CN201149700Y - Low cost UHF frequency band reader-writer - Google Patents

Abstract

Disclosed is a UHF frequency range read-write device with low cost, which comprises a voltage control oscillator VCO of the UHF frequency range, two microwave mixing detectors (D1, D2), a PIN tube D3, five resistors (R1,R2,R3,R4,R5), a transceiver antenna ANT, a control unit CPU, a microwave power amplification PA, a low-frequency pulse amplifier AMP and a PC; the voltage control oscillator VCO of the UHF frequency range is connected with the control unit CPU through the resistors (R1,R2,R3) and the frequency hopping port of the control unit CPU; meanwhile, the voltage control oscillator VCO of the UHF frequency range is connected with the microwave power amplification PA; the control circuit CPU is connected with a modulation circuit composed of the resistors (R4,R5) and the PIN tube D3; meanwhile, the control unit CPU is in parallel connection with the microwave power amplification PA and the PC respectively; the microwave power amplification PA is connected with the transceiver antenna ANT; the transceiver antenna ANT is connected with the two microwave mixing detectors (D1, D2); the microwave mixing detectors (D1, D2) are connected with the low-frequency pulse amplifier AMP; the low-frequency pulse amplifier AMP is connected with the PC.

Description

A kind of read write line of uhf band cheaply

Technical field

The utility model relates to a kind of read write line, relates in particular to a kind of read write line of uhf band with low cost.

Background technology

The serial read write line of uhf band is one of critical component of RFID industry, and its performance and cost are very big for the popularization influence of RFID.The basic principle of work of various types of read write lines in the market all is the same, different places is mainly reflected in the receive mode of label return signal, because the labeling requirement read write line provides energy to work, the faint signal microwave power emission during returning read write line of label can not be closed like this, therefore the read write line signal receiving circuit must be when very strong microwave signal and faint label return signal be mixed into, can demodulate required label signal, we can say that this is the difficult point of read write line design, the key point place is so the difference of the various scheme of read write line design also mainly concentrates on here.At present common on the market read write line signal receiving circuit mainly contains: one, zero intermediate frequency receive mode (see figure 1), two, six port receive mode (see figure 2)s, three, three kinds of receive modes such as directional couple receive mode (see figure 3).

Its circuit basic functional principle of zero intermediate frequency receive mode is as follows: please refer to (Fig. 1), at first by control module CPU locking transmission frequency, provide adjustable level controling signal APC and amplitude keying modulation signal ASK again, this level controling signal APC and amplitude keying modulation signal ASK are fed out by dual-mode antenna ANT1 through 1,2 ports of microwave power amplifying unit PA1 emission modulated wave power in circulator, and the label utilization is carried out work by the microwave energy that antenna ANT1 feeds out according to instruction.The mode that these read write line data are returned be by the echo on the label through circulator port 3 again through MIX and local oscillation signal mixing, amplify shaping through two-way low-frequency pulse amplifier (AMP1, AMP2) difference again, output I, Q two paths of signals, this I, Q two paths of data signal are sent into the CPU control module at last and upload to host computer PLL after demodulation.The advantage of this scheme is a clear concept, adjusts simply, and shortcoming is that circuit cost is too high.The read write line that reaches 5 meters with operating distance is an example, and only material cost is just near the thousands of units of Renminbi.

Its circuit basic functional principle of six port receive modes is as follows: please refer to (Fig. 2), circuit diagram in this (Fig. 2) is that the circuit diagram remaining circuit of the dotted portion in the replacement (Fig. 1) is constant, the basic functional principle of this circuit is identical with zero intermediate frequency receive mode circuit, and its difference is to utilize MIX mixting circuit and the annular device in microwave mixer detection tube (D1, D2, D3, D4) the replacement zero intermediate frequency receive mode circuit in this circuit.The advantage of this circuit is cost very low (reading/writing distance reaches 5 meters read write line circuit material cost about 300 yuan of Renminbi only), and shortcoming is that circuit structure is difficult for understanding debug difficulties.

