WO1992009906A1 - Systeme de detection electronique - Google Patents

Systeme de detection electronique Download PDF

Info

Publication number
WO1992009906A1
WO1992009906A1 PCT/SE1991/000785 SE9100785W WO9209906A1 WO 1992009906 A1 WO1992009906 A1 WO 1992009906A1 SE 9100785 W SE9100785 W SE 9100785W WO 9209906 A1 WO9209906 A1 WO 9209906A1
Authority
WO
WIPO (PCT)
Prior art keywords
transponder
reflector
antenna
transmitter
signal
Prior art date
Application number
PCT/SE1991/000785
Other languages
English (en)
Inventor
Hans Löfberg
Jan Eriksson
Original Assignee
Loefberg Hans
Jan Eriksson
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Loefberg Hans, Jan Eriksson filed Critical Loefberg Hans
Publication of WO1992009906A1 publication Critical patent/WO1992009906A1/fr

Links

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S13/00—Systems using the reflection or reradiation of radio waves, e.g. radar systems; Analogous systems using reflection or reradiation of waves whose nature or wavelength is irrelevant or unspecified
    • G01S13/74—Systems using reradiation of radio waves, e.g. secondary radar systems; Analogous systems
    • G01S13/75—Systems using reradiation of radio waves, e.g. secondary radar systems; Analogous systems using transponders powered from received waves, e.g. using passive transponders, or using passive reflectors
    • G01S13/751—Systems using reradiation of radio waves, e.g. secondary radar systems; Analogous systems using transponders powered from received waves, e.g. using passive transponders, or using passive reflectors wherein the responder or reflector radiates a coded signal
    • G01S13/753—Systems using reradiation of radio waves, e.g. secondary radar systems; Analogous systems using transponders powered from received waves, e.g. using passive transponders, or using passive reflectors wherein the responder or reflector radiates a coded signal using frequency selective elements, e.g. resonator

