CN202600755U - Radio frequency identification device (RFID) label with magnet-sensitive device and RFID system with magnet-sensitive device - Google Patents
Radio frequency identification device (RFID) label with magnet-sensitive device and RFID system with magnet-sensitive device Download PDFInfo
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- CN202600755U CN202600755U CN 201220257721 CN201220257721U CN202600755U CN 202600755 U CN202600755 U CN 202600755U CN 201220257721 CN201220257721 CN 201220257721 CN 201220257721 U CN201220257721 U CN 201220257721U CN 202600755 U CN202600755 U CN 202600755U
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Abstract
The utility model provides a radio frequency identification device (RFID) label with a magnet-sensitive device and an RFID system with the magnet-sensitive device. The magnet-sensitive device and an antenna of the RFID label form a parallel-connection structure; a connection/disconnection-controlled logic circuit and a voltage-resistance conversion device are arranged on a line of the magnet-sensitive device which is connected with a chip of the RFID label; the connecting line, the logic circuit and the voltage-resistance conversion device belong to a part of the chip; when the logic circuit is disconnected, the magnet-sensitive device is not parallelly connected with the antenna and is placed under a certain magnetic field intensity, so that a first resonant frequency and a signal intensity of the antenna are invariable; when the logic circuit is connected, the magnet-sensitive device is parallelly connected with the antenna and is placed under the certain magnetic field intensity, so that the antenna works under a second resonant frequency; and the RFID label receives an instruction sent by an RFID reader to control the connection/disconnection of the logic circuit, so that the change of a magnetic field is detected by comparing the difference between signal intensities of different frequencies from the antenna; and therefore, the change of the magnetic field can detected in a low-cost mode.
Description
Technical field
The utility model relates to RFID (Radio Frequency Identification, RF identification) technical field, relates in particular to a kind of RFID label, rfid system with magnetically sensitive device.
Background technology
In recent years, rfid system had become more prevalent.Rfid system is mainly used in the identification to people and thing.In general, this system comprises a RFID reader at least, and this RFID reader can transmit and receive the radiofrequency signal from one or more RFID labels in the scope of a setting.This RFID label generally encapsulates, and can be attached on the object, and it comprises the microchip that an ability and antenna carry out information interchange.This microchip is an integrated circuit in general, and it can be used for storing and process information, the modulation radiofrequency signal, and can move other specific function.The antenna of RFID label is to be used for receiving and sending radiofrequency signal, and is applicable to a kind of special frequency usually.
In some equipment, when the magnetic field that the rfid system that has magnetically sensitive device has been used to monitor product environment of living in has surpassed the acceptable magnetic field intensity.In general these equipment requirements induction installations will have a lasting energy source, are used for detecting the change in magnetic field, but this can increase the cost of equipment.In addition, some equipment requirements induction installations also will link to each other with a comparator circuit, thereby detect the degree size that departs from reference voltage, and this requirement has increased the cost of equipment greatly.In a word, improve rfid system and be necessary, its requires when not using lasting energy source or use a kind of adjunct circuit cheaply, can be used for detecting changes of magnetic field.
The utility model content
The utility model embodiment provides a kind of RFID label, rfid system with magnetically sensitive device, detects changes of magnetic field at lower cost.
On the one hand, the utility model embodiment provides a kind of RFID label with magnetically sensitive device, and two pins are arranged on the chip of said RFID label; Two pins of said magnetically sensitive device and this link to each other; And form parallel-connection structure with the antenna of said RFID label; The variation of external magnetic field intensity can cause magnetically sensitive device voltage or change in current; Logical circuit and a voltage-resistance conversion equipment of a control break-make are arranged on said magnetically sensitive device and circuit that the chip of RFID label is connected, and the circuit of this connection, this logical circuit and this voltage-resistance conversion equipment are the parts of chip, and voltage-resistance conversion equipment is used for converting magnetically sensitive device voltage or change in current to changes in resistance; The break-make of logical circuit determined magnetically sensitive device whether with the sky line parallel: when logical circuit breaks off; Magnetically sensitive device not with the sky line parallel, this moment be placed under certain magnetic field intensity, first resonant frequency and the signal intensity of antenna remain unchanged; When logical circuit was connected, magnetically sensitive device was placed under certain magnetic field intensity with a day line parallel, this moment, and the characteristic frequency of antenna and signal intensity have one at least and change, and this moment, antenna was operated under second resonant frequency; Said RFID label receives the break-make of the instruction of RFID reader transmission with control logic circuit, thereby realizes detecting from the difference between the signal intensity of the different frequency of antenna through comparison the change in magnetic field.
Optional, in the utility model one embodiment, the antenna of said RFID label is a monopole antenna.
Optional, in the utility model one embodiment, the antenna of said RFID label is a double-doublet antenna: said magnetically sensitive device and the voltage that links to each other with this magnetically sensitive device-resistance conversion equipment form parallel-connection structure with antenna wherein; Perhaps said magnetically sensitive device forms parallel-connection structure simultaneously with the voltage that links to each other with this magnetically sensitive device-resistance conversion equipment and two antennas.
Optional; In the utility model one embodiment; Said voltage-resistance conversion equipment comprises: a variable voltage converts the equivalent electrical circuit of variable-resistance device or a ditch type FET or FET to, and said magnetically sensitive device comprises: hall device, Hall switch integrating device, Hall linear Integrated device, magnetodiode, magnetic sensitive transistor, CMOS magnetosensitive device, Wei Gende magnetosensitive device, fluxgate sensor.
On the other hand, the utility model embodiment provides a kind of RFID label with magnetically sensitive device, and a pin is arranged on the chip of said RFID label; One end of said magnetically sensitive device links to each other with this pin; The other end is connected on the antenna of said RFID label; And form parallel-connection structure with antenna; The variation of external magnetic field intensity can cause magnetically sensitive device voltage or change in current; Logical circuit and a voltage-resistance conversion equipment of a control break-make are arranged on said magnetically sensitive device and circuit that the chip of RFID label is connected, and the circuit of this connection, this logical circuit and this voltage-resistance conversion equipment are the parts of chip, and voltage-resistance conversion equipment is used for converting magnetically sensitive device voltage or change in current to changes in resistance; The break-make of logical circuit determined magnetically sensitive device whether with the sky line parallel: when logical circuit breaks off; Magnetically sensitive device not with the sky line parallel, this moment be placed under certain magnetic field intensity, first resonant frequency and the signal intensity of antenna remain unchanged; When logical circuit was connected, magnetically sensitive device was placed under certain magnetic field intensity with a day line parallel, this moment, and the characteristic frequency of antenna and signal intensity have one at least and change, and this moment, antenna was operated under second resonant frequency; Said RFID label receives the break-make of the instruction of RFID reader transmission with control logic circuit, thereby realizes detecting from the difference between the signal intensity of the different frequency of antenna through comparison the change in magnetic field.
