CN202736098U - Non-contact IC card radio frequency interface circuit, non-contact IC card, non-contact near-field communication system - Google Patents

Abstract

The utility model relates to a non-contact IC card radio frequency interface circuit, a non-contact IC card, a non-contact near-field communication system. The non-contact IC card radio frequency interface circuit comprises an antenna and a radio frequency interface module including a variable capacitor, a tuner, a switch and an active signal source. The variable capacitor is connected in parallel to two ends of the antenna; the tuner connected in parallel to the two ends of the antenna is used for tuning the variable capacitor; the switch is switched on or switched off under the control of a control signal outputted by a modulator of the non-contact IC card, wherein the control signal indicates whether the modulator in an operating state or not; and the active signal source is connected in series with the switch, and a series circuit formed by the active signal source and the switch is connected in parallel to the two ends of the antenna, wherein the active signal source is used for generating a modulated signal according to a data signal outputted by the modulator. The non-contact IC card radio frequency interface circuit, the non-contact IC card, and the non-contact near-field communication system provided by the utility model enable demodulation of a reader-writer to be easier in the case of weak coupling, thereby improving the accuracy of the reader-writer.

Description

Contactless IC card radio-frequency interface circuit, contactless IC card, noncontact near field communication system

Technical field

The utility model relates to microelectronic, relates in particular to a kind of contactless IC card radio-frequency interface circuit, contactless IC card, noncontact near field communication system.

Background technology

(Integrated Circuit is called for short: IC) be packaged with integrated circuit in the card, in order to the Storage and Processing data integrated circuit.Since IC-card is born, experienced from storage snapping into smart card, evolution from the Contact Type Ic Card to the contactless IC card.Contactless IC card claims again radio-frequency card, is a new technology that grows up recent years in the world.Contactless IC card is comprised of IC chip, antenna, and the built-in antenna of IC chip and contactless IC card links to each other, and is encapsulated in the PVC card of a standard.Adopt the non-contact IC technology, contactless ic is stuck in the certain distance scope near the read write line surface, finishes the read-write operation of data by the transmission of radiowave.When read write line carries out read-write operation to contactless IC card, read write line sends wireless signal, the radio frequency of contactless IC card (Radio Frequency, be called for short: RF) interface circuit detects the wireless signal that read write line sends, and exchanges by RF interface circuit and read write line settling signal under the control of IC chip internal integrated circuit.

As shown in Figure 1, the equivalent circuit theory schematic diagram when carrying out signal exchange for read write line in the prior art and contactless IC card, the circuit that read write line 01 sends wireless signal comprises signal source U ₀, capacitor C ₁Equivalence is resistance R with antenna 11( ₁And inductance L ₁), the circuit that read write line 01 receives the wireless signal of contactless IC card 02 transmission comprises wave filter, amplifier and detuner.The radio-frequency interface circuit of contactless IC card 02 comprises that antenna 12(equivalence is resistance R ₂And inductance L ₂) and adjustable equivalent load Z ₂

As shown in Figure 2, send data to the circuit theory schematic diagram of contactless IC card for read write line in the prior art, when read write line 01 transmitted a signal to contactless IC card 02, read write line 01 modulated stream was crossed the electric current I of antenna 11 ₁, when passing through inductance L ₁Electric current I ₁During change, the magnetic field that can around it, change.When the antenna 12 of contactless IC card 02 enters into by inductance L ₁In the time of in the changing magnetic field that produces, can be in inductance L ₂Upper generation induced electromotive force U _Q2, wherein, induced electromotive force U _Q2By mutual inductance M and the electric current I between two antennas ₁Determine:

$U_{Q2}=\mathrm{j\ωM}\×I_1=\mathrm{j\ωk}\sqrt{L_1\·L_2}\×I_1$

Wherein, mutual inductance M is by the equivalent inductance L of the coupling coefficient k between two antennas, two antennas ₁And L ₂Determine:

$M=k\sqrt{L_1\·L_2}$

Inductance L at contactless IC card 02 ₂The induced electromotive force U of upper generation _Q2Can change electric current I ₂, the electric current I of modulating through read write line 01 like this ₁Change electric current I ₂, the detuner 14 of contactless IC card 02 is by detecting induced electromotive force U _Q2Or electric current I ₂Variation, can obtain the signal that read write line 01 sends.

