Fully Integrated On-Chip True Time Delay Phased Array Antenna Feed

ABSTRACT: Silicon photonics is booming in areas of system level integration involving electronics and photonics. It has exclusive advantages over other electronic or photonic subsystems when stands alone. On-chip true time delay antenna feed can be significantly advanced using the technologies garnered through silicon photonics. Electronic true time delay antenna feed intrinsically suffers from beam squint effect, to which photonics is the only viable solution. An integration of optical true time delay lines and electronic components would not only solve the beam squint effect but also significantly improve the performance of the antenna in terms of cost, size, weight, and power. Omega Optics, Inc., and the Nanophotonics group at the University of Texas at Austin, propose a high-density integrated 128-channel true time delay module utilizing fishbone slow light waveguide that can operate up to 200 GHz through frequency doubling and quadrupling. A linear modulator with composite phase shifters is proposed to achieve 130 dB/Hz^2/3 spur free dynamic range. The proposed module integrates a total of 512 photonic and electronic components including grating couplers, electrical-optical modulators, beam splitters, slow light waveguides, strip waveguides, and thermal phase shifters. With fishbone waveguides, the integration density will increase by five times compared to 2D photonic crystal waveguide based approach, and a time delay > 1 ns can be generated. Which is sufficient to steer antenna wave for 60 degree. The research team not only has intensive experiences in silicon photonics, optical true time delay technology, and design kit development, but also work closely with silicon photonics foundry, which assure the delivery of high quality results.; BENEFIT: The market for high performance phased array radars is a rapidly growing area in both civilian applications (mobile satellite communication, ground-based wireless communications, etc.) and military applications (air surveillance, air defense, etc.). The total market will reach $19.6 billion by 2018. The proposed 1D photonic crystal based true-time-delay lines provide an enabling technology for the construction of high-performance, squint-free, large RF bandwidth beam formers that can be monolithically integrated with other active components and provide distributed control, processing, and reconfiguration functions to achieve active and smart antenna systems with enhanced capabilities. It shows significant advantages over conventional true time delay lines in terms of cost, size, weight, and power consumption, which make it of special interest to aircraft, especially fighters, where capacity and load are limited and precious.