Optional, in the utility model one embodiment, the antenna of said RFID label is a monopole antenna.
Optional, in the utility model one embodiment, the antenna of said RFID label is a double-doublet antenna: said magnetically sensitive device and the voltage that links to each other with this magnetically sensitive device-resistance conversion equipment form parallel-connection structure with antenna wherein; Perhaps said magnetically sensitive device forms parallel-connection structure simultaneously with the voltage that links to each other with this magnetically sensitive device-resistance conversion equipment and two antennas.
Optional; In the utility model one embodiment; Said voltage-resistance conversion equipment comprises: a variable voltage converts the equivalent electrical circuit of variable-resistance device or a ditch type FET or FET to, and said magnetically sensitive device comprises: hall device, Hall switch integrating device, Hall linear Integrated device, magnetodiode, magnetic sensitive transistor, CMOS magnetosensitive device, Wei Gende magnetosensitive device, fluxgate sensor.
Another aspect; The utility model embodiment provides a kind of RFID label with magnetically sensitive device; Said magnetically sensitive device is connected on the antenna of said RFID label; And forming parallel-connection structure with antenna, the variation of external magnetic field intensity can cause magnetically sensitive device voltage or change in current, on said magnetically sensitive device and circuit that antenna is connected, a logical circuit and a voltage-resistance conversion equipment of controlling break-make is arranged; The circuit of this connection, this logical circuit and this voltage-resistance conversion equipment are the parts of chip; Voltage-resistance conversion equipment is used for converting magnetically sensitive device voltage or change in current to changes in resistance, the break-make of logical circuit determined magnetically sensitive device whether with the sky line parallel: when logical circuit breaks off, magnetically sensitive device not with the sky line parallel; Be placed under certain magnetic field intensity this moment, and first resonant frequency and the signal intensity of antenna remain unchanged; When logical circuit was connected, magnetically sensitive device was placed under certain magnetic field intensity with a day line parallel, this moment, and the characteristic frequency of antenna and signal intensity have one at least and change, and this moment, antenna was operated under second resonant frequency; Said RFID label receives the break-make of the instruction of RFID reader transmission with control logic circuit, thereby realizes detecting from the difference between the signal intensity of the different frequency of antenna through comparison the change in magnetic field.
Optional, in the utility model one embodiment, the antenna of said RFID label is a monopole antenna.
Optional, in the utility model one embodiment, the antenna of said RFID label is a double-doublet antenna: said magnetically sensitive device and the voltage that links to each other with this magnetically sensitive device-resistance conversion equipment form parallel-connection structure with antenna wherein; Perhaps said magnetically sensitive device forms parallel-connection structure simultaneously with the voltage that links to each other with this magnetically sensitive device-resistance conversion equipment and two antennas.
Optional; In the utility model one embodiment; Said voltage-resistance conversion equipment comprises: a variable voltage converts the equivalent electrical circuit of variable-resistance device or a ditch type FET or FET to, and said magnetically sensitive device comprises: hall device, Hall switch integrating device, Hall linear Integrated device, magnetodiode, magnetic sensitive transistor, CMOS magnetosensitive device, Wei Gende magnetosensitive device, fluxgate sensor.
Another aspect, the utility model embodiment provides a kind of rfid system with magnetically sensitive device, and said rfid system comprises RFID label and RFID reader, and said RFID label comprises the RFID label of above-mentioned band magnetically sensitive device; Said RFID reader sends the break-make of instruction with the logical circuit of control RFID label, thereby detects the change in magnetic field from the difference between the signal intensity of the different frequency of antenna through comparison.
Technique scheme has following beneficial effect: because adopt two pins of magnetically sensitive device and this to link to each other; And form parallel-connection structure with the antenna of RFID label; Logical circuit and a voltage-resistance conversion equipment that one control break-make is arranged on magnetically sensitive device and circuit that the chip of RFID label is connected; The circuit of this connection, this logical circuit and this voltage-resistance conversion equipment are the parts of chip: when logical circuit breaks off; Magnetically sensitive device not with the sky line parallel, this moment be placed under certain magnetic field intensity, first resonant frequency and the signal intensity of antenna remain unchanged; When logical circuit was connected, magnetically sensitive device was placed under certain magnetic field intensity with a day line parallel, this moment, and antenna is operated under second resonant frequency; The RFID label receives the break-make of the instruction of RFID reader transmission with control logic circuit; Thereby realize detecting from the difference between the signal intensity of the different frequency of antenna the technological means of the change in magnetic field through comparison; So reached the technique effect that can detect changes of magnetic field at lower cost; And the energy that utilizes RFID to obtain, solved the powerup issue of magnetic field detection.
Description of drawings
In order to be illustrated more clearly in the utility model embodiment or technical scheme of the prior art; To do to introduce simply to the accompanying drawing of required use in embodiment or the description of the Prior Art below; Obviously, the accompanying drawing in describing below only is some embodiment of the utility model, for those of ordinary skills; Under the prerequisite of not paying creative work, can also obtain other accompanying drawing according to these accompanying drawings.
The synoptic diagram that Fig. 1 is connected with the RFID label chip for the utility model embodiment magnetically sensitive device;
Fig. 2 is the equivalent circuit diagram of RFID label chip inside antenna;
Fig. 3 is the synoptic diagram that the utility model embodiment magnetically sensitive device, logic switch and voltage-resistance conversion equipment are connected with RFID label chip inside antenna equivalent electrical circuit;
The synoptic diagram that Fig. 4 directly is connected for the utility model embodiment magnetically sensitive device and RFID label antenna;
Fig. 5 is the structure key diagram of the utility model embodiment magnetically sensitive device;
Fig. 6 is the process flow diagram of the utility model embodiment based on the magnetic field intensity detection method of signal intensity.
Embodiment
To combine the accompanying drawing among the utility model embodiment below, the technical scheme among the utility model embodiment is carried out clear, intactly description, obviously, described embodiment only is the utility model part embodiment, rather than whole embodiment.Based on the embodiment in the utility model, those of ordinary skills are not making the every other embodiment that is obtained under the creative work prerequisite, all belong to the scope of the utility model protection.
The magnetically sensitive device of the utility model embodiment links to each other with the chip of RFID label and has three kinds of situation at least:
The two pins structure:
The utility model is a kind of device, system and technology that is used for detecting change of magnetic field strength.This system has comprised a label, and two pins are arranged on the chip of this label.Two pins of magnetically sensitive device and this link to each other, and form parallel-connection structure with antenna.The variation of external magnetic field intensity can cause magnetically sensitive device voltage or change in current.Logical circuit and a voltage-resistance conversion equipment of a control break-make are arranged on pin and circuit that chip is connected, and the logical circuit and the voltage-resistance conversion equipment of the circuit of this connection, control break-make are the parts of chip.The effect of voltage-resistance conversion equipment is to convert magnetically sensitive device voltage or change in current to changes in resistance.
