Electrooptic millimeter-wave downconversion and vector demodulation using phase-modulation and optical filtering

Here we have described an electrooptic technique for downconverting and demodulating high-speed vector modulated mmW signals. By using phase-modulation, the complexity of the optical transmitting end is reduced. By using phase-modulation with optical filtering, the complexity of the optical receiving end is only slightly greater than that of the IM-DD case. Furthermore, this approach allows for electrooptic frequency multiplication permitting less expensive components to be utilized. Based on this technique, we implemented a phase-diversity RF photonic RX and demonstrated downconversion of a mmW QPSK wireless signal to a suitable IF for digitization and follow-on processing. From these results, we believe that this approach is promising for the development of phase-sensitive, high-speed RF photonic receivers.