2013 IEEE International Symposium on Phased Array Systems & Technology
15 - 18 October 2013 Waltham, Massachusetts USA
Tutorial: Phased Arrays and Digital Beam Forming: Basics, Past-Accomplishments, Amazing-Developments & Future-Trends
Phased Arrays and Digital Beam Forming: Basics, Past-Accomplishments, Amazing-Developments & Future-TrendsDr. Eli Brookner, Principal Engineering Fellow, Raytheon
Summary: This tutorial covers: Array basics: electronic scanning, embedded element gain, time delay steering, elements, array factor, u-v space, errors, mutual coupling, feeds; Digital Beam Forming (DBF): Advantages of DBF; Number of bits Nb needed; Reduction of Nb with increasing number of subarrays and sampling rate; Spurious free dynamic range; Grating lobes due to forming multiple beams at the subarray level and due to frequency scanning of subarray; How overlapped subarrays reduces these grating lobes; limited scanning; advances in phased-arrays leading up to the latest amazing developments and future trends future potential, including metamaterials, graphene, DBF, micromachining, very low cost arrays, signal processing.Array Basics: Array phase scanning, embedded element gain, array factor, subarray time delay steering, thinned arrays, array elements, array blindness, mutual coupling, feeds; grating lobes due to forming multiple beams at the subarray level; how overlapped subarrays reduces these grating lobes); limited scan phased arrays. Digital beam forming (DBF) Basics: Advantages of; DBF at subarray and element level; Number of bits Nb needed; Reduction of Nb with increasing number of subarrays and sampling rate; Spurious free dynamic range, i.e., dynamic range as limited by intermods due to receiver and A/D nonlinearities.Systems: 3, 4, 6 face “Aegis” systems developed by China, Japan, Australia, Netherlands, USA. Low Cost Packaging: Raytheon funding development of low cost flat panel X-band array using COTS type printed circuit boards (PCBs); MA-COM/Lincoln-Lab. developing low cost S-band flat panel array using PCBs, overlapped subarrays and a T/R switch instead of a circulator; Extreme MMIC: 4 T/R modules on single chip at X-band costing ~$10 per T/R module; Digital Beam Forming (DBF): Israel and Australia “Aegis” AESAs have an A/D for every element channel, a major breakthrough; Lincoln Lab and AFRL developing X-band technology for element level DBF having 600 MHz instantaneous bandwidth; Low cost DBF at element for on-the-move Ethernet by IMST; Lincoln Lab using 2W chip increases spurious free dynamic range of receiver plus A/D by 20 dB; Radio Astronomy scientists looking at using arrays with DBF; Materials: GaN can now put 5X to 10X the power of GaAs in same footprint; Will be helped by use for PCs, notebooks, cell phones, servers and GaN LED industry where they are expected to replace incandescent bulbs, latter $100 billion industry; SiGe for backend, GaN for front end of T/R module; Metamaterials: Focus 6X beyond diffraction limit at 0.38 μm; 40X diffraction limit, λ/80, at 375 MHz; In cell phones provides antennas 5X smaller (1/10th λ) having 700 MHz-2.7 GHz bandwidth; Provides isolation between antennas having 2.5 cm separation equivalent to 1m separation; n-doped graphene has negative index of refraction, first such material found in nature; potential being pursued for low cost electronically steered metamaterial passive phased array. Very Low Cost Systems: Valeo Raytheon (now Valeo Radar) developed low cost, $100s only, car 25 GHz 7 beam phased array radar; about 2 million sold already, more than all the radars ever built up to a very few years ago; Commercial ultra low cost 77 GHz Roach radar on 72mm2 chip with >8 bits 1 GS/s A/D and 16 element array; Low cost 240GHz 4.2x3.2x0.15 cm2 5 gm radar for bird inspired robots and crawler robots, Frequency scans 2ox8o beam ±25o; DARPA has goal to build 28,000 element 94 GHz array costing $1/element, 50W total RF peak power. SAR/ISAR: Principal Components