The break-make of logical circuit determined magnetically sensitive device whether with the sky line parallel.When logical circuit breaks off, magnetically sensitive device not with the sky line parallel.This moment, magnetically sensitive device was placed under certain magnetic field intensity, and first resonant frequency and the signal intensity of antenna remain unchanged.When logical circuit was connected, magnetically sensitive device was placed under certain magnetic field intensity with a day line parallel, this moment, and the characteristic frequency of antenna and signal intensity have one at least and change, and this moment, antenna was operated under second resonant frequency.Reader can send the break-make of instruction control logical circuit to label, when logical circuit is connected, can detect the change in magnetic field through comparison from the difference between the signal intensity of the different frequency of antenna.
With regard to an instance, this system has comprised a label, has only an antenna (monopole antenna) on this label.Two pins are arranged on the chip of this label.Two pins of magnetically sensitive device and this link to each other, and form parallel-connection structure with antenna.Logical circuit and a voltage-resistance conversion equipment of a control break-make are arranged on pin and circuit that chip is connected, and the logical circuit and the voltage-resistance conversion equipment of the circuit of this connection, control break-make are the parts of chip.The effect of voltage-resistance conversion equipment is to convert magnetically sensitive device voltage or change in current to changes in resistance.
Magnetically sensitive device is placed under certain magnetic field intensity when logical circuit is connected, and antenna features frequency and signal intensity have one at least and change, and it is operated under second resonant frequency.Reader can send instruction to label, and the difference between the signal intensity of the different frequency during through the comparison logic break-make can detect the change in magnetic field.Or rather, voltage-resistance conversion equipment can be an equivalent electrical circuit that variable voltage is converted to variable-resistance device, ditch type FET or FET.And the instantiation of magnetically sensitive device comprises: hall device, Hall switch integrating device, Hall linear Integrated device, magnetodiode, magnetic sensitive transistor, CMOS magnetosensitive device, Wei Gende magnetosensitive device, fluxgate sensor etc.
With regard to another instance, this system has comprised a label, and two antennas (double-doublet antenna) are arranged on this label.Two kinds of situation are arranged this moment.First kind of situation is that two pins of magnetically sensitive device and this link to each other, and forms parallel-connection structure with first antenna.Logical circuit and a voltage-resistance conversion equipment of a control break-make are arranged on pin and circuit that chip is connected, and the logical circuit and the voltage-resistance conversion equipment of the circuit of this connection, control break-make are the parts of chip.The effect of voltage-resistance conversion equipment is to convert magnetically sensitive device voltage or change in current to changes in resistance.This moment voltage-resistance conversion equipment of linking to each other with magnetically sensitive device also with first sky line parallel, and second antenna is all the time with the first resonant frequency proper communication.
When logical circuit is connected, be placed under certain magnetic field intensity, first antenna features frequency and signal intensity have at least a meeting to change, and it is operated under second resonant frequency.Reader can send instruction to label, and the difference between the signal intensity of the different frequency of first and second antennas can detect the change in magnetic field when connecting through comparison logic.Difference between the signal intensity of the different frequency during logical circuit break-make through second antenna self relatively also can detect the change in magnetic field.
Second kind of situation is that two pins of magnetically sensitive device and this link to each other, and form parallel-connection structure simultaneously with two antennas.Logical circuit and a voltage-resistance conversion equipment of a control break-make are arranged on pin and circuit that chip is connected, and the logical circuit and the voltage-resistance conversion equipment of the circuit of this connection, control break-make are the parts of chip.The effect of voltage-resistance conversion equipment is to convert magnetically sensitive device voltage or change in current to changes in resistance.Voltage-resistance conversion equipment that link to each other with magnetically sensitive device this moment is also simultaneously parallelly connected with these two antennas, and the situation that this and label only contain an antenna is similar.When logical circuit is connected, be placed under certain magnetic field intensity, antenna features frequency and signal intensity have one at least and change, and it is operated under second resonant frequency.Reader can send instruction to label, and the difference between the signal intensity of the different frequency during through the comparison logic break-make can detect the change in magnetic field.
First kind of situation circuit connection is fairly simple, and the resonant frequency of two antennas maybe be different during work, can influence the precision of measurement.Second kind of situation circuit connects more complicated, but the resonant frequency of two antennas is consistent during work, and measuring accuracy is higher.Or rather, voltage-resistance conversion equipment can be an equivalent electrical circuit that variable voltage is converted to variable-resistance device, ditch type FET or FET.And the instantiation of magnetically sensitive device comprises: hall device, Hall switch integrating device, Hall linear Integrated device, magnetodiode, magnetic sensitive transistor, CMOS magnetosensitive device, Wei Gende magnetosensitive device, fluxgate sensor etc.
One pin configuration:
The chip of this label can only have a pin, and this pin outwards links to each other with an end of magnetically sensitive device, and the other end of magnetically sensitive device is directly linked on the antenna.Pin is similar in the situation of the tie point of chip internal and two pins, finally remains the purpose that will reach with day line parallel.Simultaneously on pin and circuit that the chip internal circuit is connected, a logical circuit of controlling break-make is arranged.In addition, on the circuit of antenna again the parallel connection a voltage-resistance conversion equipment, voltage-resistance conversion equipment has circuit to be connected with the two-termial line of magnetically sensitive device and logical circuit again.
When logical circuit breaks off, magnetically sensitive device not with the sky line parallel, this moment be placed under certain magnetic field intensity, first resonant frequency and the signal intensity of antenna remain unchanged.When logical circuit was connected, magnetically sensitive device was placed under certain magnetic field intensity with a day line parallel, this moment, and antenna features frequency and signal intensity have one at least and change, and it is operated under second resonant frequency.Reader can send the break-make of instruction control logical circuit to label, when logical circuit is connected, can detect the change in magnetic field through comparison from the difference between the signal intensity of the different frequency of antenna.
With regard to an instance, this system has comprised a label, has only an antenna (monopole antenna) on this label.Magnetically sensitive device links to each other with this pin, and the other end of magnetically sensitive device is directly linked on the antenna, forms parallel-connection structure with this root antenna.Logical circuit and a voltage-resistance conversion equipment of a control break-make are arranged on pin and circuit that chip is connected, and the logical circuit and the voltage-resistance conversion equipment of the circuit of this connection, control break-make are the parts of chip.The effect of voltage-resistance conversion equipment is to convert magnetically sensitive device voltage or change in current to changes in resistance.
