Radio Frequency Digital to Analog Converter and Signal Combiner

Modern radio frequency (RF) communication systems require more efficient and flexible use of wider bandwidths at higher carrier frequencies, which can be achieved only by direct digital representation of the RF signal itself, for both receivers and transmitters. Previously, HYPRES built, delivered to US Army CERDEC, and demonstrated an advanced digital-RF receiver for military satellite communications (MILSATCOM X and Ka bands). This was built around a custom bandpass superconducting analog-to-digital converter (ADC) that samples at 30 GigaSamples/s. The present project focuses on the development of an RF digital-to-analog converter (RF-DAC) for the corresponding digital-RF transmitter, that handles at least 1 GHz instantaneous bandwidth with an 8 GHz carrier (X-band). This will be implemented using state-of-the-art SiGe BiCMOS chips that can sample at rates of 30 GS/s and above. The transmitter chip design will involve digital filters and up-converters in addition to the DAC itself. Similar advanced digital transmitters should be extendable to MILSATCOM Ku (14 GHz) and Ka (30 GHz) bands.