Wafer probes

A wafer probe comprising:

• a planar, generally triangular plate-form support member having first and second opposite main faces and having an end region at a smaller end thereof which is shaped to permit said end region to be brought into close proximity with a component under test,
• an amplifier mounted on the support member at said end region and having an input terminal, an output terminal and first and second power supply terminals,
• a conductive probe element attached to the amplifier and electrically connected to said input terminal,
• a transmission line mounted on said planar support member and connected to the output terminal for transmitting signals from the amplifier to a measurement instrument, said transmission line being formed by a strip of conductive material deposited on the first main face of the support member and a layer of electrically conductive material deposited on the second main face of the support member in electrically insulating relationship with respect to said strip,
• first and second conductors for connecting the power supply terminals respectively to a power supply, said first and second conductors comprising strips of conductive material deposited on the first main face of the support member, and
• by-pass capacitors spaced from said end region of the support member and connected between said first and second conductors and said layer of electrically conductive material.