When logical circuit is connected, be placed under certain magnetic field intensity, antenna features frequency and signal intensity have one at least and change, and it is operated under second resonant frequency.Reader can send instruction to label, and the difference between the signal intensity of the different frequency during through the comparison logic break-make can detect the change in magnetic field.Or rather, voltage-resistance conversion equipment can be an equivalent electrical circuit that variable voltage is converted to variable-resistance device, ditch type FET or FET.And the instantiation of magnetically sensitive device comprises: hall device, Hall switch integrating device, Hall linear Integrated device, magnetodiode, magnetic sensitive transistor, CMOS magnetosensitive device, Wei Gende magnetosensitive device, fluxgate sensor etc.
With regard to another instance, this system has comprised a label, and two antennas (double-doublet antenna) are arranged on this label.Magnetically sensitive device with this one by one pin link to each other, the other end of magnetically sensitive device is directly linked on the antenna, forms parallel-connection structure with first antenna.Logical circuit and a voltage-resistance conversion equipment of a control break-make are arranged on pin and circuit that chip is connected, and the logical circuit and the voltage-resistance conversion equipment of the circuit of this connection, control break-make are the parts of chip.The effect of voltage-resistance conversion equipment is to convert magnetically sensitive device voltage or change in current to changes in resistance.This moment voltage-resistance conversion equipment of linking to each other with magnetically sensitive device also with first sky line parallel, and second antenna is all the time with the first resonant frequency proper communication.
When logical circuit is connected, be placed under certain magnetic field intensity, first antenna is operated under second resonant frequency, and its characteristic frequency and signal intensity have at least a meeting to change.Reader can send instruction to label, and when connecting through comparison logic, the difference between the signal intensity of the different frequency of first and second antennas can detect the change in magnetic field.Difference between the signal intensity of the different frequency during logical circuit break-make through first antenna self relatively also can detect the change in magnetic field.Or rather, voltage-resistance conversion equipment can be an equivalent electrical circuit that variable voltage is converted to variable-resistance device, ditch type FET or FET.And the instantiation of magnetically sensitive device comprises: hall device, Hall switch integrating device, Hall linear Integrated device, magnetodiode, magnetic sensitive transistor, CMOS magnetosensitive device, Wei Gende magnetosensitive device, fluxgate sensor etc.
No pin configuration:
When not having pin on the chip of RFID label, magnetically sensitive device can directly be linked on the antenna.Magnetically sensitive device and antenna form parallel-connection structure.Logical circuit and a voltage-resistance conversion equipment of a control break-make are arranged on antenna and circuit that chip is connected, and the logical circuit and the voltage-resistance conversion equipment of the circuit of this connection, control break-make are the parts of chip.The effect of voltage-resistance conversion equipment is to convert magnetically sensitive device voltage or change in current to changes in resistance.In this case, the antenna that links to each other with magnetically sensitive device can not break away from magnetically sensitive device and communicate by letter with first resonant frequency.When being placed under certain magnetic field intensity, second resonant frequency of antenna and signal intensity have one at least and change.Reader can send instruction to label apparatus, detects the change in magnetic field from the difference between the signal intensity of the different frequency of antenna through comparison.
With regard to an instance, this system has comprised a label, and two antennas (double-doublet antenna) are arranged on this label.Magnetically sensitive device directly links to each other with first antenna.Magnetically sensitive device and antenna form parallel-connection structure.Logical circuit and a voltage-resistance conversion equipment of a control break-make are arranged on antenna and circuit that chip is connected, and the logical circuit and the voltage-resistance conversion equipment of the circuit of this connection, control break-make are the parts of chip.The effect of voltage-resistance conversion equipment is to convert magnetically sensitive device voltage or change in current to changes in resistance.And second antenna do not link to each other with magnetically sensitive device all the time with the first resonant frequency proper communication.When being placed under certain magnetic field intensity, first antenna features frequency and signal intensity have at least a meeting to change, and it is operated under second resonant frequency, and the characteristic frequency of second antenna and signal intensity are constant.Reader can send instruction to label, and can detect the change in magnetic field through the difference between the signal intensity of the different frequency of first and second antennas relatively.Or rather, voltage-resistance conversion equipment can be an equivalent electrical circuit that variable voltage is converted to variable-resistance device, ditch type FET or FET.And the instantiation of magnetically sensitive device comprises: hall device, Hall switch integrating device, Hall linear Integrated device, magnetodiode, magnetic sensitive transistor, CMOS magnetosensitive device, Wei Gende magnetosensitive device, fluxgate sensor etc.
In the same way, can be with on the chip of antenna also and can not be with pin, can be with one also can be with a plurality of pins.The radical of antenna can be one, two or even many.Also can connect one or more magnetically sensitive devices accordingly, the model of magnetically sensitive device can be the same or different simultaneously.In addition, the voltage that is attached thereto-resistance conversion equipment also can have many variations.With regard to the device a kind of instantiation with regard to, when be placed on certain magnetic field intensity under, the resonant frequency of the antenna that links to each other with magnetically sensitive device and signal intensity have at least a meeting to change.Reader can send instruction to label apparatus, detects the change in magnetic field from the difference between the signal intensity of the different frequency of antenna through comparison.
With regard to a kind of instantiation of magnetically sensitive device, the method for simultaneous comparison numerical value comprises that these are compared numerical value compares with most signal strength values.These signal strength values belong to different frequencies, and interrelate with the magnetic field intensity of majority, can detect the intensity in magnetic field simultaneously based on the above-mentioned comparison of mentioning.
Yet with regard to another aspect, a rfid system comprises a RFID label apparatus and a RFID reader device.This RFID label apparatus is used to send two kinds of signals, the signal when signal when promptly above-mentioned logical circuit breaks off and logical circuit are connected, and these two kinds of signals have at least a kind of meeting that the request that receives is responded.The RFID reader device is used for the RFID label apparatus is sent a request at least.Reading device is installed is the fiducial value between the signal strength values in order to receive signal strength values and logical circuit when connecting and to break off, and be converted into the varying level in magnetic field to these fiducial values from the logical circuit of label.
In an example, the antenna of RFID label links to each other with magnetically sensitive device, and the logical circuit of a control break-make is arranged on this connection line.Magnetically sensitive device and antenna form parallel-connection structure.Logical circuit and a voltage-resistance conversion equipment of a control break-make are arranged on antenna and circuit that chip is connected, and the logical circuit and the voltage-resistance conversion equipment of the circuit of this connection, control break-make are the parts of chip.The effect of voltage-resistance conversion equipment is to convert magnetically sensitive device voltage or change in current to changes in resistance.Under logical circuit break-make whether two kinds of situation, this antenna has two kinds of corresponding with it different frequencies, i.e. first resonant frequency and second resonant frequency.Connect and be positioned over this label apparatus under certain magnetic field intensity when logical circuit,, will produce the intensity level of unlike signal owing to the variation of resonant frequency.
