CA2050832A1 - Moving vehicle transponder - Google Patents
Moving vehicle transponderInfo
- Publication number
- CA2050832A1 CA2050832A1 CA 2050832 CA2050832A CA2050832A1 CA 2050832 A1 CA2050832 A1 CA 2050832A1 CA 2050832 CA2050832 CA 2050832 CA 2050832 A CA2050832 A CA 2050832A CA 2050832 A1 CA2050832 A1 CA 2050832A1
- Authority
- CA
- Canada
- Prior art keywords
- transponder
- transmission line
- feeder
- substrate
- dipole antenna
- 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.)
- Abandoned
Links
Classifications
-
- G—PHYSICS
- G08—SIGNALLING
- G08G—TRAFFIC CONTROL SYSTEMS
- G08G1/00—Traffic control systems for road vehicles
- G08G1/01—Detecting movement of traffic to be counted or controlled
- G08G1/017—Detecting movement of traffic to be counted or controlled identifying vehicles
Abstract
ABSTRACT
MOVING VEHICLE TRANSPONDER
A transponder tag operative in the UHF range and including a substrate of dielectric material having formed on one side a conductive surface providing a ground plane and a dipole antenna a slot line within the ground plane forming a balanced antenna feeder and leading to the centre of the dipole antenna, and the substrate having mounted on the side of the substrate opposite to said one side a transmission line feeder positioned for electromagnetic coupling wtih said slot line, the transmission line feeder being coupled to transceiver circuit means and processing means mounted on the opposite side for performing a transponding function.
MOVING VEHICLE TRANSPONDER
A transponder tag operative in the UHF range and including a substrate of dielectric material having formed on one side a conductive surface providing a ground plane and a dipole antenna a slot line within the ground plane forming a balanced antenna feeder and leading to the centre of the dipole antenna, and the substrate having mounted on the side of the substrate opposite to said one side a transmission line feeder positioned for electromagnetic coupling wtih said slot line, the transmission line feeder being coupled to transceiver circuit means and processing means mounted on the opposite side for performing a transponding function.
Description
SCM/39ss e MOVING VEHICLE TRANSPONDER
F1eld of the Invent10n __ Th1s ~nventton relates to tag transponders, part~cularly though not exclusively for attach~ng to veh1cles.
Background Art A system has been devised which allows road toll fees to be collected automatically.
The syste0 compr1ses an 1nterrogator dev ke bur1ed ~n the carr~ageway and a transpond~ng tag f~tted to vehicles.
When a su1tably equlpped veh~cle approaches a toll po~nt ~ts presence ~s detected by an ~nduct~ve loop detector (s~m~lar to that used at traff~c 119hts) and the ~nterrogator ls energ~sed. Thls dev~ce transmlts a signal at 915 MHz to the veh~cle, the transmlsslon carr1es a code wh~ch 1s recogn~sed by the vehicle Utag" as a command to turn on its transmltter. The tag transmitter then sends a coded s~gnal to the interrogator ~n the carr1agewdy~ The coded lnformat~on contains the vehlcle reg~strat~on number. It ls therefore poss1ble to collect toll fees without the need for manned toll booths and wlthout the need for vehicles to slow down so that money could be transferred.
It w~ll be understood for the purposes of th1s speclf1cat10n, "transponder ta~" ls 1ntended to mean a unitary dev~ce wh~ch lncludes elements necessary for 1ts operat10n ~n rece1v~ng radiated slgnals an~ transml~ting signals tn response ~hereto.
Summary of the Inventlon It is an object of the present lnvent~on to prov~de a transponder tag wh~ch ls of a part1cularly simple, lnexpens~Ye and rel~able construct~on.
The present 1nvent~on ~s lntended to operate ~n the UHF
range, and speciflcally 915 MHz. HoweYer for the purpose of th~s specif~cat~on "UHF range" ~s ~ntended to mean any frequency below 2 GHz and excludlng frequencles ~h~ch would normally be regarded as mlcrowave.
The present ~nvent~on prov~des a transponder tag operat~ve in the UHF range and 1ncludlng a substrate of dtelectric mater~al havlng formed on one slde a conduct~ve surface prov1d~ng a ground plane and a dlpole antenna, a slot line with~n the ground plane forming a balanced antenna feeder and leading to the centre of the d~pole antenna, and the substrate having mounted on the s~de of the substrate opposite to sa~d one side a transm~ss~on line feeder pos~t~oned for electromagnetic coupl~ng wlth sald slot l~ne, the transm~ssion llne feeder belng coupled t~ transce~ver clrcuit means and processing means mounted on the opposlte s~de for perform1ng a transponding function.
