NFC signal range-extended antenna and manufacturing method

Abstract

The application provides an NFC signal range-increasing antenna and a manufacturing method. The antenna comprises a primary coil and a secondary coil. The primary coil and the secondary coil are formed by winding a winding wire. The primary coil is coupled with an antenna of an NFC reader / writer. The secondary coil is coupled with an antenna of an NFC carrier. The primary coil is coupled with the secondary coil, thereby relaying an electromagnetic wave signal communicated between the antenna of the NFC reader / writer and the antenna of the NFC carrier, increasing an inductive distance between the antenna of the NFC reader / writer and the antenna of the NFC carrier. Since the electromagnetic wave signal is relayed by directly using an inductive energy storage mode, electric energy storage is not needed, the structure is simpler, and the energy storage speed is faster.

Description

Technical Field

[0001] This invention relates to the field of data exchange, specifically to an NFC signal range extender antenna and its manufacturing method. Background Technology

[0002] Near Field Communication (NFC) is a technology that enables data exchange between devices over short distances, widely used in electronic payments and identity authentication. However, NFC's communication range is limited to within 10 centimeters. Typical NFC cards and NFC-enabled phones need to be close to an NFC reader to read and write data. If the NFC reader's casing is thick, the reading distance can be shortened, making it difficult for the reader to recognize the card. Therefore, the NFC carrier needs to be pressed firmly against the casing to complete the reading and writing process. Furthermore, some NFC carriers have their own casings or packaging, or when the carrier is placed in a bag, the NFC sensing distance may be exceeded, preventing communication between the carrier and the reader and resulting in failure.

[0003] Chinese invention patent CN102804488A discloses a near-field communication antenna using dual resonance. This antenna includes a relay unit. During communication between the NFC chip and the reader, this relay unit relays the signal transmitted by the reader antenna to the NFC antenna unit to increase the identification distance. The relay unit can also be bonded to the outer surface of the portable terminal's casing. This invention's relay unit uses LC closed-loop resonance, requiring a capacitor element to be connected in series in the antenna circuit, resulting in slow energy storage and a complex structure. Summary of the Invention

[0004] The primary objective of this invention is to provide an NFC signal range extender antenna with a simpler structure.

[0005] A second objective of this invention is to provide a method for manufacturing an NFC signal range extender antenna.

[0006] To achieve the aforementioned first objective, the present invention provides an NFC signal extension antenna, disposed within a first sensing range of an NFC carrier's antenna and a second sensing range of an NFC reader's antenna. It is used to relay a first electromagnetic wave signal transmitted from the NFC reader's antenna to the NFC carrier's antenna and a second electromagnetic wave signal transmitted from the NFC carrier's antenna to the NFC reader's antenna. The frequencies of the first and second electromagnetic wave signals are equal. The NFC signal extension antenna includes a primary coil and a secondary coil. The secondary coil includes a first primary coil and a second secondary coil. The first primary coil is connected to the primary coil, and the second secondary coil is connected to the primary coil. The number of turns of the primary coil and the number of turns of the first secondary coil are specified. The number of turns in the primary coil and the secondary coil are equal. The primary coil and the secondary coil are formed by winding a single wire. The primary coil and the secondary coil are coupled. The primary coil is coupled to the antenna of the NFC reader / writer, and the secondary coil is coupled to the antenna of the NFC carrier. The primary coil is used to receive the first electromagnetic wave signal sent by the antenna of the NFC reader / writer and send the first electromagnetic wave signal to the secondary coil. The secondary coil is used to receive the first electromagnetic wave signal and send the electromagnetic wave signal to the antenna of the NFC carrier. The secondary coil is also used to receive the second electromagnetic wave signal sent by the antenna of the NFC carrier and send the second electromagnetic wave signal to the primary coil. The primary coil is also used to receive the second electromagnetic wave signal and send the second electromagnetic wave signal to the antenna of the NFC reader / writer.

