Advanced InP-Based DDS System (Q-DOT Research Proposal 39-1385)

An advanced wideband (>2GHz), fast-switching (<100 ns), high-resolution (10-14bit) direct digital synthesis (DDS) system is proposed using InP heterojunction bipolar transistor (HBT) technology. An innovative digital-to-analog converter (d/a) compensation technique offers 10 to 20 dB improvement in signal- to-noise ratio (SNR) and spurious-free dynamic range (SFDR). A unique DDS system architecture facilitates rapid switching between standard sinusoidal and user-defined waveforms. Innovative digital and d/a circuits are proposed to realize the DDS system. The proposed InP HBT process enables clock rates beyond 20 Gs/s. The proposed combination of architecture and circuit innovation combined with an advanced InP HBT process will facilitate the production of a DDS system providing an order of magnitude performance improvement. During Phase I, the DDS' system architecture will be defined and key cells simulated to assess the design's feasibility. Prototype DDS system subcircuits will be fabricated and tested during Phase II. The significant government and commercial potential for this advanced DDS system is expected to quickly lead to Phase III product development and commercialization.