7Microwave 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.

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L4400 User’s Guide

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Agilent Technologies L4400 manual L4445A Microwave Switch/Attenuator Driver