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A phased array antenna system includes an RF front end, a radome, and an optical calibrator embedded in the radome for enabling in-situ calibration of the RF front end. The optical calibrator employs an optical timing signal generator (OTSG), a Variable Optical Amplitude and Delay Generator array (V

A phased array antenna system includes an RF front end, a radome, and an optical calibrator embedded in the radome for enabling in-situ calibration of the RF front end. The optical calibrator employs an optical timing signal generator (OTSG), a Variable Optical Amplitude and Delay Generator array (VOADGA) for receiving the modulated optical output signal and generating a plurality of VOADGA timing signals, and an optical timing signal distributor (OTSD). The in-situ optical calibrator allows for reduced calibration time and makes it feasible to perform calibration whenever necessary.

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What is claimed as new and desired to be protected by Letters Patent of the United States is: 1. A phased array antenna system, comprising: an RF front end; a radome; and an optical calibrator integral with the radome for enabling in-situ calibration of the RF front end, wherein the optical calibra

What is claimed as new and desired to be protected by Letters Patent of the United States is: 1. A phased array antenna system, comprising: an RF front end; a radome; and an optical calibrator integral with the radome for enabling in-situ calibration of the RF front end, wherein the optical calibrator comprises: an optical timing signal generator (OTSG) situated adjacent the radome and having a DFB laser source for generating an optical calibration signal; a modulator for modulating the light calibration signal and generating a modulated optical output signal; a Variable Optical Amplitude and Delay Generator array (VOADGA) for receiving the modulated optical output signal and generating a plurality of VOADGA timing signals; and an optical timing signal distributor (OTSD) situated inside the radome for receiving the plurality of VOADGA timing signals, the OTSD having a matrix-addressable PLC having N horizontal waveguides and N vertical waveguides for receiving the VOADGA timing signals, said wave guides having a plurality of intersections, each intersection having a photodiode positioned thereon for receiving a portion of the VOADGA timing signals and for generating a proportional electrical output signal for subsequent processing and calibrating of the phased array antenna. 2. A phased array antenna system as in claim 1, wherein the VOADGA includes a plurality of variable optical attenuators coupled to delay generators for each generating an output timing signal. 3. A phased array antenna system as in claim 1, further comprising a microstrip antenna with a micro RF antenna positioned on the photodiode. 4. A phased array antenna system as in claim 3, further comprising a carrier for holding a plurality of the microstrip antennas, and wherein each microstrip antenna is coupled to an optical fiber. 5. A phased array antenna system as in claim 4, further comprising a Frequency Selective Surface (FSS) for holding the plurality of microstrip antennas. 6. A phased array antenna system as in claim 5, wherein the FSS is multi-ring. 7. A phased array antenna system as in claim 1, further comprising a multi-stack radome assembly. 8. A phased array antenna system as in claim 1, wherein the photodiode is operated in a bias-free photovoltaic mode. 9. A phased array antenna system as in claim 1, wherein a micro RF antenna pattern is integrated with the PLC. 10. An optical calibrator for a phased array antenna housed within a radome, comprising: an optical timing signal generator (OTSG) having a DFB laser source for generating an optical calibration signal, a modulator for modulating the light calibration signal and generating a modulated optical output signal, and a Variable Optical Amplitude and Delay Generator array (VOADGA) for receiving the modulated optical output signal and generating a plurality of VOADGA timing signals; and an optical timing signal distributor (OTSD) housed within the radome for receiving the plurality of VOADGA timing signals, the OTSD having a matrix-addressable PLC having N horizontal waveguides and N vertical waveguides for receiving the VOADGA timing signals, said wave guides having a plurality of intersections, each intersection having a photodiode positioned thereon for receiving a portion of the VOADGA timing signals and for generating a proportional electrical output signal for subsequent processing and calibrating of the phased array antenna. 11. An optical calibrator as in claim 10, wherein the VOADGA includes a plurality of variable optical attenuators coupled to delay generators for each generating an output timing signal. 12. An optical calibrator as in claim 11, further comprising a microstrip antenna having the micro RF antenna positioned on the photodiode. 13. An optical calibrator as in claim 10, wherein each intersection of the matrix-addressable PLC includes an upper-cladding layer that is etched so as to permit evanescent beam coupling in a selected direction. 14. An optical calibrator as in claim 10, wherein each waveguide is single mode. 15. An optical calibrator as in claim 10, wherein each photodiode is a photovoltaic mode photodiode. 16. An optical calibrator as in claim 10, wherein each photodiode is a PIN InGaAs photodiode. 17. An optical calibrator as in claim 10, wherein each photodiode is selected such that mutual time delay differences are less than a target design timing resolution. 18. An optical calibrator as in claim 10, wherein the PLC has a timing precision of up to about 0.005 ps.