Electronic Device Having Angle of Arrival Detection Capabilities

Patent metadata

Field	Value
Publication number	US-2020021011-A1
Application number	US-201816035325-A
Country	US
Kind code	A1
Filing date	Jul 13, 2018
Priority date	Jul 13, 2018
Publication date	Jan 16, 2020
Grant date	—

Abstract

An electronic device may be provided with wireless circuitry that includes first, second, and third antennas used to determine the position and orientation of the electronic device relative to external equipment. The antennas may include patch elements on respective substrates mounted to a flexible printed circuit. Each substrate may include fences of conductive vias that are coupled to ground and that laterally surround the corresponding patch element. Control circuitry may identify phase differences between the first and second antennas and between the second and third antennas and may identify an angle of arrival of received ultra-wideband signals using the phase differences. The control circuitry may compare the phase differences to a set of predetermined surfaces of phase differences to identify environmental loading conditions for the antenna. The control circuitry may correct the angle of arrival using offsets identified based on the environmental loading conditions.

First claim

What is claimed is:

1 . An electronic device comprising:
a flexible printed circuit; first and second substrates mounted to the flexible printed circuit; a first antenna having a first antenna resonating element formed from a first conductive trace on the first substrate; a second antenna having a second antenna resonating element formed from a second conductive trace on the second substrate; a first set of conductive vias that extend through the first substrate and laterally surround the first conductive trace; and a second set of conductive vias that extend through the second substrate and laterally surround the second conductive trace.

2 . The electronic device defined in claim 1 , further comprising:
a third substrate mounted to the flexible printed circuit; a third antenna having a third antenna resonating element formed from a third conductive trace on the third substrate; and a third set of conductive vias that extend through the third substrate and laterally surround the third conductive trace.

3 . The electronic device defined in claim 2 , wherein the first and second antennas are aligned along a first axis and the second and third antennas are aligned along a second axis perpendicular to the first axis.

4 . The electronic device defined in claim 2 , further comprising:
a radio-frequency connector mounted to the flexible printed circuit; a first radio-frequency transmission line on the flexible printed circuit that couples the radio-frequency connector to the first antenna; a second radio-frequency transmission line on the flexible printed circuit that couples the radio-frequency connector to the second antenna; and a third radio-frequency transmission line on the flexible printed circuit that couples the radio-frequency connector to the third antenna.

5 . The electronic device defined in claim 2 , wherein the first, second, and third antennas are each configured to receive radio-frequency signals in an ultra-wideband communications band.

6 . The electronic device defined in claim 5 , wherein the first and second antennas are each configured to receive radio-frequency signals in an additional ultra-wideband communications band.

7 . The electronic device defined in claim 5 , further comprising:
control circuitry coupled to the first, second, and third antennas, wherein the control circuitry is configured to:
identify a first phase difference between the first and second antennas based on the radio-frequency signals received by the first and second antennas;
identify a second phase difference between the second and third antennas based on the radio-frequency signals received by the second and third antennas; and
determine an angle of arrival value for the radio-frequency signals based on the first and second phase differences.

8 . The electronic device defined in claim 7 , wherein the control circuitry is further configured to:
identify an operating environment for the first, second, and third antennas based on the first and second phase differences; select an offset value from a set of predetermined offset values based on the identified operating environment; and adjust the angle of arrival value using the selected offset value.

9 . The electronic device defined in claim 8 , wherein the control circuitry is configured to identify the operating environment by comparing the first and second phase differences to a predetermined surface of phase difference values stored on the electronic device.

10 . The electronic device defined in claim 1 , further comprising:
a ground trace embedded in the first substrate, wherein the first set of conductive vias is coupled to the ground trace; a signal conductor in the flexible printed circuit that is coupled to the first conductive trace by a feed via that extends through the first substrate and an opening in the ground trace; and a ground conductor in the flexible printed circuit, wherein the signal conductor and the ground conductor form a radio-frequency transmission line that conveys radio-frequency signals for the first antenna.

11 . The electronic device defined in claim 1 , wherein the first set of conductive vias surrounds a periphery of the first substrate and the second set of conductive vias surrounds a periphery of the second substrate.

12 . The electronic device defined in claim 1 , wherein the electronic device has opposing first and second faces and further comprises:
a display mounted at the first face; a dielectric layer at the second face; and a conductive layer coupled to an interior surface of the dielectric layer, wherein the conductive layer comprises an aperture that is aligned with the first antenna, and the first antenna is configured to receive radio-frequency signals through the dielectric layer and the aperture.

13 . Apparatus comprising:
a first substrate; a second substrate mounted to the first substrate; a patch antenna having an antenna resonating element formed from a conductive trace on the second substrate, wherein the patch antenna is configured to receive radio-frequency signals in an ultra-wideband communications band; a ground trace in the second substrate; a radio-frequency transmission line in the first substrate and having a signal conductor coupled to the first conductive trace by a conductive feed via that extends through the second substrate and through an opening in the ground trace; and a fence of conductive vias, wherein the fence of conductive vias is coupled to the ground trace, extends through the second substrate, and laterally surrounds the conductive feed via.

14 . The apparatus defined in claim 13 , wherein the conductive trace is formed on a surface of the second substrate and the fences of conductive vias extend from the ground trace to conductive pads on the surface of the substrate.

15 . The apparatus defined in claim 14 , wherein the conductive pads are laterally separated from the conductive trace at the surface of the second substrate by a distance, the distance being between 0.4 mm and 0.6 mm.

16 . The apparatus defined in claim 13 , wherein the first substrate comprises a flexible printed circuit and the second substrate comprises a material selected from the group consisting of: polyimide, liquid crystal polymer, and plastic.

17 . The apparatus defined in claim 13 , further comprising control circuitry configured to identify an angle of arrival of the radio-frequency signals received by the patch antenna.

18 . An electronic device comprising:
first and second antennas configured to receive radio-frequency signals; and storage and processing circuitry coupled to the first and second antennas, wherein the storage and processing circuitry is configured to:
measure a phase difference between the radio-frequency signals received by the first antenna and the radio-frequency signals received by the second antenna,
generate an angle of arrival value for the radio-frequency signals based on the measured phase difference,
identify an offset value based on the measured phase difference and a predetermined set of phase difference values, and
generate a corrected angle of arrival value by adjusting the angle of arrival value using the identified offset value.

19 . The electronic device defined in claim 18 , wherein the predetermined set of phase difference values comprises a plurality of curves of phase difference values, each curve corresponds to a respective impedance loading condition for the first and second antennas, and the storage and processi

Assignees

• Apple Inc

Inventors

• Cooper Aaron J
• Tayebi Amin
• Di Nallo Carlo
• Wang Zheyu

Classifications

• H01Q3/2605

  Array of radiating elements provided with a feedback control over the element weights, e.g. adaptive arrays · CPC title

• H01Q21/065

  Patch antenna array · CPC title

• H01Q1/243 Primary

  with built-in antennas · CPC title

• H01Q9/0407

  Substantially flat resonant element parallel to ground plane, e.g. patch antenna (dipole H01Q9/285; monopole H01Q9/40) · CPC title

• H01Q5/25

  Ultra-wideband [UWB] systems, e.g. multiple resonance systems; Pulse systems · CPC title