Definitions

  • the invention relates to systems for locating and relocating obstacles, objects etc. of different kinds, consisting of trans- itter, receiver and reflector.
  • a signal is emitted and reflected and that the reflected signal is captured and is used in different ways, in order to start an alarm, open a door, show the distance to an object etc.
  • the signal used might be of different kinds, a light beam, visible or invisible, ultrasound, radiowaves, etc.
  • the systems can principally be divided into such giving response for optional objects, such as radar for ships, the outline of land, etc., detectors giving response if a signal, such as a light beam, is broken in some way and so on, and systems giving response for a certain reflector.
  • the invention refers to systems of the latter type, and uses for locating avalanche victims, informing aircraft crews of the presence of power lines, ease the rescuing of survivors from ships wreckage, and so on.
  • a means including a trans- mitter sending electromagnetic waves on one frequency, a trans ⁇ ponder reflecting the waves with an harmonic frequency and a receiver to catch the reflected waves and emit a apprehendable signal.
  • the object of the invention is to accomplish a system accor ⁇ ding to the prior art with an improved sensitivity, range and identification ability.
  • Another object of the invention is to accomplish a system with a broad applicability for, besides retrieving avalanche victims, locating survivors from accidents at sea, warning low flying air crafts, esp. helicopters, of power lines and other obstacles.
  • the transponder according to the invention is principally in accordance with the prior art transponders, such as those dis ⁇ closed in the above mentioned patent publications. It consists like those of an antenna optimized for the two frequencys used, the incoming one coming from the transmitter and the outgoing harmonic overtone. An incoming frequency of e.g. 1000 MHz and an outgoing frequency of 2000 MHz have proven themselves to be suitable and an optimal effect can be obtained by tuning the components. In the patent publications mentioned a system with matching components is disclosed.
  • the position of the transponder on the object to be located or preferably the human body is of great importance.
  • the sum of the field inciding upon the human body and the ield reflected by the human body is a standing wave having a nodal point situa ⁇ ted in the nearest environment of the reflecting background, which in case of humans is the skin surface.
  • a transponder with the antenna directly against the skin will be located in a nodal point and therefore does not give any field and thus no signal which makes possible the localisation of the transponder.
  • the antenna part instead is placed at a distance from the skin the effect increases and at a certain distance it will give a maxi ⁇ mum signal. With a dielectric material between the reflecting skin and the antenna part this necessary distance is reduced.
  • the transponder is arranged behind any suitable dielectricum in order to give a space between the antenna and the skin under any circumstances.
  • the thickness and the dielectric con ⁇ stant of the intervening fabric or leather will act in an unpre- dictable way, and that is why the sensitivity and the range, i.e. the strength of the signal, never or only in extremly exceptional cases, can be expected to be the best possible.
  • this drawback is eliminated by always maintaining the optimum dielectric distance between the reflector and the antenna.
  • trans ⁇ ponder on the skin with intervening distance means, but accor ⁇ ding to the invention instead a special dielectricum is arranged on the back of the antenna and on top of this a special reflec- tor mounted on the back of the dielectricum.
  • the localisation in an inner pocket or outer pocket or directly onto the skin there ⁇ fore lacks importance, and the transponder will always show maxium sensitivity.
  • Maximum sensitivity in two directions can also be achieved by making the transponder double-sided by placing two transponders with the reflectors against each other or having a common reflector for two assembled transponders.
  • the reflector in this case is metallic such as a plate, optionally perforated, a metal screen, a foil, an electro-depo ⁇ sit, a metallized fabric, etc., but may also consist of another reflecting material, e.g. conductive plastic material, and the transponder is produced in the form of a laminate of protective layer, antenna, dielectricum and reflector.
  • the reflector is somewhat bigger than the antenna in order to prevent the in ⁇ fluence of the background material.
  • An existing metal surface might also be used as reflector, such as a power line pole, whereby the antenna with the dielec ⁇ tricum is mounted tight against the pole.
  • the dielectrical con ⁇ stant and the thickness of the dielectricum are tuned so that the sensitivity of the laminate is at maximum. Practical tests have shown that with the transponder according to the invention the reflecting effect is increased so that the discovery distan ⁇ ce becomes at least twice as big as compared to previously known constructions using the same transmitter. If thus the output effect is tuned so that a desired reading is obtained at a distance of 40 m to a prior art transponder, a reflected signal strength with a reading at 80 m is obtained with the transponder according to the invention.
  • the transponder may be incorporated as an integral part in different articles for every day use or in articles of clothing, at the manufacture thereof.
  • the re ⁇ flector may sit on the inside and the antenna on the outside of the leg with the space inbetween filled with the material in the boot leg, i.e. leather or plastic.
  • the antenna and the reflector are then tuned to the characteristics and thickness of the material so that the sensitivity becomes optimal in the same way as when the transponder is a separate unit.
  • the transponder according to the invention is also well suited for rescuing survivors in accidents at sea, when mounted on a life-jacket it makes it possible to quickly find people in the water.
  • the transponder might be put into the life-jackets during their manufacture and then be made in such a way that the antenna is lying directly against the reflector, and thus is passive, and to be activated only when the life- jacket is inflated.
  • the activation may be achieved in that only upon inflation a dielectrical layer is introduced between the antenna and the reflector or a loose metal plate or foil is removed from between the dielectricum and the antenna.
  • the transponders may be made in two halves with dielectricum and reflector in one half and antenna in the other, which for the activation are displaced or asembled to form the transponder according to the invention.
  • the sensitivity of the system will be dependent of the screening of the transponder from the transmitter and the angel in relation to the direction of the incoming signal.
  • the transmitter emits a high frequency signal to the passive transponder which returns an harmonic overtone to the receiver.
  • the first, the second or the third overtone may be the most suitable, for example in order to distinguish different types of re lectors or in order to be able to use a lower frequency on the transmitter and thereby enhance the penetration.
  • the damping of the signal may not become to big. For example, in snow high frequen ⁇ cies are strongly dampened, which puts a limit on the frequen ⁇ cies that may be used.
  • a relatively good balance between the equipment, weight and sensitivity has been found with an output signal of about 1000 MHz.
  • the transmitter and the reciever with the accompanying antennas may as in prior constructions be assembled into one unit which is kept in the hand and is directed manually in order to sweep a search area.
  • the batteries and parts of the construc ⁇ tion are made as a separate unit, which is carried on the back and is connected to the finder through a cable, in order to make the use of the equipment less tiresome during the fairly long time needed to search through an avalanche or a water area.
  • the weight of the part which has to be held in the hand thereby can be brought down to about a fifth of the total weight, i.e. be reduced from about 5 kg to about 1 kg.
  • the equipment can also be made for fixed installation, e.g. for searching an area from an helicopter.

