3 GS/s 7 GHz BW 12 Bit MuxDAC for direct microwave signal generation over L, S or C bands

In advanced applications such as digital radar, frequency hopping encryption data links, Micro-Wave Waveform Design Systems, Ultra Wide Bandwidth communications and software defined radio, the need for instantaneous bandwidth often drives system design decisions. The availability of powerful signal processors able to handle broadband signal vectors is not an issue anymore; the bottleneck is now the availability of high sampling rate and high linearity data converters, ADC (Analogue to Digital Converter) for reception and DAC (Digital to Analogue Converter) for transmission. Access to high speed data converters enabling up and down conversion directly in the L Band, S Band and C Band will allow system architects to operate in the digital world ever closer to the antenna, thus simplifying drastically receiver or transmitter architecture by removing costly Intermediate Frequency stages. Broadband DAC´s are key enabling components which open up new design opportunities for direct digital Synthesizer systems. In this regard, this paper describes an innovative multimode 12 Bit 3GS/s MuxDAC, offering 46ps full swing rise time (that is 7.5 GHz analogue output bandwidth), based on a 200 GHz SiGeC bipolar Technology, which enables direct micro wave signal generation of up to 1.2 GHz width arbitrary waveforms directly in the high IF (L S or C Band) region closer to the Antenna. Beyond system and DAC design considerations this paper includes extended capability measurement performed on silicon. This DAC is turning Software Defined Micro-Wave or Direct Micro-Wave Synthesis (DMWS) from pure concept into proven reality up to C-Band.