Specifications

Using RF and Microwave Modules
Using 34980A mainframe
modules to construct your
high frequency test system
has the following attributes:
Benefits:
• Convenient – no special
hardware mounting
• Easy re-configuration
using flexible cables
• Easy to add switches
by adding switch modules
• Easy to replace switches
by replacing switch modules
Limitations:
• Longer signal paths between
DUT and instruments
• Higher insertion loss
with longer, flexible cables
• Low-loss flexible cables
are very expensive
• Signal phase is harder
to control between
multiple paths
Using Discrete Switches
and Attenuators
In many applications, it is
critical to locate the switching
as close as possible to the DUT.
Discrete switches, attenuators,
couplers, filters, etc. can be
mounted near or within the
test fixture. These discrete
devices can be controlled
by a Digital Output Module,
but a better solution is to use
a Switch/Attenuator Driver
that is specifically designed
to provide all of the following
features:
• Digital Outputs to drive
relay coils in either pulsed
or constant voltage mode
• Digital Outputs that can drive
LEDs used in control panels
• Digital Inputs to sense the
position of the switches
• Power distribution between
the power supply, switches,
and control logic
• Report generation that
indicates how often switches
have been actuated
The 34980A provides the 34945A
Switch Driver module to
control discrete RF/Microwave
switches and attenuators external
to the 34980A mainframe. The
L4445A is the LXI Module ver-
sion of the 34945A. Both these
products provide all of the
above features and extend the
switching capacity to hundreds
of RF/microwave switches at
frequencies over 20 GHz.
Using discrete switches and
attenuators to construct your
high frequency test system has
the following attributes:
• Specific frequency range
components can be selected
• High performance Semi-rigid
or Hand-conformable coax
cabling can be used
• Switches can be mounted
within the test fixture
of the DUT
• All high frequency signal
routing can be contained
within a shielded box
• Shorter cables reduce
insertion loss and increase
signal integrity
• Exact length signal paths
are now possible to control
phase of signals
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