Smart card test tool

Abstract

The utility model provides an intelligent card test tool, which comprises a frequency spectrograph, a standing-wave ratio bridge and an induction circuit, the standing-wave ratio bridge is electrically connected with the frequency spectrograph, the induction circuit is electrically connected with the standing-wave ratio bridge, and the standing-wave ratio bridge is connected with a high-frequency power supply; the RFID intelligent card is in contact with the induction circuit and generates electromagnetic induction, the standing-wave ratio bridge receives an electromagnetic signal, measures the impedance characteristic of the RFID intelligent card through the high-frequency power supply, and transmits the impedance characteristic to the frequency spectrograph to present the frequency response characteristic of the RFID intelligent card. The utility model has the beneficial effects that an effective and low-cost tool for testing the hardware performance of the finished RFID intelligent card is provided, so that the resonant frequency and the bandwidth of the RFID intelligent card can be accurately tested.

Description

TECHNICAL FIELD

[0001] The utility model belongs to RFID intelligent card manufacturing technical field, especially intelligent card test frock is related. BACKGROUND

[0002] RFID intelligent card is a kind of non-contact intelligent card based on radio frequency identification technology, is widely used in access control, identity verification, payment system and logistics management etc. Field.RFID intelligent card passes through built-in antenna and chip, and carries out wireless communication with reader and writer, realizes the reading and writing of data.In the existing RFID intelligent card manufacturing process, hardware detection means mainly includes antenna performance detection, chip function test and overall performance test.Antenna performance detection is ensured the transmission performance of antenna by measuring resonant frequency, impedance and radiation efficiency;Chip function test verifies read-write function, storage capacity and communication protocol using special equipment;Overall performance test is ensured the reliability and stability of intelligent card under different conditions by simulating actual use environment.

[0003] However, RFID intelligent card manufacturers usually follow the technical process and requirements provided by chip manufacturers during production, but often lack a simple and practical professional RFID intelligent card manufacturing link test equipment to test the hardware characteristics of finished RFID intelligent cards.The existing detection means and technology have some deficiencies and limitations, including high cost, low detection efficiency, limited detection accuracy and insufficient flexibility, etc., especially in complex environment performance test, it is easy to misjudge, and it is difficult to adapt to diversified application requirements. UTILITY MODEL CONTENT

[0004] Therefore, the utility model aims at providing intelligent card test frock to provide an effective, low-cost RFID intelligent card finished card hardware performance test tool to accurately measure the resonant frequency and bandwidth of RFID intelligent card.

[0005] To achieve the above-mentioned purpose, the technical scheme of the utility model is as follows:

[0006] Intelligent card test frock.

[0007] Further, including spectrum analyzer, standing wave ratio bridge, induction circuit, standing wave ratio bridge is electrically connected with spectrum analyzer, induction circuit is electrically connected with standing wave ratio bridge, and standing wave ratio bridge is connected with high-frequency power supply;

[0008] RFID intelligent card contacts induction circuit and occurs electromagnetic induction, and standing wave ratio bridge receives the electromagnetic signal and measures the impedance characteristics of RFID intelligent card through high-frequency power supply, and is transferred to spectrum analyzer to present the frequency response characteristics of RFID intelligent card.

[0009] Further, the standing wave ratio bridge comprises a Wheatstone bridge, an input end RFInput, an impedance conversion transformer Trans, and an output end RFOutput, the input end RFInput is connected to the Wheatstone bridge as a power supply, a galvanometer end of the Wheatstone bridge is electrically connected to one end of the impedance conversion transformer Trans, and the other end of the impedance conversion transformer Trans is electrically connected to the output end RFOutput.

[0010] The high-frequency power supply is electrically connected to the high-frequency input end RFInput, and the output end RFOutput is electrically connected to the frequency spectrum instrument.

[0011] Further, the Wheatstone bridge comprises a resistor R1, a resistor R2, a resistor R3, and a load interface P1, input ends of the resistor R1 and the resistor R2 are connected in parallel to the input end RFInput, and output ends of the resistor R1 and the resistor R2 are connected in parallel to an input end of the impedance conversion transformer Trans.

[0012] The resistor R3 is connected in series with the load interface P1, and an input end of the resistor R3 and an output end of the load interface P1 are connected in parallel to the input end of the impedance conversion transformer Trans.

[0013] Further, the induction circuit comprises an induction coil and a load interface P2, the induction coil and the load interface P2 form a loop, and the load interface P2 is electrically connected to the load interface P1 through a serial interface.

[0014] Further, the induction circuit and the standing wave ratio bridge are electrically connected through a coaxial cable, and the coaxial cable, the resistor R1, the resistor R2, and the resistor R3 all have a resistance of 50 Ω.

