CN106650543A - Blind spot-resistant phase-shift transmission network system and method - Google Patents
Blind spot-resistant phase-shift transmission network system and method Download PDFInfo
- Publication number
- CN106650543A CN106650543A CN201710073469.1A CN201710073469A CN106650543A CN 106650543 A CN106650543 A CN 106650543A CN 201710073469 A CN201710073469 A CN 201710073469A CN 106650543 A CN106650543 A CN 106650543A
- Authority
- CN
- China
- Prior art keywords
- phase
- signal
- blind spot
- unit
- label
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Classifications
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06K—GRAPHICAL DATA READING; PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS
- G06K7/00—Methods or arrangements for sensing record carriers, e.g. for reading patterns
- G06K7/10—Methods or arrangements for sensing record carriers, e.g. for reading patterns by electromagnetic radiation, e.g. optical sensing; by corpuscular radiation
- G06K7/10009—Methods or arrangements for sensing record carriers, e.g. for reading patterns by electromagnetic radiation, e.g. optical sensing; by corpuscular radiation sensing by radiation using wavelengths larger than 0.1 mm, e.g. radio-waves or microwaves
- G06K7/10366—Methods or arrangements for sensing record carriers, e.g. for reading patterns by electromagnetic radiation, e.g. optical sensing; by corpuscular radiation sensing by radiation using wavelengths larger than 0.1 mm, e.g. radio-waves or microwaves the interrogation device being adapted for miscellaneous applications
- G06K7/10475—Methods or arrangements for sensing record carriers, e.g. for reading patterns by electromagnetic radiation, e.g. optical sensing; by corpuscular radiation sensing by radiation using wavelengths larger than 0.1 mm, e.g. radio-waves or microwaves the interrogation device being adapted for miscellaneous applications arrangements to facilitate interaction with further interrogation devices, e.g. such that at least two interrogation devices may function and cooperate in a network of such devices
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06K—GRAPHICAL DATA READING; PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS
- G06K17/00—Methods or arrangements for effecting co-operative working between equipments covered by two or more of main groups G06K1/00 - G06K15/00, e.g. automatic card files incorporating conveying and reading operations
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06K—GRAPHICAL DATA READING; PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS
- G06K7/00—Methods or arrangements for sensing record carriers, e.g. for reading patterns
- G06K7/10—Methods or arrangements for sensing record carriers, e.g. for reading patterns by electromagnetic radiation, e.g. optical sensing; by corpuscular radiation
- G06K7/10009—Methods or arrangements for sensing record carriers, e.g. for reading patterns by electromagnetic radiation, e.g. optical sensing; by corpuscular radiation sensing by radiation using wavelengths larger than 0.1 mm, e.g. radio-waves or microwaves
- G06K7/10366—Methods or arrangements for sensing record carriers, e.g. for reading patterns by electromagnetic radiation, e.g. optical sensing; by corpuscular radiation sensing by radiation using wavelengths larger than 0.1 mm, e.g. radio-waves or microwaves the interrogation device being adapted for miscellaneous applications
- G06K7/10376—Methods or arrangements for sensing record carriers, e.g. for reading patterns by electromagnetic radiation, e.g. optical sensing; by corpuscular radiation sensing by radiation using wavelengths larger than 0.1 mm, e.g. radio-waves or microwaves the interrogation device being adapted for miscellaneous applications the interrogation device being adapted for being moveable
- G06K7/10386—Methods or arrangements for sensing record carriers, e.g. for reading patterns by electromagnetic radiation, e.g. optical sensing; by corpuscular radiation sensing by radiation using wavelengths larger than 0.1 mm, e.g. radio-waves or microwaves the interrogation device being adapted for miscellaneous applications the interrogation device being adapted for being moveable the interrogation device being of the portable or hand-handheld type, e.g. incorporated in ubiquitous hand-held devices such as PDA or mobile phone, or in the form of a portable dedicated RFID reader
Landscapes
- Physics & Mathematics (AREA)
- Engineering & Computer Science (AREA)
- Health & Medical Sciences (AREA)
- Toxicology (AREA)
- General Physics & Mathematics (AREA)
- Theoretical Computer Science (AREA)
- Electromagnetism (AREA)
- General Health & Medical Sciences (AREA)
- Artificial Intelligence (AREA)
- Computer Vision & Pattern Recognition (AREA)
- Near-Field Transmission Systems (AREA)
Abstract
The invention provides a blind spot-resistant phase-shift transmission network system and method. The system comprises a forward transmitting unit, a directional coupler, a phase-shift unit and a reverse demodulation unit, which are connected in sequence; the forward transmitting unit is used for providing a forward signal transmitted to a label; the directional coupler is used for taking out forward and backward signals; a coupled forward signal passes through the phase-shift unit, and then provides an intrinsic signal for a mixer; a coupled backward signal is fed into the miser to demodulate; the phase-shift unit is used for switching two phases in 90 Deg; and the reverse demodulation unit is used for processing a reverse baseband signal output by mixing. The blind spot-resistant phase-shift transmission network system and method provided by the invention have the advantages of being small, low in power consumption and cost, simple in circuit, easy to debug and the like; therefore, the blind spots of a reader-writer can be reduced; and coverage is enlarged.
