Photonic Receiver

The photonic receiver front end (tuner) developed at OEwaves is designed to simplify the architecture of conventional microwave receivers and address the need to substantially reduce the size and power requirements. The photonic receiver is based on the patented technology of ultra-high quality factor (Q) crystalline whispering gallery mode (WGM) optical resonators. Resonators made with lithium niobate optical were first employed as modulators and then as a receiver (see "Whispering-gallery-mode electro-optic modulator and photonic microwave receiver", V.S. Ilchenko, A.A. Savchenkov, A.B. Matsko, and L. Maleki, JOSA B Vol.20, p.333-342; US Pats 6,473,218, 7,043,117). The scheme takes advantage of the inherent optical nonlinearity of lithium niobate that results in mixing an optical carrier and sidebands within the crystal. These optical fields create beat frequencies at the output of a photodetector; a device that functions both as a mixer in the optical domain and as a filter. OEwaves has demonstrated photonic front ends operating at X and Ka bands based on the above principle. The projected sensitivity of these front end receivers can exceed -150 dBm. The linearity of the system, measured as spurious-free dynamic range, can reach beyond 100 dB Hz2/3 in 100 MHz bandwidth. A major feature of OEwaves' photonic front end receivers is that only miniature optical components are used in their fabrication, and so they can be packaged in a very small volume, about one cubic centimeter. This is especially attractive for those mm-wave applications where the size of the receiver is important. Traditional RF solutions are not available in such a small form-factor. A wideband receiver architecture developed at OEwaves based on tunable photonic filters is capable of receiving signals with a small instantaneous bandwidth across 20 GHz, centered at any frequency in the mm-wave range. This architecture results in a significant reduction of size, mass, power, and cost in comparison to conventional wideband microwave receivers.