Impedance matched test probe

摘要

A probe for coupling electrical test equipment to a selected point of an electrical device has a spring loaded rigid pin 32 for contacting the selected point, connected to a wave guide comprising a coaxial cable 44 of substantially constant characteristic impedance for coupling the test equipment to the pin. A second probe tip 62 is attached to spring biassed sleeve 60 which is in turn connected to the outer conductor of the cable. In a second embodiment a flexible dielectric board 15 is provided on its lower surface with conductor strips 13 which connect the probe tips to coaxial cables 31. A support member 25 acts as a ground plane and the arrangement is such that the impedance characteristics of the strips 13 and member 25 are matched to that of the cables 31.