Description
Technical field
The invention belongs to communication technical field, more particularly, to the phase shift transfers net system and method for a kind of anti-blind spot.
Background technology
Current radio frequency identification (RFID) industry development is very fast, all opens in multiple fields such as traffic, logistics, monitoring
Beginning is widely used.RFID system is made up of read write line, reading and writing device antenna and label.Read write line transmits signals to label, mark
Reflected signal is signed again to reading and writing device antenna, a complete communication link is formed.Read write line substantially divides according to different using scene
For outdoor version read write line, desktop type read write line and hand-held read-write.Outdoor version read write line is primarily targeted for checking at a distance,
Reading and writing, thus it is higher to the performance requirement of read write line；Desktop type read write line is mainly responsible for the work such as the distribution and initialization of label,
Because main application scenarios are defined in desktop closely hair fastener, therefore to the less demanding of performance, but should have miniaturization, low cost
Advantage.Hand-held read-write is primarily targeted for that traffic police is hand-held to be used, and requires that read write line should have low-power consumption, miniaturization under the scene
The characteristics of.Read write line is demodulated the signal that label is returned, but because of the position relationship between label and reading and writing device antenna, typically
For can all there is blind spot.
Because read write line adopts passive label, therefore label provides energy by read write line.Read write line sends the life for checking label
After order, continue as label and energy is provided, and wait tag backscatter signal.Now label is entered using the energy that read write line is provided
Row power supply is simultaneously communicated by the way of backscattering read write line signal with read write line.Because label is adjusted by the way of scattering
System, then read write line should being demodulated using synchronous detection.Because label is different from the position of reading and writing device antenna and environment is complicated etc.
Deng factors, there is certain phase difference in the back-scattered signal of label with the local oscillation signal of read write line itself.Ordinary circumstance
Down blind spot can be overcome by the way of I/Q demodulation.But I/Q demodulation chips often power consumption larger (generally requiring 200-300mA), valency
Lattice are higher.Much room will be taken if oneself building, is not suitable for desktop type and hand-held read-write is compact and low-power consumption
Require.
The content of the invention
In view of this, it is contemplated that proposing a kind of phase shift transfers net system of anti-blind spot, to reduce the blind of read write line
Point, improves and covers.
To reach above-mentioned purpose, the technical scheme is that what is be achieved in that：
A kind of phase shift transfers net system of anti-blind spot, including the forward emitted unit, directional coupler, the shifting that are sequentially connected
Facies unit, reverse demodulating unit；
The forward emitted unit is used to provide the forward signal to label transmitting；
The directional coupler is used to take out front reverse signal, and the forward signal being coupled to is mixed after phase-shifting unit
Frequency device provides local oscillation signal, and the reverse signal being coupled to is sent into frequency mixer and is demodulated；
The phase-shifting unit is used for the phase place of two 90 ° of differences of switching；
The reverse demodulating unit is used to process the reverse baseband signal of mixing output.
Further, the forward emitted unit includes that the PLL being sequentially connected, low-noise amplifier, modulator, power are put
Big device.
Further, the phase-shifting unit includes that two-route wire length differs the microstrip line and two RF switches of λ/4.
