Relaxing the ADC Sampling Rate in High-Resolution Radar Systems Through Photonic Analogue-to-Digital Conversion

A wavelength division multiplexing (WDM) photonic (Ph)-analogue-to-digital converter (ADC) architecture with time stretching that enables digitizing a high-resolution radar signal with low sampling rate ADCs is presented and evaluated using numerical simulation. Results show that, for a radar signal with a resolution of 3 cm, 4 samples along the radar pulse width can be captured by a 20-channel WDM Ph-ADC using ADCs with 1 GS/s, leading to a localization error of 0.75 cm. For a 10-channel WDM Ph-ADC using ADCs with 1.25 GS/s, up to 3 samples along the radar pulse width can be acquired, which results in a localization error of 1.2 cm.