Radio frequency card swiping enhancement circuit based on SIM card

Abstract

The utility model discloses a radio frequency card swiping enhancement circuit based on an SIM card, which comprises an NFC chip, a radio frequency power amplifier, a duplexer, an antenna, a low noise amplifier, a baseband chip and an SIM card peripheral circuit, and is characterized in that a common end of the duplexer is connected with the antenna so as to transmit and receive signals; the baseband chip is respectively connected with the NFC chip, the radio frequency power amplifier and the low noise amplifier; a first signal end of the NFC chip is connected with an input end of the radio frequency power amplifier, an output end of the radio frequency power amplifier is connected with a first signal end of the duplexer, and a second signal end of the duplexer is connected with an input end of the low noise amplifier. The output end of the low noise amplifier is connected with the second signal end of the NFC chip; and the SIM card peripheral circuit is connected with the baseband chip, so that the card swiping signal strength of NFC can be effectively enhanced.

Description

Technical Field

[0001] The utility model relates to the technical field of communication, in particular to a radio frequency card swiping enhancement circuit based on a SIM card. Background Art

[0002] NFC (NearField Communication) is also called short-range wireless communication, which is a wireless technology. NFC is evolved from the integration of contactless radio frequency identification (RFID) and interconnection technology. It combines the functions of inductive card reader, inductive card and point-to-point on a single chip, and uses mobile terminals to identify and exchange data with compatible devices within a short distance.

[0003] NFC has the characteristics of short distance, high bandwidth and low energy consumption. It is suitable for the transmission of some sensitive information or personal data, and has advantages in security. NFC is compatible with existing contactless smart card technology and has become an official standard supported by more and more major manufacturers. Using the NFC function, you can realize a variety of applications such as consumption and access control, replacing a variety of cards in the card bag, such as mobile payment, electronic ticketing, access control, mobile identity recognition, anti-counterfeiting and other applications.

[0004] At present, some communication devices on the market do not support NFC card swiping. However, when facing scenes such as access control and ID card swiping, this technology has to be used. Therefore, devices that integrate NFC chips into SIM cards have appeared. However, due to the size limit of SIM cards, the magnetic flux of NFC is of limited size. In addition, since most mobile phone cases are made of metal and the materials of SIM card holders are different, the signal coming out of the SIM card holder inside the mobile phone is even smaller. If the card holder is deeper into the mobile phone, it will be almost impossible to swipe the card. Utility Model Content

[0005] The main purpose of the utility model is to provide a radio frequency card swiping enhancement circuit based on a SIM card, which effectively enhances the card swiping signal strength of an NFC.

[0006] To achieve the above object, the present application provides a SIM card-based radio frequency card swiping enhancement circuit, including an NFC chip, a radio frequency power amplifier, a duplexer, an antenna, a low noise amplifier, a baseband chip, and a SIM card peripheral circuit, wherein:

[0007] The common end of the duplexer is connected to the antenna to transmit and receive signals; the baseband chip is connected to the NFC chip, the RF power amplifier and the low noise amplifier respectively; the first signal end of the NFC chip is connected to the input end of the RF power amplifier, the output end of the RF power amplifier is connected to the first signal end of the duplexer, the second signal end of the duplexer is connected to the input end of the low noise amplifier, and the output end of the low noise amplifier is connected to the second signal end of the NFC chip; the SIM card peripheral circuit is connected to the baseband chip;

[0008] The baseband chip is used to control the operation of the NFC chip, the radio frequency power amplifier and the low noise amplifier;

[0009] The NFC chip is used to transmit and receive NFC signals;

[0010] The radio frequency power amplifier is used to amplify the transmission signal of the NFC chip and output it to the duplexer;

[0011] The low noise amplifier is used to amplify the received signal and output it to the NFC chip;

[0012] The duplexer is used to isolate the receiving signal from the transmitting signal to avoid signal interference.

[0013] In an optional implementation, the NFC chip, the radio frequency power amplifier, the duplexer, the antenna, the low noise amplifier and the baseband chip are all integrated into a SIM card.

[0014] In an optional implementation, the I / O contacts corresponding to the SIM card peripheral circuit are all on the back of the SIM card and match the SIM card slot of the terminal device; the terminal device supplies power to the SIM card peripheral circuit through the SIM card slot.

[0015] In an optional implementation, the gain of the RF power amplifier is 5 dBm, the center frequency is 13.56 MHz, and the operating frequency is 13.553 MHz to 13.567 MHz.

[0016] In an optional implementation, the duplexer is composed of two filters, wherein the frequency band range of the transmission part filter is 13.55 MHz to 13.57 MHz, and the frequency band range of the reception part filter is wider than the frequency band range of the transmission part filter.