of matrix formed from prominent scatterers track history used to determine target unknown motion and thus compensate for it to provide focused ISAR image; Army Research Lab demonstrated 12 dB reduction in sidelobes for forward looking SAR back projection images for IED ultra wideband radar by use of Recursive Sidelobe Minimization (RSM) Algorithm; Technology and Algorithms: MEMS: reliability reaches 300 billion cycles without failure; Has potential to reduce the T/R module count in an array by a factor of 2 to 4; Provides microwave filters 200 MHz wide tunable from 8-12 GH; COSMOS: DARPA revolutionary program: Will allow integration of III-V, CMOS and opto-electronics on one chip without bonded wires leadmg to higher performance, lower power, smaller size, components; MIMO (Multiple Input Multiple Output): Where it makes sense; Graphene: Potential for terahertz clock speed transistors, non-volatile memory, flexible displays and camouflage clothing, self cooling, switch with 100,000 to 1 on/off ratio, IBM producing 200 mm wafers with RF devices; Electron spin: For memory; Atomic Memory: 12 iron atoms for 1 bit of memory; could provide hard drive with 100X density; Revolutionary 3-D Micromachining: integrated circuitry for microwave components, like 16 element Ka-band array with Butler beamformer on 13X2 cm2 chip; 3D Display: 3D display from 2D image without the need for special eyeglasses; Superconductivity: We may still achieve superconductivity at room temperature. Superconductivity recently obtained for first time with iron compounds; DARPA UHPC (Ubiquitous High Performance Computing) Program: 100 GFlops in cell phone using only 2 W instead of the present required 600 W for the same throughput. Goal of DARPA-Intel UHPC program is for 100 to 1000 reduction in computer required power by 2018; Biodegradable Array of Transistors or LEDs: Imbedded for detecting cancer or low glucose; can then dispense chemotherapy or insulin. BiographyBEE: The City College of the City of New York, ’53; MEE and DrSc: Columbia University ’55 and ’62.Dr. Eli Brookner has been with Raytheon since 1962, where he is a Principal Engineering Fellow. There worked on ASDE-X airport radar, ASTOR Air Surveillance Radar, RADARSAT II, Affordable Ground Based Radar (AGBR), major Space Based Radar programs, NAVSPASUR S-Band upgrade, COBRA DANE, PAVE PAWS, Missile Site Radar (MSR), COBRA JUDY Replacement, THAAD, Brazilian SIVAM, SPY-3, Patriot, BMEWS, UEWR, Surveillance Radar Program (SRP), Pathfinder marine radar, Long Range Radar (upgrade for 68 ATC ARSRs), COBRA DANE Upgrade, AMDR, Space Fence, 3DELRR. Prior to Raytheon he worked on radar at Columbia University Electronics Research Lab. [now RRI], Nicolet and Rome AF Lab. Received IEEE 2006 Dennis J. Picard Medal for Radar Technology & Application “For Pioneering Contributions to Phased Array Radar System Designs, to Radar Signal Processing Designs, and to Continuing Education Programs for Radar Engineers”; IEEE ’03 Warren White Award; Journal of the Franklin Institute Premium Award for best paper award for 1966; IEEE Wheeler Prize for Best Applications Paper for 1998. Fellow of IEEE, AIAA, MSS. Member of the National Academies Panel on Sensors and Electron Devices for Review of Army Research Laboratory Sensors and Electron Devices Directorate (SEDD)Published four books: Tracking and Kalman Filtering Made Easy, John Wiley and Sons, Inc., 1998; Practical Phased Array Antenna Systems (1991), Aspects of Modern Radar (1988), and Radar Technology (1977), Artech House. Gives courses on Radar, Phased Arrays and Tracking around the world (25 countries). Over 10,000 attended these courses. Banquet/keynote speaker twelve times. >230 papers, talks and correspondences, >100 invited. Six paper reprinted in Books of Reprints (one in two books). Contributed chapters to three books.
Attendees of this tutorial will also receive a hardback copy of the book “Practical Phased-Array Antenna Systems” by Eli Brookner