Controller for Ground
Station
14 GHz Microwave Amp
Solid State Power Amplifiers
(SSPA’s) are commonly used in communication ground
stations for uplinking microwave signals to satellites. Stephen
Turner used ExpressPCB to
build a digital interface to this 25 Watt, 14 GHz SSPA. The
interface board is shown
above integrated directly into the transmitter's enclosure. The
typical use for this equipment
would be transmitting voice, video and data to satellites for
mobile news gathering
applications.
The interface board provides an
RS-232 or RS-485 serial interface to control and
monitor the functions of the transmitter. The firmware reads the
transmitter's current,
temperature and fault conditions in a feedback loop to control
its output gain. The
bare circuit boards were ordered using ExpressPCB's 4 Day
Production Service
which includes a silkscreen and solder masks.
See the
board layout in more detail
The controller is based on the Scenix SX28AC/SS surface mount 28
pin processor. In
combination with the Parallax OEM BS2SX kit, the processor is
programmable in Basic.
The onboard memory, A/D, D/A and temperature sensors are all
interfaced to the
Scenix processor using the SPI serial bus.
The photographs are courtesy of Stephen Turner
Copyright © 2007 Stephen Turner