A 6-GHz 64×3-bit ROM for DDS application in GaAs technology

A 64 × 3-bit read-only memory (ROM), employing dual decoder architecture, is designed in GaAs HBT technology. It is adopted in Direct Digital Synthesizer (DDS) for phase-to-amplitude conversion. To enhance the performance of the ROM, the memory cell is designed with a transistor to assign both a high and low bit value. The ROM draws a current of 130 mA from a -4.6 V power supply. Using 700 GaAs HBT transistors, the total area is 1.2 × 0.6 mm
²
. The ROM is integrated as part of an 8-bit DDS, which is measured to work functionally at 6 GHz. This paper demonstrates a fastest GaAs HBT ROM for DDS.