CN1239847A - Radio-frequency switch with frequency detuned circuit and aerial - Google Patents
Radio-frequency switch with frequency detuned circuit and aerial Download PDFInfo
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- CN1239847A CN1239847A CN 98115203 CN98115203A CN1239847A CN 1239847 A CN1239847 A CN 1239847A CN 98115203 CN98115203 CN 98115203 CN 98115203 A CN98115203 A CN 98115203A CN 1239847 A CN1239847 A CN 1239847A
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Abstract
The present invention relates to one RF translator capable of being detected and/or inquired by one matched radio system. Considering that the antenna of one translator may detune in frequency or mismatch in impedance, the translator can absorb small amount of radio-frequency field and energy while one other near translator absorb fully ratio-frequency field and energy for normal operation.
Description
The present invention relates to detection and/or inquiry field by means of the radio-frequency (RF) repeater of the radio frequency read-out system of detection system and/or coupling.These transponders are specially adapted to be equipped with the scouting and the identification of the moving target of transponder.
These systems are particularly useful at highway tollhouse identification mark carrier, and the mark carrier vehicle is discerned the commodity that store and sell in the shop in addition.
Transponder is the transmitter-receiver (transmitter-answering machine) of automatic-answering back device from the next external signal of the transmitter of detection system.
Being called sign or the radio transponder of label in some application also plays a part the signal that response comes from the inquiry system transmitter and launches information at a distance.
In following description, term radio (radioelectrique) will be abridged with common type ' Radio '.
The detection of well-known radio-frequency (RF) repeater and/or inquiry system comprise an emittor/receiver E and transponder T1, T2, shown in the schematic diagram of Fig. 1.
Emittor/receiver E produces a radiofrequency field B (or electromagnetic field).If transponder T1 is in the scope of B restriction, then transponder T1 intercepts and captures the field, and receives the signal that is present in the emittor/receiver E.
People use what is called " active " transponder usually, and it similarly launches for emittor/receiver E radiofrequency signal that use, that be referred to as response signal again.This response signal can comprise the information that allows the identification transponder and/or settle the target on it.
In order to launch a radiofrequency signal again, active transponder can comprise the independently energy.But preferably the energy of transponder recovery radiofrequency field B is given its electronic circuit with feed.In order fully to intercept and capture field or radiofrequency signal, transponder comprises a radio-frequency antenna.For example antenna is made of the metal spiral circle of printed circuit, and its advantage is the size that reduces transponder.
Some is called " passive " transponder and comprises short circuit metal ring antenna simply.Such transponder is present in as shown in Figure 1 the mutual inductance that has changed transmitter E loop aerial and transponder T1 loop aerial in the field of the transmitter E that is made of the loop aerial that flows through electric current.
Therefore, this transmitter and passive transponder system class are similar to piezoelectric transformer primary and secondary circuit.By detecting the change of inductive current, emittor/receiver E can detect the existence at its interior transponder.
In addition, have the transmission system of some transponders, radio frequency sending set sends some information in transponder, and these information can be recorded on the electronic inductance coupler puce continuous in the transponder.
According to general fashion, the purpose of the application's book is retouched any detection of accurate transponder and/or inquiry system, because transponder can detect or inquiry even record by emittor/receiver.The term emittor/receiver generally refers to the equipment that allows emission radiofrequency field and a detection or an inquiry interior transponder, and this equipment is more suitable for receiving the response radiofrequency signal from one of transmitter.
If when in radiofrequency field B, having many transponders simultaneously then some difficulties can occur.Under the sort of situation, the excitation that transponder responds the B field simultaneously maybe will not respond.
For fear of this confusion, propose to postpone the transponder response, after at random time, the excitation of each transponder response transmitter-initialize signal.
, in many cases, stopped over the transponder that the excitation to radiofrequency field B or radiofrequency signal does not respond, it seems that these transponders stoped.
This an open question is especially mentioned in file FR-A-2717593.It points out the fact: " two adjacent labels can exist in the field of same reader, and this may cause forbidding of its automatic reciprocity ".