In an example, the RFID label apparatus comprises first, second two antennas.Better situation is; First antenna links to each other with voltage-resistance conversion equipment with magnetically sensitive device; When this label apparatus is placed under certain magnetic field intensity, because the variation of resonant frequency, will produce the different of secondary signal intensity level and first signal strength values.
Another aspect, the utility model embodiment provides a kind of rfid system with magnetically sensitive device, and said rfid system comprises RFID label and RFID reader, and said RFID label comprises the RFID label of above-mentioned band magnetically sensitive device; Said RFID reader sends the break-make of instruction with the logical circuit of control RFID label, thereby detects the change in magnetic field from the difference between the signal intensity of the different frequency of antenna through comparison.
Again on the one hand; The utility model embodiment provides a kind of magnetic field detection method of the rfid system with magnetically sensitive device; Said magnetic field detection method is applied to the rfid system of above-mentioned band magnetically sensitive device, comprising: send the break-make of instruction with the logical circuit of control RFID label through said RFID reader; Receive the break-make of the instruction of RFID reader transmission through the RFID label: when logical circuit breaks off with control logic circuit; Magnetically sensitive device not with the sky line parallel; Be placed under certain magnetic field intensity this moment, and first resonant frequency and the signal intensity of antenna remain unchanged; When logical circuit was connected, magnetically sensitive device was placed under certain magnetic field intensity with a day line parallel, this moment, and the characteristic frequency of antenna and signal intensity have one at least and change, and this moment, antenna was operated under second resonant frequency; Utilize the comparison of said RFID reader to detect the change in magnetic field from the difference between the signal intensity of the different frequency of antenna.
As shown in Figure 1, the synoptic diagram of the magnetosensitive label 10 that is connected with the RFID label chip for the utility model embodiment magnetically sensitive device.As shown in Figure 1, label apparatus 10 comprises 13, two pins 16,17 of 15, one surface-mounted integrated circuits of a base and a double-doublet antenna 11,12.Two pins 16,17 are arranged on the surface-mounted integrated circuit 13, and these two pins outwards link to each other with magnetically sensitive device 14, and these two pins are parallelly connected with the equivalent electrical circuit of antenna at chip internal, and the logical circuit of a control break-make is arranged on the circuit that connects.Magnetically sensitive device and antenna form parallel-connection structure.Logical circuit and a voltage-resistance conversion equipment of a control break-make are arranged on antenna and circuit that chip is connected, and the logical circuit and the voltage-resistance conversion equipment of the circuit of this connection, control break-make are the parts of chip.The effect of voltage-resistance conversion equipment is to convert magnetically sensitive device voltage or change in current to changes in resistance.Whether magnetically sensitive device can be controlled by in the access chip circuit through the break-make of logical circuit, thereby the frequency of the antenna that links to each other with radio-frequency module can be influenced.When logical circuit broke off, label antenna was with the first resonant frequency communication.When logical circuit is connected, be placed under certain magnetic field intensity, antenna is operated under second resonant frequency, and its characteristic frequency and signal intensity have one at least and change.
In an example, transmitting terminal antenna 11,12 is processed by one or more different low electrical resistant materials, and these materials have higher electric conductivity; Copper for example, silver, and aluminium; They link to each other with antenna 11,12 through two pins 16,17 with the above-mentioned magnetically sensitive device of mentioning; When antenna 11,12 is placed under certain magnetic field intensity, magnetically sensitive device can cause the variation of one or more transmitting terminal generation resonant frequencies.The frequency of the frequency of this variation and reception and transmission is all different.For example, when logical circuit was connected, magnetically sensitive device was positioned under certain magnetic field intensity, will cause sending that at least one changes in frequency and the receive frequency.
In another example, the antenna frequencies value of setting at the beginning will be higher than the antenna frequencies under the certain magnetic field environment, and when reaching certain magnetic field, it will reduce then.In another example, the antenna frequencies of setting at the beginning is lower than the antenna frequencies under the certain magnetic field intensity, and it will rise when reaching certain magnetic field intensity.The such magnetically sensitive device that can be used for the utility model has: hall device, Hall switch integrating device, Hall linear Integrated device, magnetodiode, magnetic sensitive transistor, CMOS magnetosensitive device, Wei Gende magnetosensitive device, fluxgate sensor etc.
Type based on magnetically sensitive device is different, and the magnetic field intensity that causes changing possibly be that a specific magnetic field value also possibly be a scope of magnetic field value selectively.The length of time must cause the variation of antenna resonance frequency, and antenna quality also can cause different variations.The type of the magnetically sensitive device that for example, has on the antenna can influence the length that changes the antenna resonance frequency required time.
As shown in Figure 2, be the equivalent circuit diagram of RFID label antenna.In the alternating magnetic field that tag coil antenna entering read write line produces, the interaction between label antenna and the reading and writing device antenna just is similar to transformer.Both coils are equivalent to the primary coil and the secondary coil of transformer.Resonant tank by label antenna forms is as shown in Figure 2; The coil inductance (L), stray capacitance (Cp) and the shunt capacitance (C2) that comprise label antenna; Its resonance frequency is the parallelly connected equivalent capacity of Cp and C2 for C in
formula; R1, R2 are the equivalent resistance of circuit internal inductance coil and other devices.The carrier frequency that label and read write line two-way communication are used is exactly f.The tag antenna coil profile is very little when requiring; Be that area is little; And need certain operating distance, the aerial coil mutual induction amount that RFID label and read write line are asked just obviously can not practical requirement, can have the Ferrite Material of high permeability in the inner insertion of tag antenna coil; With the increase mutual induction amount, thus the little problem of compensating coil xsect.
As shown in Figure 3, be the utility model embodiment magnetically sensitive device, the logical circuit of control break-make and the synoptic diagram that voltage-resistance conversion equipment is connected with RFID label antenna equivalent electrical circuit.Resonant tank by label antenna forms is as shown in the figure; The coil inductance (L), stray capacitance (Cp) and the shunt capacitance (C2) that comprise label antenna; Its resonance frequency is the parallelly connected equivalent capacity of Cp and C2 for
formula C; R1, R2 are the equivalent resistance of circuit internal inductance coil and other devices.M is the variable resistor of representative magnetically sensitive device, and S is the logical circuit of control break-make, and R3 is the equivalent resistance of connecting with magnetically sensitive device, and F is voltage-resistance conversion equipment.When logical circuit breaks off, magnetically sensitive device not with the sky line parallel, this moment be placed under certain magnetic field intensity, first resonant frequency and the signal intensity of antenna remain unchanged.When logical circuit was connected, magnetically sensitive device was placed under certain magnetic field intensity with a day line parallel, this moment, and antenna features frequency and signal intensity have one at least and change, and this moment, antenna was operated under second resonant frequency.