Relative to prior art, a kind of phase shift transfers net system of anti-blind spot of the present invention has the advantage that：
(1) a kind of phase shift transfers net system of anti-blind spot of the present invention has miniaturization, low-power consumption, low cost,
Circuit is simple, debug the advantage such as easy, so as to reduce the blind spot of read write line, improves covering；
(2) the single frequency mixer demodulation of phase-shifting unit collocation of the present invention, can be substantially reduced PCB surface product, reduces cost, contracting
Small size；
(3) phase-shifting unit of the present invention welds the resistance of diverse location using fan-shaped resistance pose pattern by choosing,
Realize the purpose of easily debugging line length.
Another object of the present invention is to a kind of phase shift transmission method of anti-blind spot is proposed, to reduce the blind spot of read write line,
Improve and cover.
In order to achieve the above object, the technical scheme is that what is be achieved in that：
A kind of phase shift transmission method of anti-blind spot, comprises the steps：
(1) what read write line received that user sends checks after instruction, and by forward emitted unit stabilized carrier is provided, and passes through
Modulator is modulated to base band commands signal, up-conversion to 920-925MHz；
(2) sent after dependent instruction, continued to provide tone signal, for label power is provided, label has received read write line
After the forward signal sent, responded according to the coded system and speed of agreement, by the side for scattering read write line forward signal
Formula is modulated to signal；
(3) read write line single-tone is provided while etc. the data that return of label to be demodulated, specify to lead code according to agreement
Matched, if successfully decoded, reported client, complete once to interact；
(4) if read write line decoding failure, by the switch of two single-pole double throws in control phase-shifting unit, another kind of phase of switching
Position, so as to re-start again to 90 ° of local oscillator phase shift trials is checked, solution blind spot.
The phase shift transmission network system of a kind of phase shift transmission method of anti-blind spot of the present invention and a kind of above-mentioned anti-blind spot
System has identical beneficial effect, will not be described here.
Description of the drawings
The accompanying drawing for constituting the part of the present invention is used for providing a further understanding of the present invention, the schematic reality of the present invention
Apply example and its illustrate, for explaining the present invention, not constituting inappropriate limitation of the present invention.In the accompanying drawings：
Fig. 1 is the structural representation of the phase difference described in the embodiment of the present invention；
Fig. 2 is the structural representation of the phase shift transfers net system of a kind of anti-blind spot described in the embodiment of the present invention；
Fig. 3 is the structural representation of the phase-shifting unit described in the embodiment of the present invention；
Fig. 4 is that the resistance described in the embodiment of the present invention puts schematic diagram.
Specific embodiment
It should be noted that in the case where not conflicting, the embodiment and the feature in embodiment in the present invention can phase
Mutually combination.
In describing the invention, it is to be understood that term " " center ", " longitudinal direction ", " horizontal ", " on ", D score,
The orientation or position relationship of the instruction such as "front", "rear", "left", "right", " vertical ", " level ", " top ", " bottom ", " interior ", " outward " is
Based on orientation shown in the drawings or position relationship, it is for only for ease of the description present invention and simplifies description, rather than indicates or dark
Showing the device or element of indication must have specific orientation, with specific azimuth configuration and operation therefore it is not intended that right
The restriction of the present invention.Additionally, term " first ", " second " etc. are only used for describing purpose, and it is not intended that indicating or implying phase
To importance or the implicit quantity for indicating indicated technical characteristic.Thus, the feature for defining " first ", " second " etc. can
To express or implicitly include one or more this feature.In describing the invention, unless otherwise stated, " multiple "
It is meant that two or more.
In describing the invention, it should be noted that unless otherwise clearly defined and limited, term " installation ", " phase
Company ", " connection " should be interpreted broadly, for example, it may be being fixedly connected, or being detachably connected, or be integrally connected；Can
Being to be mechanically connected, or electrically connect；Can be joined directly together, it is also possible to be indirectly connected to by intermediary, Ke Yishi
The connection of two element internals.For the ordinary skill in the art, above-mentioned term can be understood by concrete condition
Concrete meaning in the present invention.
Below with reference to the accompanying drawings and in conjunction with the embodiments describing the present invention in detail.
