CA1038039A - Apparatus for locating non-linear junctions between metallic materials and/or semiconductive materials - Google Patents
Apparatus for locating non-linear junctions between metallic materials and/or semiconductive materialsInfo
- Publication number
- CA1038039A CA1038039A CA235,208A CA235208A CA1038039A CA 1038039 A CA1038039 A CA 1038039A CA 235208 A CA235208 A CA 235208A CA 1038039 A CA1038039 A CA 1038039A
- Authority
- CA
- Canada
- Prior art keywords
- frequency
- signal
- materials
- linear
- semiconductive
- 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.)
- Expired
Links
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R27/00—Arrangements for measuring resistance, reactance, impedance, or electric characteristics derived therefrom
- G01R27/02—Measuring real or complex resistance, reactance, impedance, or other two-pole characteristics derived therefrom, e.g. time constant
- G01R27/20—Measuring earth resistance; Measuring contact resistance, e.g. of earth connections, e.g. plates
- G01R27/205—Measuring contact resistance of connections, e.g. of earth connections
-
- 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
Landscapes
- Engineering & Computer Science (AREA)
- Radar, Positioning & Navigation (AREA)
- Remote Sensing (AREA)
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Computer Networks & Wireless Communication (AREA)
- Radar Systems Or Details Thereof (AREA)
- Geophysics And Detection Of Objects (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
Apparatus for locating non-linear junctions between metallic materials and/or semiconductive materials including signal generators for radiating respectively signals having frequencies f1 and f2, and receiver means for detecting the presence of a predetermined frequency, given by n1f1 + n2f2, in a return signal.
Apparatus for locating non-linear junctions between metallic materials and/or semiconductive materials including signal generators for radiating respectively signals having frequencies f1 and f2, and receiver means for detecting the presence of a predetermined frequency, given by n1f1 + n2f2, in a return signal.
Description
1:~8 m e present invention relates to apparatus for locating non-linear junctions between metallic materials and/or semicon-ductive materialsO It is becoming more essential every day to be able to detect and locate devices containing metallic materials or semiconductive materials having non-linear junctions there~
between. Diodes, transistors, semiconductive devices, and corroded joints between the electrical conductors represent some of the non-linear junctions. Such ~unctions occur in a great variety of electronic and electrical devices and in particular occur in electronic bugs and radio-controlled mechanisms. m e detection of these devices using readily available close proximity sensors, which relay on the magnetic and dielectric properties o~ materials is virtually impossible in buildings and structures. Non-linear ~unctions which exhibit a ~uare law respon~e with respec~ to voltage and current across the junction when illuminated by electromagnètic signal~ re-radiate ha~monics rela~ed to the frequency o~ the illum~nating electromagnetic signals. m ese ~unctions act as multipliers so that a signal, which may be represented by ~ sin ~lt, when multiplied by itsel~ in a square law junction, gives the standard square law response o~ equation 1.
(~ æ~n Wlt)2 = E12 (1 - cos 2 ~lt) (1) The El cos 2 ~lt term gives the second harmonic term.
Higher harmoniG terms are produced b~ a successive ~
sel~ multiplication process. ~.
~4 ~ ~
~W8~39 These signals have been a problem in th~ l~w frequency communications bands where power output and ~ransmitter density are high and in the microwave bands where the ~unctions are most efficlent. The above radiated signals are known as inter modulation interference and the prior art ha~ concentrated on locating the~e signal sources using the principal that theæe re-radiated or return ~ignals are harmonics o~ a sin~le frequency. The prior art thereore has concentrated on detectlng the second and third harmonic return signals. One o~ the~e apparati which overcomes some of the difficulties a~sociated with magnetic and dielectric detection provide~ a transmitter for transmitting a single signal of requency o and two receivers which are tuned to receive the second and third h~rmonics, 2fo and 3fO respectively o~ the trans-mitted signal. A pure signal o~ ~requency ~O 1B empLoyed to illuminate an ~rea suspected o containing non-linear ~unctions.
If the suspected area does not contain non-linear ~unctions, the area will re1ect only a signal of original frequency o, which signal is ignored, If the suspected area does contain non-linear junctions~ the re-radiated ~ignal will not only contain original frequency fO~ but will al50 contain harmonics of frequency fO.