As shown in Figure 4, be the synoptic diagram that the utility model embodiment magnetically sensitive device and RFID label antenna directly link to each other, can detect the sketch of the passive RFID tags device 40 of changes of magnetic field.As shown in Figure 4, label apparatus 40 comprises 45, one integrated circuit 43 of a base and a double-doublet antenna 41,42.The magnetically sensitive device 44 that links to each other with antenna 42 will influence the resistance of antenna 42.The material that magnetically sensitive device 44 is suitable for can be controlled the frequency that any one had both been fixed a point according to any one current voltage in the antenna 41,42.With regard to an instance, fixing up an aerial wire 41,42 can make it produce resonance in identical frequency.With regard to another instance, fixing up an aerial wire 41,42 can make it produce resonance in different frequency.
In an example, transmitting terminal antenna 41,42 is processed by one or more different low electrical resistant materials; These materials have higher electric conductivity, copper for example, silver; And aluminium, they link to each other with the above-mentioned magnetically sensitive device of mentioning, when antenna 41; 42 are placed under certain magnetic field intensity, and magnetically sensitive device can cause the variation of one or more transmitting terminal generation resonant frequencies, thereby cause a different frequency.The frequency of the variation of this frequency and reception and transmission is all different.For example, magnetically sensitive device is positioned under certain magnetic field intensity, will cause sending that at least one changes in frequency and the receive frequency.
In another example, the antenna frequencies value of setting at the beginning will be higher than the antenna frequencies under the certain magnetic field environment, and when reaching certain magnetic field, it will reduce then.In another example, the antenna frequencies of setting at the beginning is lower than the antenna frequencies under the certain magnetic field intensity, and it will rise when reaching certain magnetic field intensity.The such magnetically sensitive device that can be used for the utility model has: hall device, Hall switch integrating device, Hall linear Integrated device, magnetodiode, magnetic sensitive transistor, CMOS magnetosensitive device, Wei Gende magnetosensitive device, fluxgate sensor etc.
Type based on magnetically sensitive device is different, and the magnetic field intensity that causes changing possibly be that a specific magnetic field value also possibly be a scope of magnetic field value selectively.The length of time must cause the variation of antenna resonance frequency, and antenna quality also can cause different variations.The type of the magnetically sensitive device that for example, has on the antenna can influence the length that changes the antenna resonance frequency required time.
As shown in Figure 5, the Wei Gende magnetic-sensitive elements be according to the Wei Gende effect process magnetic-sensitive elements.Ferromagnetism metal alloys such as permalloy can make the coercive force of an ectonexine marked difference occur through after the special processing: outer field coercive force is than the big one magnitude of internal layer.This tinsel is Wei Gendesi, like figure (1).Because ectonexine coercive force difference is bigger, Wei Gendesi has two kinds of stable magnetized states: ectonexine is by equidirectional magnetization: ectonexine is by magnetic reversal.Utilize suitable external magnetic field effect, the magnetized state of Wei Gendesi internal layer is reversed suddenly, change state b suddenly into from state a, or change a suddenly into from state b, the effect of generation state counter-rotating is called the Wei Gende effect under this outside magnetic field effect.Like figure (2), be the touch sensor of processing with Wei Gendesi.The last detecting coil of being full of of Wei Gendesi, its below is one makes Wei Gendesi permanent magnet magnetized.When top key moves to downwards when contacting with lower part, top magnet is more near Wei Gendesi, but pole polarity and following magnet are opposite, and this just makes DOM counter-rotating of silk internal layer, spike pulse of detecting coil output.Wei Gendesi generally is about several centimetres, and the about 0.3mm of diameter, magneto sensor coil turn are about 1000～2000 circles, and voltage pulse output is a few voltage magnitudes, and pulse width is 20 μ s.
As shown in Figure 6, for the utility model detects a kind of method flow diagram that magnetic field changes through the label apparatus that uses many antennas.What need consider is, the above-mentioned device of mentioning uses a label integrated circuit to carry out and the exchanging of a plurality of antennas.
As shown in Figure 6,50, the RFID reader sends energy and instruction to label apparatus.52, logical circuit is in the state of disconnection at initial time, and label apparatus is with the antenna received energy and the instruction that do not link to each other with magnetically sensitive device.54, label apparatus is converted into DC (direct current) voltage to the electromagnetic wave that carries energy, thereby just can make label carry out the requirement of indication.And this conversion need be used a charge pump, and a rectification circuit perhaps interconnects it, perhaps will use other energy conversion device.56, label apparatus sends signal through the sky alignment reader that does not link to each other with magnetically sensitive device.58, the energy intensity of receiving signal is measured and write down to reader.60, reader sends the instruction of connecting logical circuit to label apparatus.62, label apparatus is used the antenna transmission data that link to each other with magnetically sensitive device.64, the energy intensity of signal is received in the reader measurement.66, reader calculated goes out the fiducial value of a reflected signal intensity.68, reader changes into different field strength values with fiducial value.With regard to an instance, reader can be set the signal that a time period is used for receiving label, if do not receive signal, reader will be recorded as 0 with signal intensity.
In this system, reader will compare its signal strength values with the label antenna that links to each other with magnetically sensitive device from the signal strength values of the antenna that does not link to each other with magnetically sensitive device as a reference value.Through receive from the signal that links to each other with magnetically sensitive device with the transmitting terminal that does not link to each other with magnetically sensitive device, reader can be collected the fiducial value of representing unlike signal intensity.Then, the RFID reader can be converted into the residing magnetic field intensity of label to such fiducial value.With regard to a concrete instance, disposing this RFID reader is to be converted into magnetic field value for the difference from the RF signal intensity that connects the antenna that does not perhaps connect magnetically sensitive device that will receive through the reference data of using storage.
Best situation is, with the antenna that does not connect magnetically sensitive device as a reference, can be with owing to the variation that coupling caused between label and the reader filters out.In addition, as before mention, magnetically sensitive device is applied to the time length that variation and the label of the resistance value that can make it in the design be placed under the specific magnetic fields and forms relation one to one.For example, magnetically sensitive device is only positioned on an antenna, can allow like this to change within the specific limits as a kind of function from the signal of RFID label apparatus, and this function just antenna be placed on the function that just has after the time under the certain magnetic field.The same, through using the utility model, under the passive condition of RFID label, the RFID reader can detect label apparatus and whether within the acceptable range whether be placed under certain magnetic field and this magnetic field.
Do not use the various RFID labels of two antennas also can perceive the variation in magnetic field with magnetically sensitive device, the variation that the variation in perception magnetic field is based on resonant frequency on the antenna also can recognize the variation that antenna receives signal.
For example pass through design to the antenna that links to each other with magnetically sensitive device; The frequency that can make antenna is at ISM (Industrial Scientific Medical; Industry, science, medical science) the interior variation of frequency range, can connect this antenna that links to each other with magnetically sensitive device and logical circuit on the label of standard.