The present invention is employed the following technical solutions to overcome blind spot：
Herein using AM come the scattering of approximate analysis label.Assume the signal that read write line is returned after label modulation through orientation
Coupler is superimposed with the leakage signal of forward direction to be obtained：
Vrev=Vm*(ma*cosΩt)*cos ωct+Vm*cos(ωct+θ)
Wherein θ is the phase difference of the carrier wave that label is returned and directional coupler leakage signal
Local oscillation signal is：
Vlo=cos (ωct+φ)
Wherein φ is the phase difference of the local oscillation signal of the carrier wave that label is returned and frequency mixer
Into frequency mixer demodulation after and filter high frequency and direct current, obtain:
Wherein cos ΩtFor the data that label returns to read write line
As can be seen here, the amplitude of the signal after demodulation is returned with label carrier wave and the phase difference of the local oscillation signal of frequency mixer
φ is directly proportional.
If the two phase difference is 0 °, cos0 °=1, read write line demodulation obtains maximum amplitude, as phase difference is increased to
90 ° (cos90 °=0), the reverse signal that demodulation is obtained is less and less, until there is vanishing, blind spot occurs.If now made
With λ/4 (quarter-wave) transmission line, phase shift is carried out to local oscillator, you can so that script phase difference becomes 180 ° for 90 °, formed
Maximum.
To sum up, such as Fig. 1, if phase difference drops into shadow region, you can phase-shifting unit is selected into quarter-wave
Transmission line so that phase difference leaves shadow region.Two phase places mutually switch and are capable of achieving baseband signal that demodulation obtains all the time
It is more than(being approximately equal to 0.707) demodulated signal again.
Whole system is divided into forward emitted unit, directional coupler, phase-shifting unit, reverse demodulating unit.Block diagram such as Fig. 2：
Forward emitted unit：It is made up of PLL, low-noise amplifier, modulator, power amplifier etc..Mainly responsible offer
To the forward signal (transmission is checked order or sends single-tone and provides energy for label) of label transmitting.
Directional coupler：Front reverse signal is taken out using directional coupler, (read write line sends the forward signal being coupled to
Signal) provide local oscillation signal for frequency mixer after phase-shifting unit, the reverse signal that is coupled to (signal that label is returned) send
Enter frequency mixer to be demodulated.
Phase-shifting unit：Phase-shifting unit is made up of the microstrip line and two RF switches that two-route wire length differs λ/4, such as Fig. 3.Root
According to the line length of the quarter-wave microstrip line that respective frequencies are calculated using the dielectric constant of pcb board material, but actually make
The change due to dielectric constant or the compatibility of frequency range with, it may be necessary to the length of microstrip line is finely tuned, using sector in the present invention
Resistance pose pattern, by the resistance of choosing weldering diverse location, realize the purpose of easily debugging line length, such as Fig. 4.It is final changeable
The phase place of two 90 ° of differences reaches the purpose for reducing blind spot.
Reverse demodulating unit：Filtering etc., last collection analysis are amplified to the reverse baseband signal of mixing output.
Receive that user sends checks after (reading and writing) instruction, provides stabilized carrier by forward emitted unit first, leads to
Ovennodulation device is modulated to base band commands signal, up-conversion to 920-925MHz.
After having sent dependent instruction, continue to provide tone signal, for label power is provided.Now label receives read write line
After the forward signal sent, responded according to the coded system and speed of agreement, by the side for scattering read write line forward signal
Formula is modulated to signal.
Read write line single-tone is provided while etc. the data that return of label to be demodulated.Lead code is carried out according to agreement regulation
Matching.If successfully decoded, client is reported, complete once to interact.
If read write line decoding failure, by the switch of two single-pole double throws in control phase-shifting unit, another kind of phase place of switching, from
And 90 ° of local oscillator phase shift is re-started again and is checked (reading and writing) and is attempted (repeating carries out above-mentioned steps), solve the problems, such as blind spot.
Present invention is mainly applied in hand-held read-write and desktop type read write line, label position and day in actual use
Line position (several milliseconds) before and after phase shift will not change, and must once be more than in phase shift twice(being approximately equal to 0.707)
Maximum again.So as to overcome blind spot problem.
The present invention is capable of achieving：
Low-power consumption：The alternative device of I/Q modulators is limited, and to ensure that inside is mixed wanting for the power to local oscillator
Ask, generally all integrated internal radio frequency amplifier is amplified to local oscillator, and power consumption is not suitable for adopting battery generally in 200mA or so
Hand-held read-write.And read write line radio-frequency power itself is higher, local oscillation power, can directly using passive mixed without the need for individually amplifying
Frequency device.The frequency mixer adopted in the present invention belongs to passive frequency mixer, will not consume dc power.