As shown in Figure 3, send data to the equivalent radio frequency interface circuit principle schematic of read write line for contactless IC card in the prior art, when contactless IC card 02 transmitted a signal to read write line 01, contactless IC card 02 changed equivalent load Z according to the data-signal of its modulator 13 outputs ₂Thereby modulated stream is crossed antenna 12(inductance L ₂) electric current I ₂, based on the mutual inductance principle, can be in antenna (inductance L ₁) the upper induced electromotive force that produces, this induced electromotive force is with equiva lent impedance Z ' _TAGExpression, equiva lent impedance Z ' _TAGDetermined by following formula:

${Z^{\′}}_{\mathrm{TAG}}=\frac{{\mathrm{\ω}}^2{k}^2{L}_1{L}_2}{R_2+\mathrm{j\ω}{L}_2+Z_2}$

As can be seen from the above equation, the data-signal of exporting according to the modulator of contactless IC card changes the equivalent load Z on the contactless IC card 02 ₂, can change the electric current I on the read write line 01 ₁, the detuner of read write line 01 is by detecting electric current I ₁Variation, can obtain the signal that contactless IC card 02 sends.

The signal exchange of Fig. 2 and both direction shown in Figure 3 all is to be undertaken by the coupling between the antenna (inductance), need not by wired contact, the principle of work of Here it is contactless IC card.

As shown in Figure 4, be the equivalent load Z of contactless IC card in the prior art ₂The equivalent circuit theory schematic diagram, equivalent load Z ₂Equivalence is variable capacitance C in parallel ₂With variable resistor R _L, integrated circuit changes Z on contactless IC card 02 ₂Mode have two kinds: change variable capacitance C ₂And variable resistor R _LTo change variable resistor R _LBe example, according to the data-signal that the modulator of contactless IC card is exported, variable resistor R _LCan between low-resistance and two resistances of high resistant, switch.Wherein, as variable resistor R _LWhen the low-resistance place, can think variable resistor R _LResistance be 0, be equivalent to short circuit, as variable resistor R _LWhen the high resistant place, can think variable resistor R _LResistance be ∞, be equivalent to the open circuit.For example, when modulator output data " 0 ", variable resistor R _LAt the low-resistance place, when modulator output data " 1 ", variable resistor R _LAt the high resistant place.

As variable resistor R _LWhen the low-resistance place, equiva lent impedance Z ' _TAGCan be expressed as:

${Z^{\′}}_{\mathrm{TAG}}=\frac{{\mathrm{\ω}}^2{k}^2{L}_1{L}_2}{R_2+\mathrm{j\ω}{L}_2}$

As variable resistor R _LWhen the high resistant place, equiva lent impedance Z ' _TAGCan be expressed as:

${Z^{\′}}_{\mathrm{TAG}}=\frac{{\mathrm{\ω}}^2{k}^2{L}_1{L}_2}{R_2+\mathrm{j\ω}{L}_2+\frac{1}{\mathrm{j\ω}{C}_2}}$

There is following relation in frequency of carrier signal in contactless IC card 02 work:

$R_2<<\mathrm{\&omega;}{L}_2,R_2<<\frac{1}{\mathrm{\&omega;}{C}_2}$

Therefore, at the detuner of read write line 01, as variable resistor R _LWhen low-resistance, equiva lent impedance Z ' _TAGImpedance minimum; As variable resistor R _LWhen high resistant, equiva lent impedance Z ' _TAGImpedance maximum.The scope of coupling coefficient k between contactless IC card 02 antenna (inductance L 2) and read write line 01 antenna (inductance L 1) is: 0≤k≤1.Wherein, when k=0, corresponding to fully not coupling between two antennas.Work as k=1, corresponding to fully coupling between two antennas, in full accord by the magnetic flux of two antennas.And in actual use, coupling coefficient k is far smaller than 1.Because be subjected between the physical size, relative position, antenna of two antennas and the impact of the many factors such as physical shielding on every side, coupling coefficient k can be reduced to only has 1%.Referring to Fig. 3, the detuner of read write line 01 need to detect equiva lent impedance Z ' again _TAGVariation.Equiva lent impedance Z ' _TAGBe and square being directly proportional of coupling coefficient k, even as variable resistor R _LAt low-resistance place, equiva lent impedance Z ' _TAGImpedance when maximum because coupling coefficient k is very little, cause R _LEquiva lent impedance Z ' at the high resistant place _TAGWith respect to R _LEquiva lent impedance Z ' at the low-resistance place _TAGVariation very faint, cause when coupling coefficient k is very little, the demodulation of read write line 01 is very difficult, easily makes mistakes, thereby causes the accuracy of read write line 01 lower.

