Wireless communication device

Abstract

One example discloses a wireless communication device comprising: a first receiver input configured to be coupled to a first end of an antenna and a first end of a sense resistor; wherein the sense resistor is coupled in series with the antenna; a second receiver input configured to be coupled to a second end of the sense resistor; a controller configured to determine an antenna current (Iant) flowing through the antenna based on a voltage between the first receiver input and the second receiver input; wherein the controller is configured to increase the antenna current if the antenna current is below a first predetermined value; and wherein the controller is configured to decrease the antenna current if the antenna current is above a second predetermined value.

Description

Technical Field

[0001] This specification relates to systems, methods, apparatus, devices, articles of manufacture, and instructions for wireless communication. Background Technology

[0002] Battery-powered, wirelessly connected smart devices (such as smartphones, smart cards, etc.) are ubiquitous and are therefore hosted by numerous platforms, such as vehicles, buildings, and furniture. Typically, these platforms have embedded pads, trays, surfaces, etc., for communicating with and charging these wireless devices placed on them. Summary of the Invention

[0003] According to an example embodiment, a wireless communication device includes: a first receiver input configured to be coupled to a first end of an antenna and a first end of a sensing resistor; wherein the sensing resistor is coupled in series with the antenna; a second receiver input configured to be coupled to a second end of the sensing resistor; and a controller configured to determine an antenna current (Iant) flowing through the antenna based on a voltage between the first receiver input and the second receiver input; wherein the controller is configured to increase the antenna current when the antenna current is below a first predetermined value; and wherein the controller is configured to decrease the antenna current when the antenna current is above a second predetermined value.

[0004] In another example embodiment, the controller is configured to calculate the power loss ratio based on the antenna current (Iant).

[0005] In another example embodiment, if the power loss ratio is higher than a predetermined ratio, the controller is configured to determine that the first wireless communication device is near the antenna.

[0006] In another example embodiment, if the power loss ratio is below a predetermined ratio, the controller is configured to determine that the second wireless communication device is near the antenna.

[0007] In another example embodiment, if the power loss ratio is higher than a predetermined ratio, the controller is configured to increase the antenna current (Iant).

[0008] In another example embodiment, if the power loss ratio is below a predetermined ratio, the controller is configured to reduce the antenna current (Iant).

[0009] In another example embodiment, if the power loss ratio is greater than 2, the controller is configured to determine that the smartphone is close to the antenna.

[0010] In another example embodiment, if the power loss ratio is less than 2, the controller is configured to determine that the smart card is near the antenna.

[0011] In another example embodiment, the controller is configured to calculate the power loss ratio as equal to P(l, with load) / P(l, without load), where: P(l, with load) = Pin(with load) - Pant(with load), and P(l, without load) = Pin(without load) - Pant(without load).

[0012] In another example embodiment, the controller is configured to operate in differential mode using both the first receiver input and the second receiver input to determine the antenna current (Iant).

[0013] In another example embodiment, the controller is configured to operate in single-ended mode using only the second receiver input to wirelessly communicate with the smart device.

[0014] In another example embodiment, the antenna is a coil configured to communicate using near-field signals.

[0015] In another example embodiment, it further includes: a first transmitter output configured to be coupled to a second end of a sensing resistor; and a second transmitter output configured to be coupled to a second end of an antenna.

[0016] In another example embodiment, a wireless charging coil is also included, which is configured to charge the wireless device.

[0017] In another example embodiment, the wireless charging coil is physically located next to the antenna.

[0018] In another example embodiment, the wireless charging coil is physically overlapped with the antenna.

[0019] The foregoing discussion is not intended to represent every example embodiment or every implementation within the scope of the present or future claims. Various example embodiments are also illustrated in the drawings and the following detailed description.

[0020] The various exemplary embodiments can be more fully understood by considering the following specific implementations in conjunction with the accompanying drawings. Attached Figure Description

[0021] Figure 1 This is the first example of a wireless communication device.

[0022] Figure 2 This is a second example representing a wireless communication device.

[0023] Figure 3 This is the third example of a wireless communication device.

[0024] Figure 4 This is the fourth example of a wireless communication device.

