DE1901868C - Circuit arrangement for determining the impedance of a coaxial line - Google Patents

Description

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Coaxial line is connected, with its series circuit as a breathing resistance ^^^^ Atedduss ^ circuit with one end via a second high-line connected isL ^ JT ^^^ _the coaxial resistance to the DC voltage resistance is demW J ™ * ^ jjer am Abangeschlossen and also with one end of lines ^I ^ ^er ? ⁿ ^ ^w ^ _t _ _n '7f ^, _an iiungsab £ aUbeim a switching contact of the switching device, which with 5 closing resistor 9 ^au j ^tre * "" -X _itumien and the switching contact lying on the terminating resistor, one of the ^ ° ^ "^^ resistor is connected together 9, is laid. This reference anschfießender EnUMung electron KoaxialleituBi · results in each discharge on is tapped and Bektronenstrahl cm-Oszülographen an illustration Oszfllograph 10 dargesteui. _lflm ^ ₂ J _{n, of} emer normal impedance, with whose courtyards the elec- io The KoaxiaUeitung 1 ^{can be calibrated with ° f ™ r} S _e krtziöts amount electron beam oszülograph or the DC sequence: UM: jna ™ t ^ later the continuously charged as a comparison value between the test; the ^ ⁿ g ^v ^ £ * HT from the

which is continuously charged as a comparison value between the test; the ^^ Γ ^ ΜώβΓνοη the ver

lings measurements is shown. In this way, the rate of discharge of the charge is suspended

both a numerical measurement of the impedance, division of the ** & ** "?% *** [ " 5S test item 2 as well as a comparative determination with regard to i ₅ test item2. WW the line 1 ™ ^l «^ jJSSj

to a given impedance. through the 8I mercury switch

To stop the switching device, a resistor 9 can be switched, so that the ui will be

Fan pulse generator serve as a sine wave stored charge discharge umu _s 500 to 700 HD Shl kdb ^^^^ 'SSSS

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generator from 500 to 700 Hz. The switch can end or ^

here in each case for a duration of just under Ims so their course on

remain closed to then be shown by opening 10. the

again the loading process of the interconnected shows the changes in the

To introduce coaxial cable. Cables. Priifline 2 constant,

More details, advantages and features of Is the impedance along ^ ™haben ^ Ϊ £ φ _1υ &

Invention will become apparent from the following descriptions a ₅ so uine change takes the Spannungsmput

exercise. In the drawing, the invention is exemplified instead of being carried out during a Ze t von.Wi ™? ™

wisely represented, and z ^ ar shows what is twice the J ^^ SS ^ trii

Fig. 1 is a circuit diagram of the invention by the length of the test object 2 mean ^ut * _o j? ^s <™

Formwork arrangement, so a square wave. On * «V2g * g!

2a to 2e representations of various with 30 2t _kiwiiu1 is what is twice the de, impuls ™ W

: r, äut ^ S ^

According to Fig. 1, in an intermediate section an "an ideak \

Koa ^ ialleitungl with known electrical data bulge. IS J ^ JJf ^^ TdIe

a test item 2 in the form of a coaxial line, the 35 line 2 Jl «^^^ pfg. 2b to

Impedance should be measured by connector J ^ g ^ g ^ S ^ * $ ££ ,? T of those

switched on. There is also a second Ko-2e. The shape of this 1 nipu ^ *. _{fl k hits} .

axial line 3 with known electrical data one opposite the be, the ^ Jj ^ Sdtt. ^ \

N0rmal-Koaxialleitung4 in the same way - ^^^ f ¹¹ ^^^^^^^

switches, like the test item2 in the coaxial line 1 4 »higher or lower than the wave wiaers

is switched on The second coaxial line 3 can, the reference impedance * o ^we ' ^se " f ⁸ ^ ^e g _d

if no comparison standard is desired, briefly ^^^ J ^ J ^ l ^ x ^^ der

closed or their connections can be subordinated: Form on. Is according to j

be punched so that this part of the measuring switching Ko "£" gJÜS ^ fSi to

ΐ ⁴⁵ ^ S ^ b

is ül> ₅ r a high resistance 5 or 6 with the measure of

a resistor 9 of 50 ohms, which is then easily possible in each beam oscilloscope.

For this! Sheet drawings.

