Phased-Array and Adaptive-Array Fundamentals and Their Recent Advances

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Spring 2017 Course

Dates: Mondays, Feb. 27, March 6, 13, 20, 27, April 3, 10, 24, May 1, 15 (Snow/make-up days May 22, June 5, 12)

Time: 6 – 9 pm

Decision date: Monday, February 20, 2017

Early Registration Date deadline Extended: Friday, February 24, 2017

Before Early Registration Date:
Members $300
Non-members $340

After Early Registration Date:
Members $340
Non-members $370

WHERE: MITRE Corporation
202 Burlington Road
Bedford, MA

Phone 781-245-5405
Fax 781-245-5406

If paying by check, the check must be received before the appropriate dates for Early Registration and Decision Dates.

Make Checks payable and send to:
IEEE Boston Section
One Centre Street, Suite 203
Wakefield, MA 01880

Speaker: Dr. Eli Brookner, Raytheon (Retired)

Course Overview:

Phased-Array and Adaptive-Array Fundamentals and Their Recent Advances

“Practical Phased Array Antenna Systems”, Dr. Eli Brookner, Editor, Artech House, 1991, Hardcover, 258 pages, List Price $179, Hardcover, 258 pages. Covers array fundamentals: phase and time-delay steering; grating lobes for 1- and 2-dimensional arrays; effects of errors and failures on gain, sidelobes and angle accuracy; array weighting, thinning, blindness, mutual coupling, elements, phase-shifters and feeds; limited field of view (LFOV) arrays; SPY-1; example design.

This course is based on the book entitled Practical Phased Array Antenna Systems by Dr. Eli Brookner. The book covers array basics and fundamentals which do not change with time. The course, the book and the notes will provide an ideal introduction to the principles of phased array antenna design and adaptive arrays. The course material and notes cover in addition recent developments in phased arrays updated to 2017.

With the explicitly tutorial approach the course and book offers a concise, introductory-level survey of the fundamentals without dwelling on extensive mathematical derivations or abstruse theory. Instead a physical feel will be given. The book provides extensive curves, tables and illustrative examples. Covered in easy terms will be sidelobe cancellation, full adaptive array processing without suffering its computation complexity (through the use of adaptive-adaptive array processing also called beam-space processing and eigenbeam processing). Finally, Space-Time Adaptive Array (STAP) for airborne platforms will be explained and related to the displaced phase center antenna (DPCA).

All Attendees of the class will receive trial trial license of MATLAB and Phased Array System Toolbox from MathWorks in addition to a set of examples which help demonstrate key array concepts covered in the course.

This course is intended for the engineer or scientist not familiar with phased-array antennas as well as the antenna specialist who wants to learn about other aspects of phased-array antenna systems as well as get the latest developments in array systems, such as: MIMO, metamaterial arrays, Extreme MMIC arrays, stealthing and cloaking. The major emphasis will be on the system aspects of phased-arrays.

Lecture #1. Monday February 27; Phased Array Fundamentals: Electronically Scanned Array (ESA) explained with tube COBRA DANE used as example. Covered will be: Near and Far Field Definitions, Phased Steering, Switched-Line Phase Steering; Time Delay Steering, Subarraying, Array Weighting, Monopulse, Duplexing, Array Thinning, Embedded Element, dual polarized circular waveguide element, advantage of triangular lattice over square lattice, Tour of COBRA DANE (6 stories high) via color slides.

Lecture #2. Monday March 6; Linear Array Fundamentals: Conditions for no grating lobes; beamwidth vs scan angle; sine space; Array Factor; sidelobe level vs antenna beamwidth; directivity; antenna efficiency factors; array weightings; array frequency scanning; array bandwith.

Lecture #3. Monday March 13; Planar Arrays: Array Factor; array separability; sine-space (sinα-sinß space, T- space); grating lobes location for triangular and rectangular lattice; directivity; very useful bell curve approximation; array thinning system issues.

Lecture #4. Monday March 20; Array Errors: Effects of element phase and amplitude element errors and element failures; simple physical derivation of error effects; paired echo theory; subarray errors; quantization errors; examples.

Lecture #5. Monday March 27; Radiating Elements: Waveguide; dipole; slotted waveguide; microstrip patch; stacked patch; notch (wideband); spiral; matching (wide-angle); waveguide simulator; practical limitations, mutual coupling and array blindness; scattering matrix; design procedure; polarization miss-match loss.

Lecture #6. Monday April 3; Active Phased Arrays: 2nd generation solid state hybrid active electronically scanned array (AESAs) covered using PAVE PAWS as example, T/R Module Introduced, Cross Bent Dipole Element, Mutual Coupling, Array Blindness, Tour of PAVE PAWS (6 stories) via color slides. 3rd Generation AESAs: THAAD (TPY-2), SPY-3, IRIDIUM, F-15 APQ-63(V)2, APG-79, XBR, AMDR and upgraded Patriot; GaAs and GaN microwave integrated circuits (Monolithic Microwave Integrated Circuit, MMIC).