The objective of the invention is to make the detection and/or the inquiry optimization of the multichannel transponder that exists in detector and/or the reader field.
Another purpose is that the repeater function of avoiding causing because of the transponder that is close to other is disturbed.
A kind of explanation that the transponder reciprocity is forbidden is: a transponder causes the visible radio frequency shadow effect of Fig. 1, therefore, is in another interior transponder of shade and can not receives to be enough field or energy of suitable running.
According to the present invention, the antenna of considering transponder can be that frequency detuning or impedance are lost, so that transponder and less absorption radiofrequency field of its electronic circuit and energy, and these purposes are achieved.
Therefore, be in off resonance or mistake another transponder that the transponder vicinity is located and fully be received as necessary radiofrequency field of suitable running or energy.
At this moment, transmission system can detect or inquire about this another transponder, just as it separately exists in the field B of transmitter.
According to the present invention, preferably consider to be in the interior transponder of radiofrequency field of certain frequency, this transponder comprises an antenna of the radiofrequency field that can receive certain frequency and the electronic circuit that antenna is coupled, this circuit absorbs and disengages the energy that the place that received by antenna provides, it is characterized by: mismatch device when transponder comprises the radiofrequency field that receives certain frequency and the coalignment when receiving the radiofrequency field of certain frequency, if transponder is in the state of selection, use coalignment, if transponder is in non-selected state, absorb energy and/or field in order to limit the transponder that is in nonselection mode, use the mismatch device.
Preferably stipulate: coalignment allows to come tuned antenna according to certain rf frequency, and allows the fact of antenna to certain rf frequency off resonance from the mismatch device, to realize the present invention.
Implementing first mode of the present invention stipulates: mismatch and/or coalignment are to change capacitance, because antenna has inductance value, thereby for the certain frequency of radiofrequency signal, the tuned frequency of antenna changes.
Implementing second mode of the present invention stipulates: mismatch and/or coalignment allow to change the impedance matching between antenna and electronic circuit.
In an example of implementing the present invention's second mode, mismatch and/or coalignment are change of load and/or resistance value, so that change the resistance value of antenna and/or the resistance value of electronic circuit.
Therefore according to characteristic curve, if two transponders are in the same radiofrequency field, no matter to the position of another transponder how a transponder, arbitrary radiofrequency field and/or signal that receives certain frequency in the transponder, each transponder comprises coupling and mismatch device, the radio frequency electrical interference that causes with the vicinity of avoiding another transponder.
According to another characteristic curve, transponder changes the state of selection in turn into, has only unique transponder or minority transponder to be in the state of selection in a flash.
According to another characteristic curve, at the time durations that postpones corresponding to transponder to forbid, transponder changes non-selected state into.
According to the present invention, also prepared transmission system to the transponder coupling.
By reading following explanation and the accompanying drawing that is provided by non-limitative example, the present invention will be fine understanding; These accompanying drawings have:
Fig. 1 represents the schematic diagram according to the transponder transmission system of the status of technology;
Fig. 2 represents the schematic diagram according to transponder transmission system of the present invention;
Fig. 3 represents the repeater circuit figure according to first embodiment of the invention;
Fig. 4 represents the repeater circuit figure according to second embodiment of the invention.
Fig. 1 is illustrated in typical two transponder T1 and the T2 that exist in the field B of emittor/receiver E.Transponder T1 is with the opposed direction of transmitter E, received field B suitably.Radiofrequency field provides energy to give it in order to turn round, and signals for emittor/receiver E, points out its existence, perhaps transmits the response radiofrequency signal and gives it.In the layout of Fig. 1, transponder T1 is between transmitter E and transponder T2, and at this moment, the latter is difficult to receive radiofrequency field B '.
Radiofrequency field B and energy thereof are forwarded device T1 really and absorb, and T1 almost becomes the shielding of radio frequency.The fine detection of transponders T2 of the normal obstruction of this radio frequency shadow effect, it can not receive and be necessary radiofrequency field and the energy of running well.
