RF channelizer based on parametrically generated combs derived from a single master seed

A radio frequency (RF) channelizer comprising:

• a master laser configured to generate a reference beam at a reference frequency;
• a splitter configured to split the reference beam into first and second beams;
• an RF reference oscillator;
• a first modulator module configured to convert the first beam into a first modulated beam comprising a multitude of frequencies spaced from the reference frequency by integer multiples of a first RF frequency that is referenced to the RF reference oscillator;
• a second modulator module configured to convert the second beam into a second modulated beam comprising a multitude of frequencies spaced from the reference frequency by integer multiples of a second RF frequency that is referenced to the RF reference oscillator;
• a first seed tone generator configured to derive at least three seed beams from the first modulated beam, at least two seed beams with high optical power with frequency spaced by 2ΔfP and a given seed beam with frequency offset by ΔfP/2 from one of the other seed beams, where ΔfP/2 is equal to or a multiple of the first RF frequency;
• a signal modulator configured to modulate a received RF signal to be channelized onto the given seed beam, wherein the first seed tone generator is further configured to filter and combine the at least three seed beams into a single first seed tone beam;
• a first parametric mixer configured to receive and convert the first seed tone beam into a first comb comprising a comb of lines spaced by 2ΔfP and multicasted copies of the modulated given seed beam with spacing ΔfP and offset in frequency by ΔfP/2 from the comb of lines spaced by 2ΔfP;
• a second seed tone generator configured to derive from the second modulated beam a second seed tone beam comprising at least two second seed tones, spaced by (ΔfP+δ)/n, where n is a positive integer and the absolute value of δ is the channel spacing, or resolution bandwith, of the channelizer, and where (ΔfP+δ)/n is a multiple of the second RF frequency;
• a second parametric mixer configured to receive and convert the second seed tone beam into a second comb with frequency pitch (ΔfP+δ)/n;
• a first optical filter configured to receive and separate the first comb into a plurality of first filtered beams, the center frequency of each first filtered beam corresponding to a frequency of an individual line of the second comb;
• a second optical filter configured to receive and separate the second comb into a plurality of second filtered beams, each second filtered beam corresponding to an individual line of the second comb;
• and
• a coherent detection array configured to select, combine, and detect corresponding pairs from the first filtered beams and the second filtered beams, and further configured to provide as an output a contiguous bank of channelized coherent I/Q down-converted intermediate frequency (IF) signals, spaced in frequency by the absolute value of δ covering the bandwidth of the received RF signal.

A method for channelizing a received radio frequency (RF) signal comprising the following steps:

• generating a reference beam having a reference frequency;
• splitting the reference beam into first and second beams;
• converting the first beam into a first modulated beam comprising a multitude of frequencies spaced from the reference frequency by integer multiples of a first RF frequency that is referenced to an RF reference oscillator;
• converting the second beam into a second modulated beam comprising a multitude of frequencies spaced from the reference frequency by integer multiples of a second RF frequency that is referenced to the RF reference oscillator;
• deriving a first seed tone beam comprising at least two seed frequencies spaced by ΔfP, where ΔfP is a multiple of the first RF frequency, from the first modulated beam;
• deriving a second seed tone beam comprising at least two seed frequencies spaced by (ΔfP+δ)/n where (ΔfP+δ)/n is a multiple of the second RF frequency, from the second modulated beam;
• converting the first seed tone beam into a first comb with a first parametric mixer;
• modulating a received RF signal onto the first comb;
• converting the second seed tone beam into a second comb with a second parametric mixer;
• separating the first comb into a plurality of first filtered beams, the center frequency of each first filtered beam corresponding to the frequency of an individual line of the second comb;
• separating the second comb into a plurality of second filtered beams each second filtered beam corresponding to an individual line of the second comb;
• and
• selecting, combining, and detecting corresponding pairs from first filtered beams and the second filtered beams, and providing at the output of a coherent detection array a contiguous bank of channelized coherent I/Q down-converted intermediate frequency (IF) signals, spaced in frequency by the absolute value of δ covering the bandwidth of the received RF signal.