SBIR-STTR Award

Pacific Wave Industries, Inc. ("PWI") propose to develop a new optically controlled phased array antenna system which is based upon a serial-feed concept. This system represents a major change from conventional parallel-feed; approaches and offers major simplifications in both optical and microwave components. The system we have designed offers true time delay for beem steering and requires but a single laser, optical modulator and time delay element. The system is uniquely robust in that it can have redundant components at modest cost. It is extremely broadband and can handle 2-D arrays and multiple beams with minor modifications. Our approach is uniqely photonic in design in that the use of fiber-optic techniques, such as low loss delay lines, is intrinsic to this new architecture. This distinguishes it from the current generation of optically controlled systems which merely substitute optical components for appropriate RF elements. The concept we propose has been validated with a simple two-element two-wavelenght transmit prototype. Due to the dynamic nature of the system, we therefore propose to evaluate this concept with an intensive computer modeling and simulation. This evaluation will be used in determining the parameters of the final system implementation. Serial-feed concept opens up a possibility for a low cost, affordable RF Sensor system. The unique timing capability of proposed concept is naturally suited to the implementation of multibit true time delay steering for two dimensional arrays. Applications range from Army air defense radars and FAA air traffic radars to vehicle collision avoidance Systems.

Keywords:
Optical Control True Time Delay Serial-Feed Tunable Laser Chirped Grating Phased Array

Based upon our successful demonstration of a serially fed 1D optically controlled phased array, we propose to develop a 2D 4 x 4 array. This 2D system will operate in both transmit and receive functions and have a bandwidth of 4 GHz about center frequency of 18 GHz. It will be configured for operation in several modes with both long and short pulse capability. Sing our new Ladder distribution network we will also extend this work to a 4 x 4 element subarray. This will be the first of six such units which form an 18 GHz array having a 20 x 5D beam pattern. Several newly developed elements will also be incorporated in this next generation system. Three tunable lasers will be used in cascaded timing modules to provide extremely precise phase control for both azimuth and elevation steering. The use of a second delay line will permit the system to operate at extremely high repetition rates. This serially fed system will require a minimum number of laser and grating delay lines. It will therefore be suitable for many commercial applications where costs and weight are important and yet performance is critical. The directivity and instantaneous bandwidth of this antenna will make it useful for high frequency communication links.

Benefits:
This program will develop the next generation of optically controlled phased array radars which will be lightweight and extremely broadband. The use of our serial feed will open up new applications for the military, FAA and commercial markets. These range from air traffic control to weather radars, vehicle collision avoidance and highly directional communication systems.

Keywords:
Phased Array Antenna True Time Relay 2-D System Optical Fibre Grating Serial Feed Wavelength Tunable