These harmonics will be detected by multiple receivers tuned to these harmonic frequencies. Th~ d~tector contains a transmitter ~hat generate~ and radiates a pure signal of frequency fO. This tranæmitter is carefully shielded and iltered so as to prevent the leakage of harmonicæ from the transmitter. The detector al50 contains two receivers, on~ tuned to the seco~d harmonic 2o of the transmitted frequency~ The local o~cillators of both of these receivers are derived from the transmitted frequency.
However, this apparatus ha~ ~ot been entirely satis-~actory since the sens~tivity o~ the apparatus is limited due tothe problem of having to decouple transmitter harmonics ~rom the receiver channel as well as to avoid harmonic response in the 3~38~139 receiver to the fundamental transmitter frequency~ The latter sources of spurious re~ponse ~eriously limit the sensitivity of the apparatus. It becomeæ increasingly costly ~o attempt to improve the sensitiv~ty o the device by improYin~ the decoupling o the transmitter harmonic~ from the receiver channel and/or eliminztion of harmonics from the transmitted frequency.
~hs applicant has provided a novel apparatus providing improved sensiti~it~ without the a~tendant complexity and expense of prior art apparatus. In a pre~erred em~odiment, the apparatus la comprises means for radiating a firæt signal having a frequency fl, means for radiating a second signal having a frequency f2 different rom said first signal, and mean~ for detecting the presence of a predetermined frequency in a return signal, said predetermined frequency being glvan by nlfl~n2f2 where nl and n~ are inta~ers~
The apparatus will be de~cribed in greater d~tail with reference to the dr~wings in which:
Figure 1 i~ a block diagram of the apparatus.
Fig~, 2 and 3 are block dlagrams of other embodiments of the apparatus.
Fig. 4 show~ an embodiment of the sonic transponder.
In the pre~ent i~vention9 the applicant provides as shown in Figure 1 in bl~ock form, signal generators 1 and 2, w*~h output carrier freque~cies of fl and f2 respectively, ~nteDna~ 3 and 4 for radiating the carrier signals fl and f2, an antenna 5 which receives signalsg returned by a device 8 to be located, to provide an input to a receiver 6, and a display unit 7 which presents the receiver output in a sultable ~orm.
Although i~em~ 3, 4 and 5 are shown as separate elements in the figures, it is to be understood that they may be combined into a single unit, such as by the use o~ a multiplexer.
V~rious other changes and improvements such as providing frequencies fl and f2 from a singl~ oscillator as well as the local oscillator signal for the tuned rece~ver are co~templated.
The principal o operatio~ of the appl~cants novel app~ratus will now be more ully de~cribed with the aid o~ the following equa~ionæ.
The expansion of the product o two slgnals represented by Elsin CJ lt and E~sin ~ 2t is giv~n by equation 2.
(Elsin ~ lt ~ E2sin ~ 2t) ~ E1sin ~ lt ~ 2 ElE2sin ~ 1t.sln ~ 2t E2S~n2 ~ 2t (2) The squared terms may be expanded to produce El coæ 2 ~ lt and E2 cos 2 ~ 2t (3)
between. Diodes, transistors, semiconductive devices, and corroded joints between the electrical conductors represent some of the non-linear junctions. Such ~unctions occur in a great variety of electronic and electrical devices and in particular occur in electronic bugs and radio-controlled mechanisms. m e detection of these devices using readily available close proximity sensors, which relay on the magnetic and dielectric properties o~ materials is virtually impossible in buildings and structures. Non-linear ~unctions which exhibit a ~uare law respon~e with respec~ to voltage and current across the junction when illuminated by electromagnètic signal~ re-radiate ha~monics rela~ed to the frequency o~ the illum~nating electromagnetic signals. m ese ~unctions act as multipliers so that a signal, which may be represented by ~ sin ~lt, when multiplied by itsel~ in a square law junction, gives the standard square law response o~ equation 1.
(~ æ~n Wlt)2 = E12 (1 - cos 2 ~lt) (1) The El cos 2 ~lt term gives the second harmonic term.
Higher harmoniG terms are produced b~ a successive ~
sel~ multiplication process. ~.