[0025] While this disclosure allows for various modifications and alternatives, details thereof have been illustrated by way of example in the drawings and will be described in detail. However, it should be understood that other embodiments besides the specific embodiments described are also possible. All modifications, equivalents, and alternative embodiments falling within the spirit and scope of the appended claims are also covered. Detailed Implementation

[0026] In some cases, these wireless devices use NFC (Near Field Communication) to communicate and are charged according to the Qi-Charging standard.

[0027] To support communication and charging, these embedded pads, trays, surfaces, etc., include an antenna for wireless communication and a separate set of charging coils for wireless charging. The antenna and coils are typically quite large to allow for user flexibility when placing wireless devices on them.

[0028] These large antennas and coils are also placed very close together and / or stacked on top of each other. Such close spacing causes at least strong detuning of the communication antennas, resulting in a weak RF signal at the communication receiver of the wireless device.

[0029] Q-Charging technology poses a potential risk to physically placed cards during the charging process. In some cases, the card may be damaged and become inoperable. This issue necessitates a robust detection mechanism to prevent damage and ensure safe operation. A charging device (such as a mobile phone) may act as a shield, preventing communication with the card and card detection. Detecting vulnerable smart cards under a smartphone is often problematic. To address these scenarios and detect smart cards, using higher TX power is important.

[0030] Various example embodiments of circuitry for automatic power adjustment (APA) are now discussed, which respond to different types of wireless devices placed on such embedded pads, trays, surfaces, etc., so as to be able to communicate with and charge these wireless devices without damaging them.

[0031] As discussed in this article, APAs include: enabling smart card protection; allowing for more flexible antenna designs; controlling the maximum power transmitted; increasing power only when the RF field is too low; avoiding excessively high RF field strength if only a smart card is placed nearby; and compensating for any RF field shielding caused by overlapping devices.

[0032] Figure 1 This represents a first example 100 of a wireless communication device. The first example device 100 includes a communication controller 102, a tuning circuit 104, an antenna 106, and a power supply.

[0033] In the first example device 100, the TXLDO in the communication controller 102 senses the TX (transmission) current between pins TX1 and TX2. The power controller (DPC) in the communication controller 102 then adjusts the transmission power (Pant / RF field strength) of the antenna 106 to keep the Pane within a defined operating range. For example, the DPC could reduce the voltage between pins TX1 and TX2 to set a minimum Pane power that still enables wireless communication with the NFC smart card device while preventing the NFC smart card from being damaged by too much Pane power (e.g., by limiting the field and thus not triggering the maximum field limit specified by application requirements or standards).

[0034] Figure 2 A second example 200 of a wireless communication device is shown. The second example device 200 includes a communication controller 202, a tuning circuit 204, an antenna 206, and a power supply. The second example device 200 also includes a first receiver input (RXp) and a second receiver input (RXn) respectively coupled to each end of a sensing resistor 208 (Rsen).

[0035] Note that only the circuitry used for wireless communication (e.g., NFC) is shown. A separate circuit (not shown) performs wireless charging (e.g., the Qi standard).

[0036] The communication controller 202 is configured to determine the antenna current (Iant) flowing through the antenna 206 based on the voltage difference (VDIF) between the first receiver input (RXp) and the second receiver input (RXn). The communication controller 202 is then configured to increase the antenna current (Iant) (i.e., increase the transmission power (Pout / Pant)) when the antenna current is below a first predetermined value, and to decrease the antenna current (Iant) (i.e., decrease the transmission power (Pout / Pant)) when the antenna current is above a second predetermined value.

[0037] As an alternative or supplement to using TX1 and TX2 to transmit current, the communication controller 202 performs automatic power adjustment (APA) by using RXp and RXn to measure the actual antenna current (Iant). This automatic power adjustment enables robust wireless communication with various types of smart devices, even in very tight coupling scenarios (e.g., zero distance) that would detune the wireless communication (e.g., NFC) antenna 206.

[0038] Without APC, detuning of communication antenna 206 will result in a high measured transmit current (i.e., using TXLDO as well as pins TX1 and TX2), but will result in a weak antenna current (Iant). If the antenna current (Iant) becomes too low, the driver voltage will increase regardless of the high TXLDO current.

