Ultra-broadband differential voltage probes

A balanced test probe apparatus, comprising:

• a first probe having a first surface mount resistor electrically connected between a first probe tip and a first center conductor, said first probe including a first conductive outer shield coaxially located with said first center conductor;
• a first coaxial cable electrically connected to said first probe at a first end;
• a second probe having a second surface mount resistor connected between a second probe tip and a second center conductor, said second probe including a second conductive outer shield coaxially located with said second center conductor, said first conductive outer shield and said second conductive outer shield being electrically coupled at intervals substantially along the entire length;
• and
• a second coaxial cable of substantially equal length with said first coaxial cable, said second coaxial cable electrically connected to said second probe at a second end;
• said second surface mount resistor having a resistance value equal to said first surface mount resistor;
• said first probe including at least one third surface mount resistor electrically connected between said first center conductor and a distal end of said first outer shield;
• and
• said second probe including at least one fourth surface mount resistor electrically connected between said second center conductor and a distal end of said second outer shield.

A passive test probe apparatus for use with a signal analysis device, comprising:

• a probe body;
• a conductive probe tip supported by and axially protruding from said probe body;
• a center conductor supported by said probe body;
• a first surface mount resistor electrically connected between said probe tip and said center conductor;
• an outer conductive shield coupled to said probe body, said outer conductive shield insulated from said probe tip and said center conductor;
• and
• second and a third surface mount resistors electrically connected in parallel between said center conductor and a distal end of said outer conductive shield.

A passive test probe apparatus for use with a signal analysis device, comprising:

• a conductive probe body;
• a conductive probe tip supported by and protruding from said probe body;
• a center conductor supported by and substantially electrically insulated from said probe body;
• an outer conductive shield coupled to said probe body, said outer conductive shield being insulated from said probe tip and said center conductor;
• a first surface mount resistor electrically connected between said probe tip and said center conductor;
• and
• two 100 ohm second surface mount resistors electrically connected in parallel between said center conductor and said probe body adjacent a distal end of said probe body.