Frequency Agile Broadband Communications System

The success of missile defense relies on state-of-the-art communications systems that can provide broad bandwidth, agility and security. The goal of this project is to develop a broadband, frequency agile, secure, wireless communications system suitablefor aerial and space platforms. The unique aspect of our approach is to use microwave-photonic techniques that provide flexibility and performance, not currently achievable with conventional microwave and millimeter-wave based wireless systems. Theenabling technology, developed by F&H, is an electro-optic microchip laser that generates an optical carrier with one or more millimeter wave subcarriers up to 100 GHz, with extremely low phase noise. A photodetector at the base station removes the opticalcarrier and recovers the millimeter wave subcarrier, which becomes the wireless carrier at the antenna. The input information and coding with, an aggregate bandwidth of 10 GHz, are placed on the wireless carrier in the optical domain. Therefore, the onlyfunction of the wireless base station has is to amplify and radiate the millimeter wave carrier with the information. Fast frequency hopping and sophisticate coding like OFDM, MSFK and MPSK are benefits. Preliminary experimentations have proved theviability of this approach. Our dynamically tunable electro-optic lasers will provide numerous benefits to advanced communications systems. The carrier frequency will be directly tunable from 10 to 100 GHz (currently photodiode limited to 60 GHz). Can befrequency hopped at durations of 1 ns. Optical wavelengths possible are 1.06, 1.34 and 1.55 microns with output powers of 100 mW to 1 Watt. The phase noise of the optical carrier is expected to be below -90 dBc/Hz @ 10 kHz offset with time jitter below0.01 picoseconds. This will enable insertion of this technology into varied military and commercial communication systems.