Its circuit basic functional principle of directional couple receive mode is as follows: please refer to (Fig. 3), circuit diagram in this (Fig. 3) is that the circuit diagram remaining circuit of the dotted portion in the replacement (Fig. 1) is constant, the basic functional principle of this circuit is identical with zero intermediate frequency receive mode circuit, its difference is to utilize the circulator with in the directional coupler replacement zero intermediate frequency receive mode circuit in this circuit, other principle of work and zero intermediate frequency are basic identical.The advantage of this scheme is that circuit concept is clear, but cost higher (the read write line cost connects nearly 1,000 yuan), and debug difficulties.

More than three kinds of circuit be the main flow scheme and the price of at present homemade uhf band read write line signal receiving circuit, the scheme product that also has some mutation is in market sale, but no matter be any scheme at present, the price of the signal receiving circuit in this kind read write line is the signal receiving circuit in the high frequency read write line all, and this is because the signal receiving circuit functional block price of the read write line of uhf band exceeds the price of HF frequency range and low frequency read write line far away.Scheme from main flow, because the reading/writing distance of UHF is far away, need to solve the problem of many phase mutual interference, equipment requirements frequency hopping, time-sharing work, requirement to the signal receiving circuit functional block is just very high, the assembly cost of a common cover signal receiving circuit functional block reaches more than 40 yuan of Renminbi, also has power amplifier unit, modulating unit, control module and receiving element, the difference of the price of each assembly causes the price of read write line to differ greatly at last, has also directly influenced the marketing and the utilization of the read write line of uhf band.

The utility model content

The technical problems to be solved in the utility model is: the read write line that a kind of uhf band cheaply is provided, the read write line signal receiving circuit functional block material cost of this uhf band has only about 30 yuan of Renminbi, and can connect suitable antenna on this module, its read-write can reach 6 meters passive electronic label farthest.

A kind of read write line of uhf band cheaply, it mainly is made up of voltage controlled oscillator VCO, two microwave mixer detection tubes (D1, D2), PIN pipe D3, five resistance (R1, R2, R3, R4, R5), a dual-mode antenna ANT, a control module CPU, a microwave power amplifying unit PA, a low-frequency pulse amplifier AMP, a PC of a uhf band.

The voltage controlled oscillator VCO of this uhf band is connected with control module CPU by the hop ports of resistance (R1, R2, R3) and control module CPU; The voltage controlled oscillator VCO of this uhf band also links to each other with microwave power amplifying unit PA simultaneously; This control module CPU is connected in the modulation circuit of being made up of resistance (R4, R5), PIN pipe D3; This control module CPU also distinguishes microwave power amplifying unit PA in parallel, PC simultaneously; This microwave power amplifying unit PA links to each other with dual-mode antenna ANT; This dual-mode antenna ANT is connected in two microwave mixer detection tubes (D1, D2); This two microwave mixers detection tube (D1, D2) is connected in low-frequency pulse amplifier AMP; This low-frequency pulse amplifier AMP is connected in PC.

Its basic functional principle is as follows: at first send automatic electric-level control signal APC by control module CPU to microwave power amplifying unit PA, microwave power amplifying unit PA opens subsequently, then by the resistance (R1 of control module CPU by being connected with its hop ports, R2, R3), the voltage controlled oscillator VCO of uhf band is set frequency of operation, control module CPU sends one road amplitude keying modulation signal ASK again and is added to by resistance (R4 subsequently, R5), in the modulation circuit that PIN pipe D3 forms, at this moment modulated microwave signal is launched by dual-mode antenna ANT after amplifying through microwave power amplifying unit PA again.Electronic tag is started working according to the order of modulation after the microwave signal that receives by dual-mode antenna ANT emission.It for example is the Card Reader order, at this moment label emits the data message that carries by the antenna of modulating self, and the dual-mode antenna ANT that connects by read write line receives, read write line at the modulated microwave reflection signal that receives through two microwave mixer detection tube (D1, D2) 90 degree quadrature mixing, demodulate the data of label, amplify through low-frequency pulse amplifier AMP again, shaping is sent into control module CPU again and is deciphered, last control module CPU is uploaded to PC or miscellaneous equipment as requested with the data of decoding, control module CPU turn-offed automatic electric-level control signal APC after all the work of Card Reader was finished, microwave power amplifying unit PA enters dormant state, waits for the arrival of next work period.