[0017] In an optional implementation, the gain of the low noise amplifier is 3 dBm.

[0018] In an optional implementation, the SIM card-based radio frequency card swiping enhancement circuit further includes a switch.

[0019] The present application provides a radio frequency card swiping enhancement circuit based on a SIM card, including an NFC chip, a radio frequency power amplifier, a duplexer, an antenna, a low noise amplifier, a baseband chip, and a SIM card peripheral circuit, wherein:

[0020] The common end of the duplexer is connected to the antenna to transmit and receive signals; the baseband chip is connected to the NFC chip, the RF power amplifier and the low noise amplifier respectively; the first signal end of the NFC chip is connected to the input end of the RF power amplifier, the output end of the RF power amplifier is connected to the first signal end of the duplexer, the second signal end of the duplexer is connected to the input end of the low noise amplifier, and the output end of the low noise amplifier is connected to the second signal end of the NFC chip; the SIM card peripheral circuit is connected to the baseband chip; the baseband chip is used to control the NFC chip, the RF power amplifier, and the NFC chip. The NFC chip is used to transmit and receive NFC signals; the RF power amplifier is used to amplify the transmitted signal of the NFC chip and output it to the duplexer; the low noise amplifier is used to amplify the received signal and output it to the NFC chip; the duplexer is used to isolate the received signal from the transmitted signal to avoid signal interference; when the NFC transmits a signal, the device amplifies the signal through the RF amplifier to increase the card swiping distance, and when receiving the NFC signal, the low noise amplifier increases the receiving signal distance. The device can effectively enhance the NFC card swiping signal strength. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0022] in:

[0023] Figure 1 A schematic diagram of the structure of a radio frequency card swiping enhancement circuit based on a SIM card provided in an embodiment of the present application;

[0024] Figure 2 A structural schematic diagram of the back side of a SIM card provided in an embodiment of the present application. DETAILED DESCRIPTION

[0025] In order to enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0026] The terms "first", "second", etc. in the specification and claims of this application and the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but optionally includes steps or units that are not listed, or optionally includes other steps or units inherent to these processes, methods, products or devices.

[0027] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0028] The SIM (Subscriber Identity Module) card involved in the embodiments of the present application is an IC card held by a mobile user of the GSM system, called a user identification card. The GSM system identifies GSM users through SIM cards, and the same SIM card can be used on different mobile phones. A GSM mobile phone can only be connected to the network after a SIM card is inserted.

[0029] The low noise amplifier (LNA) involved in the embodiments of the present application is an amplifier with a very low noise coefficient. It is generally used as a high-frequency or intermediate-frequency preamplifier of various radio receivers, and an amplifier circuit of a high-sensitivity electronic detection device. When amplifying weak signals, the noise of the amplifier itself may seriously interfere with the signal, so it is hoped to reduce this noise to improve the output signal-to-noise ratio.

[0030] The RF power amplifier (PA) is an important part of the transmission system. It is used to amplify high-frequency signals so that the transmitter end stage can obtain sufficiently large transmission power and then radiate it through the antenna.

[0031] The present application mainly provides a radio frequency card swiping enhancement circuit based on a SIM card, which integrates modules such as a radio frequency amplifier and a low noise amplifier in the SIM card to amplify the NFC transmission and reception signals, thereby extending the card swiping distance.

[0032] The embodiments of the present application are described below in conjunction with the drawings in the embodiments of the present application.

[0033] See also Figure 1 , is a structural diagram of a radio frequency card swiping enhancement circuit based on a SIM card provided in an embodiment of the present application, such as Figure 1 As shown, the SIM card-based radio frequency card swiping enhancement circuit includes an NFC chip S01, a radio frequency power amplifier S02, a duplexer S03, an antenna S04, a low noise amplifier S05 and a baseband chip S06, and may also include a SIM card peripheral circuit S07 ( Figure 1 ), where:

[0034] The common end of the duplexer S03 is connected to the antenna S04 to transmit and receive signals; the baseband chip S06 is respectively connected to the NFC chip, the RF power amplifier and the low noise amplifier; the first signal end a1 of the NFC chip S01 is connected to the input end of the RF power amplifier, the output end of the RF power amplifier S02 is connected to the first signal end b1 of the duplexer S03, the second signal end b2 of the duplexer S03 is connected to the input end of the low noise amplifier S05, and the output end of the low noise amplifier S05 is connected to the second signal end a2 of the NFC chip S01; the SIM card peripheral circuit S07 can be connected to the baseband chip S06;

[0035] The baseband chip S06 is used to control the operation of the NFC chip S01, the RF power amplifier S02 and the low noise amplifier S05;

[0036] The NFC chip S01 is used to transmit and receive NFC signals;

[0037] The RF power amplifier S02 is used to amplify the transmission signal of the NFC chip S01 and output it to the duplexer S03;

[0038] The low noise amplifier S05 is used to amplify the received signal and output it to the NFC chip S01;

[0039] The duplexer S03 is used to isolate the receiving signal from the transmitting signal to avoid signal interference.

