CN111860018A - An RFID reading device with intelligent change of emission frequency - Google Patents

Abstract

The invention provides an RFID reading device with an intelligent change in transmission frequency, including a controller, a frequency converter and a frequency combiner. The input end of the controller is connected to a frequency generator in the reading device, and the output end of the controller is connected to the frequency converter. The output end of the frequency converter is connected with the frequency combiner, the input end of the frequency combiner is also connected with a pairing control circuit and a wake-up circuit, and the output end of the frequency combiner is connected with the transceiver integrated machine, which is installed on the transceiver integrated machine. There are antennas, and multiple groups of frequency generating circuits are arranged on the frequency generator; in the present invention, a plurality of radio frequency circuits are arranged in the same reader, and receiving signals of different frequencies can be sent out through the radio frequency circuits, so that the RFID tags in the area are It can be quickly identified, making the reader device more intelligent and changeable, improving the application scope of the reader, improving the industry restriction of one card and one use, and accelerating the reader's dominant position in the RFID industry.

Description

An RFID reading device with intelligent change of emission frequency

technical field

The invention relates to the technical field of radio frequency identification, in particular to an RFID reading device with an intelligent change in emission frequency.

Background technique

Radio Frequency Identification (RFID) is the abbreviation of Radio Frequency Identification. Its principle is to carry out non-contact data communication between the reader and the tag to achieve the purpose of identifying the target. RFID is widely used. Typical applications include animal chips and car chips. equipment, access control, parking lot control, production line automation, material management. Radio frequency identification technology does not contact fast information exchange and storage technology through radio waves, combines data access technology through wireless communication, and then connects to the database system to achieve non-contact two-way communication, thereby achieving the purpose of identification, for data exchange, A very complex system is connected in series. In the identification system, the reading, writing and communication of electronic tags are realized through electromagnetic waves. According to the communication distance, it can be divided into near field and far field. For this reason, the data exchange method between the read/write device and the electronic tag is correspondingly divided into load modulation and backscatter modulation.

At present, except for the reader device used in remote tracking, which has a variable frequency, the others are reading devices with a certain frequency, which is limited to the difference in the distance and parameters of the RFID tag used, especially now that the RFID technology has not been fully Mature, no unified protocol has been formed. At least five known protocols are widely used, which means that different RFID standards are defined in these protocols. When using a reader under the framework of a protocol When the device is working, the device can only identify the RFID tags under the framework of this protocol. However, with the continuous updating of technology, the scope of RFID applications is getting wider and wider. With the development of the industry, the number of RFID tags has little impact on the industry, and the limitations of the reader equipment directly lead to the obstruction of the development of the industry. With the advent of the intelligent society, RFID under different framework agreements needs a Supports reader devices under a variety of different protocol frameworks, which is directly reflected in the control of the RFID frequency by the reader device. By controlling the frequency of the RFID reader device, it can match different standards under different protocol frameworks. The frequency, which is high frequency, medium frequency or low frequency, and intelligent identification only in one type of frequency is the technical problem to be solved by the present invention.

SUMMARY OF THE INVENTION

The present invention aims to provide an RFID reading device with intelligently changing transmission frequency that overcomes the above problems or at least partially solves the above problems, so as to solve the problem that the reader device cannot switch frequencies in high frequency or low frequency under different protocol frameworks .

In order to achieve the above object, the technical scheme of the present invention is specifically realized in this way:

The present invention provides an RFID reading device with an intelligent change in transmission frequency, including a controller, a frequency converter and a frequency combiner. The input end of the controller is connected to a frequency generator in the reading device, and the output end of the controller is connected to The frequency converter is connected, the output end of the frequency converter is connected with the frequency combiner, the input end of the frequency combiner is also connected with a pairing control circuit and a wake-up circuit, and the output end of the frequency combiner is connected with the transceiver integrated machine. An antenna is installed, a plurality of frequency generating circuits are arranged on the frequency generator, and each frequency generating circuit is independent of each other, the frequency generating circuits are all arranged in parallel in the reading device, and each frequency generating circuit is connected in series with a resistor, an inductance and Capacitance, and the parameters of resistance, inductance and capacitance in each group of frequency generating circuits are different to transmit different frequencies. The radio frequency signal of the reader is coupled with the radio frequency circuit of the tag to produce the function of reading the code. The frequency generating circuit The capacitors in each are individually connected to the RF circuit.

