Flann Microwave
SD5902 Waveguide Switch Driver
SD5902
Doc No ER15 Version 1.3
June 2020
5
GENERAL INFORMATION
Product Description
The SD5902 Waveguide Switch Driver is designed to control and operate Flann Microwave’s range of
Series 333 Precision Waveguide Switches. It provides the interface between an IEEE 488 Bus (GPIB) or
Universal Serial Bus (USB) and Precision Waveguide Switches, and allows for manual operation with
display of current status. The SD5902 will drive either a 2 channel or a 3 channel switch without the need
to reconfigure.
Flann’s Precision Waveguide Switches offer unrivalled repeatability, high reliability and extremely long
service life, making them ideal for automated test and systems applications. They are
four port devices and
are available with either a two- or three-channel rotor. (See Figure 1). They provide high R.F. isolation
between non coupled ports by means of an efficient choke design. Accurate channel to port alignment and
excellent repeatability are achieved by a light and positive rotor locating mechanism.
Switch Type
Position 1
Position 2
Position 3
Position 4
3-Channel
(-3E)
P1
P3
P2
P4
P1
P3
P2
P4
P1
P3
P2
P4
P1
P3
P2
P4
2-Channel
(-2E)
P1
P3
P2
P4
P1
P3
P2
P4
Figure 1: Precision Waveguide Switch Rotor Positions
Series 333 switches, in conjunction with the SD5902, allow the user to choose between ‘Precision Mode’
and ‘Speed Mode’. There are two alternative rotor positions for each of the switch channel configurations,
spaced by 180°, that have identical waveguide paths. In Precision Mode, only one of these two alternative
rotor positions is used, ensuring optimum microwave path repeatability. In Speed Mode, switching time is
minimised by using all possible rotor positions.
All switches are supplied in the E plane configuration as standard.
The opto electronic position sensors provide either two or four signals depending upon the type of rotor (2
or 3 channel). The outputs of the sensors are TTL compatible, positive logic. The motor output shaft drives
the microwave switch rotor through a loose coupling, which is designed to allow the precision indexing
mechanism to operate correctly without excessive settling time. Full power is only applied to the motor
during switch repositioning.
The Model Number and Serial Number of the Waveguide Switch Driver will be found on the rear panel.
Similar information for the Microwave Switch will be found on the switch top cover. It is essential to quote
the model and serial numbers of both the Waveguide Switch Driver and the instruments connected to it
when contacting the manufacturer for service information.
