Method of resonance analysis for electrical fault isolation
A method, system and computer readable medium for determination of distance to an electrical fault within a device. A signal generator excites the device with an electrical input signal. The device comprises an open circuited electrical transmission line. A frequency domain analyzer analyzes part of the signal reflected from the device for determination of the locations of resonant frequency of the signal within the device. A computer calculates the distance to the fault within the device, based on the resonant frequency. The distance to the fault is one quarter wavelength distance into the device at the resonant frequency. A frequency sweeper sweeps the frequency of the input signal and repeated calculation of the distance to the fault made at a plurality of resonant frequencies during the frequency sweep confirms the distance to the fault by convergence of the result of the repeated calculations to substantially the same location.
1. A method of determining distance to an electrical fault within a device, the method comprising:
exciting the device with an electrical input signal, the device comprising an open circuited electrical transmission line;
analyzing, by a frequency domain analyzer, a part of the signal reflected from the device;
determining, from the analyzing, locations of resonant frequency of the signal within the device; and
calculating the distance to the fault within the device based on the resonant frequency, wherein the distance to the fault (DTF) is calculated as
DTF
=
.25
×
Velocity
factor
×
3
×
10
8
f
R
=
0.25
λ
where
f
R
is
the
resonant
frequency
,
and
Velocity
factor
is
a
property
of
the
material
of
the
device
.
2. The method of claim 1 wherein the distance to the fault is one quarter wavelength distance into the device at the resonant frequency.
3. The method of claim 1 , the method further comprising confirming the distance to the fault by repeatedly calculating the distance to the fault at a plurality of resonant frequencies in a frequency sweep of the signal, the confirmation comprising convergence of the result of the repeated calculations to substantially a same location.
4. The method of claim 3 wherein confirming the distance to the fault by repeatedly calculating the distance to the fault at a plurality of resonant frequencies comprises applying the equation
DTF
=
0.25
N
×
velocity
factor
×
3
×
10
8
f
rN
=
0.25
N
λ
Where
f
rN
is
the
Nth
resonant
frequency
of
the
frequency
sweep
;
velocity
factor
is
a
property
of
the
material
of
the
device
;
and
N
is
an
integer
that
varies
as
1
,
2
,
3
,
…
and
goes
on
.
5. The method of claim 1 wherein the signal comprises a sinusoidal voltage waveform and a sinusoidal current waveform ninety degrees out of phase with the voltage waveform, and the resonant frequency locations in the device comprise locations at which the current is zero.
6. The method of claim 1 wherein the device comprises one of a substrate trace or a micro-bump interconnect or a through-silicon via (TSV) chain.
7. The method of claim 6 wherein the device comprises silicon and a non-silicon substrate through which a TSV chain is routed.
8. The method of claim 1 wherein the device comprises a hyperchip structure or an embedded multichip interconnect bridge.
9. The method of claim 1 wherein the distance to the fault is the distance to the first location of resonant frequency in the device.
10. The method of claim 1 wherein nodes and antinodes of the signal occur at multiples of quarter wavelengths from the fault.
11. The method of claim 1 wherein an impedance profile of the device is the value of the voltage wave divided by the value of the current wave along a wavelength within the device at the resonant frequency.
12. The method of claim 11 wherein the signal is applied to the device via a signal divider, and the ratio of reflected signal to applied signal is used to determine the impedance profile at the input of the device.
13. The method of claim 12 wherein the location of the resonant frequency is determined from the impedance profile.
14. A system for determination of distance to an electrical fault within a device, the system comprising:
a signal generator configured to excite the device with an electrical input signal, the device comprising an open circuited electrical transmission line;
a signal divider configured to apply the input signal to the device;
a frequency domain analyzer configured for analysis of a part of the signal reflected from the device and for determination from the analysis the locations of resonant frequency of the signal within the device; and
at least one hardware processor configured to:
calculate the distance to the fault within the device based on the resonant frequency,
calculate an impedance profile of the device as the value of the voltage wave divided by the value of the current wave along a wavelength within the device at the resonant frequency; and
calculate the ratio of reflected signal to applied signal to determine the impedance profile at the input of the device.
15. The system of claim 14 wherein the distance to the fault (DTF) is calculated as
DTF
=
.25
×
Velocity
factor
×
3
×
10
8
f
R
=
0.25
λ
where
f
R
is
the
resonant
frequency
,
and
Velocity
factor
is
a
property
of
the
material
of
the
device
.
16. The system of claim 14 wherein the distance to the fault is one quarter wavelength distance into the device at the resonant frequency.
17. The system of claim 14 , the system further comprising a frequency sweep device configured to sweep the frequency of the input signal to confirm the distance to the fault by repeated calculation of the distance to the fault at a plurality of resonant frequencies during a frequency sweep of the input signal, the confirmation comprising convergence of the result of the repeated calculations to substantially a same location.
18. The system of claim 14 wherein the signal comprises a sinusoidal voltage waveform and a sinusoidal current waveform ninety degrees out of phase with the voltage waveform, and the resonant frequency locations in the device comprise locations at which the current is zero.
19. The system of claim 18 wherein confirmation of the distance to the fault by repeated calculation of the distance to the fault at a plurality of resonant frequencies comprises application, by the at least one hardware processor, of the equation
DTF
=
0.25
N
×
velocity
factor
×
3
×
10
8
f
rN
=
0.25
N
λ
Where
f
rN
is
the
Nth
resonant
frequency
;
velocity
factory
is
a
property
of
the
material
of
the
device
;
and
N
is
an
interger
that
varies
as
1
,
2
,
3
,
…
and
goes
on
.
20. The system of claim 14 wherein the device comprises one of a substrate trace or a micro-bump interconnect or a through-silicon via (TSV) chain.
21. The system of claim 20 wherein the device comprises silicon and a non-silicon substrate through which a TSV chain is routed.
22. The system of claim 14 wherein the device comprises a hyperchip structure or an embedded multichip interconnect bridge.
23. The system of claim 14 wherein the distance to the fault is the distance to the first location of resonant frequency of the input signal in the device.
24. The system of claim 14 wherein nodes and antinodes of the signal occur at multiples of quarter wavelengths from the fault.
25. The system of claim 14 , wherein the at least one hardware processor is further configured to calculate the location of the resonant frequency from the impedance profile.
26. A system for determination of distance to an electrical fault within a device, the system comprising:
a signal generator configured to excite the device with an electrical input signal, the device comprising an open circuited electrical transmission line;
a frequency domain analyzer configured for analysis of a part of the signal reflected from the device and for determination from the analysis the locations of resonant frequency of the signal within the device; and
at least one hardware processor configured to:
calculate the distance to the fault within the device based on the resonant frequency,
calculate an impedance profile of the device as the value of the voltage wave divided by the value of the current wave along a wavelength within the device at the resonant frequency; and
calculate the location of the resonant frequency from the impedance profile.