Description of drawings

Fig. 1 is the circuit theory diagrams of directional couple receive mode.

Fig. 2 is the circuit theory diagrams of six port receive modes.

Fig. 3 is the circuit theory diagrams of directional couple receive mode.

Fig. 4 is the circuit theory diagrams of the read write line of a kind of uhf band cheaply of the utility model.

Embodiment

See also Fig. 4, a kind of read write line of uhf band cheaply, it mainly is made up of voltage controlled oscillator VCO, two microwave mixer detection tubes (D1, D2), PIN pipe D3, five resistance (R1, R2, R3, R4, R5), a dual-mode antenna ANT, a control module CPU, a microwave power amplifying unit PA, a low-frequency pulse amplifier AMP, a PC of a uhf band.The voltage controlled oscillator VCO of this uhf band is connected with control module CPU by the hop ports of resistance (R1, R2, R3) and control module CPU; The voltage controlled oscillator VCO of this uhf band also links to each other with microwave power amplifying unit PA simultaneously; This control module CPU is connected in the modulation circuit of being made up of resistance (R4, R5), PIN pipe D3; This control module CPU also distinguishes microwave power amplifying unit PA in parallel, PC simultaneously; This microwave power amplifying unit PA links to each other with dual-mode antenna ANT; This dual-mode antenna ANT is connected in two microwave mixer detection tubes (D1, D2); This two microwave mixers detection tube (D1, D2) is connected in low-frequency pulse amplifier AMP; This low-frequency pulse amplifier AMP is connected in PC.

Its basic functional principle is as follows: at first send automatic electric-level control signal APC by control module CPU to microwave power amplifying unit PA, microwave power amplifying unit PA opens subsequently, then by the resistance (R1 of control module CPU by being connected with its hop ports, R2, R3), the voltage controlled oscillator VCO of uhf band is set frequency of operation, control module CPU sends one road amplitude keying modulation signal ASK again and is added to by resistance (R4 subsequently, R5), in the modulation circuit that PIN pipe D3 forms, at this moment modulated microwave signal is launched by dual-mode antenna ANT after amplifying through microwave power amplifying unit PA again.Electronic tag is started working according to the order of modulation after the microwave signal that receives by dual-mode antenna ANT emission.It for example is the Card Reader order, at this moment label emits the data message that carries by the antenna of modulating self, and the dual-mode antenna ANT that connects by read write line receives, read write line at the modulated microwave reflection signal that receives through two microwave mixer detection tube (D1, D2) 90 degree quadrature mixing, demodulate the data of label, amplify through low-frequency pulse amplifier AMP again, shaping is sent into control module CPU again and is deciphered, last control module CPU is uploaded to PC or miscellaneous equipment as requested with the data of decoding, control module CPU turn-offed automatic electric-level control signal APC after all the work of Card Reader was finished, microwave power amplifying unit PA enters dormant state, waits for the arrival of next work period.

Utilize the voltage controlled oscillator VCO of uhf band to replace host computer PLL in the read write line circuit of traditional uhf band in the utility model.The basis that can replace is, carrier wave and reception carrier that label returns are in full accord, though the degree of stability of the voltage controlled oscillator VCO of uhf band is very poor, but emission is almost nil with the carrier wave error that receives in several nanoseconds, and this echoed signal goes out two orders of magnitude than the hot-tempered sound pitch of the phase place of the voltage controlled oscillator VCO of uhf band, and the circuit mixing is separated the timing signal to noise ratio (S/N ratio) and can be met the demands fully.Actual test has also proved this point.The material cost of the voltage controlled oscillator VCO of uhf band has only about 2 yuan of Renminbi, and this is one of the key measure that reduces the read write line of this cost uhf band.

