Fig. 4: Conceptual illustration of an ultra-broadband analogue photonic-electronic front end.
From: 320 GHz photonic-electronic analogue-to-digital converter (ADC) exploiting Kerr soliton microcombs
The front end relies on a single Mach-Zehnder modulator (MZM) for simultaneous readout of an array of bow-tie slot antennas. Within this array, each antenna is optimised for a specific frequency band (centre frequencies fA, fB, fC) and coupled to the ground-signal-ground (GSG) coplanar transmission line of the MZM, thus allowing for efficient multiplexing of various received millimetre-wave signals on the same optical carrier. The resulting optical signal is transmitted through optical fibres and further processed in the photonic-electronic signal processing engine, see Fig. 1 above. Assuming an MZM with sufficient bandwidth, the illustrated concept allows for efficient acquisition of ultra-broadband signals with overall bandwidths of hundreds of GHz. In comparison to conventional millimetre-wave receivers, the illustrated concept replaces bulky and costly analogue components such as RF filters, intermediate frequency (IF) amplifiers, and RF mixers with a compact and robust fibre-coupled photonic-electronic front-end converter