Contiguous when traditional transponder, thereby transponder can not correctly detect and maybe can not transmit response when giving emittor/receiver, and people observe attenuation effect or reciprocity inhibiting effects with general fashion.
In order to make traditional transponder preferably have the size of dwindling, the expert has designed and produced the tuning especially and antenna that mate fully for the electronic circuit impedance that is connected with antenna of the radio-frequency (RF) field frequency that should receive for antenna.
In surprising mode, the present invention has prepared the antenna mismatch device of transponder, under non-selected transponder situation, limits it and absorbs radiofrequency field.Therefore, adjacent transponder is received RF field and detected suitably, or gets in touch with emittor/receiver.
On the contrary, preparing adjacent repeater antennae coalignment is for abundant received RF field.
At Fig. 2, similar with Fig. 1, people also can see and being arranged in by two transponder P1 and P2 in the radiofrequency field B of emittor/receiver E emission.
We think the antenna mismatch of transponder P1 in the example of Fig. 2, and in other words, antenna seldom absorbs radiofrequency field B, even we can say and do not absorb radiofrequency field B fully.On the horizontal plane of the second transponder T2, radiofrequency field B ' has a calibration power, does not exist as transponder P1.Therefore, transponder P2 receives the energy of enough runnings, and detected or emittor/receiver responded.
Therefore, the radio frequency shadow effect that causes by the transponder of the state of the art the radio shielding effect descends or decay (with Fig. 1 relatively).
First execution mode of repeater antennae mismatch device is to make the frequency detuning of antenna to the transmitter radiofrequency field, and this certain frequency is remembered with fe.
The antenna of transponder constitutes by comprising the resonant circuit that an inductance shown in Figure 3 and an electric capacity constitutes usually.Inductance L can have the form of spiral coil.Capacitor C can be made of single capacitor.Preferably by the C1 of parallel connection, the capacitor bank of C2 constitutes for it, and therefore, each capacitor C1 in the capacitor bank and the capacitance of C2 all add.
The resonance frequency that a kind of like this crowd of circuit knows is by the product decision of inductance L value and capacitance C.
Antenna off resonance device be tuned antenna with the frequency of radiofrequency field or the resonance frequency fd different with the frequency of the radiofrequency signal that is transferred to transponder.Like this, the antenna of transponder is to the frequency f e off resonance of transmission.At this moment the field that transponder and day line absorption thereof is few or the radiofrequency signal of transmitter.
On the contrary, the present invention has prepared the repeater antennae coalignment.These coalignments allow transponders where necessary, especially selects complete received field or radiofrequency signal at transponder.First execution mode is tuned on the frequency of transmission signals or field by the resonance frequency of antenna, makes antenna match.
As shown in Figure 3, to comprise a variable capacitance beneficial for the tuner of antenna resonant frequency.According to the example of Fig. 3, variable capacitance obtains by the capacitor V1 that the change over switch I1 with capacitor C1 and C2 parallel connection is connected.If switch I 1 closure, then the capacitor C of resonant circuit is
C＝C1＋C2＋V1
Wherein C1, C2, V1 represent the capacitance of capacitor C1, C2, V1 respectively.
The coupling antenna resonance frequency fd determine by following product,
LC＝L(C1＋C2＋V1)
Therefore, the antenna frequencies fd of coupling will with by following product
LC＝L(C1＋C2)
The antenna frequencies fd difference of the mismatch of determining.
By appropriate selection capacitor C 1, C2 and V1 value, frequency f d will suitably be offset frequency f a.
For example, if the radiofrequency field of transmission or the frequency f e of signal are 130KHz, then by selecting the following numerical value of these elements, antenna will be tuned at the frequency of 130KHz,
-inductance L is 1 μ H,
-identical capacitor C1, C2 and V1, capacitance are 0.5 μ F, at this moment the product of inductance and capacitance is:
L(C1＋C2＋V1)＝1.5·10
-6S
2，
This product is equivalent to resonance frequency 130KHz.