Claims (3)

give recognize. The well-known measuring system proves to be patent claims: however, as guÄsst.cBfnzil ία der DnKhführung. Any discontinuity, even if ae is already in the measurement 1. Circuit arrangement for determining the arrangement ßegt changes the entire BUd. For impedance eineiKoaaaUelung, with the s business management of measurement requires a Prazosions-TO coaxial tested in series CONNECTED pulse generator nut very steep and accurately defi . senen second coaxial line with known elec- tronic rising edge and, in addition, both Irish data with a terminator - very sensitive as well as very high! Frequencies stand can be connected, whereby the electron beam oszdiographs laid out on this Terminal resistance when flowing through one of the only very weak declining position from the io position Impedance of the coaxial line to be tested from impulse. pending impulse stereoresis · thawing voltage · In contrast, the invention has the task by observation on an electron beam basis, an oscillograph with moderate equipment expenditure serves as a measure for the impedance, manageable, relatively onempdue to interference characterized in that the one 15 finite measurement of the impedance of the test end to enable the connected KoaäaUeitun- coaxial cable. This task will gen (1) is open and the other end - via a further development of a circuit arrangement of the high-ohmic resistor (5) to a type mentioned at the same time solved by the fact that the one Voltage source (7) and also over one end of the connected coaxial lines Switching device (8) of high current load capacity is open and the other end has a high level and high switch-on speed to the ohmic resistor to a DC voltage source !! Terminating resistor (9) is connected. and also a switching device of high 2. Circuit arrangement according to claim 1, there- current capacity and high switch-on speed, characterized in that a further coaxial speed is connected to the terminating resistor.
line, the electrical data of which corresponds to that of the 35 With this circuit, the coaxial line known for the first time is the same, impulses delivering impulses are omitted and in the same way as this with the to be tested the tested cable itself is used together with the coaxial line (2) with a reference Coaxially connected to it, known coaxial line (4) connected to it, the serial cable of which is used as a charge storage device. In the case of the high-speed circuit (3) with one end via a second 30 switching device, which can be implemented in particular by a high-resistance resistor (6) on the direct-mercury switch, shock voltage source (7) is connected and the charged is also connected in a fashionable manner One end to a switching contact of the line with the terminating resistor flows the switching device (8), which can be switched together with the charge on the terminating coaxial cables through the resistor (9) and generates a terminating resistor is. Voltage drop that occurs over time 3. Circuit arrangement according to claim 1 of the previous charge distribution and Impedanzveroder 2, characterized in that the switching pitch corresponds along the cable. Since the co-device (8) is a mercury switch. Axiaileilungen after switching the switching device 40 device, in particular the mercury switch, are terminated with a resistor that approximates but is not critically adapted to its wave resistance, the discharge takes place with negligible small time constant. It is a kind of ♦ 5 leakage of the cargo according to the running The invention relates to a switching speed of the elementary charges in the line arrangement for determining the impedance of a Koung. For example, it may be possible to axial line, with one to the coaxial line to be tested with the test object for 1 ms each line in series connected second coaxial charge and discharge during 50 ns, whereby line with known electrical data, which with 50 the rise time after switching through the mercury a terminating resistor can be connected, the silver switch being 0.2 ns, at this terminating resistor when there is a flow through it is possible to use the coaxial line to be tested on the impedance of the coaxial line to be tested behind the known coaxial line or depending on the pulse current, the voltage dropping them between two pieces of the well-known coaxial to be inserted by observation on an electron beam line. In the latter case, there is one Oscillograph is used as a measure of the impedance. ^; clear comparison option on the oscilloscope In this way it is a pulse refiectometry or image. Time domain reflectometry method known, the die during the discharge of the cable to be tested is based on the fact that a pulse is passed into the test object, the voltages occurring are relatively large, and reflections of the pulse that occur at discontinuities 60 so that a relatively insensitive electron can be established, the time domain ray oscilloscope can serve as it is without major between the incoming and the backward technical effort, also for high cut-off frequencies Impulse information about the distance of the discontinuous can be represented. placement mediated. Is used as an emitted pulse. A further development of the invention consists in a unit jump pulse is used, then at 65 that a further coaxial line, whose electrical On the electron beam oscilloscope, consider data with those of the first known coaxial slide Shape of the reflecting pulse the impedance line match, in the same way as this Changes along the line to be measured compared to the coaxial line to be tested with ether reference