[0039] The communication controller 202 is configured to operate in differential mode using both the first receiver input (RXp) and the second receiver input (RXn) to determine the antenna current (Iant). The communication controller 202 is also configured to operate in single-ended mode using only the second receiver input (RXn) for wireless communication with a smart device (not shown).

[0040] When a smart device (not shown) is placed near antenna 206, communication controller 202 is triggered.

[0041] To determine the type of smart device (e.g., smartphone, smart card, etc.) placed on antenna 206, communication controller 202 measures the differential voltage (VDIF) around sensing resistor (Rsen) 208 and thereby calculates the power loss ratio (Pl,r).

[0042] Power loss ratio (Pl,r) = P(l, with load) / P(l, without load), where:

[0043] P(l, under load) = Pin(under load) - Pant(under load);

[0044] P(l, no load) = Pin(no load) - Pant(no load);

[0045] Pin (Power Input) = VDDPA • Transmission Current (measured by the TXLDO between TX1 and TX2);

[0046] VDDPA is the output of the TXLDO and the transmitter power supply, and VUP is the input supply voltage of the TXLDO.

[0047] Pant (antenna power) = Rsen•VDIF*2; and

[0048] VDIF is the voltage difference between the first receiver input (RXp) and the second receiver input (RXn).

[0049] In various example embodiments, if the power loss ratio (Pl,r) is 2 or greater (e.g., 2.17, 2.13, or 2.32), the smartphone is placed on or near the antenna 206, and if the power loss ratio (Pl,r) is less than 2 (e.g., 1.48 and 1.5), the smart card is placed on or near the antenna 206.

[0050] As mentioned above, Pant is calculated by controller 202 using the RXp / RXn differential voltage (VDIF) near Rsen.

[0051] In some example embodiments, Pant is calculated by measuring the I and Q outputs of an ADC (analog-to-digital converter) within the communication controller 202, and the ADC is coupled to receive RXp / RXn inputs (see also below). Figure 4 The amplitude (A) of the received signal is calculated as: A = sqrt(I² / Q²).

[0052] The amplitude (A) is related to the actual differential voltage (VDIF) around the sensing resistor Rsen 208. By measuring the pan (i.e., the power at the antenna), the power loss ratio (Pl,r) can be used to calculate the power loss from the transmitter to the antenna. The power loss ratio (Pl,r) is then used to determine whether the wirelessly connected device includes a smartphone or simply a smart card as mentioned above.

[0053] Figure 3 The third example 300 represents a wireless communication device. The third example device 300 includes a communication controller 302, a tuning circuit 304, an antenna 306, and a power supply. The third example device 300 also includes a first receiver input (RXp) and a second receiver input (RXn) respectively coupled to each end of a sensing resistor 308 (Rsen).

[0054] The communication controller 302 is configured to determine the antenna current (Iant) flowing through the antenna 306 based on the voltage difference (VDIF) between the first receiver input (RXp) and the second receiver input (RXn).

[0055] The third example device 300 is generally similar to the second example device 200, except that it now additionally includes a DC-DC boost circuit 310 depending on whether the communication controller 302 is in differential mode (see [link]). Figure 2 ) or single-ended mode (see Figure 2 This is used to increase the antenna current (Iant).

[0056] Here, the communication controller 302 is configured to select a different RSSI target for the differential mode than for the single-ended mode due to the different voltage levels of each mode.

[0057] Figure 4 The fourth example 400 represents a wireless communication device. The fourth example device 400 includes a communication controller 402, a tuning circuit 404, an antenna 406, and a power supply. The fourth example device 400 also includes a first receiver input (RXp) and a second receiver input (RXn) respectively coupled to each end of a sensing resistor 408 (Rsen).

[0058] The communication controller 402 is configured to determine the antenna current (Iant) flowing through the antenna 406 based on the voltage difference (VDIF) between the first receiver input (RXp) and the second receiver input (RXn).

[0059] The fourth example device 400 is largely similar to the third example device 300, except that more internal details of the communication controller 402 are shown. Here, a lookup table (LUT) is implemented to adjust the VDDPA voltage based on the power loss ratio calculated from Vdif.