[0015] Further, the induction circuit further comprises a plurality of capacitors, and the plurality of capacitors are connected in parallel between the induction coil and the load interface P2.

[0016] Further, the frequency range of the high-frequency power supply is 10 MHz to 20 MHz.

[0017] Further, the induction coil has a resonance frequency greater than or equal to 60 MHz, and has a resistance less than or equal to 0.5 Ω between 12 MHz and 16 MHz.

[0018] Compared with the prior art, the intelligent card test tool has the following beneficial effects:

[0019] (1) The detection system can accurately measure the resonance frequency and bandwidth of the RFID intelligent card by means of the induction coil and the frequency spectrum instrument, and can effectively guide the frequency performance measurement of the RFID intelligent card, and can guide the card winding and product inspection.

[0020] (2) The standing wave ratio bridge, the Wheatstone bridge is connected to the RF inductive detection component through the 50Ω coaxial cable, can measure the voltage under different loads, the system adopts the no-load detection of the RFID detector under different frequencies, obtains a series of voltage values, and then the frequency points are zeroed and compensated, that is, normalized, effectively eliminates the measurement error, and improves the reliability and consistency of the measurement.

[0021] (3) The impedance conversion transformer Trans is arranged between the standing wave ratio bridge and the spectrum analyzer, signal transmission is carried out through the impedance conversion transformer Trans, unnecessary signals can be effectively isolated, electromagnetic signals are converted into signals required by the spectrum analyzer, the purity of the signals is improved, and the accuracy and reliability of the measurement results are ensured.

[0022] (4) The detection system includes the normalization calibration step of the inductive coil, ensures that the system can be in the best state before each detection, improves the accuracy of the measurement, simplifies the maintenance and calibration process of the system, and reduces the operation complexity. BRIEF DESCRIPTION OF DRAWINGS

[0023] The accompanying drawings, which form a part of this application, are included to provide a further understanding of the application and are incorporated herein in their entirety. The application illustratively described herein suitably can be practiced in the absence of any element or step not specifically disclosed. In the accompanying drawings:

[0024] Figure 1 The detection system principle schematic view is described for the embodiment of the utility model;

[0025] Figure 2 The detection system hardware schematic view is described for the embodiment of the utility model;

[0026] Figure 3 The detection system electrical principle schematic view is described for the embodiment of the utility model;

[0027] Figure 4 The inductive coil appearance schematic view is described for the embodiment of the utility model. DETAILED DESCRIPTION

[0028] It should be noted that the embodiments in the utility model and the features in the embodiments can be combined with each other without conflict.

[0029] The utility model will be described in detail below with reference to the drawings and in combination with the embodiments.

[0030] The intelligent card test tool, and its detection principle is as follows: Figure 1As shown, the impedance characteristics of RF transmission lines at different frequencies will result in different power losses and reflections. By using VSWR (Voltage Standing Wave Ratio Bridge) to measure the transmission efficiency of RF signals at different frequencies from the transmitter to the receiver, the frequency response characteristics of the RFID card under test can be obtained.

[0031] like Figure 2 As shown, the detection system includes a spectrum analyzer, a VSWR bridge, and an induction circuit. The VSWR bridge is electrically connected to the spectrum analyzer, and the induction circuit is electrically connected to the VSWR bridge. The VSWR bridge is connected to a high-frequency power supply. When the RFID smart card comes into contact with the induction circuit, electromagnetic induction occurs. The VSWR bridge receives this electromagnetic signal, measures the impedance characteristics of the RFID smart card through the high-frequency power supply, and transmits it to the spectrum analyzer to present the frequency response characteristics of the RFID smart card. When the RFID smart card under test is placed in the induction circuit, the impedance output at different frequencies is obtained through the Wheatstone bridge. This output is then converted into the signal required by the spectrum analyzer by a specific transformer, while isolating unwanted signals.

[0032] Specific examples Figure 3 As shown, the VSWR bridge includes a Wheatstone bridge, an input terminal RFInput, an impedance transformation transformer Trans, and an output terminal RFOutput. The input terminal RFInput serves as the power supply connected to the Wheatstone bridge. The galvanometer end of the Wheatstone bridge is electrically connected to one end of the impedance transformation transformer Trans, and the other end of the impedance transformation transformer Trans is electrically connected to the output terminal RFOutput. The high-frequency power supply is electrically connected to the high-frequency input terminal RFInput, and the output terminal RFOutput is electrically connected to the spectrum analyzer.

[0033] The Wheatstone bridge includes resistors R1, R2, and R3, and a load interface P1. The input terminals of resistors R1 and R2 are connected in parallel to the input terminal RFInput, and the output terminals of resistors R1 and R2 are connected in parallel to the input terminal of the impedance transformation transformer Trans. Resistor R3 is connected in series with the load interface P1, and the input terminal of resistor R3 and the output terminal of the load interface P1 are connected in parallel to the input terminal of the impedance transformation transformer Trans.