[0040] Specifically: the NFC chip S01 may include two signal terminals, a transmitting signal terminal (a2) and a receiving signal terminal (a1), which respectively transmit and receive NFC signals, and work under the control of the baseband chip S06.

[0041] The RF power amplifier S02 includes a signal input terminal and a signal output terminal, and is controlled by the baseband chip S06. When the NFC chip S01 transmits a signal, the RF power amplifier S02 amplifies the transmit signal and then outputs it to the duplexer S03 through the output terminal.

[0042] The duplexer S03 has three ports, an input port (b1) for transmitting signals, an output port (b2) for receiving signals, and a common port, which is connected to the antenna S04 for transmitting and receiving signals. The duplexer isolates the receiving signal from the transmitting signal, avoids signal interference, and achieves the characteristics that the receiving and transmitting signals can work simultaneously.

[0043] The input end of the low noise amplifier S05 receives the received signal, amplifies the received signal, and then outputs the signal to the NFC chip S01 through the output end.

[0044] The baseband chip S06 controls the enabling of the NFC chip S01, the RF power amplifier S02 and the low noise amplifier S05, and is connected to the SIM card peripheral circuit S07 to perform power supply conversion and other functions.

[0045] Specifically, in the embodiment of the utility model, the above-mentioned SIM card can be inserted into the corresponding card holder, and the terminal device supplies power to the SIM card peripheral circuit S07 through the card holder. The SIM card peripheral circuit S07 is connected to the baseband chip S06, and the baseband chip S06 can control and enable modules such as the NFC chip S01, the RF power amplifier S02, and the low noise amplifier S05 through the GPIO port; when the baseband chip S06 requires the NFC chip S01 to transmit a signal, the NFC chip S01 outputs a signal from the first signal terminal a1, and the signal enters the RF power amplifier S02 and is power-enhanced, and the signal is amplified, and then output to the first signal terminal b1 of the duplexer S03, and after being filtered by the duplexer S03, the signal is output from the common terminal to the antenna S04. Since the signal is amplified and filtered, the card swiping effect of NFC can be enhanced, and the card swiping distance can be farther. On the contrary, when the antenna S04 receives an NFC signal, the signal is input through the common end of the duplexer S03, and the duplexer S03 filters it and outputs the received signal from the second signal end b2. The received signal enters the low noise amplifier S05, where it is amplified, and then enters the NFC chip S01. Therefore, even weak signals that are far apart can be processed by the NFC chip after amplification by the LNA, thereby enhancing the effect of the NFC card swiping technology.

[0046] The terminal device in the embodiment of the present application may be a mobile terminal with communication function, such as a mobile phone.

[0047] In an optional implementation, the NFC chip S01, the RF power amplifier S02, the duplexer S03, the antenna S04, the low noise amplifier S05 and the baseband chip S06 are all integrated inside the SIM card; the I / O contacts corresponding to the SIM card peripheral circuit S07 are all on the back of the SIM card and match the SIM card slot of the terminal device, so the terminal device can power the SIM card peripheral circuit through the SIM card slot.

[0048] In a specific implementation, the peripheral circuit S07 can be the same as the peripheral circuit of a normal SIM card, can be matched with the SIM card slot of a smart device, and all I / O contacts are on the back of the SIM card; the corresponding NFC chip S01, RF power amplifier S02, duplexer S03, antenna S04, low noise amplifier S05 and baseband chip S06 are all integrated inside the SIM card.

[0049] You can refer to Figure 2 , Figure 2 This is a schematic diagram of the back structure of a SIM card provided in an embodiment of the present application. Figure 2As shown, the I / O contacts corresponding to the SIM card peripheral circuit S07 can be displayed on the surface on the back of the SIM card, which can match the SIM card slot of the smart device. When the SIM card is inserted into the SIM card slot of the terminal device and the terminal device is turned on, the SIM card can be powered and data can be exchanged with the SIM card.

[0050] Further optionally, the gain of the RF power amplifier S02 in the embodiment of the present application is 5 dBm, the center frequency is 13.56 MHz, and the operating frequency is 13.553 MHz to 13.567 MHz, which are the operating frequencies and operating bandwidths of NFC in the NFC standard.

[0051] Optionally, the duplexer S03 is composed of two filters, which can achieve the function of sending and receiving at the same time. The filtering range of the transmitting part filter is 13.55MHz~13.57MHz, and the frequency band range of the receiving part filter should be wider, because the operating frequency of the card swiping devices of different manufacturers cannot be completely guaranteed to be around 13.56MHz. For example, the receiving filter frequency range can be selected to be 13.51MHz~13.61MHz.