Low cost, easily debugging：The Material Cost of frequency mixer is more much smaller than i/q demodulator, and without the need for power supply, substantially reduces
BOM costs.In practical application, such as Fig. 4, using fan-shaped resistance pose pattern, by the resistance of choosing weldering diverse location, is realized
Easily debug the purpose of line length.
Miniaturization：Demodulated using single channel frequency mixer, it will cause blind spot problem to solve.And the I/ built using oneself
Q demodulators can take very large area again.Using the single frequency mixer demodulation of the phase shifter element collocation of the present invention, PCB can be substantially reduced
Area, reduces cost reduces volume.
P1dB compression points are high：Frequency mixer is widely used, and alternative material is very more, and P1dB compression points are high.Due to reading
Write that device relative power is larger, the echo of antenna and inner link will be reflexed on demodulator, held using common i/q demodulator
By high-power input i/q demodulator will be caused to compress, nonlinearity product increases, so as to affect the demodulation of read write line.
Presently preferred embodiments of the present invention is the foregoing is only, not to limit the present invention, all essences in the present invention
Within god and principle, any modification, equivalent substitution and improvements made etc. should be included within the scope of the present invention.
Claims (4)
1. a kind of phase shift transfers net system of anti-blind spot, it is characterised in that：Including the forward emitted unit, orientation that are sequentially connected
Coupler, phase-shifting unit, reverse demodulating unit, also including label；
The forward emitted unit is used to provide the forward signal to label transmitting；
The directional coupler is used to take out front reverse signal, and the forward signal being coupled to is frequency mixer after phase-shifting unit
Local oscillation signal is provided, the reverse signal being coupled to is sent into frequency mixer and is demodulated；
The phase-shifting unit is used for the phase place of two 90 ° of differences of switching；
The reverse demodulating unit is used to process the reverse baseband signal of mixing output.
2. the phase shift transfers net system of a kind of anti-blind spot according to claim 1, it is characterised in that：The forward emitted
Unit includes PLL, low-noise amplifier, modulator, the power amplifier being sequentially connected.
3. the phase shift transfers net system of a kind of anti-blind spot according to claim 1, it is characterised in that：The phase-shifting unit
The microstrip line and two RF switches of λ/4 are differed including two-route wire length.
4. a kind of phase shift transmission method of anti-blind spot, it is characterised in that：Comprise the steps：
(1) what read write line received that user sends checks after instruction, stabilized carrier is provided by forward emitted unit, by modulation
Device is modulated to base band commands signal, up-conversion to 920-925MHz；
(2) sent after dependent instruction, continued to provide tone signal, for label power is provided, label has received read write line and sent
Forward signal after, according to agreement coded system and speed responded, scatter read write line forward signal by way of pair
Signal is modulated；
(3) read write line single-tone is provided while etc. the data that return of label to be demodulated, lead code is carried out according to agreement regulation
Matching, if successfully decoded, reports client, completes once to interact；
(4) if read write line decoding failure, by the switch of two single-pole double throws in control phase-shifting unit, another kind of phase place of switching, from
And 90 ° of local oscillator phase shift is re-started again and checks trial, solve blind spot.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710073469.1A CN106650543B (en) | 2017-02-10 | 2017-02-10 | Anti-blind-spot phase-shift transmission network system and method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710073469.1A CN106650543B (en) | 2017-02-10 | 2017-02-10 | Anti-blind-spot phase-shift transmission network system and method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN106650543A true CN106650543A (en) | 2017-05-10 |
| CN106650543B CN106650543B (en) | 2023-09-19 |
Family
ID=58846391