For example label antenna can so be set in a concrete instance; Before in being exposed to the certain magnetic field environment; The resonant frequency of antenna is 902-928MHZ, but in a single day label is exposed in the certain magnetic field environment, because the influence in magnetic field; The resonant frequency of antenna is just reduced to 899.5-927.5MHZ; Frequency frequency range (902-928MHZ) at U.S. RFID is split into 52 channels, and reader can be skipped the channel that can not receive at random in these 52 channels, and the benefit of this jump of reader is exactly can a plurality of readers of effectively preventing in same physical space, to attempt the conflict of using same frequency to cause.
For example in an example, RFID frequency range (902-928MHZ) is not to be divided into 52 channels but the antenna settings that on average has been divided into n channel tag is carried out work under this frequency range (902-928MHZ).Because label antenna links to each other with magnetically sensitive device, so as long as magnetic field has surpassed the scope of predefined value, the frequency of operation of antenna tag antenna just drops among (899.5-927.5MHZ) this frequency range.Therefore compare just channel n to be got rid of from band limits with original frequency range and go, the frequency range (899.5-927.5MHZ) after therefore changing is carried out exchanging of information with regard to no longer allowing label with channel n.
In concrete instance; If the environment at label place has surpassed the magnetic field range of expection; Reader can only send instruction to label through channel 1 to n-1, and label also can be made a response, because the antenna in the label just can only be worked in this frequency range; When reader with the frequency of n channel when label sends instruction; Because the variation in label magnetic field has caused the resonant frequency of label antenna to drop to 899.5-927.5MHZ, just no longer make a response so no longer reach the 928MHZ label, pass information back reader.
Favourable aspect is because magnetic field has exceeded the variation of the operating frequency of antenna that predefined value causes, is just reflected by the disappearance of this information interchange.
In model; Reader can send an instruction between channel n-1 and channel n to label and further check that drift has taken place the operating frequency range of label antenna; Because label can receive the instruction that sends through channel n-1; And can be to the reader feedback information through channel n-1; Because label can not receive the instruction that sends through channel n, and can not can so just confirm that drift has taken place the operating frequency range of label antenna to the reader feedback information through channel n.
The variation in magnetic field causes the frequency of operation of label antenna to take place upwards to be not limited in downward drift and the utility model frequency range on average is divided into n channel.
The utility model embodiment can detect changes of magnetic field at lower cost, and the energy that utilizes RFID to obtain, and has solved the powerup issue of magnetic field detection.
The enforcement of each characteristics of this system may relate to software; The combination that hardware also possibly relate to software and hardware just can reach, and for example the enforcement of many advantages of system is to realize with the mutual mode that exchanges of computer and other equipment machines with object oriented programming languages with a kind of high-caliber processing through programming.Each such function program for example possibly be stored in the storage intermediary in the ROM (read-only memory) to be read by a computer and processor and realize above-mentioned function.
Those skilled in the art can also recognize the various illustrative components, blocks (illustrative logical block) that the utility model embodiment lists, and unit and step can be passed through electronic hardware, computer software, or both combinations realize.Be the clear replaceability (interchangeability) of showing hardware and software, above-mentioned various illustrative components (illustrative components), unit and step have been described their function generally.Such function is to realize depending on the designing requirement of certain applications and total system through hardware or software.Those skilled in the art can be for every kind of certain applications, and can make ins all sorts of ways realizes described function, but this realization should not be understood that to exceed the scope of the utility model embodiment protection.
Various illustrative logical block described in the utility model embodiment; Or the unit can pass through general processor, digital signal processor, special IC (ASIC); Field programmable gate array (FPGA) or other programmable logic device; Discrete gate or transistor logic, discrete hardware components, or the design of above-mentioned any combination realizes or operates described function.General processor can be microprocessor, and alternatively, this general processor also can be any traditional processor, controller, microcontroller or state machine.Processor also can realize through the combination of calculation element, for example digital signal processor and microprocessor, a plurality of microprocessors, Digital Signal Processor Core of one or more microprocessors associatings, or any other similarly configuration realize.
The method described in the utility model embodiment or the step of algorithm can directly embed hardware, the software module of processor execution or the two combination.Software module can be stored in the storage medium of other arbitrary form in RAM storer, flash memory, ROM storer, eprom memory, eeprom memory, register, hard disk, moveable magnetic disc, CD-ROM or this area.Exemplarily, storage medium can be connected with processor, so that processor can read information from storage medium, and can deposit write information to storage medium.Alternatively, storage medium can also be integrated in the processor.Processor and storage medium can be arranged among the ASIC, and ASIC can be arranged in the user terminal.Alternatively, processor and storage medium also can be arranged in the various parts in the user terminal.
In one or more exemplary designs, the described above-mentioned functions of the utility model embodiment can realize in hardware, software, firmware or this three's combination in any.If in software, realize, these functions can be stored on the media with computer-readable, or are transmitted on the media of computer-readable with one or more instructions or code form.The computer-readable media comprises that the computer storage medium lets computer program transfer to other local telecommunication media from a place with being convenient to make.Storage medium can be the useable medium that any general or special computer can access.For example; Such computer readable media can include but not limited to RAM, ROM, EEPROM, CD-ROM or other optical disc storage, disk storage or other magnetic storage device, or other any can be used to carry or store with instruction or data structure and other can be read the media of the program code of form by general or special computer or general or special processor.In addition; Any connection can suitably be defined as the computer-readable media; For example, if software is through a concentric cable, optical fiber computer, twisted-pair feeder, Digital Subscriber Line (DSL) or also being comprised in the defined computer-readable media with wireless mode transmission such as for example infrared, wireless and microwaves from a web-site, server or other remote resource.Described video disc (disk) and disk (disc) comprise Zip disk, radium-shine dish, CD, DVD, floppy disk and Blu-ray Disc, and disk is usually with the magnetic duplication data, and video disc carries out the optical reproduction data with laser usually.Above-mentioned combination also can be included in the computer-readable media.
Above-described embodiment; Purpose, technical scheme and beneficial effect to the utility model have carried out further explain, it should be understood that the above is merely the embodiment of the utility model; And be not used in the protection domain that limits the utility model; All within the spirit and principle of the utility model, any modification of being made, be equal to replacement, improvement etc., all should be included within the protection domain of the utility model.
