SBIR-STTR Award

A candidate advanced Airborne Early Warning (AEW) developmental radar concept has been identified for insertion of photonic components to improve performance, reduce weight and cost and add to the overall reliability and maintainability of the system. The next step to be carried out is a detailed evaluation of demonstrated hardware approaches for specific application in the candidate AEW radar system. Key component areas to consider are photonic true time delay devices, lightwave transmit-receive beamforming manifolds and monolithic microwave/opto-electric integrated circuit T/R modules for the active aperture. Optical time delay networks are broadband and eliminate the need to compensate for beam squinting in large aperture arrays. Lightwave beamforming manifolds for phased arrays have been demonstrated for both transmit and receive applications that can be packaged very compactly and are comparatively small in size and weight. In addition, this study would seek to exploit the developments of monolithic microwave and photonic gallium arsenide circuits carried out under the ARPA sponsored MIMIC Program during the past five years that has enabled special and multi-purpose transmit/receive (T/R) modules to be manufactured by several companies. ANTICIPATED

Benefits:
The photonic technology insertion to be investigated for the AEW surveillance radar application lends itself also, to space-based and ground airport surveillance radars used for commercial and general aviation traffic control purposes. Further, the commercialization of fiber-optic data and personal communication systems for the information superhighway are anticipated to require compact, lightweight, photonically controlled active arrays capable of producing multiple, simultaneous, steerable beams on the ground, at sea and in space.

The principal technical objective of this Phase II Program is the reduction to practice of a breadboard and prototype photonic beamformer for application to an advanced Airborne Early Warning surveillance radar system to be installed on a carrier-based EX platform by Boeing Company as a replacement for the U.S. Navy E2C - Hawkeye. The fiber-optic Rotman lens (FORL), or beamforming network, is a lightwave analog of the well known Rotman-Turner microwave lens that has found extensive application in microwave electronic warning receiver systems that must operate over broad bandwidths. The Phase II Photonic Radar System Beamformer Development effort described in this proposal comprises an eighteen month set of basic tasks that will demonstrate the feasibility of the optical Rotman beamformer concept with fabrication and text of a breadboard model. The initial tasks include a comprehensive analysis of analog fiber-optic link components and performance parameters to be carried out, in part, through a cooperative agreement with the technical staff of the Lightwave and Microwave Subsystems Group, MIT Lincoln Laboratory. An optional set of tasks is also proposed that extends the Phase II Program for an additional twelve months in order to develop a prototype fiber-optic Rotman beamforming network for demonstration with an existing conformal phased array. The prototype beamformer will meet the functional requirements of both sequential transmit beam and multiple simultaneous receive beam capability for the EX application. The system simulation of the prototype FORL will be conducted with a scale model wing-mounted EX antenna array that previously had been fabricated and tested by Boeing Company at their Seattle, Washington antenna test range facility. The fiber-optic Rotman lens will have important long-range application to a class of phased array antenna beamformers. The UHF/L-band operation represented by the EX surveillance radar are a class of military systems that will directly benefit by insertion. Potentia non-military applications of the photonic hardware include surveillance radars employed by the Federal Aviation Administration for en route air traffic control, both ground-based, and geo...