Aeronix’s SD-ERNST is a high performance digital modulation signal generator. It is capable of covering 4 simultaneous independent frequency bands. The SD-ERNST is a processor FPGA based system designed to evolve to meet its users needs and enable unique customer specific modifications. Common applications include interference testing, antenna testing, and radio receiver isolation testing. Each of the 4 channels are capable of independent modulation, independent frequency selection, independent selectable output power levels , and independent associated status. The system is for use with TDMA, FDMA, and CDMA waveforms.