As a further solution of the present invention, the controller is provided with a control circuit, the control circuit is used to manage multiple groups of frequency-transmitting signals, and the control circuit classifies the radio-frequency signals generated by the frequency generator through the control circuit to form a corresponding number of frequency generating circuits signal channel.

As a further solution of the present invention, the frequency converter is an amplifying mechanism of the frequency generator circuit, and the frequency converter is started under the action of transmission over a large distance.

As a further solution of the present invention, the frequency combiner is to filter and cut off the multi-channel radio frequency in the frequency combiner, and a pairing control circuit is arranged outside the frequency combiner, and the pairing control circuit accurately transmits the signal obtained from the tag to the frequency combiner. frequency converter.

As a further solution of the present invention, the pairing control circuit is connected to the wake-up circuit through a frequency combiner, and the wake-up circuit is simultaneously connected to the frequency combiner and the pairing control circuit, and the pairing control circuit pre-transmits successively decreasing frequencies.

As a further solution of the present invention, the wake-up circuit is connected with direct current.

As a further solution of the present invention, the wake-up circuit wakes up the frequency combiner when the frequency generator generates multiple frequencies.

As a further solution of the present invention, the integrated transceiver transmits the frequency accurately screened in the frequency combiner through the antenna, and receives the matching frequency from the tag.

The invention provides an RFID reading device with an intelligent change in emission frequency, and the beneficial effects are: the reader device of the invention can identify RFID tags under different protocol frameworks in the same use environment, that is, through the change of frequency, it can be realized in different protocols Switching between, the present invention sets up multiple radio frequency circuits in the same reader, and can send receiving signals of different frequencies through the radio frequency circuit, so that the RFID tags in the area can be quickly identified, according to the different scope of use The frequency conversion circuit can also be added, so that the frequency of the reader device is not unchanged, and the recognition ability of the reader can be adjusted according to the progress of technology. The combination of these two methods greatly improves the intelligent recognition performance of the reader device. The RFID tag with a unique code can be recognized by the reader device, making the reader device more intelligent and changeable, improving the application scope of the reader, improving the industry restriction of one card and one use, and speeding up the reader's use in the RFID industry. leading position.

Description of drawings

In order to illustrate the technical solutions of the embodiments of the present invention more clearly, the following briefly introduces the accompanying drawings used in the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can also be obtained from these drawings without any creative effort.

FIG. 1 is a frame diagram of an internal information transmission frame of a reading device provided by an embodiment of the present invention.

FIG. 2 is a schematic diagram of an information transmission circuit between a reading device and a label according to an embodiment of the present invention.

FIG. 3 is a schematic diagram of a wireless radio frequency circuit according to an embodiment of the present invention.

Detailed ways

Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be embodied in various forms and should not be limited by the embodiments set forth herein. Rather, these embodiments are provided so that the present disclosure will be more thoroughly understood, and will fully convey the scope of the present disclosure to those skilled in the art.

Referring to FIG. 1-FIG. 3, an RFID reading device with an intelligently changing transmission frequency provided by an embodiment of the present invention includes a controller, a frequency converter and a frequency combiner, and the input end of the controller is connected to a frequency generator in the reading device, The output end of the controller is connected with the frequency converter, the output end of the frequency converter is connected with the frequency combiner, the input end of the frequency combiner is also connected with a pairing control circuit and a wake-up circuit, and the output end of the frequency combiner is connected with the transceiver integrated machine. An antenna is installed on the all-in-one machine, and multiple sets of frequency generating circuits are set on the frequency generator, and each frequency generating circuit is independent of each other. Inductance and capacitance, and the parameters of resistance, inductance and capacitance in each group of frequency generating circuits are different to transmit different frequencies. The radio frequency signal of the reader is coupled with the radio frequency circuit of the tag to produce the function of reading the code. The capacitors in the generating circuit are all connected with the radio frequency circuit separately. Therefore, the function of the frequency generating circuit is independent and does not interfere with each other, so that a reading device can send out receiving signals of various frequencies, so that the correct Identifying RFID tags entering the location allows one reader to be used for multiple purposes.