Thus in accordance w~th the ~nvention a transponder of part~cularly s~mple construction ~s provided operating ~n the UHF
range ~ncludlng an antenna and balanced feeder arrangement formed ln a partlcularly s~mpte manner on oppos~te s~des of a dlelectr~c substrate.
As preferred the dipole antenna ls formed by remo~lng for example by etching selected parts of sa1d conduct~ve surface~ leav~ng a str~p def~nlng a d~pole antenna wh~ch ~s connected to the ground plane at the central reg~on of the strlp.
As preferred the transm1ss~on llne feeder comprlses a conductlve strlp, /4 long and term~natlng at a pos~t~on generally oppos~te the slot line for max~mum coupling to the slot llne.
The transcelver means campr1ses an osclllator coupled v1a a buffer (power) ampl~f~er to the transm1ssion l~ne feeder, the collector of an RF trans~stor of the ampl~fler belng dlrectly coupled to the feeder. As preferred the osc~llator and ampl1f1er are CW
modulated by switching of the power supplled to the osc~llator and ampllf~er by means of output data signals from the processor.
The receiver ~s capacitlvely coupled to the feeder w~th the base of a recelver translstor be~ng directly connected to the AC
coupllng. The recelver demodulates recelved RF signals and provldes the demodulated data to the process~ng means, whlch preferably comprlses a processor and memory ~ncludlng stored programs, all provlded ln a slngle ASIC.
Br~ef Descr~ptlon of the Drawln~s A preferred embodlment of the ~nventlon w~ll now be descrlbed wlth reference to the accompanylng draw~ngs, whereln :-F~gure 1 is a block diagram of the transponder accord~ngto the ~nventlon;
Flgure 2 ~s a circu~t d~agram of the transce~ver of F~gure l; and Flgure 3 is a plan vlew of the transponder show~ng the antenna and antenna feed arrangement.
Descrlptlon of the Preferred Embodlment Referrlng now to thè drawings Figure 1 ~s a block dlagram of the tag accordlng to the inventlon and shows a d~pole antenna 2 coupled vla an antenna coupler 6 to a receiver detector 8 whlch demodulates data received by the antenna and passes the demodulated data to a data processor 10 formed as an ASIC. Output data provlded by processor IO ~s coupled to an RF osclllator 12 wh~ch osclllates a 915 MHz and to a buffer (power) ampllf~er 14 whlch amplifles the osclllator slgnals and feeds the signals to antenna coupler 6. The data on output llne 16 from processor lO modulates the osc~llator and buffer amplifer ln a CW modulation mode wherein both the osc~llator and ampllfler are swltched on/off d7rectly by the output data.
Referring now to Flgure 3, thls ~s a plan v~ew of the tag transponder comprls~ng a substrate block 30 a relatlvely low dielectric value polyester res1n and having on 1ts upper s~de a conduct1ve surface 32 (for example copper) coated thereon. The surface 32 forms a ground plane and port~ons of the surface 32 are removed as at 34 to provlde on one s~de of the surface a dipole antenna strip 36 hav~ng an ~nput ~mpedance of 75 ohms at 1ts centre.
A slot l~ne 38 ~s formed ln the ground plane extend~ng from the mld po~nt of the antenna 36 and forming a right angled bend as at 40.
On the other slde of the d~electr k body as ~nd~cated ~n dotted l~nes, the electr~cal components ~ndlcated ln F19ure 1 are mounted as at 42, preferably by means of surface mount technology on an array of solder bumps. The electron k components 42 are coupled to the antenna by means of a transm~ss~on llne 44. Transm~ss10n l~ne 44 ~s formed as a str~p of conductlve metal coated on d~electr1c block 30 and hav1ng a length ~/4 w1th the free end of the strlp 46 terminat~ng close to a pos~tlon d~rectly opposlte slot l~ne ~8.
The end of str~p 46 is coupled via a capac~t~ve coupl~ng 48 to ground plane 42. This arrangement prov~des a maxtmum electromagnetlc coupl~ng between the end of str~p 46 and slot line 40, the radlat~on be~ng coupled to slot l~ne 40 and then be~ng conduct~ve ~n a balanced feed arrangement on e~ther stde of the slot llne to the d~pole antenna to provlde a balanced feed to the dipole antenna.
The dlpole antenna is printed on the same PWB (printed w~ring board) as the tag electronics.
