A software-defined and filter-free 0–26.5 GHz ultra-wideband RF transmitter enabled by photonics

An innovative software-defined photonics-based RF transmitter is presented. Stemming from a single widely tunable up-converting stage, the architecture exhibits large instantaneous and operating bandwidths, and avoids bulky RF components like synthesizes, multiple mixers and bandpass Alters. A dual-use scenario (radar plus communication) is created in laboratory, where an operative bandwidth from near DC up to 26.5 GHz is experimentally demonstrated. Laboratory constraints limited the total current bandwidth that in principle can be extended up to 40 GHz and beyond, exploiting commercially available electro-optical devices with better performance. The transmitter has reached a carrier leakage suppression and a sideband suppression greater than 45 dB, exceeding the preperformance of the filter-free electronic counterparts. The system also presents high linearity and dynamic range in terms of linear dynamic range (141 dB/Hz) and an IMD3-limited spurious free dynamic range (107 dB/Hz
^2/3
). In addition, photonic integration will provide a chip-scale solution with improved compactness and environmental stability.