[0007] As can be seen from the above scheme, the present invention is provided with a primary coil and a secondary coil. The secondary coil includes a first secondary coil and a second secondary coil, which are formed by winding a single wire. This allows the antenna of the NFC reader / writer to form signal eddy current coupling with the primary coil, the primary coil with the secondary coil, and the secondary coil with the antenna of the NFC carrier. This enables the primary coil to receive the first electromagnetic wave signal sent by the antenna of the NFC reader / writer and transmit it to the secondary coil. The secondary coil then transmits the first electromagnetic wave signal to the antenna of the NFC carrier. This allows the secondary coil to receive the second electromagnetic wave signal sent by the antenna of the NFC carrier and transmit it to the primary coil. The primary coil then transmits the second electromagnetic wave signal to the antenna of the NFC reader / writer. Thus, the present invention can relay the electromagnetic wave signal for communication between the antenna of the NFC reader / writer and the antenna of the NFC carrier, increasing the sensing distance between the antenna of the NFC reader / writer and the antenna of the NFC carrier. Furthermore, since the electromagnetic wave signal is relayed directly using inductor energy storage, capacitor energy storage is not required, resulting in a simpler structure and faster energy storage speed.

[0008] A further option is to use enameled wire for winding.

[0009] A further approach is to etch the NFC signal extension antenna onto a printed circuit board, with the winding wires being the conductors etched onto the printed circuit board.

[0010] A further option is that the NFC reader / writer includes a first housing, and an NFC signal range extender antenna is disposed on the outer surface of the first housing.

[0011] A further option is that the NFC carrier includes a second housing, and the NFC signal range extender antenna is disposed on the outer surface of the second housing.

[0012] A further proposed approach is to use a frequency of 13.56MHz for both the first and second electromagnetic wave signals.

[0013] To achieve the second objective mentioned above, the present invention provides a method for manufacturing an NFC signal range extender antenna, wherein: the number of turns of the NFC signal range extender antenna is designed according to the frequency of the first electromagnetic wave signal and the frequency of the second electromagnetic wave signal; the NFC signal range extender antenna is wound according to the number of turns: a winding wire is used to first wind the primary coil, then the secondary coil, and finally the secondary coil; the NFC signal range extender antenna is placed on a corresponding carrier according to the usage environment of the NFC signal range extender antenna.

[0014] As can be seen from the above scheme, the present invention first calculates the number of turns of the NFC signal extension antenna based on the frequency of the first electromagnetic wave signal and the frequency of the second electromagnetic wave signal, and then winds the first primary coil, the primary coil, and the second secondary coil in sequence according to the number of turns of the NFC signal extension antenna. Then, the NFC signal extension antenna is set on the corresponding carrier according to the usage scenario, thereby completing the fabrication of the NFC signal extension antenna. The fabricated NFC signal extension antenna can increase the sensing distance between the antenna of the NFC carrier and the antenna of the NFC reader / writer, and the fabrication method is simple and feasible.

[0015] A further option is to mount the NFC signal extension antenna on a PVC carrier or a paper carrier.

[0016] Therefore, it is evident that using PVC as a carrier can provide waterproofing, while using paper as a carrier can save on production costs.

[0017] A further embodiment is that the NFC reader / writer includes a first housing; the NFC signal range extender antenna is attached to or placed on the outer surface of the first housing.

[0018] A further option is that the NFC carrier includes a second housing; the NFC signal range extender antenna is adhered to or placed on the outer surface of the second housing. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of an NFC signal range extender antenna according to the present invention.

[0020] Figure 2This is an antenna winding pattern for an NFC signal range extender antenna according to the present invention.

[0021] Figure 3 This is a schematic diagram of the practical application of an NFC signal range extender antenna according to the present invention.

[0022] Figure 4 This is a flowchart of a method for manufacturing an NFC signal range extender antenna according to the present invention.

[0023] The present invention will be further described below with reference to the accompanying drawings and embodiments. Detailed Implementation

[0024] This invention is used to relay electromagnetic wave signals transmitted between the antenna of an NFC reader and the antenna of an NFC carrier. When the electromagnetic wave signal from the antenna of the NFC reader is transmitted to the primary coil, the primary coil transmits the electromagnetic wave signal to the secondary coil, and the secondary coil transmits the electromagnetic wave signal to the antenna of the NFC carrier, thereby increasing the sensing distance between the antenna of the NFC reader and the antenna of the NFC carrier.

