Method and apparatus for locating and measuring wave guide discontinuities

Claim 2

A waveguide discontinuity measurement system for determining the magnitude and location of a single discontinuity of interest within a waveguide having a plurality of discontinuities, comprising: a waveguide having discontinuities; a pulse modulated signal source; means connecting said signal source to said waveguide; a waveguide shorting switch connected to said waveguide for reflecting a reference pulse; a variable attenuator having an input connected to receive the reflected signals from said waveguide shorting switch when said switch is closed or from a particular discontinuity in the waveguide when said waveguide shorting switch is open; means responsive to the adjustment of said variable attenuator for producing a signal representative of the ratio of the power incident on the waveguide to the power reflected by said particular discontinuity, when said variable attenuator is adjusted so the signal reflected from the waveguide shorting switch and appearing at the output of said adjusted attenuator is equal in amplitude to the signal reflected from said particular waveguide discontinuity and appearing at the output of said attenuator; said ratio being the apparent loss of the particular discontinuity of interest; means connected to said responsive means for processing said respresentative signal, according to the following relationship,

Claim 3

A waveguide discontinuity measurement system for determining the magnitude and location of a single discontinuity of interest within a waveguide having a plurality of discontinuities, comprising: a waveguide having discontinuities; a pulse modulated signal source; means connecting said signal source to said waveguide having the discontinuity; a waveguide shorting switch connected to said waveguide for reflecting a reference pulse; a variable attenuator having an input connected to receive the reflected signals from said waveguide shorting switch when said switch is closed or from a particular discontinuity in the waveguide when said waveguide shorting Switch is open; means responsive to the adjustment of said variable attenuator for producing a signal representative of the ratio of the power incident on the waveguide to the power reflected by said particular discontinuity, when said variable attenuator is adjusted so the signal reflected from the waveguide shorting switch and appearing at the output of said adjusted attenuator is equal in amplitude to the signal reflected from said particular waveguide discontinuity and appearing at the output of said attenuator; said ratio being the apparent loss of the particular discontinuity of interest; a first connecting waveguide; a detector, connected to said signal source by said first connecting waveguide for receiving a sample of a signal, generated by said source, at the time said signal would be received at the output of said variable attenuator if said signal were reflected by said shorting switch; and means connected to receive the sample and reflected signals for comparing the time interval there between and indicating the location of the particular discontinuity.

Claim 4

A waveguide discontinuity measurement system for determining the magnitude and location of a single discontinuity of interest within a waveguide having a plurality of discontinuities, comprising: a waveguide having discontinuities; a pulse modulated signal source; means connecting said signal source to said waveguide having the discontinuity; a waveguide shorting switch connected to said waveguide for reflecting a reference pulse; a variable attenuator having an input connected to receive the reflected signals from said waveguide shorting switch when said switch is closed or from a particular discontinuity in the waveguide when said waveguide shorting Switch is open; means responsive to the adjustment of said variable attenuator for producing a signal representative of the ratio of the power incident on the waveguide to the power reflected by said particular discontinuity, when said variable attenuator is adjusted so the signal reflected from the waveguide shorting switch and appearing at the output of said adjusted attenuator is equal in amplitude to the signal reflected from said particular waveguide discontinuity and appearing at the output of said attenuator; said ratio being the apparent loss of the particular discontinuity of interest; a first connecting waveguide; a detector, connected to said signal source by said first connecting waveguide for receiving a sample of a signal, generated by said source, at the time said signal would be received at the output of said variable attenuator if said signal were reflected by said shorting switch; and means connected to receive the sample and reflected signals for comparing the time interval there between and indicating the location of the particular discontinuity.

Claim 5

The wave guide location and measurement system as recited in claim 2 wherein said pulse modulated signal has a periodic wave form, said wave form being a train of pulses of equal amplitude, and each pulse having a width t within the period T of said constant frequency signal.

Claim 6

The wave guide discontinuity and measurement system of claim 1 wherein: said connecting means comprises a ferritte circulator having a first port connected to said signal source and a second port successively displaced from said first port in the path of signal circulation through said ferrite circulator; said ferrite circulator having a third port successive to said second port in the order of signal circulation through said ferrite circulator; a directional coupler connecting said second port to said wave guide shorting switch; and including a first detector connected to said directional coupler for producing an incident pulse sample; said variable attenuator being connected to receive the output of said circulator third port; a second detector connected to the output of said attenuator; and said pulse reflected from said wave guide shorting switch when said switch is closed or from a wave guide discontinuity in the wave guide when said shorting switch is open passing through said directional coupler, entering said ferrite circulator at said second port and leaving said ferritte circulator at said third port and being passed through said variable signal attenuator to said second detector.

Claim 7

The wave guide fault and measuring system of claim 4 wherein the path from the first port of said ferritte circulator through the ferritte circulator to said second port and from said second port through the directional coupler to said first detector input is equal to the length of the path from the first port of said circulator through said circulator to said second port, through said directional coupler to said wave guide shorting switch, back through said directional coupler to said second port of said circulator, through said ferrite circulator from said second port to said third port and through said variable attenuator.