[0052] Optionally, the gain of the low noise amplifier is 3dBm.

[0053] Among them, the models of modules such as NFC chip, RF power amplifier, low noise amplifier, etc. can be selected as needed, and the embodiments of the present application do not limit this.

[0054] In addition, the frequency range of the chip used is not fixed. As long as NFC can work normally, the filtering frequency range can be expanded, and the embodiments of the present application do not limit this.

[0055] The shape and material of the antenna are not limited in the embodiments of the present application.

[0056] In an optional implementation, the SIM card-based radio frequency card swiping enhancement circuit further includes a switch.

[0057] The specific structure of the circuit in the embodiment of the present application is not fixed. A switch can be added to control whether the circuit is enabled. The number of filters can also be increased to enable it to process 2.4G signals. In this way, the SIM card can process both NFC signals and higher frequency signals such as 2.4G, and the operation is more stable.

[0058] In summary, the utility model provides a radio frequency card swiping enhancement circuit based on a SIM card, which controls an NFC chip, a low noise amplifier and a radio frequency power amplifier through a baseband chip, amplifies the transmitted signal and outputs it, and filters and amplifies the received weak signal and then processes it, so as to increase the card swiping distance, thereby realizing the enhancement of the card swiping technology, so that a communication device without NFC can also achieve the card swiping effect of a normal smart device after inserting the SIM card, thereby increasing the communication distance of the SIM card NFC card swiping terminal.

[0059] Compared with traditional super SIM cards, seven-core cards, etc., the solution of the utility model is to enhance the NFC card swiping distance of this type of card, so that the card swiping effect can be comparable to that of normal NFC smart devices. Even if you replace communication devices without NFC, such as Apple mobile phones, some student ID cards, watches and other products, you can use the radio frequency SIM card to insert into the communication device to swipe the card at a medium distance like a normal NFC smart device, without having to suffer from problems such as not being able to find a swiping point or being unable to swipe the card for a long time.

[0060] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0061] The above-mentioned embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.

Claims

1. A radio frequency card swiping enhancement circuit based on SIM card, It is characterized in that It includes NFC chip, RF power amplifier, duplexer, antenna, low noise amplifier, baseband chip and SIM card peripheral circuit, among which: The common end of the duplexer is connected to the antenna to transmit and receive signals; the baseband chip is connected to the NFC chip, the RF power amplifier and the low noise amplifier respectively; the first signal end of the NFC chip is connected to the input end of the RF power amplifier, the output end of the RF power amplifier is connected to the first signal end of the duplexer, the second signal end of the duplexer is connected to the input end of the low noise amplifier, and the output end of the low noise amplifier is connected to the second signal end of the NFC chip; the SIM card peripheral circuit is connected to the baseband chip; The baseband chip is used to control the operation of the NFC chip, the radio frequency power amplifier and the low noise amplifier; The NFC chip is used to transmit and receive NFC signals; The radio frequency power amplifier is used to amplify the transmission signal of the NFC chip and output it to the duplexer; The low noise amplifier is used to amplify the received signal and output it to the NFC chip; The duplexer is used to isolate the receiving signal from the transmitting signal to avoid signal interference.

2. According to the SIM card-based radio frequency card swiping enhancement circuit of claim 1, It is characterized in that The NFC chip, the radio frequency power amplifier, the duplexer, the antenna, the low noise amplifier and the baseband chip are all integrated inside the SIM card.

3. According to the SIM card-based radio frequency card swiping enhancement circuit of claim 2, It is characterized in that The I / O contacts corresponding to the SIM card peripheral circuit are all on the back of the SIM card and match the SIM card slot of the terminal device; the terminal device supplies power to the SIM card peripheral circuit through the SIM card slot.

4. According to the SIM card-based radio frequency card swiping enhancement circuit of claim 1, It is characterized in that The gain of the radio frequency power amplifier is 5 dBm, the center frequency is 13.56 MHz, and the operating frequency is 13.553 MHz to 13.567 MHz.

5. According to the SIM card-based radio frequency card swiping enhancement circuit of claim 1, It is characterized in that The duplexer is composed of two filters, wherein the frequency band range of the transmission part filter is 13.55MHz-13.57MHz, and the frequency band range of the reception part filter is wider than the frequency band range of the transmission part filter.

6. According to the SIM card-based radio frequency card swiping enhancement circuit of claim 1, It is characterized in that The gain of the low noise amplifier is 3dBm.

7. According to claim 1, the radio frequency card swiping enhancement circuit based on the SIM card, It is characterized in that The SIM card-based radio frequency card swiping enhancement circuit also includes a switch.

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