[0025] In this embodiment, when the antennas of the two NFC devices communicate, the antenna of the NFC device that first sends the electromagnetic wave signal is the antenna of the NFC reader / writer, and the antenna of the NFC device that receives the electromagnetic wave signal is the antenna of the NFC carrier. The antenna of the NFC reader / writer is located on the NFC reader / writer, and the antenna of the NFC carrier is located on the NFC carrier. The NFC carrier can be a bank card, access card, public transport card, mobile smart terminal, etc., that supports NFC communication, and the NFC reader / writer can be an interactive device that communicates with the NFC carrier via NFC. Furthermore, both the first and second electromagnetic wave signals are electromagnetic wave signals, and the frequency of the first electromagnetic wave signal is equal to the frequency of the second electromagnetic wave signal.

[0026] An embodiment of an NFC signal range extender antenna according to the present invention:

[0027] See Figure 1 and Figure 2The NFC signal range extender antenna includes a primary coil 21 and a secondary coil 22. The secondary coil includes a first primary coil 221 and a second primary coil 222. The first primary coil 221 is connected to the primary coil 21, and the second primary coil 222 is connected to the primary coil 21. The number of turns in the primary coil 21, the first secondary coil 221, and the second secondary coil 222 are all equal. This equality means that the number of turns in the first secondary coil 221 and the second secondary coil 222 are respectively equal to the number of turns in the primary coil 21. The number of turns in the primary coil can be precisely calculated based on the frequency of the relayed electromagnetic wave signal. However, since the NFC signal range extender antenna is wound with a single wire, regardless of whether the winding starts from position 241 or 242, it will pass through the first connecting line 231 and the second connecting line 232, resulting in an increased number of turns. Therefore, although the number of turns in the first secondary coil 221 and the second secondary coil are equal to the number of turns in the primary coil 21, the number of turns in the secondary coil 22 as a whole is slightly greater than that in the primary coil 21. As in this embodiment, refer to... Figure 2 The primary coil 21 has 4.5 turns, and the secondary coil 22 has approximately 9.9 turns. The specific calculation process is as follows:

[0028] This embodiment takes the frequency requirement of NFC signals as an example. It is known that the required signal frequency for NFC communication is fo = 13.56MHz. The antenna 12 of the NFC reader / writer needs to communicate with the antenna 32 of the NFC carrier. Based on the size of the NFC reader / writer, an NFC signal range extender antenna is fabricated. The coil side length A = 50mm is made using enameled wire with a diameter D = 0.1mm. First, the required inductance, capacitance C, and inductance L of the NFC signal range extender antenna are calculated. Then, the number of turns of the primary coil 21 is calculated according to the formula for hollow coils. Specifically, based on:

[0029] The formula for inductor and capacitor is C = 25330.3 / (fo * fo), which gives C = 138pF.

[0030] Inductance formula L=[(1 / fo) / 2π] 2 / C, we get L=0.991uH; where π is the ratio of a circle's diameter to its diameter.

[0031] The formula for calculating the number of turns in the hollow coil is: L = (0.001 * D * T * T) / (W / D + 0.44), where L is the inductance (H); D is the wire diameter (mm); T is the number of turns; and W is the coil circumference (mm). Therefore, the number of turns in the primary coil T is calculated to be 4.5 turns. Thus, the number of turns in both the first-stage coil 221 and the second-stage coil 222 is also 4.5 turns. Based on this number of turns, the first-stage coil 221 is wound first, then the primary coil 21 is wound, and finally the second-stage coil 222 is wound to complete the winding of the NFC signal range extender antenna. Since the side length of the secondary coil 22 is designed to be 25cm in this embodiment, the number of turns in the wound secondary coil 22 is 9.9 turns. The wire spacing of the primary coil 21 and the secondary coil 22 can be designed according to the specific dimensions of the NFC reader / writer. The coil lengths of the primary coil 21 and the secondary coil 22 can be designed according to the specific size of the NFC reader / writer, but the coil length of the secondary coil 22 must be shorter than that of the primary coil 21. It can be understood that, besides using enameled wire, NFC signal extender antennas can also be fabricated by etching wires onto a printed circuit board.

