Agilent Technologies L4400 - Manual (Page 150)

138 L4400 User’s Guide
7 L4445A Microwave Switch/Attenuator Driver
L4445A Microwave Switch/Attenuator Driver
The L4445A consists of a driver interface instrument (L4445A) and one or
more remote modules (34945EXT). The first remote module is electrically
attached to the driver instrument using a provided cable (equipped with
9- pin D- Sub connectors). The first remote module attached to the driver
instrument is referred to as the master module. Additional remote
modules are referred to as slave modules.
Additional remote modules (34945EXT) are connected in a daisy- chain
fashion using RJ- 45 connectors and cables. A cable is provided with each
module. Up to eight remote modules can be controlled by a single L4445A.
Each remote module is divided into four banks for switch control.

Each bank has a connector for a distribution board. The distribution
boards provide an electrical connection between the user- supplied
microwave switches or attenuators and the remote module. A variety

of distribution boards are available that provide the most common
connections to Agilent microwave switches and attenuators. A screw
terminal distribution board is also available for other devices. A list of the
available distribution boards is shown on
page 154 . The microwave
switches or attenuators and the cables connecting them to the distribution
boards are not supplied with the L4445A.
The cables and the remote modules allow the microwave switches and
attenuators to be located closer to the device under test. This helps to
keep the signal transmission paths shorter and corresponding signal

losses lower.
Microwave switches and attenuators have larger power requirements than
other switch devices. The L4445A instrument is able to power 24 Volt
switches or attenuators on the first (master) remote module. Additional
remote modules (slaves) require an external power supply since no power
is supplied through the expansion bus cable. The first (master) remote
module may use either an external power supply or the L4445A to supply
high power devices or devices requiring drive voltages other than 24 Volt.
Each remote module has screw terminals for the external power supply
connections.