Radio frequency system for wearable device
A radio frequency (RF) system includes an RF integrated circuit (IC) die, and an antenna coupled to the RF IC die. The RF system further includes a reflector layer over the RF IC die, the reflector layer extending over at least a portion of the antenna, a combination of the antenna and the reflector layer having a radiation pattern that comprises a main lobe in a first direction parallel to a top surface of the reflector layer.
1. A wearable device comprising:
a housing, the housing having a top portion, a bottom portion, and a sidewall connecting the top portion to the bottom portion;
a circuit board within the housing and over the bottom portion of the housing;
a radio frequency (RF) system mounted on the circuit board, the RF system comprising:
an RF integrated circuit (IC) die;
an antenna coupled to the RF IC die; and
a reflector layer over the RF IC die and the antenna; and
a display disposed over the RF system, wherein a radiation pattern of the RF system has a main lobe in a first direction parallel to a top surface of the display, and wherein the first direction intersects with the sidewall of the housing.
2. The wearable device of claim 1 , wherein the RF IC die comprises radar circuitry coupled to the antenna.
3. The wearable device of claim 2 , further comprising gesture recognizing processing circuitry coupled to the RF IC die.
4. The wearable device of claim 1 , wherein the radiation pattern has a side lobe in a second direction perpendicular to the first direction, the second direction intersecting with the display.
5. The wearable device of claim 4 , wherein a gain of the main lobe is greater than a gain of the side lobe.
6. The wearable device of claim 1 , wherein the top portion of the housing and the bottom portion of the housing comprise a metal or a metal alloy.
7. The wearable device of claim 1 , wherein at least a portion of the sidewall of the housing is formed of a material transparent for mm-wave RF signals.
8. The wearable device of claim 1 , wherein a portion of the sidewall of the housing is not transparent for mm-wave RF signals.
9. The wearable device of claim 1 , wherein the reflector layer comprises a metal or a metal alloy.
10. The wearable device of claim 1 , wherein the reflector layer is configured to provide a heat dissipation path from the RF IC die to the top portion of the housing.
11. The wearable device of claim 1 , wherein the top portion of the housing comprises a high thermal conductivity material.
12. The wearable device of claim 1 , wherein the bottom portion of the housing comprises a low thermal conductivity material.
13. The wearable device of claim 1 , wherein the wearable device is a smart watch.
14. A wearable device comprising:
a housing;
a mm-wave gesture sensing system within the housing, the mm-wave gesture sensing system comprising a radio frequency (RF) system, the RF system comprising:
an RF integrated circuit (IC) die;
an antenna coupled to the RF IC die; and
a reflector layer over the RF IC die and the antenna, a combination of the antenna and the reflector layer having a radiation pattern comprising a main lobe in a first direction parallel to a top surface of the reflector layer; and
a display disposed over the mm-wave gesture sensing system, wherein the first direction is parallel to a top surface of the display, and wherein the first direction intersects with a sidewall of the housing.
15. The wearable device of claim 14 , wherein the reflector layer comprises a metal or a metal alloy.
16. The wearable device of claim 14 , wherein the reflector layer is configured to act as a heat sink for the RF IC die.
17. The wearable device of claim 14 , wherein the RF system further comprises a molding material encapsulating the RF IC die and the reflector layer.
18. The wearable device of claim 14 , wherein the antenna is a Yagi-Uda antenna.
19. The wearable device of claim 14 , wherein the radiation pattern has a side lobe in a second direction perpendicular to the first direction.
20. The wearable device of claim 19 , wherein the reflector layer is configured to redirect an energy of RF signals from the second direction to the first direction.
21. A wearable device comprising:
a housing, the housing having a top portion, a bottom portion, and a sidewall portion extending between the top portion and the bottom portion;
a circuit board between the top portion and the bottom portion of the housing;
a mm-wave gesture sensing system mounted on the circuit board, the mm-wave gesture sensing system comprising a radio frequency (RF) system, the RF system comprising:
an RF integrated circuit (IC) die;
an antenna coupled to the RF IC die; and
a reflector layer over the RF IC die, the reflector layer extending over at least a portion of the antenna, wherein a highest gain direction of a main lobe of a radiation pattern of the RF system intersects with the sidewall portion of the housing; and
a display disposed over the RF system, wherein the highest gain direction of the main lobe of the radiation pattern of the RF system is parallel to a top surface of the display.
22. The wearable device of claim 21 , wherein a portion of the sidewall portion of the housing intersecting with the highest gain direction comprises a material transparent for mm-wave RF signals.
23. The wearable device of claim 21 , wherein the reflector layer comprises a high thermal conductivity material.
24. The wearable device of claim 21 , wherein the antenna is a directional antenna.
25. The wearable device of claim 21 , wherein the RF system further comprises a molding material encapsulating the RF IC die, the antenna and the reflector layer.
26. The wearable device of claim 21 , wherein the top portion of the housing comprises a metallic material.
27. The wearable device of claim 21 , wherein the bottom portion of the housing comprises a low thermal conductivity material.