[0060] The various example embodiments of the communication controllers 202, 302, and 402 just discussed can be implemented, in whole or in part, using logic gates, dedicated chips, firmware, software instructions stored in non-transitory computer-readable or computer-usable media, and / or other hardware or software.

[0061] It will also be readily understood that the elements of the various exemplary embodiments described herein and illustrated in the accompanying drawings can be arranged and designed in a wide variety of different configurations. Therefore, the detailed descriptions of the various embodiments illustrated in the accompanying drawings are not intended to limit the scope of this disclosure, but merely to illustrate various embodiments. Although various aspects of the embodiments are presented in the drawings, the drawings are not necessarily drawn to scale unless specifically indicated otherwise.

[0062] The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The described embodiments should be considered in all respects as illustrative rather than restrictive. Therefore, the scope of the invention is indicated by the appended claims rather than by a detailed description thereof. All modifications falling within the equivalent meaning and scope of the claims should be covered within their scope.

[0063] References to features, advantages, or similar language throughout this specification do not imply that all features and advantages achievable using the invention should be included in or in any single embodiment of the invention. In fact, language relating to features and advantages should be understood to mean that a particular feature, advantage, or characteristic described in connection with an embodiment is included in at least one embodiment of the invention. Therefore, the discussion of features and advantages and similar language throughout this specification may (but need not) refer to the same embodiment.

[0064] Furthermore, the features, advantages, and characteristics described in this invention can be combined in one or more embodiments in any suitable manner. Those skilled in the art will recognize that, in view of the description herein, this invention can be practiced without one or more of the specific features or advantages of a particular embodiment. In other instances, additional features and advantages that may not be present in all embodiments of the invention may be identified in certain embodiments.

[0065] Throughout this specification, references to "an embodiment," "an embodiment," or similar language mean that a particular feature, structure, or characteristic described in connection with the indicated embodiment is included in at least one embodiment of the invention. Therefore, the phrases "in an embodiment," "in an embodiment," and similar language throughout this specification may (but not necessarily) all refer to the same embodiment.

Claims

1. A wireless communication device, characterized in that, include: A first receiver input is configured to be coupled to a first end of the antenna and a first end of the sensing resistor; The sensing resistor is coupled in series with the antenna; A second receiver input is configured to be coupled to a second terminal of the sensing resistor; A controller configured to determine the antenna current Iant flowing through the antenna based on the voltage between the first receiver input and the second receiver input; The controller is configured to increase the antenna current when the antenna current is below a first predetermined value; and The controller is configured to reduce the antenna current when the antenna current is higher than a second predetermined value.

2. The apparatus according to claim 1, characterized in that: The controller is configured to calculate the power loss ratio based on the antenna current Iant.

3. The apparatus according to claim 2, characterized in that: If the power loss ratio is higher than a predetermined ratio, the controller is configured to determine that the first wireless communication device is near the antenna.

4. The apparatus according to claim 3, characterized in that: If the power loss ratio is lower than the predetermined ratio, the controller is configured to determine that the second wireless communication device is close to the antenna.

5. The apparatus according to claim 2, characterized in that: If the power loss ratio is higher than a predetermined ratio, the controller is configured to increase the antenna current Iant.

6. The apparatus according to claim 5, characterized in that: If the power loss ratio is lower than the predetermined ratio, the controller is configured to reduce the antenna current Iant.

7. The apparatus according to claim 2, characterized in that: If the power loss ratio is greater than 2, the controller is configured to determine that the smartphone is close to the antenna.

8. The apparatus according to claim 7, characterized in that: If the power loss ratio is less than 2, the controller is configured to determine that the smart card is near the antenna.

9. The apparatus according to claim 2, characterized in that: The controller is configured to calculate the power loss ratio as equal to P(l, with load) / P(l, without load), where: P(l, with load) = Pin(with load) - Pant(with load), and P(l, without load) = Pin(without load) - Pant(without load).

10. The apparatus according to claim 1, characterized in that: The controller is configured to operate in differential mode using both the first receiver input and the second receiver input to determine the antenna current Iant.

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