Proximity sensor for RF control

Patent metadata

Field	Value
Publication number	US-12512583-B2
Application number	US-202217894814-A
Country	US
Kind code	B2
Filing date	Aug 24, 2022
Priority date	Sep 23, 2021
Publication date	Dec 30, 2025
Grant date	Dec 30, 2025

Abstract

The invention relates to an electronic component for adapting a pre-set matched impedance for an antenna. The electronic component comprises 1) a capacitance measurement circuit for measuring capacitance of a sensor, wherein the measured capacitance is indicative of a use case of the antenna, 2) a Radio Frequency (RF) switch configured for electrically connecting at least one selected impedance to an RF output, wherein the at least one selected impedance is an impedance in a group of impedances having at least two elements, wherein the RF switch is capable of providing an electrical connection between any impedance in the group of impedances and the RF output, and wherein the at least one selected impedance is configured for adapting the pre-set matched impedance, and 3) a digital processor having access to at least one threshold and the measured capacitance. The digital processor is configured (i) to compare the measured capacitance of the sensor provided by the capacitance measurement circuit to the at least one threshold, (ii) to determine, based on the comparison, which impedance in the group of impedances is the at least one selected impedance, and (iii) to instruct the RF switch to provide an electrical connection between the at least one selected impedance and the RF output. The invention also relates to a method for adapting a pre-set matched impedance for an antenna.

First claim

The invention claimed is:

1 . Electronic component on a single chip for adapting a pre-set matched impedance for an antenna, comprising
1) A RF pin connectable to the antenna,
a capacitance sense pin connectable to the antenna,
a group of selectable first pins connectable to the antenna via the RF pin,
a second pin connectable to the antenna,
wherein the RF pin, the capacitance sense pin, the selectable first pins and the second pin are separated and distinct pins, 2) a capacitance measurement circuit connected to the capacitance sense pin for measuring a capacitance of a sensor or of the antenna, 3) a Radio Frequency (RF) switch configured to establish a selectable connection between a selected first pin in the group of selectable first pins and the RF pin, having at least two elements, wherein the RF switch is capable of providing an electrical connection between any pin in the group of selectable first pins and the RF pin, 4) a variable capacitor connectable to the antenna via the second pin of the electronic component, and 3) a digital processor having access to at least one threshold and the measured capacitance, wherein the digital processor is configured
(i) to compare the measured capacitance of the sensor provided by the capacitance measurement circuit to the at least one threshold,
(ii) to decide, based on the comparison, whether an external object is in the vicinity of the antenna,
(iii) to determine, based on the comparison, which impedance in the group of impedances is the at least one selected impedance, and
(iv) to instruct the RF switch to provide an electrical connection between the at least one selected impedance and the RF output,
(v) to change a capacitance of the variable capacitor based on the measured capacitance,
wherein the antenna is arranged to be connected to a matching network which provides the pre-set matched impedance, wherein the at least one selected impedance adapts the pre-set matched impedance, creating an adapted matched impedance which is better suited for the antenna than the pre-set matched impedance.

2 . Electronic component according to claim 1 , the RF pin being connected to a cellular antenna.

3 . Electronic component according to claim 2 , wherein the antenna is a planar inverted-F antenna.

4 . Electronic component according to claim 1 , the capacitance sense pin being connected to a floating piece of conductor separate from the antenna acting as sensor.

5 . Electronic component according to claim 4 , wherein the floating piece of conductor is metal plate or as a printed circuit board (PCB) pad or as a flexible printed circuit (FPC) pad.

6 . Electronic component according to claim 1 , wherein the selectable first pins are each connected to one impedance in a group of impedances for adapting the pre-set matched impedance between an RF transceiver and the antenna.

7 . Electronic component according to claim 6 , wherein the electronic component comprises the RF transceiver, and wherein the RF transceiver is connected via the RF switch to the antenna.

Assignees

• Semtech Corp

Inventors

• Rouaissia Chaouki

Classifications

• H01Q1/243

  with built-in antennas · CPC title

• H01Q5/335

  at the feed, e.g. for impedance matching · CPC title

• H04B1/18

  Input circuits, e.g. for coupling to an antenna or a transmission line (coupling networks between antennas or lines and receivers independent of the nature of the receiver H03H) · CPC title

• H01Q1/48 Primary

  Earthing means; Earth screens; Counterpoises · CPC title

• H04B1/0458 Primary

  Arrangements for matching and coupling between power amplifier and antenna or between amplifying stages (matching circuits in general H03H) · CPC title