 and 1615 which, in the embodiment shown in FIG. 16, faces the bottom 411 of the shell 402. The first and second opposing sides 1614 and 1615 have a height, h, which is less than the depth, d, of the shell 402. More particularly, the first and second opposing sides 1614 and 1615 can have a height, h, which is less than about 50% of the depth, d, of the shell 402 (e.g., between ˜20%-40% of d).

FIG. 17 illustrates a folded antenna of a hearing device in accordance with other embodiments. The hearing device 1700 shown in FIG. 17 includes a shell 402 comprising a first side 424, an opposing second side 426, a bottom 411, and a removable top 413. The shell 402 has a depth, d, defined between the bottom 411 and the top 413 (when attached). Disposed within the shell 402 is a spine which supports electronics of the hearing device 1700, collectively shown as spine/electronics 405. Feeds 1718a and 1718b extend through the opposing sides 424 and 426 and electrically connect a folded antenna 1710 disposed on the exterior of the shell 402 with a radio of the spine/electronics 405. Scaling material can be used to seal the apertures in the opposing sides 424 and 426 through which the feeds 1718a and 1718b pass. The folded antenna 1710 is shaped to generally conform to exterior surfaces 407 of the shell 402. In some embodiments, the folded antenna 1710 is configured to encompass at least part of the spine/electronics 405 of the hearing device 1700.

The folded antenna 1710 shown in FIG. 17 comprises a belly 1716 that extends along the top 413 of the shell 402 and generally conforms to the shape of the top 413. Extending from the belly 1716 are first and second opposing sides 1714 and 1715 that extend along and generally conform to the shape of a limited portion of the first and second sides 424 and 426 of the shell 402. The folded antenna 1710 has an elongated gap 1701 defined between opposing first and second sides 1714 and 1715 which, in the embodiment shown in FIG. 17, faces the bottom 411 of the shell 402. The first and second opposing sides 1714 and 1715 have a height, h, which is less than about one-third or one-quarter of the depth, d, of the shell 402. More particularly, the first and second opposing sides 1714 and 1715 can have a height, h, which is less than about 25% of the depth, d, of the shell 402 (e.g., between ˜0%-20% of d). A protective material can be disposed on the exterior surface of the folded antennas shown in FIGS. 15-17. The protective material can be a coating or one or more layers of protective material. Suitable materials include those listed above with reference to FIG. 14 (e.g., layer(s) 1119).

FIG. 18 illustrates a folded antenna of a hearing device in accordance with further embodiments. The hearing device 1800 shown in FIG. 18 includes a shell 402 comprising a first side 424, an opposing second side 426, a bottom 411, and a removable top 413. The shell 402 has a depth, d, defined between the bottom 411 and the top 413 (when attached). Disposed within the shell 402 is a spine which supports electronics of the hearing device 1800, collectively shown as spine/electronics 405. Feeds 1818a and 1818b electrically connect a folded antenna 1810 disposed on and within the shell 402 with a radio of the spine/electronics 405. The folded antenna 1810 is shaped to generally conform to exterior surfaces 407 and interior surfaces 403 of the shell 402. More specifically, the folded antenna 1810 shown in FIG. 18 is disposed on exterior surfaces 407 of the shell 402 and extends at least partially along interior surfaces 403 of the shell 402. In this regard, the folded antenna 1810 may be considered a double-layer folded antenna. The folded antenna 1810 is configured to encompass at least part of the spine/electronics 405 of the hearing device 1800.

The folded antenna 1810 comprises a belly 1816 that extends along the bottom 411 (exterior) of the shell 402 and generally conforms to the shape of the bottom 411. Extending from the belly 1816 are first and second opposing exterior sides 1814a and 1815a. The first and second opposing exterior sides 1814a and 1815a extend along and generally conform to the shape of first and second sides 424 and 426 of the shell 402. The first and second opposing exterior sides 1814a and 1815a wrap around respective end surfaces 404 and 406 of the first and second sides 424 and 426 and extend along at least a portion of interior surfaces 403 of the shell 402 as first and second opposing interior sides 1814b and 1815b. The folded antenna 1810 has an elongated gap 1801 defined between opposing first and second sides 1814a/1814b and 1815a/1815b. In the embodiment shown in FIG. 18, the elongated gap 1801 faces the top 413 of the shell 402.

The first and second opposing exterior sides 1814a and 1815a of the folded antenna 1810 have a height, h₁, which is about the same as the depth, d, of the shell 402 (e.g., +/−10%). The first and second opposing interior sides 1814b and 1815b of the folded antenna 1810 have a height, h₂, which can be about the same as the depth, d, of the shell 402 (e.g., +/−10%). In some configurations, the first and second opposing interior sides 1814b and 1815b have a height, h₂, which is between about 50% and 100% of the depth, d, of the shell 402 (e.g., >80% or 90% of d).