The antenna mismatch device can be realized by the connection of opening switch I 1 disconnection capacitor V1 simply.At this moment the amassing of the inductance of mismatch antenna and capacitance is:
L(C1＋C2)＝1·10
-6S
2
The about 160KHz of resonance frequency fd that should long-pending be equivalent to the mismatch antenna.Because antenna is tuned at frequency f d, it is away from the field of being launched by transmitter or the frequency f a of signal, and it will receive a bit this emission slightly, and not hinder adjacent transponder received field or signal.
Fig. 2 has provided this situation of interior two transponder T1 of the radiofrequency field that is in transmitter E and T2.Consider that transponder P1 is in the off resonance state, although people see transponder P1 in it, a B still is sent to transponder P2 suitably.
In the mode of equivalence, if switch I 1 is opened, then the tuning of antenna can be obtained, and at this moment inductance L and capacitor C1 and C2 are corresponding to the frequency f e of transmitter.By Closing Switch I1, the antenna off resonance promptly passes through to connect capacitor V1 or by a plurality of switch I 1, I2 connects a plurality of capacitor V1, V2.
Preferably the resonance frequency fd of mismatch antenna approaches the frequency f e of transmitter, thereby approaches to mate the resonance frequency fa of antenna.In fact, mismatch antenna received RF field or signal slightly under the sort of situation.At this moment transponder has very little energy, but enough makes coalignment work, as switch I 1, and changes matching status into.This effect can be advantageously used in transponder is worked in turn, as following will see.
Second execution mode of repeater antennae mismatch device is to make the impedance mismatching between the electronic circuit D of antenna and transponder.
In fact, repeater antennae presents a constant impedance to the signal of transmission or the frequency f e of field.
In order to make the electronic circuit D that links to each other with antenna receive enough signals and energy, implement impedance matching usually, that is: calculate and the adjustment electronic circuit, for for the electronic signal with certain frequency fe, its input impedance is obviously identical with antenna output impedance.
Fig. 4 allows better to understand this second execution mode.It provides the similar transponder with Fig. 3, connects a resistance R in the antenna circuit of Fig. 3, so that impedance is lost.Antenna comprises inductance L and capacitor C1 all the time, C2, and in a second embodiment, the capacitance of capacitor is fixed.(L, C) antenna resonant frequency of the product of value decision is fixed, the field that it is equivalent to launch and the frequency of signal by inductance and electric capacity.In second execution mode, there is frequency detuning.Switch I allows antenna element L, C1, a C2 and electronic circuit D resistance R in parallel.
Select resistance value R, so that change the resistance value of antenna and the resistance value of electronic circuit D, still, resistance value is preferably very little.Under opposite extreme situations, resistance value R can be zero, and at this moment, the mismatch device reverts to the short circuit antenna again, and at this moment, transponder neither absorbs energy, also received field not.
On function, field and the signal of the common receive frequency fe of antenna.
Work as switch closure, then resistance R changes antenna L, C1, and the impedance of C2, antenna is to the impedance mismatching of electronic circuit.
In such mismatch Conditions, electronic signal and energy that antenna receives seldom are transferred to electronic circuit.
According to second execution mode, at matching status, open switch I, resistance R disconnects circuit.Antenna L, C1, C2 provide coupled electronic circuit impedance phase impedance for matching.The signal of it its reception of bundle of lines and energy are transferred to electronic circuit D fully.Transponder absorption field B and energy.Therefore I1 can be detected suitably by emittor/receiver E, because the absorption of E detected energy.According to a kind of scheme, the energy that the transponder utilization absorbs is so that be transmitted into emittor/receiver E to strong resonance signal again.
Other embodiment of controlled impedance mismatching/coupling can both be considered not surmounting the scope of the invention.The use of 1/4 wavelength line, the use of impedance transformer ... it is two kinds that for example belong in the multiple impedance matching of expert domination and the mismatch device.
More generally, very familiar other coupling and the mismatch device to a signal and a transmission of expert can be considered with equivalent way.
Hereinafter, we will be in the coupling attitude and use some transponders to the aforementioned coalignment of a radiofrequency signal or a transmission usually with its antenna of word ' coupling transponder ' express.