Referring now to Flgure 2, this shows a c~rcuit d~agram of the transce~ver arrangement as comprising d rece~ver or detector 50 coupled to transmisslon l~ne 44 v~a a capac~tance 52, the base of an RF detector trans~stor 54 being directly coupled to capac~tor 52.
The collector of translstor 54 ~s coupled to the base and, vla a d~ode 56, to the emitter of a further trans1stor 58. A tun~ng circuit for the detector ~s formed by the quarter-wave transmlss~on line 449 while trans~stors 659 66, capacltor C1 and ~nductor Ll provide act~ve blas for the detector trans~stor 54. The comb~nation of trans~tor 54 dlode 56 and trans~stor 58 provlde a means of demodulating the data from the input RF slgndl and the demodulated data ls fed to processor 10. Processor lO responds to the lnput data by provlding data on output llne 16 for modulation of an oscillator 12 compr1slng a trans~stor 60 and a resonant c1rcuit arrangement L2, C3, C4, the frequency of osc111at~on be1ng determlned by a m1cro strip 62. The osc111ator 1s coupled to buffer ampllf1er 14 compr1slng an RF transistor 64 coupled 1n common base mode to osclllator 12 and having lts collector dlrectly coupled to feeder 44.
The processor c~rcu~t 10 ~5 powered by a llth1um battery (not shown) and the battery and transponder tag are housed ~n an overall plastics encapsulatlon.
F1eld of the Invent10n __ Th1s ~nventton relates to tag transponders, part~cularly though not exclusively for attach~ng to veh1cles.
Background Art A system has been devised which allows road toll fees to be collected automatically.
The syste0 compr1ses an 1nterrogator dev ke bur1ed ~n the carr~ageway and a transpond~ng tag f~tted to vehicles.
When a su1tably equlpped veh~cle approaches a toll po~nt ~ts presence ~s detected by an ~nduct~ve loop detector (s~m~lar to that used at traff~c 119hts) and the ~nterrogator ls energ~sed. Thls dev~ce transmlts a signal at 915 MHz to the veh~cle, the transmlsslon carr1es a code wh~ch 1s recogn~sed by the vehicle Utag" as a command to turn on its transmltter. The tag transmitter then sends a coded s~gnal to the interrogator ~n the carr1agewdy~ The coded lnformat~on contains the vehlcle reg~strat~on number. It ls therefore poss1ble to collect toll fees without the need for manned toll booths and wlthout the need for vehicles to slow down so that money could be transferred.
It w~ll be understood for the purposes of th1s speclf1cat10n, "transponder ta~" ls 1ntended to mean a unitary dev~ce wh~ch lncludes elements necessary for 1ts operat10n ~n rece1v~ng radiated slgnals an~ transml~ting signals tn response ~hereto.
Summary of the Inventlon It is an object of the present lnvent~on to prov~de a transponder tag wh~ch ls of a part1cularly simple, lnexpens~Ye and rel~able construct~on.
The present 1nvent~on ~s lntended to operate ~n the UHF
range, and speciflcally 915 MHz. HoweYer for the purpose of th~s specif~cat~on "UHF range" ~s ~ntended to mean any frequency below 2 GHz and excludlng frequencles ~h~ch would normally be regarded as mlcrowave.
The present ~nvent~on prov~des a transponder tag operat~ve in the UHF range and 1ncludlng a substrate of dtelectric mater~al havlng formed on one slde a conduct~ve surface prov1d~ng a ground plane and a dlpole antenna, a slot line with~n the ground plane forming a balanced antenna feeder and leading to the centre of the d~pole antenna, and the substrate having mounted on the s~de of the substrate opposite to sa~d one side a transm~ss~on line feeder pos~t~oned for electromagnetic coupl~ng wlth sald slot l~ne, the transm~ssion llne feeder belng coupled t~ transce~ver clrcuit means and processing means mounted on the opposlte s~de for perform1ng a transponding function.
Thus in accordance w~th the ~nvention a transponder of part~cularly s~mple construction ~s provided operating ~n the UHF
range ~ncludlng an antenna and balanced feeder arrangement formed ln a partlcularly s~mpte manner on oppos~te s~des of a dlelectr~c substrate.
As preferred the dipole antenna ls formed by remo~lng for example by etching selected parts of sa1d conduct~ve surface~ leav~ng a str~p def~nlng a d~pole antenna wh~ch ~s connected to the ground plane at the central reg~on of the strlp.
As preferred the transm1ss~on llne feeder comprlses a conductlve strlp, /4 long and term~natlng at a pos~t~on generally oppos~te the slot line for max~mum coupling to the slot llne.