The utility model content

The utility model provides a kind of contactless IC card radio-frequency interface circuit, contactless IC card, noncontact near field communication system, in order to realize in the weak coupling situation, so that the demodulation of read write line becomes easily, improves the accuracy of read write line.

The utility model provides a kind of contactless IC card radio-frequency interface circuit, comprising:

Antenna is used for being coupled with read write line; And

Radio frequency interface module comprises variable capacitance, tuner, switch and active signal source, wherein:

Described variable capacitance is connected in the two ends of described antenna in parallel;

Described tuner is connected in the two ends of described antenna in parallel, is used for tuning described variable capacitance;

Described switch disconnects under the control of the control signal of the modulator output of described contactless IC card or is closed, and wherein, described control signal represents whether described modulator works;

Described active signal source and described switch are connected in series, and the series arm that described active signal source and described switch form is connected in the two ends of described antenna in parallel, and described active signal source is used for the data-signal according to described modulator output, generates modulated signal.

The utility model also provides a kind of contactless IC card, comprises radio-frequency interface circuit and logic processing circuit, and described radio-frequency interface circuit comprises:

Antenna is used for being coupled with read write line; And

Radio frequency interface module comprises variable capacitance, tuner, switch and active signal source, wherein:

Described variable capacitance is connected in the two ends of described antenna in parallel;

Described tuner is connected in the two ends of described antenna in parallel, is used for tuning described variable capacitance;

Described switch disconnects under the control of the control signal of the modulator output of described contactless IC card or is closed, and wherein, described control signal represents whether described modulator works;

Described active signal source and described switch are connected in series, and the series arm that described active signal source and described switch form is connected in the two ends of described antenna in parallel, and described active signal source is used for the data-signal according to described modulator output, generates modulated signal.

The utility model also provides a kind of contactless IC card, comprises radio-frequency interface circuit and logic processing circuit, and described radio-frequency interface circuit comprises:

Antenna is used for being coupled with read write line; And

Radio frequency interface module comprises variable capacitance, tuner, switch and active signal source, wherein:

Described variable capacitance is connected in the two ends of described antenna in parallel;

Described tuner is connected in the two ends of described antenna in parallel, is used for tuning described variable capacitance;

Described switch disconnects under the control of the control signal of the modulator output of described contactless IC card or is closed, and wherein, described control signal represents whether described modulator works;

Described active signal source and described switch are connected in series, and the series arm that described active signal source and described switch form is connected in the two ends of described antenna in parallel, and described active signal source is used for the data-signal according to described modulator output, generates modulated signal;

Described switch disconnects under the control of the control signal of the modulator output of described contactless IC card or closure comprises:

When described modulator work, described switch is closed under the control of the control signal of described modulator output;

When described modulator was not worked, described switch disconnected under the control of the control signal of described modulator output.

The utility model also provides a kind of contactless IC card, comprises radio-frequency interface circuit and logic processing circuit, and described radio-frequency interface circuit comprises:

Antenna is used for being coupled with read write line; And

Radio frequency interface module comprises variable capacitance, tuner, switch and active signal source, wherein:

Described variable capacitance is connected in the two ends of described antenna in parallel;

Described tuner is connected in the two ends of described antenna in parallel, is used for tuning described variable capacitance;

Described switch disconnects under the control of the control signal of the modulator output of described contactless IC card or is closed, and wherein, described control signal represents whether described modulator works;

Described active signal source and described switch are connected in series, and the series arm that described active signal source and described switch form is connected in the two ends of described antenna in parallel, and described active signal source is used for the data-signal according to described modulator output, generates modulated signal;

Described radio frequency interface module also comprises:

Carrier wave and clock extracting circuit are connected with an end of described antenna, are used for extracting carrier wave and the clock information that described read write line sends, and described carrier wave and clock information are sent to the detuner of described modulator and described contactless IC card.

The utility model also provides a kind of noncontact near field communication system, comprises read write line and above-mentioned arbitrary described contactless IC card.

In the utility model embodiment, when contactless IC card during to the read write line transmitted signal, the induced electromotive force of read write line end is directly proportional with coupling coefficient k, with respect to equivalent impedance Z in the prior art ' _TAGWith square being directly proportional of coupling coefficient k, even coupling coefficient k is very little, the detuner of read write line still can be seen enough large electric current I ₁Variation, thereby so that the demodulation of read write line becomes easily, improved the accuracy of read write line.

