Embodiments in accordance With the invention alloW fordirect digitization of Wideband RF signals Without the needfor doWn conversion or the use of mixers. In one embodiment,a preprocessed input analog signal is applied to three Wideband Mach-Zehnder interferometers (MZI), e.g., modulators,to amplitude modulate a continuous Wave laser signal. Aphotodetector is used at the output of each interferometer toconvert the amplitude modulated optical signal into an electrical signal. This is followed by an ampli?er and a loW-pass?lter (LPF) to increase the signal level and to reduce the noise.A small ml- comparator bank at the output of each LPF isclocked at the sampling frequency and encodes the electricalsignal from each detector into a thermometer code that represents an integer value Within the modulus. A ?eld programmable gate array (FPGA) then combines the thermometercode from each comparator bank in order to generate a moreconvenient 6-bit binary representation, i.e., a digital output.
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