The transcelver means campr1ses an osclllator coupled v1a a buffer (power) ampl~f~er to the transm1ssion l~ne feeder, the collector of an RF trans~stor of the ampl~fler belng dlrectly coupled to the feeder. As preferred the osc~llator and ampl1f1er are CW
modulated by switching of the power supplled to the osc~llator and ampllf~er by means of output data signals from the processor.
The receiver ~s capacitlvely coupled to the feeder w~th the base of a recelver translstor be~ng directly connected to the AC
coupllng. The recelver demodulates recelved RF signals and provldes the demodulated data to the process~ng means, whlch preferably comprlses a processor and memory ~ncludlng stored programs, all provlded ln a slngle ASIC.
Br~ef Descr~ptlon of the Drawln~s A preferred embodlment of the ~nventlon w~ll now be descrlbed wlth reference to the accompanylng draw~ngs, whereln :-F~gure 1 is a block diagram of the transponder accord~ngto the ~nventlon;
Flgure 2 ~s a circu~t d~agram of the transce~ver of F~gure l; and Flgure 3 is a plan vlew of the transponder show~ng the antenna and antenna feed arrangement.
Descrlptlon of the Preferred Embodlment Referrlng now to thè drawings Figure 1 ~s a block dlagram of the tag accordlng to the inventlon and shows a d~pole antenna 2 coupled vla an antenna coupler 6 to a receiver detector 8 whlch demodulates data received by the antenna and passes the demodulated data to a data processor 10 formed as an ASIC. Output data provlded by processor IO ~s coupled to an RF osclllator 12 wh~ch osclllates a 915 MHz and to a buffer (power) ampllf~er 14 whlch amplifles the osclllator slgnals and feeds the signals to antenna coupler 6. The data on output llne 16 from processor lO modulates the osc~llator and buffer amplifer ln a CW modulation mode wherein both the osc~llator and ampllfler are swltched on/off d7rectly by the output data.
Referring now to Flgure 3, thls ~s a plan v~ew of the tag transponder comprls~ng a substrate block 30 a relatlvely low dielectric value polyester res1n and having on 1ts upper s~de a conduct1ve surface 32 (for example copper) coated thereon. The surface 32 forms a ground plane and port~ons of the surface 32 are removed as at 34 to provlde on one s~de of the surface a dipole antenna strip 36 hav~ng an ~nput ~mpedance of 75 ohms at 1ts centre.
A slot l~ne 38 ~s formed ln the ground plane extend~ng from the mld po~nt of the antenna 36 and forming a right angled bend as at 40.
On the other slde of the d~electr k body as ~nd~cated ~n dotted l~nes, the electr~cal components ~ndlcated ln F19ure 1 are mounted as at 42, preferably by means of surface mount technology on an array of solder bumps. The electron k components 42 are coupled to the antenna by means of a transm~ss~on llne 44. Transm~ss10n l~ne 44 ~s formed as a str~p of conductlve metal coated on d~electr1c block 30 and hav1ng a length ~/4 w1th the free end of the strlp 46 terminat~ng close to a pos~tlon d~rectly opposlte slot l~ne ~8.
The end of str~p 46 is coupled via a capac~t~ve coupl~ng 48 to ground plane 42. This arrangement prov~des a maxtmum electromagnetlc coupl~ng between the end of str~p 46 and slot line 40, the radlat~on be~ng coupled to slot l~ne 40 and then be~ng conduct~ve ~n a balanced feed arrangement on e~ther stde of the slot llne to the d~pole antenna to provlde a balanced feed to the dipole antenna.
The dlpole antenna is printed on the same PWB (printed w~ring board) as the tag electronics.
Referring now to Flgure 2, this shows a c~rcuit d~agram of the transce~ver arrangement as comprising d rece~ver or detector 50 coupled to transmisslon l~ne 44 v~a a capac~tance 52, the base of an RF detector trans~stor 54 being directly coupled to capac~tor 52.
The collector of translstor 54 ~s coupled to the base and, vla a d~ode 56, to the emitter of a further trans1stor 58. A tun~ng circuit for the detector ~s formed by the quarter-wave transmlss~on line 449 while trans~stors 659 66, capacltor C1 and ~nductor Ll provide act~ve blas for the detector trans~stor 54. The comb~nation of trans~tor 54 dlode 56 and trans~stor 58 provlde a means of demodulating the data from the input RF slgndl and the demodulated data ls fed to processor 10. Processor lO responds to the lnput data by provlding data on output llne 16 for modulation of an oscillator 12 compr1slng a trans~stor 60 and a resonant c1rcuit arrangement L2, C3, C4, the frequency of osc111at~on be1ng determlned by a m1cro strip 62. The osc111ator 1s coupled to buffer ampllf1er 14 compr1slng an RF transistor 64 coupled 1n common base mode to osclllator 12 and having lts collector dlrectly coupled to feeder 44.