[0032] An NFC signal extension antenna is positioned between the antenna 12 of the NFC reader / writer and the antenna 32 of the NFC carrier. 11 is the read / write control circuit of the NFC reader / writer, and 31 is the transaction device body circuit of the NFC carrier. Since the number of turns of the primary coil 21 and the secondary coil 22 is determined according to the communication frequency between the antenna 12 of the NFC reader / writer and the antenna 32 of the NFC carrier, the primary coil 21 is coupled to the antenna 12 of the NFC reader / writer, enabling the primary coil 21 to receive electromagnetic wave signals from the antenna 12 of the NFC reader / writer; similarly, the secondary coil 22 is coupled to the antenna 32 of the NFC carrier, enabling the secondary coil 22 to receive electromagnetic wave signals from the antenna 32 of the NFC carrier. Because either the primary coil 21 or the secondary coil 22 receives an electromagnetic wave signal, eddy currents in opposite directions are formed, allowing electromagnetic wave signals to be transmitted between the primary coil 21 and the secondary coil 22. Therefore, in practical applications of the NFC signal extender antenna, the read / write control circuit 11 converts the NFC reader signal into a fixed-frequency 13.56MHz electromagnetic wave signal output through the NFC reader antenna 12. The primary coil 21 receives the electromagnetic wave signal of this frequency from the NFC reader antenna 12. The primary coil 21 and the secondary coil 22 are mutually inductive, transmitting the electromagnetic wave signal to the secondary coil 22. The secondary coil 22 receives the electromagnetic wave signal and continuously transmits it outward. The NFC carrier antenna 32 receives the electromagnetic wave signal. After the NFC carrier transaction device body circuit 31 starts corresponding calculations, it emits a 13.56MHz electromagnetic wave signal through the NFC carrier antenna 32. The secondary coil 22 and the primary coil 21 are mutually inductive, transmitting the electromagnetic wave signal to the primary coil 21. The primary coil 21 continuously transmits the electromagnetic wave signal outward. The NFC reader antenna 12 receives the electromagnetic wave signal. Thus, the NFC signal extender antenna realizes the relay of electromagnetic wave signals between the NFC reader antenna 12 and the NFC carrier antenna 32.

[0033] Reference Figure 3The antenna 12 of the NFC reader / writer is housed within the housing 33 of the NFC reader / writer. An NFC signal extension antenna 20 is mounted on the outer surface of the housing 33. Electromagnetic signals transmitted between the NFC reader / writer 12 and the antenna 32 of the NFC carrier are relayed through the NFC signal extension antenna 20, preventing the housing 33 from being too thick and causing the antenna 32 of the NFC carrier to exceed the sensing range of the NFC reader / writer's antenna 12. If the NFC signal extension antenna 20 is made of enameled wire, it can be mounted on a PVC carrier for waterproofing. For cost savings, a paper carrier can also be used. If the NFC signal extension antenna 20 is manufactured using printed circuit board etching, the printed circuit board can be a rigid or flexible circuit board. The manufactured NFC signal extension antenna can also undergo further protection treatment, such as waterproofing, depending on the specific application scenario, and is then mounted on the surface of the housing 33 of the NFC reader / writer through adhesion or placement. It is easy to understand that if the housing of the NFC carrier is too thick, the NFC signal extension antenna can also be set on the housing of the NFC carrier, which can also achieve the effect of relaying the electromagnetic wave signal transmitted between the NFC reader / writer 12 and the antenna 32 of the NFC carrier.

[0034] An embodiment of the manufacturing method of an NFC signal range extender antenna according to the present invention:

[0035] Reference Figure 4 The number of turns of the NFC signal range extender antenna is designed based on the frequency of the first electromagnetic wave signal and the frequency of the second electromagnetic wave signal, i.e., step S1 is executed. The calculation method for the number of turns of the NFC signal range extender antenna, the selection of the winding wire, and the selection of the coil length are the same as those in the above-described embodiment of an NFC signal range extender antenna, and will not be repeated here.

[0036] Then, step S2 is performed to wind the NFC signal range extender antenna according to the number of turns. The specific winding process is the same as the above-described NFC signal range extender antenna embodiment, and will not be repeated here.

[0037] Finally, step S3 is executed, where the NFC signal extender antenna is mounted on the appropriate carrier according to its operating environment. The specific execution method is the same as the aforementioned NFC signal extender antenna embodiment, and will not be repeated here.