Description of drawings

Fig. 1 is the equivalent circuit theory schematic diagram when read write line and contactless IC card carry out message exchange in the prior art;

Fig. 2 is the equivalent radio frequency interface circuit principle schematic that read write line sends data to contactless IC card in the prior art;

Fig. 3 is the equivalent radio frequency interface circuit principle schematic that contactless IC card sends data to read write line in the prior art;

Fig. 4 is the equivalent load Z of contactless IC card in the prior art ₂The equivalent circuit theory schematic diagram;

Fig. 5 is the circuit diagram of the utility model noncontact near field communication system the first embodiment;

Fig. 6 be among the utility model noncontact near field communication system the first embodiment read write line to the equivalent radio frequency interface circuit principle of work schematic diagram of contactless IC card transmitted signal;

Fig. 7 be among the utility model noncontact near field communication system the first embodiment contactless IC card to the equivalent radio frequency interface circuit principle of work schematic diagram of read write line transmitted signal;

Fig. 8 is the circuit diagram of the utility model noncontact near field communication system the second embodiment.

Embodiment

The utility model will be further described below in conjunction with specification drawings and specific embodiments.

As shown in Figure 5, circuit diagram for the utility model noncontact near field communication system the first embodiment, this noncontact near field communication system can comprise read write line 01 and contactless IC card 02, and wherein, contactless IC card 02 can comprise radio-frequency interface circuit 51 and logic processing circuit 53.Wherein, radio-frequency interface circuit 51 can comprise antenna 12 and radio frequency interface module 52, and radio frequency interface module 52 can comprise variable capacitance C ₂, tuner 521, K switch and active signal source U _TAGVariable capacitance C ₂Be connected in the two ends of antenna 12 in parallel; Tuner 521 is connected in the two ends of antenna 12 in parallel.Active signal source 522 is connected in series active signal source U with K switch _TAGThe series arm that forms with K switch is connected in the two ends of antenna 12 in parallel.

Antenna 12 is used for being coupled with read write line 01.Tuner 521 is used for tuning variable capacitance, with radio-frequency interface circuit 51 be tuned on the resonance frequency that needs.K switch disconnects under the control of the control signal of modulator 13 outputs of contactless IC card 02 or is closed, and wherein, control signal represents whether modulator 13 works; Particularly, when modulator 13 work, K switch is closed under the control of the control signal of modulator 13 outputs; When modulator 13 was not worked, K switch disconnected under the control of the control signal of modulator 13 outputs.Active signal source U _TAGBe used for the data-signal according to modulator 13 outputs of contactless IC card 02, generate modulated signal.This modulated signal can be voltage signal or current signal, and its size changes along with the data-signal of modulator 13 outputs.

As shown in Figure 6, be the equivalent radio frequency interface circuit principle of work schematic diagram of read write line among the utility model noncontact near field communication system the first embodiment to the contactless IC card transmitted signal, when contactless IC card 02 receives the signal of read write line 01 transmission, modulator 13 is not worked, modulator 13 disconnects to the K switch gauge tap K that transmits control signal, thereby with active signal source U _TAGBreak from receiving loop.Read write line 01 modulated stream is crossed the electric current I of antenna 11 ₁, when passing through inductance L ₁Electric current I ₁During change, can be in inductance L ₁Around the magnetic field that changes, when the antenna 12 of contactless IC card 02 enters into by inductance L ₁In the changing magnetic field that produces, can be in inductance L ₂Upper generation induced electromotive force U _Q2, induced electromotive force U _Q2By mutual inductance M and the electric current I between two antennas ₁Determine:

$U_{Q2}=\mathrm{j\&omega;M}\&times;I_1=\mathrm{j\&omega;k}\sqrt{L_1\&CenterDot;L_2}\&times;I_1$

Wherein mutual inductance M is by the equivalent inductance L of the coupling coefficient k between two antennas, two antennas ₁, L ₂Determine:

$M=k\sqrt{L_1\&CenterDot;L_2}$

When passing through inductance L ₁Electric current I ₁During change, in the inductance L of contactless IC card 02 ₂The induced electromotive force U of upper generation _Q2Can change, and then change electric current I ₂The electric current I of modulating by read write line 01 like this ₁Change electric current I ₂Detuner 14 on the contactless IC card 02 is by detecting induced electromotive force U _Q2Or electric current I ₂Variation, can obtain the information that read write line 01 sends.