The processor c~rcu~t 10 ~5 powered by a llth1um battery (not shown) and the battery and transponder tag are housed ~n an overall plastics encapsulatlon.
Claims (8)
1. A transponder tag operative in the UHF range and including a substrate of dielectric material having formed on one side a conductive surface providing a ground plane and a dipole antenna, a slot line within the ground plane forming a balanced antenna feeder and leading to the centre of the dipole antenna, and the substrate having mounted on the side of the substrate opposite to said one side a transmission line feeder positioned for electromagnetic coupling with said slot line, the transmission line feeder being coupled to transceiver circuit means and processing means mounted on the opposite side for performing a transponding function.
2. A transponder according to Claim 1 wherein the dipole antenna is formed by removing parts of said conductive surface leaving a strip defining said dipole antenna which is connected to the ground plane at the central region of the strip.
3. A transponder according to Claim 1, wherein the transmission line feeder comprises a conductive strip, /4 long and terminating at a position generally opposite the slot line for optimum electromagnetic coupling.
4. A transponder according to Claim 1, wherein the transceiver circuit means comprises an oscillator and output amplifier, both of which are CW modulated by output data from the processing means.
5. A transponder as claimed in Claim 1 wherein the transceiver circuit means includes a transmitter output RF transistor whose collector is directly coupled to the transmission line feeder.
6. A transponder as claimed in claim 1 wherein the transceiver circuit means includes receiver means including a detecting transistor coupled to the transmission line feeder via a capacitor.
7. A transponder as claimed in Claim 1 wherein said processing means is comprised in an ASIC.
8. A transponder substantially as described with reference to the accompanying drawings.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB9019645.2 | 1990-09-07 | ||
| GB909019645A GB9019645D0 (en) | 1990-09-07 | 1990-09-07 | Moving vehicle transponder |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2050832A1 true CA2050832A1 (en) | 1992-03-08 |
Family
ID=10681879
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2050832 Abandoned CA2050832A1 (en) | 1990-09-07 | 1991-09-06 | Moving vehicle transponder |
Country Status (3)
| Country | Link |
|---|---|
| EP (1) | EP0474440A3 (en) |
| CA (1) | CA2050832A1 (en) |
| GB (2) | GB9019645D0 (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100603617B1 (en) | 2004-06-29 | 2006-07-24 | 한국전자통신연구원 | Antenna for RFID transponder and transponder using the antenna |
| WO2017166307A1 (en) | 2016-04-01 | 2017-10-05 | 深圳市大疆创新科技有限公司 | Antenna, communication assembly and unmanned aircraft |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB1348478A (en) * | 1970-06-20 | 1974-03-20 | Emi Ltd | Aerial arrangements |
| US3845490A (en) * | 1973-05-03 | 1974-10-29 | Gen Electric | Stripline slotted balun dipole antenna |
| US4068232A (en) * | 1976-02-12 | 1978-01-10 | Fairchild Industries, Inc. | Passive encoding microwave transponder |
| US4104630A (en) * | 1976-06-21 | 1978-08-01 | Chasek Norman E | Vehicle identification system, using microwaves |
| FR2487588A1 (en) * | 1980-07-23 | 1982-01-29 | France Etat | DOUBLE REPLIES IN PLATES FOR VERY HIGH FREQUENCY AND NETWORKS OF SUCH DOUBLETS |
| US4816839A (en) * | 1987-12-18 | 1989-03-28 | Amtech Corporation | Transponder antenna |
-
1990
- 1990-09-07 GB GB909019645A patent/GB9019645D0/en active Pending
-
1991
- 1991-08-30 GB GB9118647A patent/GB2249924B/en not_active Expired - Fee Related
- 1991-08-30 EP EP19910307965 patent/EP0474440A3/en not_active Withdrawn
- 1991-09-06 CA CA 2050832 patent/CA2050832A1/en not_active Abandoned
Also Published As
| Publication number | Publication date |
|---|---|
| GB9118647D0 (en) | 1991-10-16 |
| GB2249924A (en) | 1992-05-20 |
| GB2249924B (en) | 1994-06-15 |
| EP0474440A3 (en) | 1993-07-07 |
| EP0474440A2 (en) | 1992-03-11 |
| GB9019645D0 (en) | 1990-10-24 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| FZDE | Dead |