In opposite situation, we are called the mismatch transponder.
According to the present invention, the function of transponder combination as the host-host protocol of transponder system, plans now to illustrate that this will allow explanation other advantage more of the present invention.
Static transponder promptly outside radiofrequency field B, preferably is in the mismatch attitude.
Therefore, when many transponders enter a B simultaneously, each transponder can change the coupling attitude into, and can be launched the detection or the inquiry of machine/receiver under the transponder that does not have other mismatch disturbs.
In the mismatch attitude, can expect: transponder receives few field and energy.Therefore, transponder has minimum energy, and this is by for example switch I, I1, and it is necessary that the I2 action changes the coupling attitude into from a mistake attitude.
This condition satisfies easily, because be tuned at antenna seldom received RF field and the energy thereof forever that departs from the launching site frequency a little.Similarly the impedance mismatching between antenna and the electronic circuit allows seldom transmitting radio frequency signal and energy forever.
First agreement of detection/inquiry is expected: transponder changes the coupling attitude into random fashion.Reduce if transponder rests on the time interval of coupling attitude, then the probability that mates simultaneously of two transponders is very little.Therefore, people advantageously obtain good detection of transponder or good response.
Thereby the reading protocol stage is as follows:
Mismatch when-transponder begins.
-be present in interior many transponders, receive a little energy, wherein a transponder changes the coupling attitude into random fashion.
Radiofrequency signal exchanges between the transponder of this coupling and emittor/receiver E.
-this transponder becomes the mismatch transponder again.
Second agreement is to expect: after the appropriate control signal of transmitter E, a transponder changes the coupling attitude into.
Therefore, transponder can become active in turn, but given instantaneous, has only unique transponder to become coupling.
People also can expect: if transponder is all slack, then transponder all is in matching status.In the 3rd agreement, at this moment transmitter can send an order to transponder, allows it change the mismatch attitude into.Therefore, the emission function makes all transponders that are in it, all removes excitation except one.At this moment, transponder and the transmission phase signal between the transmitter in this selection can launch.
After this interchange, transmitter encourages another transponder.
Proceed to transmitter has inquired till each transponder in it always.
This order of transmitter is preferably on the known protocol of transponder code identification a bit one than specially combination.
People can also utilize detection/inquiry agreement, and agreement is from the initialize signal beginning of emittor/receiver in this detection/inquiry, and after the time interval that is equivalent to its identification code element, each transponder is launched a search signal again.
Some agreements and detection/inquiry system are for example being described in the patent EP-B-0495708 like this, and with applicant's name, and it is described content and enrolls in the application.
The present invention considers that also a kind of transponder of many transponders that comprise a radio frequency sending set/receiver and can exist as previously mentioned detects and/or inquiry system in it.
Fig. 2 has provided this detection system one example.Thereby we see three transponder P0, P1, P2 and the combination that can detect and/or inquire their emittor/receiver E.
Two transponder P1 and P2 are in by in the radiofrequency field B of transmitter E emission, the limited field that dots.
Each transponder comprises an antenna, and the form with inductance, electric capacity, load and electronic circuit in the example of Fig. 2 is represented.
Preferably this antenna should received RF field B and energy thereof, and the radiofrequency signal of launching when modulated Field B.In this case, and signal all be the same frequency of above-mentioned certain frequency f e.
People also can expect: be in different frequencies with signal because the antenna of transponder receive transmitter E certain frequency signal and on the other hand the electronic circuit of transponder receive a B and the energy thereof of any one frequency.
People can also expect: the signal of the antenna emission certain frequency of transponder is given receiver E usefulness, and the electronic circuit of transponder receives the field B of any one frequency respectively.
Each transponder comprises an antenna, and it can launch the signal of certain radio frequency between emittor/receiver E and transponder.
If according to the present invention, transponder P1, P2 are in the B, transponder P1 can mismatch or off resonance.Thereby the transmission that people avoid producing between emittor/receiver E and transponder P2 because of other transponder P1 that is present in the B is disturbed.