Claims (10)
1. the RFID label with magnetically sensitive device is characterized in that, two pins are arranged on the chip of said RFID label; Two pins of said magnetically sensitive device and this link to each other; And form parallel-connection structure with the antenna of said RFID label; The variation of external magnetic field intensity can cause magnetically sensitive device voltage or change in current; Logical circuit and a voltage-resistance conversion equipment of a control break-make are arranged on said magnetically sensitive device and circuit that the chip of RFID label is connected, and the circuit of this connection, this logical circuit and this voltage-resistance conversion equipment are the parts of chip, and voltage-resistance conversion equipment is used for converting magnetically sensitive device voltage or change in current to changes in resistance; The break-make of logical circuit determined magnetically sensitive device whether with the sky line parallel: when logical circuit breaks off; Magnetically sensitive device not with the sky line parallel, this moment be placed under certain magnetic field intensity, first resonant frequency and the signal intensity of antenna remain unchanged; When logical circuit was connected, magnetically sensitive device was placed under certain magnetic field intensity with a day line parallel, this moment, and the characteristic frequency of antenna and signal intensity have one at least and change, and this moment, antenna was operated under second resonant frequency; Said RFID label receives the break-make of the instruction of RFID reader transmission with control logic circuit, thereby realizes detecting from the difference between the signal intensity of the different frequency of antenna through comparison the change in magnetic field.
2. according to claim 1 with the RFID label of magnetically sensitive device, it is characterized in that the antenna of said RFID label is a monopole antenna.
3. according to claim 1 with the RFID label of magnetically sensitive device, it is characterized in that the antenna of said RFID label is a double-doublet antenna: said magnetically sensitive device and the voltage that links to each other with this magnetically sensitive device-resistance conversion equipment form parallel-connection structure with antenna wherein; Perhaps said magnetically sensitive device forms parallel-connection structure simultaneously with the voltage that links to each other with this magnetically sensitive device-resistance conversion equipment and two antennas.
4. the RFID label with magnetically sensitive device is characterized in that, a pin is arranged on the chip of said RFID label; One end of said magnetically sensitive device links to each other with this pin; The other end is connected on the antenna of said RFID label; And form parallel-connection structure with antenna; The variation of external magnetic field intensity can cause magnetically sensitive device voltage or change in current; Logical circuit and a voltage-resistance conversion equipment of a control break-make are arranged on said magnetically sensitive device and circuit that the chip of RFID label is connected, and the circuit of this connection, this logical circuit and this voltage-resistance conversion equipment are the parts of chip, and voltage-resistance conversion equipment is used for converting magnetically sensitive device voltage or change in current to changes in resistance; The break-make of logical circuit determined magnetically sensitive device whether with the sky line parallel: when logical circuit breaks off; Magnetically sensitive device not with the sky line parallel, this moment be placed under certain magnetic field intensity, first resonant frequency and the signal intensity of antenna remain unchanged; When logical circuit was connected, magnetically sensitive device was placed under certain magnetic field intensity with a day line parallel, this moment, and the characteristic frequency of antenna and signal intensity have one at least and change, and this moment, antenna was operated under second resonant frequency; Said RFID label receives the break-make of the instruction of RFID reader transmission with control logic circuit, thereby realizes detecting from the difference between the signal intensity of the different frequency of antenna through comparison the change in magnetic field.
5. like the RFID label of the said band magnetically sensitive device of claim 4, it is characterized in that the antenna of said RFID label is a monopole antenna.
6. like the RFID label of the said band magnetically sensitive device of claim 4, it is characterized in that the antenna of said RFID label is a double-doublet antenna: said magnetically sensitive device and the voltage that links to each other with this magnetically sensitive device-resistance conversion equipment form parallel-connection structure with antenna wherein; Perhaps said magnetically sensitive device forms parallel-connection structure simultaneously with the voltage that links to each other with this magnetically sensitive device-resistance conversion equipment and two antennas.
7. RFID label with magnetically sensitive device; It is characterized in that; Said magnetically sensitive device is connected on the antenna of said RFID label; And forming parallel-connection structure with antenna, the variation of external magnetic field intensity can cause magnetically sensitive device voltage or change in current, on said magnetically sensitive device and circuit that antenna is connected, a logical circuit and a voltage-resistance conversion equipment of controlling break-make is arranged; The circuit of this connection, this logical circuit and this voltage-resistance conversion equipment are the parts of chip; Voltage-resistance conversion equipment is used for converting magnetically sensitive device voltage or change in current to changes in resistance, the break-make of logical circuit determined magnetically sensitive device whether with the sky line parallel: when logical circuit breaks off, magnetically sensitive device not with the sky line parallel; Be placed under certain magnetic field intensity this moment, and first resonant frequency and the signal intensity of antenna remain unchanged; When logical circuit was connected, magnetically sensitive device was placed under certain magnetic field intensity with a day line parallel, this moment, and the characteristic frequency of antenna and signal intensity have one at least and change, and this moment, antenna was operated under second resonant frequency; Said RFID label receives the break-make of the instruction of RFID reader transmission with control logic circuit, thereby realizes detecting from the difference between the signal intensity of the different frequency of antenna through comparison the change in magnetic field.
8. like the RFID label of the said band magnetically sensitive device of claim 7, it is characterized in that the antenna of said RFID label is a monopole antenna.
9. like the RFID label of the said band magnetically sensitive device of claim 7, it is characterized in that the antenna of said RFID label is a double-doublet antenna: said magnetically sensitive device and the voltage that links to each other with this magnetically sensitive device-resistance conversion equipment form parallel-connection structure with antenna wherein; Perhaps said magnetically sensitive device forms parallel-connection structure simultaneously with the voltage that links to each other with this magnetically sensitive device-resistance conversion equipment and two antennas.
10. rfid system with magnetically sensitive device, said rfid system comprises RFID label and RFID reader, it is characterized in that,
Said RFID label comprises the RFID label of each said band magnetically sensitive device among the claim 1-3, or the RFID label of each said band magnetically sensitive device among the claim 4-6, or the RFID label of each said band magnetically sensitive device among the claim 7-9;
Said RFID reader sends the break-make of instruction with the logical circuit of control RFID label, thereby detects the change in magnetic field from the difference between the signal intensity of the different frequency of antenna through comparison.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201220257721 CN202600755U (en) | 2012-06-01 | 2012-06-01 | Radio frequency identification device (RFID) label with magnet-sensitive device and RFID system with magnet-sensitive device |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201220257721 CN202600755U (en) | 2012-06-01 | 2012-06-01 | Radio frequency identification device (RFID) label with magnet-sensitive device and RFID system with magnet-sensitive device |
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| CN202600755U true CN202600755U (en) | 2012-12-12 |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110610111A (en) * | 2019-09-16 | 2019-12-24 | 电子科技大学 | Remote passive wireless magnetic field quantity sensing system |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110610111A (en) * | 2019-09-16 | 2019-12-24 | 电子科技大学 | Remote passive wireless magnetic field quantity sensing system |
| CN110610111B (en) * | 2019-09-16 | 2021-01-12 | 电子科技大学 | Remote passive wireless magnetic field quantity sensing system |
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Granted publication date: 20121212 Termination date: 20170601 |