FIG. 19 illustrates a folded antenna of a hearing device in accordance with further embodiments. The hearing device 1900 shown in FIG. 19 includes a shell 402 comprising a first side 424, an opposing second side 426, a bottom 411, and a removable top 413. The shell 402 has a depth, d, defined between the bottom 411 and the top 413 (when attached). Disposed within the shell 402 is a spine which supports electronics of the hearing device 1900, collectively shown as spine/electronics 405. Feeds 1918a and 1918b electrically connect a folded antenna 1910 disposed on and within the shell 402 with a radio of the spine/electronics 405. The folded antenna 1910 is shaped to generally conform to exterior surfaces 407 and interior surfaces 403 of the shell 402. More specifically, the folded antenna 1910 shown in FIG. 19 is disposed on exterior surfaces 407 of the shell 402 and extends at least partially along interior surfaces 403 of the shell 402. In this regard, the folded antenna 1910 may be considered a double-layer folded antenna. The folded antenna 1910 is configured to encompass at least part of the spine/electronics 405 of the hearing device 1900.

The folded antenna 1910 comprises a belly 1916 that extends along the bottom 411 (exterior) of the shell 402 and generally conforms to the shape of the bottom 411. Extending from the belly 1916 are first and second opposing exterior sides 1914a and 1915a. The first and second opposing exterior sides 1914a and 1915a extend along and generally conform to the shape of first and second sides 424 and 426 of the shell 402. The first and second opposing exterior sides 1914a and 1915a wrap around respective end surfaces 404 and 406 of the first and second sides 424 and 426 and extend along at least a portion of interior surfaces 403 of the shell 402 as first and second opposing interior sides 1914b and 1915b. The folded antenna 1910 has an elongated gap 1901 defined between opposing first and second sides 1914a/1914b and 1915a/1915b. In the embodiment shown in FIG. 19, the elongated gap 1901 faces the top 413 of the shell 402.

The first and second opposing exterior sides 1914a and 1915a of the folded antenna 1910 have a height, h₁, which is about the same as the depth, d, of the shell 402 (e.g., +/−10%). The first and second opposing interior sides 1914b and 1915b of the folded antenna 1910 have a height, h₂, which is less than the depth, d, of the shell 402. In some configurations, the first and second opposing interior sides 1914b and 1915b have a height, h₂, which is less than about 50% of the depth, d, of the shell 402 (e.g., between ˜10%-40% of d).

FIG. 20 illustrates a folded antenna of a hearing device in accordance with some embodiments. The hearing device 2000 shown in FIG. 20 includes a shell 402 comprising a first side 424, an opposing second side 426, a bottom 411, and a removable top 413. The shell 402 has a depth, d, defined between the bottom 411 and the top 413 (when attached). Disposed within the shell 402 is a spine which supports electronics of the hearing device 2000, collectively shown as spine/electronics 405. Feeds 2018a and 2018b electrically connect a folded antenna 2010 disposed on and within the shell 402 with a radio of the spine/electronics 405. The folded antenna 2010 is shaped to generally conform to exterior surfaces 407 and interior surfaces 403 of the shell 402. More specifically, the folded antenna 2010 shown in FIG. 20 is disposed on exterior surfaces 407 of the shell 402 and extends at least partially along interior surfaces 403 of the shell 402. In this regard, the folded antenna 2010 may be considered a double-layer folded antenna. In some embodiments, the folded antenna 2010 is configured to encompass at least part of the spine/electronics 405 of the hearing device 2000.

The folded antenna 2010 comprises a belly 2016 that extends along the bottom 411 (exterior) of the shell 402 and generally conforms to the shape of the bottom 411. Extending from the belly 2016 are first and second opposing exterior sides 2014a and 2015a. The first and second opposing exterior sides 2014a and 2015a extend along and generally conform to the shape of first and second sides 424 and 426 of the shell 402. The first and second opposing exterior sides 2014a and 2015a wrap around respective end surfaces 404 and 406 of the first and second sides 425 and 426 and extend along at least a portion of interior surfaces 403 of the shell 402 as first and second opposing interior sides 2014b and 2015b. The folded antenna 2010 has an elongated gap 2001 defined between opposing first and second sides 2014a/2014b and 2015a/2015b. In the embodiment shown in FIG. 20, the elongated gap 2001 faces the top 413 of the shell 402. The first and second opposing exterior sides 2014a and 2015a of the folded antenna 2010 have a height, h₁, which is about the same as the depth, d, of the shell 402 (e.g., +/−10%). The first and second opposing interior sides 2014b and 2015b of the folded antenna 2010 have a height, h₂, which is less than about 25% of the depth, d, of the shell 402 (e.g., between ˜0%-20% of d).

