A software defined radio system is described. The software defined radio comprises a modem bank at least partially defined by software running on a processor. The SDR also comprises an antenna group translator coupled to the modem bank. Further, the SDR comprises at least one antenna coupled to the antenna group translator. The antenna group translator comprises an antenna switch comprising RF filtering functions and RF front ends comprising frequency conversion functions. To greatly reduce the complexity and cost of the system, the architecture includes an antenna group translator having RF front end hardware that is specific to the frequency band of each antenna. In addition, the modem bank includes banded frequency converters.