[0038] In summary, this invention utilizes an NFC signal range extender antenna wound with a single wire, comprising a primary coil and a secondary coil. The primary coil is coupled to the antenna of the NFC reader / writer, and the secondary antenna is coupled to the antenna of the NFC carrier. The primary coil is also coupled to the secondary coil. This enables the invention to relay the electromagnetic wave signals communicating between the antennas of the NFC reader / writer and the NFC carrier, increasing the sensing distance between them. Furthermore, since the electromagnetic wave signals are relayed directly using inductive energy storage, no electrical energy storage is required, resulting in a simpler structure and faster energy storage speed.

Claims

1. An NFC signal range extender antenna, disposed within a first sensing range of an NFC reader / writer's antenna and a second sensing range of an NFC carrier's antenna, for relaying a first electromagnetic wave signal transmitted from the NFC reader / writer's antenna to the NFC carrier's antenna, and relaying a second electromagnetic wave signal transmitted from the NFC carrier's antenna to the NFC reader / writer's antenna, wherein the frequency of the first electromagnetic wave signal is equal to the frequency of the second electromagnetic wave signal, characterized in that: The NFC signal range extender antenna includes a primary coil and a secondary coil. The secondary coil includes a first primary coil and a second secondary coil. The first primary coil is connected to the primary coil, and the second secondary coil is connected to the primary coil. The number of turns of the primary coil, the first primary coil, and the second secondary coil are all equal. The primary coil and the secondary coil are formed by winding a single wire. The primary coil is coupled to the secondary coil; the primary coil is coupled to the antenna of the NFC reader / writer, and the secondary coil is coupled to the antenna of the NFC carrier; The primary coil is used to receive the first electromagnetic wave signal sent by the antenna of the NFC reader and send the first electromagnetic wave signal to the secondary coil. The secondary coil is used to receive the first electromagnetic wave signal and send the electromagnetic wave signal to the antenna of the NFC carrier. The secondary coil is also used to receive the second electromagnetic wave signal sent by the antenna of the NFC carrier and send the second electromagnetic wave signal to the primary coil. The primary coil is also used to receive the second electromagnetic wave signal and send the second electromagnetic wave signal to the NFC reader antenna.

2. The NFC signal range extender antenna as described in claim 1, characterized in that: The winding wire is enameled wire.

3. The NFC signal range extender antenna as described in claim 1, characterized in that: The NFC signal range extender antenna is etched on a printed circuit board, and the winding wire is a conductor etched on the printed circuit board.

4. An NFC signal range extender antenna as described in any one of claims 1 to 3, characterized in that: The NFC reader / writer includes a first housing, and the NFC signal range extender antenna is disposed on the outer surface of the first housing.

5. An NFC signal range extender antenna as described in any one of claims 1 to 3, characterized in that: The NFC carrier includes a second housing, and the NFC signal range extender antenna is disposed on the outer surface of the second housing.

6. An NFC signal range extender antenna as described in any one of claims 1 to 3, characterized in that: The frequency of the first electromagnetic wave signal and the frequency of the second electromagnetic wave signal are both 13.56MHz.

7. A method for manufacturing an NFC signal range extender antenna as described in any one of claims 1 to 6, characterized in that: The number of turns of the NFC signal range extender antenna is designed based on the frequencies of the first electromagnetic wave signal and the second electromagnetic wave signal. The NFC signal range extender antenna is wound according to the number of turns: the first primary coil is wound first using one winding wire, then the primary coil is wound, and finally the second primary coil is wound. Depending on the usage environment of the NFC signal extender antenna, the NFC signal extender antenna is mounted on the corresponding carrier.

8. A method for manufacturing an NFC signal range extender antenna as described in claim 7, characterized in that: The NFC signal extension antenna is mounted on a PVC carrier or a paper carrier.

9. A method for manufacturing an NFC signal range extender antenna as described in claim 7 or 8, characterized in that: The NFC reader / writer includes a first housing; The NFC signal range extender antenna is adhered to or placed on the outer surface of the first housing.

10. A method for manufacturing an NFC signal range extender antenna as described in claim 7 or 8, characterized in that: The NFC carrier includes a second housing; The NFC signal range extender antenna is adhered to or placed on the outer surface of the second housing.

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