As shown in Figure 7, be the equivalent radio frequency interface circuit principle of work schematic diagram of contactless IC card among the utility model noncontact near field communication system the first embodiment to the read write line transmitted signal, when contactless IC card 02 transmits a signal to read write line 01, modulator 13 work.Modulator 13 transmits control signal down to K switch, and gauge tap K is closed, thereby with active signal source U _TAGBe linked into and receive in the loop active signal source U _TAGData-signal according to modulator 13 sends generates modulated signal.In the present embodiment, this modulated signal is voltage signal, because the voltage U of this modulated signal _TAGTherefore the difference of the data-signal that sends along with modulator 13 and changing has changed the electric current I that flows through antenna 12 ' ₂When passing through inductance L ₂Electric current I ' ₂During change, can be in inductance L ₂Around the magnetic field that changes.When the antenna 12 of contactless IC card 02 arrives near the antenna 11 of read write lines 01, can be in the inductance L of read write line 01 ₁Upper generation induced electromotive force U _{TAG '}Induced electromotive force U _{TAG '}By the mutual inductance M between two antennas with pass through inductance L ₂Electric current I ' ₂Determine:

$U_{{\mathrm{TAG}}^{\&prime;}}=\mathrm{j\&omega;M}\&times;{I^{\&prime;}}_2=\mathrm{j\&omega;k}\sqrt{L_1\&CenterDot;L_2}\&times;{I^{\&prime;}}_2$

Because active signal source U _TAGThe variation of the voltage of output and change pass through inductance L ₂Electric current I ' ₂Be calculated according to the following formula:

${I^{\&prime;}}_2\&ap;\frac{U_{\mathrm{TAG}}}{\mathrm{j\&omega;}{L}_2}$

Therefore, in the antenna 11(of read write line 01 inductance L ₁) the upper induced electromotive force U that produces _{TAG '}Can be expressed as:

$U_{{\mathrm{TAG}}^{\&prime;}}=\mathrm{j\&omega;M}\&times;{I^{\&prime;}}_2=\mathrm{j\&omega;k}\sqrt{L_1{L}_2}\&times;\frac{U_{\mathrm{TAG}}}{\mathrm{j\&omega;}{L}_2}=\frac{k\sqrt{L_1}}{\sqrt{L_2}}\&times;U_{\mathrm{TAG}}$

Induced electromotive force U _{TAG '}Variation can cause the electric current I of read write line 01 ₁Variation, the detuner of read write line 01 is by detecting electric current I ₁Variation, can obtain the signal that contactless IC card 02 sends.Because induced electromotive force U _{TAG '}With coupling coefficient k and active signal source U _TAGThe voltage U of output _TAGBe directly proportional, with respect to equivalent impedance Z in the prior art ' _TAGWith square being directly proportional of coupling coefficient k, even coupling coefficient k is very little, the detuner of read write line 01 still can be seen enough large electric current I ₁Variation, thereby so that the demodulation of read write line 01 becomes easily, improved the accuracy of read write line 01.

As shown in Figure 8, be the circuit diagram of the utility model noncontact near field communication system the second embodiment, be with the difference of schematic diagram shown in Figure 5, radio frequency interface module 52 can also comprise carrier wave and clock extracting circuit 523, is connected with an end of antenna 12.

In the present embodiment, carrier wave and clock extracting circuit 523 is used for extracting carrier wave and the clock information that read write line 01 sends, and carrier wave and clock information sent to the detuner 14 of modulator 13 and contactless IC card 02.Like this, modulator 13 adopts this carrier wave and clock information to modulate, so that read write line 01 can carry out more accurately demodulation to the signal that contactless IC card 02 sends.Detuner 14 adopts this carrier wave and clock information to carry out more accurately demodulation to the signal that read write line 01 sends.

Tuning methods first embodiment of contactless IC card radio-frequency interface circuit

The present embodiment can be applied to the radio-frequency interface circuit 51 of contactless IC card 02 shown in Figure 5, can comprise the steps:

Step 91, employing tuner 521, tuning variable capacitance C ₂

This step can with radio-frequency interface circuit 51 be tuned on the resonance frequency that needs.

