Current small satellite platforms such as CubeSats, require robust and versatile communication subsystems that allow the reconfiguration of the critical operation parameters such as carrier frequency, transmission power, bandwidth, or filter roll-off factor. In this paper, a reconfigurable Analog Back-End for CubeSat communications is proposed. This prototype is implemented using CAD software, on a 6-layer PCB of 10 cm^2 to implement a transceiver that operates from 0.070 to 6 GHz and complying with CubeSat and IPC-2221 standards. An Software-Defined Radio approach implemented on a baseband processor is used for control purposes. Measurements showed that the signal power at the output of the proposed analog back-end is suitable to feed the subsequent antenna subsystem.