[0034] The induction circuit includes an induction coil and a load interface P2. The induction coil and the load interface P2 are connected to form a loop. The load interface P2 is electrically connected to the load interface P1 through a serial interface.

[0035] Optionally, the Wheatstone bridge is connected to an RF sensing detection component adapted to the specific frequency range of the RFID smart card through a 50Ω coaxial cable to obtain the voltage under different loads. The original Wheatstone bridge outputs a voltage equal to 0 when the load is equal to 50Ω, while the present application adopts the open circuit detection of the RFID detector under different frequencies to obtain a series of voltage values, and then compensates for the zero point of these frequency points, i.e. normalization. Therefore, in the present application, the induction circuit and the standing wave ratio bridge are electrically connected through a coaxial cable, and the resistance value of the coaxial cable, the resistance R1, the resistance R2 and the resistance R3 are all 50Ω. The test method of the detection system includes: first, normalizing and calibrating the induction coil, and then the electromagnetic induction occurs between the to-be-tested RFID smart card and the induction coil. The input frequency range of the standing wave ratio bridge is set to 10MHz to 20MHz, and the spectrum analyzer measures the received spectrum return loss to obtain the response frequency and bandwidth characteristics of the to-be-tested card, so as to determine whether the smart card meets the performance requirements.

[0036] Optionally, the induction circuit further includes a plurality of capacitors connected in parallel between the induction coil and the load interface P2. The capacitors are used to adjust the response frequency of the special RFID card.

[0037] Optionally, the frequency range of the high-frequency power supply is 10MHz to 20MHz. The resonance frequency of the induction coil is greater than or equal to 60MHz, and the resistance value thereof is less than or equal to 0.5Ω between 12MHz and 16MHz. The induction coil is made of PCB, the board material is FR4, 1mm thick, the dielectric constant is 4.6, and the coil shape size is shown in Figure 4

[0038] Specifically, the information transmission, signal processing, control mode and control logic involved in the technical solution can be realized by using the prior art.

[0039] Finally, it should be pointed out that: the above embodiments are only used to illustrate the technical solutions of the present application, but not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application, and they should be covered in the scope of the claims and the description of the present application.

[0040] The above is only a preferred embodiment of the present application, and does not limit the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. A smart card test fixture, characterized by: The device comprises a spectrum analyzer, a standing wave ratio bridge, and an induction circuit, the standing wave ratio bridge is electrically connected with the spectrum analyzer, the induction circuit is electrically connected with the standing wave ratio bridge, and the standing wave ratio bridge is connected with a high-frequency power supply.

2. The smart card test fixture of claim 1, wherein: The standing wave ratio bridge comprises a Wheatstone bridge, an input end RFInput, an impedance conversion transformer Trans, and an output end RFOutput, the input end RFInput is connected to the Wheatstone bridge as a power supply, the current meter end of the Wheatstone bridge is electrically connected with one end of the impedance conversion transformer Trans, and the other end of the impedance conversion transformer Trans is electrically connected with the output end RFOutput. The high-frequency power supply is electrically connected with the high-frequency input end RFInput, and the output end RFOutput is electrically connected with the spectrum analyzer.

3. The smart card test fixture of claim 2, wherein: The Wheatstone bridge comprises a resistor R1, a resistor R2, a resistor R3, and a load interface P1, the input ends of the resistors R1 and R2 are connected in parallel to the input end RFInput, and the output ends of the resistors R1 and R2 are connected in parallel to the input end of the impedance conversion transformer Trans. The resistor R3 is connected in series with the load interface P1, and the input end of the resistor R3 and the output end of the load interface P1 are connected in parallel to the input end of the impedance conversion transformer Trans.

4. The smart card test fixture of claim 3, wherein: The induction circuit comprises an induction coil and a load interface P2, the induction coil and the load interface P2 form a loop, and the load interface P2 is electrically connected with the load interface P1 through a serial interface.

5. The smart card test fixture of claim 4, wherein: The induction circuit is electrically connected with the standing wave ratio bridge through a coaxial cable, and the resistance values of the coaxial cable, the resistors R1, R2, and R3 are all 50Ω.

6. The smart card test fixture of claim 4, wherein: The induction circuit further comprises a plurality of capacitors connected in parallel between the induction coil and the load interface P2.

7. The smart card test fixture of claim 1, wherein: The frequency range of the high-frequency power supply is 10MHz-20MHz.

8. The smart card test fixture of claim 4, wherein: The resonance frequency of the induction coil is greater than or equal to 60MHz, and the resistance value of the induction coil is less than or equal to 0.5Ω at 12MHz-16MHz.

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