Agilent Technologies B1500A Training Manual page 68

Simplifying RF Connections
Triax is not necessary...bias currents are > 1 nA.
Use triax to coax adapters with floating guard.
Bias Network
RF in
Bias
F
Above 1 nA guarding is of little use. Cable capacitance has a negligible effect on the bias port. Use
the floating guard triax(m) to BNC(f) adapter at the B1500A rear panel. Then use standard coax
BNC cables. Use sense to minimize series resistance error. 100 mV errors can occur in bias voltages
if remote sensing is not used.
Some recent bias tees from Agilent Technologies are specially designed to mate easily to triax SMU
ports.
DUT
Bias Sensing
S
SMU1
5-48
Bias Network
RF out
Bias Bias Sensing
F S
SMU2
Module 5
Basic Measurement