A protective material can be disposed on the exterior surface of the folded antennas shown in FIGS. 18-20. The protective material can be a coating or one or more layers of protective material. Suitable materials include those listed above with reference to FIG. 14 (e.g., layer(s) 1119). An electrical insulator (e.g., dielectric material) can be disposed between interior portions of the folded antennas shown in FIGS. 18-12 and the spine/electronics 405. In some embodiments, the insulator can be a coating or layered material applied directly to the antenna surface (e.g., layer(s) 419 shown in FIG. 7).

Embodiments of a folded antenna discussed hereinabove are configured to encompass at least some of the spine/electronics disposed within the shell of the hearing device. The spine and/or electronics can serve as a loading dielectric that can increase the effective length of the folded antenna. The spine and/or electronics disposed within the shell can also become part of the matching network that effectively tunes the folded antenna. In some embodiments, portions of the folded antenna extend along at least some of the interior surfaces of the shell, which effectively serves as a tuning capacitor for the folded antenna (e.g., for tuning the input impedance through a distributed capacitance effect). The feed location of the folded antenna can be adjusted along the elongated gap to provide reasonable impedance to be matched relatively easily. It can be appreciated that the configuration and dimensions of the folded antenna can be adjusted to achieve desired antenna performance characteristics.

FIG. 21 is a Smith chart that demonstrates the improvement in impedance matching of the folded antenna by encompassing internal components (e.g., spine, electronics such as flex circuits, battery, receiver, etc.) disposed within the shell of the hearing device. Curve B shows the impedance matching characteristics of a folded antenna disposed within a hearing device shell devoid of a spine and electronics. Curve A shows the impedance matching characteristics of the folded antenna disposed within a hearing device which includes a spine and electronics. FIG. 21 demonstrates that the presence of the spine and/or electronics within the shell improves the impedance matching characteristics of the folded antenna.

The human head significantly impacts the performance of a folded antenna disposed in a hearing device when the hearing device is properly positioned on the car of a wearer. The three-dimensional radiation pattern of a representative folded antenna in free space is illustrated in FIG. 22. FIG. 23 illustrates the three-dimensional radiation pattern of the representative folded antenna when positioned on the wearer's ear immediately adjacent the head. As is evident in FIGS. 22 and 23, head loading significantly improves the performance of the folded antenna. More particularly, head loading makes the folded antenna form smooth approximately semi-sphere coverage as is shown in FIG. 23. The head-loaded folded antenna has right E-field polarization which is substantially normal to the head and a significant amount of radiated power at the hearing device/head interface plane (the y-z plane), which is important for effecting reliable ear-to-ear communication.

The two-dimensional gain pattern of FIG. 24, for example, shows significant power is directed around the back of the head (curve A), which is an indicator that creeping waves can be launched to facilitate ear-to-ear communication. In FIG. 24, curve A (vertical polarization to head) and curve B (horizontal polarization to head) show antenna gain patterns parallel to the head (e.g., the y-z plane shown in FIG. 23). Stronger creeping waves can be launched using a folded antenna because of the stronger radiation pattern directed toward the back surface of the head. It is noted that, in FIG. 24, the +x and +y axes are indicated, which correspond to x and y axes shown in FIG. 23.

It is known that conventional dipole antennas can be affected severely (e.g., at least by 3 dB) by head loading. In contrast, a folded antenna in accordance with embodiments of the present disclosure has about the same level of radiation efficiency in free space and on the head, as is evidenced in Table 1 below.

TABLE 1

Freq
On-head Radiation
Free-space Radiation

(GHz)
Efficiency (dB)
Efficiency (dB)

2.40
−7.45
−7.45

2.42
−7.45
−7.83

2.44
−7.46
−7.62

2.46
−7.39
−7.42

2.48
−7.43
−7.79

Moreover, head loading improves the impedance matching condition as is shown in FIG. 25. FIG. 25 provides an S-parameter comparison of a folded antenna on-head (curve A) and in free space (curve B). FIG. 25 shows an improved impedance matching condition when the folded antenna is properly positioned on the wearer's ear immediately adjacent the head.

An experiment was performed on a test head to compare the total radiated power for different antenna topologies. FIG. 26 shows the graphical results of this experiment. In the experiment, two different antenna topologies were evaluated; a conventional dipole antenna (curve A) and a folded antenna (curve B) implemented in accordance with the present disclosure. The graph of FIG. 26 is divided between the channels on the left car and channels on the right car. The frequency associated with each channel can be calculated using the formula 2402 MHz+(2×Channel Number) in MHz. For example, Channel 38 corresponds to a frequency of 2402 MHz+(2×38) MHz=2478 MHz (or 2.478 GHz).