Similarly, in another stage of the agreement of transmitting, for fear of all interference of transmitting between emittor/receiver E and transponder P1, transponder P2 can be by mismatch or off resonance.
In order to be converted to this another stage, would rather consider: emittor/receiver E sends a select command to a transponder in the existing transponder combination.This command signal can be, for example, and the identification code of transponder.After emittor/receiver E sent, relevant transponder preferably was in selection mode in this order.
In a word, the present invention considers: detection/inquiry system is included in the transmitter that the wave band that dwindles has frequency scanning.
If people use the transponder that antenna can frequency detuning, then this layout is good.Therefore, failing a transponder detected or that read in the inquiry stage can be detected in the frequency scanning stage.
According to above-mentioned example, if certain frequency fe obviously equals to mate the tuning frequency f a of antenna of transponder, be 130KHz, then emittor/receiver can comprise frequency scanning in 130KHz～160KHZ frequency range.Frequency range comprises the resonance frequency fa that mates antenna and the resonance frequency fd of mismatch antenna.
The working method regulation of above-mentioned transponder: transmitter produces the unique radiofrequency field with certain frequency, and this perhaps transmits some information to transponder with the form of radiofrequency signal as request signal or initialize signal.This radiofrequency signal is the simple modulation of radiofrequency field preferably.
According to general fashion, the present invention can implement with the transponder of the receiving system of the certain energy that comprises the radiofrequency signal receiving system.
In addition, in the application of aforementioned consideration, the unique fact of mentioning of people is: the repeater antennae mismatch, and to avoid absorbing the field or the radiofrequency signal of transmitter.
But, also can be absorbed by adjacent transponder by the resonance signal that from the transponder to the emittor/receiver, sends according to mode more generally.General because transponder has for this launches minimum energy again, and this effect is restricted more.
Thereby, for fear of absorbing the resonance signal of launching again by transponder, consider that other transponder mismatch is favourable.
According to general fashion, the present invention considers a kind of transponder that can be present in the radiofrequency field, this transponder comprise can absorb and recover by this provide energy electronic circuit and can launch the antenna of the radiofrequency signal of certain frequency, principal character is: antenna comprises to the mismatch device of the signal of certain frequency transmission with to the coalignment of the signal transmission of certain frequency, be in the state of selection when transponder, the coalignment of antenna comes into operation, when transponder is in non-selected state, so that non-selected transponder shows the limited absorption of radiofrequency signal of certain frequency, and the mismatch device of antenna comes into operation.
The present invention uses beneficial in the transmission system of reader that comprises the target that the information that is used to read on the label or detection contain these labels or detector.This system especially adapts to commerce, for example to product and inventory tracking, grasps the key of corresponding product price, identification and output.
Other of the execution mode that proposes used and scheme can be understood the scope of the present invention of not leaving for the relevant personnel.
Claims (12)
1. transponder (P1), it can be present in the radiofrequency field (8), this transponder (P1) comprises and can absorb and recover the electronic circuit (D) of energy to be provided and can to launch the antenna (L of the radiofrequency signal of certain frequency by this, C1, C2), it is characterized by, antenna comprises to the mismatch device of the signal of certain frequency transmission with to the coalignment of the signal transmission of certain frequency, be in the state of selection when transponder, the coalignment of antenna comes into operation, when transponder is in non-selected state, so that non-selected transponder shows the limited absorption of radiofrequency signal of certain frequency, and the mismatch device of antenna comes into operation.
2. transponder according to claim 1, it can be present in the radiofrequency field of certain frequency, this transponder (P1) comprises the antenna (L of the radiofrequency field (B) that can receive certain frequency, C1, C2) and antenna (L, C1, C2) Ou He electronic circuit (D), the energy that this circuit absorbs and recovers to be provided by the place that antenna receives, it is characterized by: this transponder comprise mismatch device that the certain frequency radiofrequency field is received (V1, R) and coalignment (V1, I1 that the certain frequency radiofrequency field is received, R, I), if transponder is in the state of selection, then coalignment comes into operation, if transponder is in non-selected state, absorb an energy and/or (a B in order to limit the transponder (P1) that is in nonselection mode
1), the mismatch device comes into operation.