~4 ~ ~
~W8~39 These signals have been a problem in th~ l~w frequency communications bands where power output and ~ransmitter density are high and in the microwave bands where the ~unctions are most efficlent. The above radiated signals are known as inter modulation interference and the prior art ha~ concentrated on locating the~e signal sources using the principal that theæe re-radiated or return ~ignals are harmonics o~ a sin~le frequency. The prior art thereore has concentrated on detectlng the second and third harmonic return signals. One o~ the~e apparati which overcomes some of the difficulties a~sociated with magnetic and dielectric detection provide~ a transmitter for transmitting a single signal of requency o and two receivers which are tuned to receive the second and third h~rmonics, 2fo and 3fO respectively o~ the trans-mitted signal. A pure signal o~ ~requency ~O 1B empLoyed to illuminate an ~rea suspected o containing non-linear ~unctions.
If the suspected area does not contain non-linear ~unctions, the area will re1ect only a signal of original frequency o, which signal is ignored, If the suspected area does contain non-linear junctions~ the re-radiated ~ignal will not only contain original frequency fO~ but will al50 contain harmonics of frequency fO.
These harmonics will be detected by multiple receivers tuned to these harmonic frequencies. Th~ d~tector contains a transmitter ~hat generate~ and radiates a pure signal of frequency fO. This tranæmitter is carefully shielded and iltered so as to prevent the leakage of harmonicæ from the transmitter. The detector al50 contains two receivers, on~ tuned to the seco~d harmonic 2o of the transmitted frequency~ The local o~cillators of both of these receivers are derived from the transmitted frequency.
However, this apparatus ha~ ~ot been entirely satis-~actory since the sens~tivity o~ the apparatus is limited due tothe problem of having to decouple transmitter harmonics ~rom the receiver channel as well as to avoid harmonic response in the 3~38~139 receiver to the fundamental transmitter frequency~ The latter sources of spurious re~ponse ~eriously limit the sensitivity of the apparatus. It becomeæ increasingly costly ~o attempt to improve the sensitiv~ty o the device by improYin~ the decoupling o the transmitter harmonic~ from the receiver channel and/or eliminztion of harmonics from the transmitted frequency.
~hs applicant has provided a novel apparatus providing improved sensiti~it~ without the a~tendant complexity and expense of prior art apparatus. In a pre~erred em~odiment, the apparatus la comprises means for radiating a firæt signal having a frequency fl, means for radiating a second signal having a frequency f2 different rom said first signal, and mean~ for detecting the presence of a predetermined frequency in a return signal, said predetermined frequency being glvan by nlfl~n2f2 where nl and n~ are inta~ers~
The apparatus will be de~cribed in greater d~tail with reference to the dr~wings in which:
Figure 1 i~ a block diagram of the apparatus.
Fig~, 2 and 3 are block dlagrams of other embodiments of the apparatus.
Fig. 4 show~ an embodiment of the sonic transponder.
In the pre~ent i~vention9 the applicant provides as shown in Figure 1 in bl~ock form, signal generators 1 and 2, w*~h output carrier freque~cies of fl and f2 respectively, ~nteDna~ 3 and 4 for radiating the carrier signals fl and f2, an antenna 5 which receives signalsg returned by a device 8 to be located, to provide an input to a receiver 6, and a display unit 7 which presents the receiver output in a sultable ~orm.
Although i~em~ 3, 4 and 5 are shown as separate elements in the figures, it is to be understood that they may be combined into a single unit, such as by the use o~ a multiplexer.
V~rious other changes and improvements such as providing frequencies fl and f2 from a singl~ oscillator as well as the local oscillator signal for the tuned rece~ver are co~templated.
The principal o operatio~ of the appl~cants novel app~ratus will now be more ully de~cribed with the aid o~ the following equa~ionæ.
The expansion of the product o two slgnals represented by Elsin CJ lt and E~sin ~ 2t is giv~n by equation 2.
(Elsin ~ lt ~ E2sin ~ 2t) ~ E1sin ~ lt ~ 2 ElE2sin ~ 1t.sln ~ 2t E2S~n2 ~ 2t (2) The squared terms may be expanded to produce El coæ 2 ~ lt and E2 cos 2 ~ 2t (3)
2 2 and the product term may be expanded to produce , . . _ 1 2 1 ~J 2)t - ElE2 cos ( ~
Higher order harmonic terms ~nd terms with frequencies given by nl ~ 1 * n2 C~ 2 (where nl and n2 are integers) are pro-duced in addition to those indicated by equations 3 and 4 by a succes~ive sel~ multiplication process.
