Variable impedance test probe
AssigneeHewlett-Packard Development Company, L.P.
InventorsSachin Navin Chheda, Robert William Dobbs, Andrew Barr
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Abstract
A variable impedance test probe of the present invention comprises a first signal conductor, a first ground reference conductor, and a first dielectric element disposed between the first signal conductor and the first ground reference conductor. The dielectric element is configured to selectively vary an impedance of the first signal conductor relative to the ground reference conductor.
Claims19
A variable impedance test probe comprising:
- a first signal conductor and a first ground reference conductor;
- and
- a first dielectric element disposed between the first signal conductor and the first ground reference conductor and being configured to vary an impedance of the first signal conductor relative to the ground reference conductor.
A test probe comprising:
- a first conductor configured for carrying a first portion of a differential signal;
- a second conductor configured for carrying a second portion of a differential signal;
- a first variable dielectric chamber disposed between the first conductor and the second conductor and configured for holding a variable volume of dielectric fluid a third ground reference conductor spaced from the first conductor;
- a second variable dielectric chamber disposed between the first conductor and the third ground reference conductor and configured for holding a variable volume of dielectric fluid to vary the distance between the first conductor and the third ground reference conductor a fourth ground reference conductor spaced from the second conductor;
- a third variable dielectric chamber disposed between the second conductor and the fourth ground reference conductor and configured for holding a variable volume of dielectric fluid to vary the distance between the second conductor and the fourth ground reference conductor;
- and
- wherein varying the volume of one or more of the first, second, and third chambers results in varying the differential impedance of the first conductor and the second conductors relative to the third and fourth ground reference conductors.
A test probe comprising:
- means for carrying a first test signal relative to a ground reference;
- and
- means for varying an impedance of the first test signal relative to the ground reference.
A method of testing signal integrity attributes in a target conductive element, the method comprising:
- variably controlling an impedance of a probe, between a test signal conductor of the probe and a ground reference conductor of the probe, to substantially match an impedance of the target conductive element;
- and applying a test signal from the probe to the target conductive element.
A method of testing signal attributes carried on a differential pair of first and second conductive elements, the method comprising:
- providing a first signal test lead of a first signal conductor and providing a second signal test lead of second signal conductor with an impedance of the first and second signal conductors relative to a ground reference;
- applying the first signal test lead to a first differential signal conductive element and applying the second signal test lead to a second differential signal conductive element;
- measuring a signal attribute exhibited by the differential pair of first and second conductive elements;
- and
- selectively varying the impedance of the probe by selectively varying the impedance of the first signal conductor and the second signal conductor, relative to the ground reference.
Dependencies are inferred from the claim text.