Preferably, a control circuit is provided in the controller, and the control circuit is used to manage multiple groups of frequency-transmitting signals. The control circuit classifies the radio-frequency signals generated by the frequency generator through the control circuit to form a signal channel corresponding to the number of frequency generating circuits. When the RF signal is transmitted over a long distance, the signal is weak, and the multiple groups of RF signals are amplified by the frequency converter.

Preferably, the frequency converter is an amplifying mechanism of the frequency generator circuit. The amplifying circuit is the same as the Q2 amplifying circuit in Figure 3. The frequency converter adjusts and amplifies the signals of different frequencies according to the collected situation, or can be used directly without amplification. The frequency converter is a The structure is selected, and the frequency converter is usually used under the action of transmission over a large distance.

Preferably, the frequency combiner is to filter and cut off the multi-channel radio frequency in the frequency combiner, and a pairing control circuit is arranged outside the frequency combiner, and the pairing control circuit accurately transmits the signal obtained from the tag to the frequency combiner, so as to be Select the frequency suitable for the tag in the frequency converter, and cancel other non-matching frequencies to achieve the purpose of intelligent selection.

Preferably, the pairing control circuit is connected to the wake-up circuit through a frequency combiner, the wake-up circuit is connected to the frequency combiner and the pairing control circuit at the same time, and the pairing control circuit transmits successively decreasing frequencies in advance. GHz, 5.8GHz, low frequency of 125KHz, 13.56MKHz, etc. This kind of conversion from high to low is not in high frequency and low frequency. It is a change from high to low for the high frequency and low frequency ranges specified under different protocol frameworks. The surrounding tags are scanned to pair with similar tag frequencies.

Preferably, the wake-up circuit is connected to direct current, and the direct current has the function of storing electricity, which is continuously charged when connected to the power source, and provides power for the paired control circuit entering the working state, so as to keep it continuously working with low energy consumption.

Preferably, when the frequency generator generates multiple frequencies, the wake-up circuit wakes up the frequency combiner to make it enter the working state.

Preferably, the integrated transceiver transmits the accurately screened frequency in the frequency combiner through the antenna, and receives the matching frequency from the tag, so that the reading device and the tag have mutual information transmission.

As shown in Figure 2, the basic principle of the RF antenna is a series RLC circuit, which is composed of a resistor R, an inductor L, and a capacitor C connected in series. The function to be realized is to convert the input square wave into a sine signal on the RF antenna L. The sinusoidal signal excites the alternating magnetic field in the air to achieve the purpose of radio frequency. In order to prevent the frequencies of multiple groups of frequency generating circuits from interfering with each other, impedances are set in the frequency generating circuits. When the inductive reactance is greater than the capacitive reactance, it is greater than When the inductive reactance is less than 0, the circuit is capacitive; when the inductive reactance is equal to the capacitive reactance, the impedance in the circuit is neither capacitive nor inductive, but only purely resistive. At this time, the impedance Z=R, the impedance angular current I=I(max), that is, the inductive reactance=capacitive reactance, the RF antenna works in a fully resonant state, the impedance value is the smallest at this time, the working current on the RF antenna is the largest, and the resulting RF signal strength It is also the strongest. In general, the impact of environmental interference on the RFID system is concentrated on the three parameters of the resistance R, inductance L, and capacitance C of the radio frequency antenna. In practical applications, the resistance R and capacitance C of the radio frequency antenna are The SMD components are soldered on the circuit board, and the environment has little effect on them. The alternating magnetic field generated by the RF antenna inductance L will be affected by the flowing medium or metal in the environment. The effect is equivalent to the original RFID system without the environment. In the case of interference, the equivalent inductance value L of the radio frequency antenna changes.

When the radio frequency antenna is disturbed by the environment, the inductive reactance of the radio frequency antenna changes greatly, resulting in the inductive reactance≠capacitive reactance. The final result is the impedance current I≠I(max), the resonance frequency of the radio frequency antenna changes, and the new value After being affected by environmental factors, the new resonance frequency and the new equivalent inductance value, if the working frequency of the RF antenna remains unchanged, that is, equal to the original resonance frequency, the RIFD system works in a non-resonant state, and the impedance of the RF antenna increases. The working current on the radio frequency antenna is reduced, and the strength of the generated radio frequency signal is weakened, resulting in failure of normal communication. Therefore, to ensure the normal operation of RFID, it is necessary to dynamically adjust the working frequency of the RF antenna to keep the working frequency consistent with the changing resonant frequency, so that the RIFD system works in a resonance state and the RF antenna transmits the maximum power.