The applicants apparatus by providing two transmitter frequencies, i~ able to cause the non-linear ~unction to re-radiate frequenc~es which are not only harmon~cs or squared term product~ as given in eq~ation 3, and as is the case in prior art apparatus, ~ut frequencies whlch are the sum and diference of the transmitted requencies or product term ~reguenci~ given by equation 4. This allows the applicant~ apparatus to have unexpectedly higher discrimination and selectivity than prior art apparatus of the same complexity.
It is to be understood that where the ~erm non-linear ~unctions ~s used, it is meant to comprise semiconductive ~unctions such as occur in de~ices made ~rom semiconductin~ material ~or example, transistors, integrated circuit~ and related devices, semiconductive ~unctions formed by oxidatlon products of metals 1 ~3 and related phenomena~
The above apparatus may be adapted ~or use in location of radio oontrolled apparatus, unlicensed or unauthorized equip-ment, airport surveillance9 detection of stolen goods~ detection and location of electronic bugging devices and remote sensors placed for intelligence purposes.
A second embodiment a~ shown in Figure 2 i8 similar to that shown in Figure 1, except that it ~how~ modulation signals 9 and 10 superimpo~ed on the carrler signals to provide increased ~ensitivity, in detection and identification by providing improved discrimination and diferention between desired and spurious signals. With increased power and the increase of sensi-tivlty and discrimination available through the u~e o ~odulated carrier si~nals, the apparatus may be adapted ~or the det~ction oE aircra~t, either foreign or cr~shed, detection and location o~ ships over the horlzon, and sub~arines.
The present invention al80 contemplates the use of carr~er modulation scheme~ to obtain additional in~ormation such as range and bearlng of the d~vice to be located as well as providing range and be~rlng selectivity. With range and bearlng capability, the above apparatus could be used for the provision o~ channel markers as an aid to navigation at night and in bad weather9 collision avoidance, search and re~cue operations, pro-vi~ion o passive markers for surveying purposes~ and automatic focusing of movle and television cameras on moving ob~ects or on fixed ob~ects when the camera is moving.
It is also contemplated that devices containing non-linear elements could be placed at ~obile or ~ixed locations or various re~ote sensing, interrogating control and communication purposes~ The above apparatus could then be used for remote sensor interrogation, motion detectorfi, proximity indicators and uses, and securing communications by having a sender modulate the mlxing efficiency of a diode connected to an ante~na which is illumlnated by two signals at fre~uencies ~upplied by the intended receiver.
In another embodiment o~ the invent~on, it is conte~plated that the present inventlon may act a8 a sonic transponder. The sonic transponder consists of a ~ound e~ergy to electrical energy converter or transducer 11 a6 shown in Figure 4. The electrical output of the transducer i9 fed to a non-linear element 12 which produces currents having requencies equal to the Sums and differ-ences between harmonic~ of the frequencies of the ~ound waves 13incident on the tran~ducer. The transducer co~verts these currents into sound waves 14 which eminate there~rom in such a manner that the sonic transponder behaves like a ~onic rectifier.
In Figure 37 which is ~imilar to Figure 2, the transmitter 2 o~' frequency ~2 i8 modulated by a 8ignal 9 with a requency ~3.
The output o the tuned receiver i8 fed to ~ phase detector 15 which compares the pha~e o~ the 8ignal 9 with the demodulated output 16 from the tuned receiver. The element 5 may be an antenna or a suitable recep~ion transponder, The elements 11 a~d 12 form the sonic rectifier or transponder. The outputs 17 and 18 are respectively output~ to a range indicator and a direction indlcator.