The control signal of modulator 13 outputs of step 92, employing contactless IC card 02, gauge tap K disconnects or is closed;

Wherein, control signal represents whether modulator 13 works; When modulator 13 work, adopt the control signal of modulator 13 outputs, gauge tap K is closed; When modulator 13 is not worked, adopt the control signal of modulator 13 outputs, gauge tap K disconnects.

Step 93, employing active signal source U _TAG, according to the data-signal of modulator 13 outputs, generate modulated signal;

By this step, active signal source U _TAGThe output modulated signal, and the size of this modulated signal changes along with the data-signal of modulator 13 output, and this modulated signal can be voltage signal or current signal.

Referring to schematic diagram shown in Figure 7, when modulator 13 work, K switch is closed, active signal source U _TAGThe output modulated signal is because the voltage U of this modulated signal _TAGChange, cause the inductance L at the antenna 11(of read write line 01 ₁) the upper induced electromotive force U that produces _{TAG '}With coupling coefficient k and active signal source U _TAGThe voltage U of output _TAGBe directly proportional, with respect to equivalent impedance Z in the prior art ' _TAGWith square being directly proportional of coupling coefficient k, even coupling coefficient k is very little, the detuner of read write line 01 still can be seen enough large electric current I ₁Variation, thereby so that the demodulation of read write line 01 becomes easily, improved the accuracy of read write line 01.

Tuning methods second embodiment of contactless IC card radio-frequency interface circuit

The present embodiment can be applied to the radio-frequency interface circuit 51 of contactless IC card 02 shown in Figure 8, is with the difference of a upper embodiment, can also comprise the steps: after the step 91

Step 101, adopt carrier wave and clock extracting circuit 523, extract carrier wave and clock information that read write line 01 sends, carrier wave and clock information are sent to the detuner 14 of modulator 13 and contactless IC card 02.

Carrier wave and clock extracting circuit 523 extract carrier wave and the clock information that read write line 01 sends, carrier wave and clock information are sent to the detuner 14 of modulator 13 and contactless IC card 02, modulator 13 and detuner 14 adopt this carrier wave and clock information to carry out modulation and demodulation, can be so that the signal that 01 pair of contactless IC card of read write line 02 sends carry out more accurately demodulation, the signal that 14 pairs of read write lines of detuner 01 send carries out more accurately demodulation.

It should be noted that at last: above embodiment is only unrestricted in order to the technical solution of the utility model to be described, although with reference to preferred embodiment the utility model is had been described in detail, those of ordinary skill in the art is to be understood that, can make amendment or be equal to replacement the technical solution of the utility model, and not break away from the spirit and scope of technical solutions of the utility model.

Claims (5)

1. a contactless IC card radio-frequency interface circuit is characterized in that, comprising:

Antenna is used for being coupled with read write line; And

Radio frequency interface module comprises variable capacitance, tuner, switch and active signal source, wherein:

Described variable capacitance is connected in the two ends of described antenna in parallel;

Described tuner is connected in the two ends of described antenna in parallel, is used for tuning described variable capacitance;

Described switch disconnects under the control of the control signal of the modulator output of described contactless IC card or is closed, and wherein, described control signal represents whether described modulator works;

Described active signal source and described switch are connected in series, and the series arm that described active signal source and described switch form is connected in the two ends of described antenna in parallel, and described active signal source is used for the data-signal according to described modulator output, generates modulated signal.

2. contactless IC card radio-frequency interface circuit according to claim 1 is characterized in that, described switch disconnects under the control of the control signal of the modulator output of described contactless IC card or closure comprises:

When described modulator work, described switch is closed under the control of the control signal of described modulator output;

When described modulator was not worked, described switch disconnected under the control of the control signal of described modulator output.

3. contactless IC card radio-frequency interface circuit according to claim 1 is characterized in that, described radio frequency interface module also comprises:

Carrier wave and clock extracting circuit are connected with an end of described antenna, are used for extracting carrier wave and the clock information that described read write line sends, and described carrier wave and clock information are sent to the detuner of described modulator and described contactless IC card.

4. a contactless IC card comprises radio-frequency interface circuit and logic processing circuit, it is characterized in that, described radio-frequency interface circuit comprises the arbitrary described contactless IC card radio-frequency interface circuit of claim 1-3.

5. noncontact near field communication system, comprise read write line and contactless IC card, described contactless IC card comprises radio-frequency interface circuit and logic processing circuit, it is characterized in that, described radio-frequency interface circuit comprises the arbitrary described contactless IC card radio circuit of claim 1-3.

Images