The read-write system communication speed of uhf band is generally all very high, generally can reach 300KHZ, so high speed generally is that the microwave switch (switching speed reaches about 50ns) by special use is modulated microwave signal, such microwave switch market price is at Renminbi about in the of 30 yuan, utilize resistance (R4, R5) and PIN pipe D3 to form modulation circuit in the utility model, purpose is to reduce pulse discharge time, improves modulating pulse speed.On the other hand, electronic tag is when the amplitude keying modulation signal ASK that the reception read write line is sent, require the degree of modulation of amplitude keying modulation signal ASK to get final product greater than 30%, therefore, modulation circuit in the utility model has promptly reduced cost (1 yuan of not enough Renminbi), also can satisfy actual demand simultaneously.

The utility model is not I, the Q two-way way of output on the ordinary meaning that utilizes in the traditional circuit in the data-signal receiving circuit in addition.Its cardinal principle that can handle like this is because the distance of general label and work is near, so its echoed signal is strong, breakpoint is not clearly, under the situation of having saved No. one receiving circuit, cost has also just lowered naturally.Secondly, what adopt in the receiving circuit in the utility model is that 12 NPN3904 (about 1 yuan of total value Renminbi) triode constitutes low-frequency pulse amplifier AMP, replace the such integration module of three similar AT04 (being worth 100 yuan of Renminbi) among traditional low-frequency pulse amplifier AMP, still because the echo of label is stronger, its signal to noise ratio (S/N ratio) is far longer than the input requirement of low-frequency pulse amplifier AMP to the reason that can replace in the utility model.Make the scheme cost of whole receiving circuit be reduced to 1/10th of standard six port receive mode circuit.

The utility model,, can be stablized and read 3 meters with interior label when connecting the 7dBi circular polarized antenna 1 watt of power amplifier output power with the circuit of above lower cost solution design, can reach 6 meters farthest.And the material cost of read write line has only about 50 yuan of Renminbi, and price is 1/5th to 1/10th of like product, and is suitable with the cost of low frequency card reader.

Claims (4)

1, a kind of read write line of uhf band cheaply, it mainly is made up of voltage controlled oscillator VCO, two microwave mixer detection tubes (D1, D2), PIN pipe D3, five resistance (R1, R2, R3, R4, R5), a dual-mode antenna ANT, a control module CPU, a microwave power amplifying unit PA, a low-frequency pulse amplifier AMP, a PC of a uhf band, and it is characterized in that: the voltage controlled oscillator VCO of this uhf band is connected with control module CPU by the hop ports of resistance (R1, R2, R3) and control module CPU; The voltage controlled oscillator VCO of this uhf band also links to each other with microwave power amplifying unit PA simultaneously; This control module CPU is connected in the modulation circuit of being made up of resistance (R4, R5), PIN pipe D3; This control module CPU also distinguishes microwave power amplifying unit PA in parallel, PC simultaneously; This microwave power amplifying unit PA links to each other with dual-mode antenna ANT; This dual-mode antenna ANT is connected in two microwave mixer detection tubes (D1, D2); This two microwave mixers detection tube (D1, D2) is connected in low-frequency pulse amplifier AMP; This low-frequency pulse amplifier AMP is connected in PC.

2, the read write line of a kind of uhf band cheaply according to claim 1, it is characterized in that: the amplitude keying modulation signal ASK that automatic electric-level control signal APC that sends to microwave power amplifying unit PA via control module CPU and control module CPU send to the modulation circuit of being made up of resistance (R4, R5), PIN pipe D3, after microwave power amplifying unit PA amplification, launch by dual-mode antenna ANT again.

3, the read write line of a kind of uhf band cheaply according to claim 1 is characterized in that: control module CPU sets frequency of operation by the resistance (R1, R2, R3) that is connected with its hop ports, the voltage controlled oscillator VCO of uhf band.

4, the read write line of a kind of uhf band cheaply according to claim 1, it is characterized in that: the data message that read write line returns on receiving by label demodulates data on the label through 90 degree quadrature mixing of two microwave mixer detection tubes (D1, D2), again through low-frequency pulse amplifier AMP amplify, shaping sends into control module CPU again and deciphers.

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