3. according to the described transponder of one of aforementioned claim, it is characterized by: coalignment (V1) allows antenna tuning according to certain rf frequency, and (V1 I1) allows certain rf frequency is made the antenna off resonance mismatch device.
4. according to the described transponder of one of aforementioned claim, it is characterized by: because antenna has inductance value (L), so coalignment (V1) and/or mismatch device (V1, I1) essence is to change electric capacity (C1+C2-V1) value, thereby the tuned frequency of antenna is to the certain frequency change of radiofrequency signal.
5. according to the described transponder of one of aforementioned claim, it is characterized by: (R, I) permission changes the impedance matching between antenna and the electronic circuit for coalignment (R) and/or mismatch device.
6. according to the described transponder of one of aforementioned claim, it is characterized by: coalignment and/or mismatch device essence are to change load and/or resistance (R) value, so that change antenna (L, C1, the resistance value of resistance value C2) and/or electronic circuit (D).
7. according to the combination of the described transponder of one of aforementioned claim, it is characterized by: as two transponder (P1, P2) be in the radiofrequency field, no matter transponder (P2) is to the position of another transponder (P1), arbitrary (P2) receives the radiofrequency field and/or the signal of certain frequency in the transponder, each transponder comprises coalignment and mismatch device, with the radio frequency interference of avoiding another transponder vicinity to cause.
8. according to the combination of the described transponder of one of aforementioned claim, it is characterized by: transponder is in the state of selection in turn, the unique or instantaneous state that is in selection of minority transponder.
9. according to the combination of the described transponder of one of aforementioned claim, it is characterized by: at the time durations that postpones corresponding to transponder to forbid, transponder changes non-selected state into.
10. the detection of transponder and/or inquiry system, comprise radio frequency sending set/receiver (E) and many interior transponders of radiofrequency field (B) that can be in by emittor/receiver (E) emission, each transponder comprises an antenna (L, C), this antenna can be launched certain radiofrequency signal between emittor/receiver (E) and transponder, this system is characterized as: according to one of aforementioned claim, it comprises some transponders, to avoid being present in the interference of transmitting between inherent emittor/receiver of radiofrequency field and the transponder because of other transponder.
11. system according to claim 10, it is characterized by: radio frequency sending set/receiver comprises frequency scanning at the wave band around certain frequency, an energy that provides of emittor/receiver emission is provided for the transponder that is in nonselection mode, and change the state of selection into, so that transponder is detected and/or inquiry.
12. according to claim 10 or 11 described systems, it is characterized by: after the order of radio frequency sending set/receiver had come, transponder changed the state of selection into.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 98115203 CN1239847A (en) | 1998-06-23 | 1998-06-23 | Radio-frequency switch with frequency detuned circuit and aerial |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 98115203 CN1239847A (en) | 1998-06-23 | 1998-06-23 | Radio-frequency switch with frequency detuned circuit and aerial |
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| Publication Number | Publication Date |
|---|---|
| CN1239847A true CN1239847A (en) | 1999-12-29 |
Family
ID=5224456
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 98115203 Pending CN1239847A (en) | 1998-06-23 | 1998-06-23 | Radio-frequency switch with frequency detuned circuit and aerial |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN1239847A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102279939A (en) * | 2011-06-07 | 2011-12-14 | 上海集成电路技术与产业促进中心 | RFID tag simulator |
| CN101147329B (en) * | 2005-03-31 | 2012-11-14 | 英特尔公司 | Transceiver with receive path overload protection and method |
-
1998
- 1998-06-23 CN CN 98115203 patent/CN1239847A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101147329B (en) * | 2005-03-31 | 2012-11-14 | 英特尔公司 | Transceiver with receive path overload protection and method |
| CN102279939A (en) * | 2011-06-07 | 2011-12-14 | 上海集成电路技术与产业促进中心 | RFID tag simulator |
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