The sonic transponder ~ay be used as a sonlc position ; 1ndicator. The distance between a reference marker containing the sonic transpo~der a~d the transmit-receive assembly ie obtained from the phase di~ference between the modulation signal f3 at the transmitter and its demodulated version at the receiver. The direction of the reference marker is obtained by rotating the direction~l transmit-receive array consisting of elements 3, 4 and 5 to maximize the de~odulated receiver output. If the difference requency 1 - f2 is an audio-~requency, it could also be used or direction indlng. It can thus be seen that the prasent invention is capable of operation in air, liquid, gas or solid and may be - - -~ 31~
used to detect man-made devices a~d natural m~ter~al~ exhibiting sonic rect~fication, In summary, the applicant has pro~ided in a preferred embodiment, a first slgnal generator means providin~ a firæt carrler signal having a frequency fl~ a ~econd ~ignal ~enerator means providing a second carr~er æignal having a frequency f2, first and ~econd ~ntennas or radiating the carri~r signals, a third antenna, and a receiver connected to the third antenna and~
tuned to detect 8ign~18 radiatlng from any non-linear element, which signals have requencies given by the sum and difference of the products of nl times the fir~t carrier signal and n2 time~
the 6econd carrier signal where nl and n2 are integers.
Higher order harmonic terms ~nd terms with frequencies given by nl ~ 1 * n2 C~ 2 (where nl and n2 are integers) are pro-duced in addition to those indicated by equations 3 and 4 by a succes~ive sel~ multiplication process.
The applicants apparatus by providing two transmitter frequencies, i~ able to cause the non-linear ~unction to re-radiate frequenc~es which are not only harmon~cs or squared term product~ as given in eq~ation 3, and as is the case in prior art apparatus, ~ut frequencies whlch are the sum and diference of the transmitted requencies or product term ~reguenci~ given by equation 4. This allows the applicant~ apparatus to have unexpectedly higher discrimination and selectivity than prior art apparatus of the same complexity.
It is to be understood that where the ~erm non-linear ~unctions ~s used, it is meant to comprise semiconductive ~unctions such as occur in de~ices made ~rom semiconductin~ material ~or example, transistors, integrated circuit~ and related devices, semiconductive ~unctions formed by oxidatlon products of metals 1 ~3 and related phenomena~
The above apparatus may be adapted ~or use in location of radio oontrolled apparatus, unlicensed or unauthorized equip-ment, airport surveillance9 detection of stolen goods~ detection and location of electronic bugging devices and remote sensors placed for intelligence purposes.
A second embodiment a~ shown in Figure 2 i8 similar to that shown in Figure 1, except that it ~how~ modulation signals 9 and 10 superimpo~ed on the carrler signals to provide increased ~ensitivity, in detection and identification by providing improved discrimination and diferention between desired and spurious signals. With increased power and the increase of sensi-tivlty and discrimination available through the u~e o ~odulated carrier si~nals, the apparatus may be adapted ~or the det~ction oE aircra~t, either foreign or cr~shed, detection and location o~ ships over the horlzon, and sub~arines.
The present invention al80 contemplates the use of carr~er modulation scheme~ to obtain additional in~ormation such as range and bearlng of the d~vice to be located as well as providing range and be~rlng selectivity. With range and bearlng capability, the above apparatus could be used for the provision o~ channel markers as an aid to navigation at night and in bad weather9 collision avoidance, search and re~cue operations, pro-vi~ion o passive markers for surveying purposes~ and automatic focusing of movle and television cameras on moving ob~ects or on fixed ob~ects when the camera is moving.
It is also contemplated that devices containing non-linear elements could be placed at ~obile or ~ixed locations or various re~ote sensing, interrogating control and communication purposes~ The above apparatus could then be used for remote sensor interrogation, motion detectorfi, proximity indicators and uses, and securing communications by having a sender modulate the mlxing efficiency of a diode connected to an ante~na which is illumlnated by two signals at fre~uencies ~upplied by the intended receiver.
In another embodiment o~ the invent~on, it is conte~plated that the present inventlon may act a8 a sonic transponder. The sonic transponder consists of a ~ound e~ergy to electrical energy converter or transducer 11 a6 shown in Figure 4. The electrical output of the transducer i9 fed to a non-linear element 12 which produces currents having requencies equal to the Sums and differ-ences between harmonic~ of the frequencies of the ~ound waves 13incident on the tran~ducer. The transducer co~verts these currents into sound waves 14 which eminate there~rom in such a manner that the sonic transponder behaves like a ~onic rectifier.
In Figure 37 which is ~imilar to Figure 2, the transmitter 2 o~' frequency ~2 i8 modulated by a 8ignal 9 with a requency ~3.
