The following is work done by the first satellite team.
The CAPE1 communications subsystem consisted of a TNC (Terminal Node Controller), Transceiver, RF Amplifier and Antennas. A Microchip PIC18LF452 microcontroller acts as the TNC, which will create and decode the AX.25 protocol which contains the team’s data. The transceiver being used is the Chipcon CC1020, which was chosen because of its extremely small size, low power, and low cost. The CC1020 gives the CAPE team the ability to communicate with the satellite.
For CAPE2, the communication team will develop a forward error correction (FEC) encoder onboard the TNC to enhance telemetry with coding gain. Due to the difficulties with the CC1020, a new radio will probably be researched.
Firmware documentation for the flight version of the communications system firmware resides at http://svn.jonathanwagner.net/cape/CAPE1/Communications/Software/Documentation/trunk/latex/refman.pdf (right-click and save as).
The code is available for anonymous subversion checkout at http://svn.jonathanwagner.net/cape/CAPE1/Communications/Code/ and can be browsed by clicking the link in your browser.
Here are some ideas for CAPE 2 radio:
Single Chip Transcievers
Chipcon CC1000 is the radio first tested by CalPoly.
Chipcon CC1020. This is the radio employed on CAPE 1.
Analog Devices AD8346. QAM quadrature modulator. Could prove useful for other ISM bands.
Notice the inputs and outputs.
List of important system documents. PDF needs [http://www.adobe.com/products/acrobat/readstep2.html Acrobat Reader] installed.