Design, implementation, and preliminary tests of the
emergency beacon transmitter of the OUFTI-1
nanosatellite of the University of Liège, as of March 2013
Architecture
Prototype
Functions
Modulator
Nicolas Crosset
+, Xavier Werner
+, Jonathan Pisane
+, Amandine Denis°, Valéry Broun
$, Jacques G. Verly
++
Dept. of EECS, University of Liège; °LTAS, University of Liège, BELGIUM ;
$Engineering Dept., HEPL
• The beacon transmits a Morse code message
consisting of a header and some key measurements. • The Morse code message is converted into an
analog waveform driving an AM modulator
• The transmitter is always ON except if shut down from ground
• The operating frequency is 145.980 MHz
µC A (MSP430) µC B (MSP430) PORT 4 UART 1 PORT 4 UART 1 ADC (PORT 6) PORT 1 ADC (PORT 6) PORT 1 8 measurements 8 status bits 8 status bits 8 measurements C o nt ro l D at a Mod A (RF2516) Mod B (RF2516) Frame Frame Ampli A (AH117) Ampli B (AH117) Combiner Combiner
From COM subsystem
On/off On/off 10 dBm 10 dBm 26 dBm 26 dBm 23 dBm 20 dBm Filter