As shown in Figure 3, Q1 is a common-emitter transformer-coupled oscillator circuit, and the load is the coil of the transformer T. After the collector output signal is coupled by T, it is sent to the base from the secondary through C1 to form a positive feedback, start-up, base At the same time, a low-frequency modulation signal is sent to perform amplitude modulation on the generated high-frequency oscillation. Q2 makes the buffer amplifier stage, the output of Q1 is coupled to the base of Q2 through C3, L1 is the load inductance of Q2, and is sent to the antenna for transmission through the C4/L2 series resonant circuit, R2 is grounded, that is, zero offset, due to the amplitude of the input signal It is larger and uses the C4/L2 resonant circuit to select the frequency, so it is not afraid of distortion and has high efficiency. There are connection points at T, L1 and DC. Since the base has no DC bias, the circuit works in class C amplification. The phase between the primary and secondary of T is opposite, that is, the increase of the collector current of Q1 is the primary of T. The induced electromotive force is positive on the right and negative on the left, and the secondary produces a positive electromotive force on the left and negative on the right, which increases the charging current of C1. When the collector current decreases, it is the opposite of the above situation. The frequency is determined by the capacity of C1 and the inductance of T.

The above are merely examples of the present application, and are not intended to limit the present application. Various modifications and variations of this application are possible for those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of this application shall be included within the scope of the claims of this application.

Claims (8)

1. a kind of RFID reading equipment that transmits frequency intelligently changes, it is characterized in that, comprise controller, frequency converter and frequency combiner, described controller input end is connected with the frequency generator in the reading equipment, the output end of described controller It is connected with the frequency converter, the output end of the frequency converter is connected with the frequency combiner, the input end of the frequency combiner is also connected with a pairing control circuit and a wake-up circuit, and the output end of the frequency combiner is connected with the transceiver integrated machine. An antenna is installed on the machine, and there are multiple sets of frequency generating circuits on the frequency generator, and each frequency generating circuit is independent of each other. Capacitance, and the parameters of the resistance, inductance and capacitance in each group of frequency generating circuits are different to transmit different frequencies. The radio frequency signal of the reader is coupled with the radio frequency circuit of the tag, and the capacitors in the frequency generating circuit are connected separately with RF circuit. 2. The RFID reading device with intelligent change in transmission frequency according to claim 1, wherein the controller is provided with a control circuit, the control circuit is used to manage multiple groups of frequency-transmitting signals, and the control circuit generates the frequency generator by the control circuit. The radio frequency signal is classified by the control circuit to form a signal channel corresponding to the number of frequency generating circuits. 3 . The RFID reading device with intelligently changing transmission frequency according to claim 1 , wherein the frequency converter is an amplification mechanism of the frequency generator circuit, and the frequency converter is activated under the transmission effect of a relatively large distance. 4 . 4. The RFID reading device with intelligent change in transmission frequency according to claim 1, wherein the frequency combiner is to screen and cut off multiple radio frequencies in the frequency combiner, and the frequency combiner is provided with a pairing control outside the frequency combiner circuit, the pairing control circuit will accurately transmit the signal obtained from the tag to the frequency combiner. 5. The RFID reading device of claim 1, wherein the pairing control circuit is connected to the wake-up circuit through a frequency combiner, and the wake-up circuit is connected to the frequency combiner and the pairing control circuit at the same time, and the pairing control circuit The circuit pre-transmits successively decreasing frequencies. 6. The RFID reading device of claim 1, wherein the wake-up circuit is connected to a direct current. 7 . The RFID reading device of claim 1 , wherein the wake-up circuit wakes up the frequency combiner when the frequency generator generates multiple frequencies. 8 . 8 . The RFID reading device with intelligently changing transmission frequency according to claim 1 , wherein the integrated transceiver transmits the frequency accurately screened in the frequency combiner through the antenna, and receives the matching frequency from the tag. 9 .

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