Landscapes

  • Engineering & Computer Science (AREA)
  • Radar, Positioning & Navigation (AREA)
  • Remote Sensing (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Radar Systems Or Details Thereof (AREA)

Abstract

On décrit un système composé d'un émetteur et d'un répondeur permettant de repérer des objets de types differents, de rechercher des victimes d'avalanches, ou de débris de navires abîmés en mer etc, et d'avertir en cas de danger etc. Un signal émis par l'émetteur est réfléchi par le répondeur sous forme d'un son harmonique du signal émis. Le répondeur, qui peut être à deux côtés avec un réflecteur situé entre les deux, est composé d'une antenne avec un ou plusieurs semiconducteurs, d'un réflecteur et d'un diélectrique intermédiaire dimensionné pour produire un signal réfléchi de sortie de puissance maximale. Le diélectrique peut faire partie intégrante d'un vêtement ou d'un objet. Il peut également être conçu pour être introduit entre l'antenne et le réflecteur, par exemple au gonflage d'une brassière de sauvetage. Les brassières non utilisées peuvent alors rester inactives et par conséquent ne gênent pas lors des recherches des personnes flottant en mer. Afin de faciliter sa manipulation, l'émetteur peut également être divisé de sorte que seule une petite partie de celui-ci doive être tenue dans la main, les piles et le reste de l'équipement étant alors portés sur le dos. Les poids de la partie mobile peut alors être ramené à un cinquième du poids total (environ 1 kg), ce qui représente un soulagement important dans le cas de recherches qui durent plusieurs heures.
PCT/SE1991/000785 1990-11-21 1991-11-20 Systeme de detection electronique WO1992009906A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
SE9003698A SE467640B (sv) 1990-11-21 1990-11-21 Elektroniskt soeksystem
SE9003698-9 1990-11-21

Publications (1)

Publication Number Publication Date
WO1992009906A1 true WO1992009906A1 (fr) 1992-06-11

Family

ID=20380960

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/SE1991/000785 WO1992009906A1 (fr) 1990-11-21 1991-11-20 Systeme de detection electronique

Country Status (3)

Country Link
AU (1) AU9029391A (fr)
SE (1) SE467640B (fr)
WO (1) WO1992009906A1 (fr)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1998023971A1 (fr) * 1996-11-26 1998-06-04 Tagmaster Ab Transpondeur omnidirectionnel
WO2002047206A1 (fr) * 2000-12-05 2002-06-13 Telefonaktiebolaget Lm Ericsson (Publ) Structure d'antenne et dispositif de communication pourvu d'une telle structure
WO2003080996A1 (fr) * 2002-03-27 2003-10-02 Tracto-Technik Gmbh Procede permettant de determiner la position d'une tete de forage dans la terre
WO2004111678A1 (fr) * 2003-05-13 2004-12-23 Link Jean Paul Systeme de controle d'acces et de localisation de personnes ou d'objets
US11415667B2 (en) * 2019-02-06 2022-08-16 The Boeing Company Signaling device for passively transmitting signals

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4331957A (en) * 1979-04-20 1982-05-25 Bengt Enander Transponder for use in locating avalanche victims
US4656478A (en) * 1984-07-30 1987-04-07 Asulab S.A. Passive transponder for locating avalanche victims
WO1988005546A1 (fr) * 1987-01-19 1988-07-28 Midi Robots Societe Anonyme Systeme et balise d'identification et/ou de localisation
GB2215933A (en) * 1988-03-18 1989-09-27 Gen Electric Co Plc Proximity detection
US4890111A (en) * 1986-10-22 1989-12-26 Eta S.A. Fabriques D'ebauches Passive transponder

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4331957A (en) * 1979-04-20 1982-05-25 Bengt Enander Transponder for use in locating avalanche victims
US4656478A (en) * 1984-07-30 1987-04-07 Asulab S.A. Passive transponder for locating avalanche victims
US4890111A (en) * 1986-10-22 1989-12-26 Eta S.A. Fabriques D'ebauches Passive transponder
WO1988005546A1 (fr) * 1987-01-19 1988-07-28 Midi Robots Societe Anonyme Systeme et balise d'identification et/ou de localisation
GB2215933A (en) * 1988-03-18 1989-09-27 Gen Electric Co Plc Proximity detection

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1998023971A1 (fr) * 1996-11-26 1998-06-04 Tagmaster Ab Transpondeur omnidirectionnel
US6246356B1 (en) 1996-11-26 2001-06-12 Tagmaster Ab Omnidirectional transponder
WO2002047206A1 (fr) * 2000-12-05 2002-06-13 Telefonaktiebolaget Lm Ericsson (Publ) Structure d'antenne et dispositif de communication pourvu d'une telle structure
WO2003080996A1 (fr) * 2002-03-27 2003-10-02 Tracto-Technik Gmbh Procede permettant de determiner la position d'une tete de forage dans la terre
WO2004111678A1 (fr) * 2003-05-13 2004-12-23 Link Jean Paul Systeme de controle d'acces et de localisation de personnes ou d'objets
US11415667B2 (en) * 2019-02-06 2022-08-16 The Boeing Company Signaling device for passively transmitting signals

Also Published As

Publication number Publication date
SE467640B (sv) 1992-08-17
SE9003698D0 (sv) 1990-11-21
SE9003698L (sv) 1992-05-22
AU9029391A (en) 1992-06-25

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