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201710073469.1A Active CN106650543B (en) | 2017-02-10 | 2017-02-10 | Anti-blind-spot phase-shift transmission network system and method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN106650543B (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108734040A (en) * | 2018-05-22 | 2018-11-02 | 苏州大学 | The quick detection device of passive RFID tags |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2006229433A (en) * | 2005-02-16 | 2006-08-31 | Denso Wave Inc | Rfid tag system, rfid tag, and tag reader |
| CN101079097A (en) * | 2007-06-14 | 2007-11-28 | 华南理工大学 | Small-sized modular type UHF radio frequency identification read-write equipment |
| CN203909808U (en) * | 2014-06-05 | 2014-10-29 | 北京康拓红外技术股份有限公司 | Radio frequency processing apparatus in intelligent tracking equipment for railway train numbers |
| CN206546580U (en) * | 2017-02-10 | 2017-10-10 | 天津中兴智联科技有限公司 | A kind of phase shift transfers net system of anti-blind spot |
-
2017
- 2017-02-10 CN CN201710073469.1A patent/CN106650543B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2006229433A (en) * | 2005-02-16 | 2006-08-31 | Denso Wave Inc | Rfid tag system, rfid tag, and tag reader |
| CN101079097A (en) * | 2007-06-14 | 2007-11-28 | 华南理工大学 | Small-sized modular type UHF radio frequency identification read-write equipment |
| CN203909808U (en) * | 2014-06-05 | 2014-10-29 | 北京康拓红外技术股份有限公司 | Radio frequency processing apparatus in intelligent tracking equipment for railway train numbers |
| CN206546580U (en) * | 2017-02-10 | 2017-10-10 | 天津中兴智联科技有限公司 | A kind of phase shift transfers net system of anti-blind spot |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108734040A (en) * | 2018-05-22 | 2018-11-02 | 苏州大学 | The quick detection device of passive RFID tags |
| CN108734040B (en) * | 2018-05-22 | 2021-07-13 | 苏州大学 | Passive RFID label rapid detection equipment |
Also Published As
| Publication number | Publication date |
|---|---|
| CN106650543B (en) | 2023-09-19 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US8292175B2 (en) | Tag device, reader device, and RFID system | |
| US7155172B2 (en) | RFID receiver apparatus and method | |
| US4963887A (en) | Full duplex transponder system | |
| US6686830B1 (en) | Homodyne I/Q transceiver for a spread spectrum reader | |
| KR100726596B1 (en) | Radio Frequency IDentification reader | |
| CN110086552B (en) | Antenna combination equipment and mobile terminal | |
| CN101300716B (en) | Polarization diversity antenna system | |
| CN1881969B (en) | Direct conversion radio apparatus | |
| US6046668A (en) | Interrogator circuit arrangement | |
| KR101114166B1 (en) | Radio Frequency IDentification reader transmitter of direct quadrature demodulation type | |
| US20110140853A1 (en) | Rfid reader and signal receiving method thereof | |
| US5606737A (en) | Oscillator mixer and a multiplier mixer for outputting a baseband signal based upon an input and output signal | |
| CN206546580U (en) | A kind of phase shift transfers net system of anti-blind spot | |
| CN106650543A (en) | Blind spot-resistant phase-shift transmission network system and method | |
| US7528699B2 (en) | Transponder in communication system | |
| US9455769B2 (en) | RFID communication system | |
| WO2009025425A1 (en) | Rfid reader supporting dense mode | |
| CN202196417U (en) | Radio frequency identification reader module | |
| Kuo et al. | Single-antenna FDD reader design and communication to a commercial UHF RFID tag | |
| JP5137128B2 (en) | RFID reader / writer | |
| KR101189400B1 (en) | Radio Frequency IDentification reader | |
| CN210222762U (en) | Ultrahigh frequency RFID reader-writer and ultrahigh frequency RFID reading-writing system | |
| CN111585598B (en) | Microwave sensor and data communication method thereof | |
| KR100836469B1 (en) | Rfid reader and rfid system | |
| JPH04147082A (en) | Responder of moving body identifying apparatus |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| CB02 | Change of applicant information | ||
| CB02 | Change of applicant information |
Address after: 300308 Tianjin Binhai New Area Airport Economic Zone Dongqidao No.2 ZTE Industrial Base Applicant after: Zte Intelligent Iot Technology Co.,Ltd. Address before: 300308 Tianjin Binhai New Area Airport Economic Zone Dongqidao No.2 ZTE Industrial Base Applicant before: ZTE INTELLIGENT IOT TECHNOLOGY Co.,Ltd. |
|
| GR01 | Patent grant | ||
| GR01 | Patent grant |