The output o the tuned receiver i8 fed to ~ phase detector 15 which compares the pha~e o~ the 8ignal 9 with the demodulated output 16 from the tuned receiver. The element 5 may be an antenna or a suitable recep~ion transponder, The elements 11 a~d 12 form the sonic rectifier or transponder. The outputs 17 and 18 are respectively output~ to a range indicator and a direction indlcator.
The sonic transponder ~ay be used as a sonlc position ; 1ndicator. The distance between a reference marker containing the sonic transpo~der a~d the transmit-receive assembly ie obtained from the phase di~ference between the modulation signal f3 at the transmitter and its demodulated version at the receiver. The direction of the reference marker is obtained by rotating the direction~l transmit-receive array consisting of elements 3, 4 and 5 to maximize the de~odulated receiver output. If the difference requency 1 - f2 is an audio-~requency, it could also be used or direction indlng. It can thus be seen that the prasent invention is capable of operation in air, liquid, gas or solid and may be - - -~ 31~
used to detect man-made devices a~d natural m~ter~al~ exhibiting sonic rect~fication, In summary, the applicant has pro~ided in a preferred embodiment, a first slgnal generator means providin~ a firæt carrler signal having a frequency fl~ a ~econd ~ignal ~enerator means providing a second carr~er æignal having a frequency f2, first and ~econd ~ntennas or radiating the carri~r signals, a third antenna, and a receiver connected to the third antenna and~
tuned to detect 8ign~18 radiatlng from any non-linear element, which signals have requencies given by the sum and difference of the products of nl times the fir~t carrier signal and n2 time~
the 6econd carrier signal where nl and n2 are integers.
Claims
1. A method of detecting elements non-linearly responsive to incident oscillatory energy comprising, radiating energy from a first source of a first frequency f and from a second source of a second frequency kf where k is not a whole number, permitting energy from both said sources to impringe on at least one of said elements, whereby said element responds to said energy to produce energy of a third frequency n1f ? n2 kf where n1 and n2 are integers, wherein said element is non-resonant at said first, second or third frequency.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA235,208A CA1038039A (en) | 1975-09-11 | 1975-09-11 | Apparatus for locating non-linear junctions between metallic materials and/or semiconductive materials |
| GB3684576A GB1527399A (en) | 1975-09-11 | 1976-09-06 | Locating non-linear junctions between metallic materials and/or semi-conductive materials |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA235,208A CA1038039A (en) | 1975-09-11 | 1975-09-11 | Apparatus for locating non-linear junctions between metallic materials and/or semiconductive materials |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1038039A true CA1038039A (en) | 1978-09-05 |
Family
ID=4104013
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA235,208A Expired CA1038039A (en) | 1975-09-11 | 1975-09-11 | Apparatus for locating non-linear junctions between metallic materials and/or semiconductive materials |
Country Status (2)
| Country | Link |
|---|---|
| CA (1) | CA1038039A (en) |
| GB (1) | GB1527399A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6897777B2 (en) * | 2001-02-13 | 2005-05-24 | Audiotel International Limited | Non-linear junction detector |
| RU2480787C1 (en) * | 2011-09-12 | 2013-04-27 | Владимир Авенирович Кропотов | Method and system for remote detection of objects |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6057765A (en) * | 1998-10-07 | 2000-05-02 | Research Electronics International | Non-linear junction detector |
| US6163259A (en) * | 1999-06-04 | 2000-12-19 | Research Electronics International | Pulse transmitting non-linear junction detector |
| GB2381078B (en) * | 1999-06-04 | 2003-10-01 | Res Electronics Internat | Pulse transmitting non-linear junction detector |
| DE102004025870B4 (en) * | 2004-05-27 | 2008-06-26 | Iq-Mobil Gmbh | A method for wireless signal transmission and use of such a method |
-
1975
- 1975-09-11 CA CA235,208A patent/CA1038039A/en not_active Expired
-
1976
- 1976-09-06 GB GB3684576A patent/GB1527399A/en not_active Expired
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6897777B2 (en) * | 2001-02-13 | 2005-05-24 | Audiotel International Limited | Non-linear junction detector |
| RU2480787C1 (en) * | 2011-09-12 | 2013-04-27 | Владимир Авенирович Кропотов | Method and system for remote detection of objects |
Also Published As
| Publication number | Publication date |
|---|---|
| GB1527399A (en) | 1978-10-04 |
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