Patent ID: 11909442
Assignee: RAYTHEON BBN TECHNOLOGIES CORP.
Field: Telecommunications (Electrical engineering)
Classification: CPC H  G | IPC G  H

Claim 17:
18. The photonic RF I/Q signal correlator of claim 1, wherein an I/Q photo receiver of the M I/Q photo receivers comprises:
an optical balanced in-phase coupler of index m having a first input, a second input, a first output and a second output, where m=0 to M−1, the optical balanced in-phase coupler configured to receive and combine the mth different delayed first RF modulated optical signal S1′(t−-mΔτ) and one of the m second RF modulated signal S2′(t) to output a first in-phase coupled RF modulated optical signal and a second in-phase coupled RF modulated optical signal;
a balanced photodetector coupled to the optical balanced in-phase couplers, wherein the balanced photodetector is configured to receive the first in-phase coupled RF modulated optical signal and the second in-phase coupled RF modulated optical signal from the optical balanced in-phase coupler and output the in-phase (I) integrated correlated weight coefficient χreal(m);
an optical balanced quadrature-phase coupler of index m having a first input, a second input, a first output and a second output, the optical balanced quadrature-phase coupler configured to receive and combine the mth different delayed first RF modulated optical signal S1′(t−mΔτ) and one of the m second RF modulated signal S2′(t) phase shifted by 90 degrees to output a first quadrature phase coupled RF modulated optical signal and a second quadrature phase coupled RF modulated optical signal; and
a balanced photodetector coupled to the optical balanced quadrature-phase coupler, wherein the balanced photodetector is configured to receive the first quadrature phase coupled RF modulated optical signal and the second quadrature phase coupled RF modulated optical signal from the optical balanced quadrature-phase coupler and output the quadrature-phase (Q) integrated correlated weight coefficient χimag(m).