Claim 8

A wave guide fault location and measurement system of claim 2, wherein the time difference between the sample pulse and the reflected signal pulse is proportional to the distance between the wave guide shorting switch and the discontinuity within the wave guide.

Claim 11

A method for locating and measuring discontinuities in a wave guide, as recited in claim 7, wherein said producing step comprises the steps of: attenuating the signal amplitude reflected from the shorted wave guide to the level of said signal reflected from said particular discontinuity; and deriving a signal, proportional to the apparent loss, and functionally related to the level of attenuation.

Claim 12

The method of claim 7 comprising the step of displaying the reflected signal juxtaposed in time with the incident signal, the displacement in time between the incident pulse and the reflected pulse being indicative of the distance from the wave guide short to the particular discontinuity within the wave guide.

Claim 15

The method for locating and measuring a discontinuity within a wave guide, as recited in claim 10, further comprising: the step of detecting the difference between the time for the incident signal to reach the wave guide and the time for the incident signal to reach the wave guide discontinuity to determine the location of the discontinuity.

Claim 16

A waveguide discontinuity detection apparatus for determining the magnitude and location of each discontinuity within the waveguide comprising: a pulse modulated signal source; a first detector; a second detector; a first wave propagation path connecting said signal source to one end of the waveguide under test and connecting said waveguide end to said first detector; a second wave propagation path connecting said source to said second detector; said first path being equal in length to said second path; and each of said discontinuities being located at a distance from said detectors and proportional to the time difference between the appearance of a signal, generated by said source, at said second detector and the appearance of said generated signal, reflected by a discontinuity, at said first detector; means connected tO said first and second detector for comparing said time difference and indicating the location of each discontinuity relative to said waveguide end; means for reflecting mounted on said waveguide end; each of said waveguide discontinuities having a magnitude proportional to the ratio of a signal amplitude reflected from said means for reflecting to the signal amplitude reflected from each discontinuity; and means connected to said first detector for comparing the signal reflected by the reflecting means and reflected by each discontinuity for indicating the magnitude of each discontinuity.

Claim 17

A waveguide discontinuity detection apparatus for determining the magnitude and location of each discontinuity within the waveguide comprising: a pulse modulated signal source; a first detector; a second detector; a first wave propagation path connecting said signal source to one end of the waveguide under test and connecting said waveguide end to said first detector; a second wave propagation path connecting said source to said second detector; said first path being equal in length to said second path; and each of said discontinuities being located at a distance from said detectors and proportional to the time difference between the appearance of a signal, generated by said source, at said second detector and the appearance of said generated signal, reflected by a discontinuity, at said first detector; means connected tO said first and second detector for comparing said time difference and indicating the location of each discontinuity relative to said waveguide end; means for reflecting mounted on said waveguide end; each of said waveguide discontinuities having a magnitude proportional to the ratio of a signal amplitude reflected from said means for reflecting to the signal amplitude reflected from each discontinuity; and means connected to said first detector for comparing the signal reflected by the reflecting means and reflected by each discontinuity for indicating the magnitude of each discontinuity.

Claim 18

The apparatus of claim 12 wherein said signal source is of constant frequency having a pulse wave form output.

Claim 19

A waveguide discontinuity measurement system for determining the magnitude and location of a particular discontinuity of interest within a waveguide having a plurality of discontinuities, comprising: a pulse modulated signal generator; a first detector; a first microwave transmission path connecting said generator to the waveguide, and said waveguide to said first detector for propagating reflecting pulses from said waveguide to said first detector; said waveguide having a shorting means for reflecting substantially all of the incident pulse to said first detector; means connected to said first detector for comparing the amplitude of said pulse reflected from said waveguide shorting switch and from a particular discontinuity within the waveguide, for determining the magnitude of said particular discontinuity. a second detector; a second path connecting said generator to said second detector; said second path having a propagation length, with respect to the signal frequency, equal to the length of said first path from said generator to said shorting switch to said first detector; means connected to said first and second detectors for comparing the time of arrival of a pulse transmitted from said generator through said second path to the time of arrival of said pulse propagated from said generator to said waveguide through said first path and reflected by said waveguide to said first detector for determining the location of said particular discontinuity.

Claim 20

A waveguide discontinuity measurement system for determining the magnitude and location of a particular discontinuity of interest within a waveguide having a plurality of discontinuities, comprising: a pulse modulated signal generator; a first detector; a first microwave transmission path connecting said generator to the waveguide, and said waveguide to said first detector for propagating reflecting pulses from said waveguide to said first detector; said waveguide having a shorting means for reflecting substantially all of the incident pulse to said first detector; means connected to said first detector for comparing the amplitude of said pulse reflected from said waveguide shorting switch and from a particular discontinuity within the waveguide, for determining the magnitude of said particular discontinuity. a second detector; a second path connecting said generator to said second detector; said second path having a propagation length, with respect to the signal frequency, equal to the length of said first path from said generator to said shorting switch to said first detector; means connected to said first and second detectors for comparing the time of arrival of a pulse transmitted from said generator through said second path to the time of arrival of said pulse propagated from said generator to said waveguide through said first path and reflected by said waveguide to said first detector for determining the location of said particular discontinuity.

Claim 21

The apparatus of claim 14 wherein said signal source is of constant frequency having a pulse waveform output.