Lecture #7. Monday April 10; Array Feeds: Corporate and space fed; Reactive (lossless) and matched (Wilkinson); even/odd node analysis. Serial; Ladder; Lopez; Blass; Radial, Butler matrix; microstrip/stripline; Rotman Lens; SLQ-32; PATRIOT space-fed array; reflectarray.
System Considerations: sequential detection, beam shape loss; receiver and A/D dynamic range; polarization miss-match loss; AESA noise figure and system temperature taking into account array mismatch.

Phase Shifters: Diode switched-line, hybrid-coupled, loaded-line; ferrite phase-shifters: non-reciprocal latching; diode vs ferrite; MEMS (Micro-Electro-Mechanical Systems) and its potential for a low cost ESA.

Lecture #8. Monday April 24; Limited Scan (Limited Field of View [LFOV]) Arrays: Explained using simple high school optics for TPS-25, 1st Electronically Scanned Array (ESA) put in production. Fundamental Theorem specifying minimum number of phase shifters needed for a specified scan angle. Method for realizing this minimum using overlapped array antenna elements as with HIPSAF lens array system and Microwave Landing System (MLS); reflector; randomized oversized elements; LFOV using sum and difference patterns; use of spatial filters to reduce grating lobes and sidelobes. Hemispherical Coverage Dome Antenna.

Lecture #9. Monday May 1; Phased Array Amazing Advances and Breakthroughs —
Part 1: SYSTEMS: Patriot now has GaN active electronically scanned array (AESA) providing 360o coverage, now a 2015 state-of-the-art AESA radar system; S-band AMDR provides 30 times the sensitivity and number of tracks as SPY-1D(V); 3, 4, 6 faced “Aegis” radar systems developed by China, Japan, Australia, Netherlands, USA;

EXTREME MMIC: can now put on single chip 256-Element 60 GHz Transmit Phased Array, such arrays may be used for the internet-of-things and in cell phones which by 2020 is expected to number 50 billion, expect such single chip arrays to cost only few dollars in future; All the RF circuitry for mm-wave automobile radars being put on a chip, in future such radars could be produced for just a few dollars; Valeo Raytheon (now Valeo Radar) developed low cost, $100s, car 25 GHz 7 beam phased array radar; ~2 million sold.

LOW COST PACKAGING: Raytheon, Rockwell Collins, Lincoln-Lab./MA-COM and South Korea developing low cost flat panel S and X-band AESAs using commercial components, practices and printed circuit boards (PCBs); DIGITAL BEAM FORMING (DBF): Israel, Thales, Australia and Lockheed Martin(LM) have under development array with an A/D for every element channel (LM array has 172,000 channels and A/Ds); Raytheon developing mixer-less direct RF A/D having >400 MHz instantaneous bandwidth, reconfigurable between S and X-band.

MOORE’S LAW: Not dead yet; Slowed down but has much more to go; potential advance via: graphene, spintronics, memristors, synaptic transistors and quantum computing.

MATERIALS: GaN can now put 5X to 10X the power of GaAs in same footprint, 38% less costly, 100 million hr MTBF, Raytheon invested $200 million to develop GaN.

METAMATERIALS: Material custom made (not found in nature): 20 and 30 GHz metamaterial electronically steered antennas demonstrated December 2013 transmission to satellites and back, goal is $1K per antenna, how this antenna works explained for first time; 2-20GHz stealthing by absorption simulated using <1 mm coating; target made invisible over 50% bandwidth at L-band using fractals; 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; The Army Research Laboratory in Adelphi MD has funded the development of a low profile metamaterial 250-505 MHZ antenna having a /20 thickness; Provides isolation between antennas with 2.5 cm separation equivalent to 1 m separation; used for phased array WAIM. Sidelobe Cancellers (SLC): The simple single-loop, feed-forward canceller is introduced in easy physical terms. This is followed by a discussion of the simple single-loop feedback canceller with and without hard limiting. The normalized feedback SLC will also be covered. Next the multiple-loop SLC (MSLC) will be covered. Applied to the MSLC will be the Gram-Schmidt, Givens and Householder orthonormal transformation methods. Systolic array implementations will be given. Lecture #10. Monday May 15; Fully Adaptive Arrays: The optimum weight for a fully adaptive array is developed using a very simple derivation. Methods for calculating this optimum weight are given using the Sample Matrix Inversion (SMI) algorithm, the Applebaum-Howells adaptive feedback loop method, a recursive method, and Gram-Schmidt, Givens and Householder orthonormal transformations developed for the tracking problem and for the MSLC. The use of eigenvector beams and a whitening filter will also be developed. It will be shown how the latter reduces the transient response. Methods for obtaining the benefits of a fully adaptive array without its high computation and large transient time disadvantages are given. These are the adaptive-adaptive array processing procedures, the use of eigenbeam space, and the method of finding the largest eigenvectors and in turn their eigenbeams. The STAP algorithm covered. Phased Array Amazing Advances and Breakthroughs -- Part 2: NEW MIMO (MULTIPLE INPUT MULTIPLE OUTPUT) ARRAYS: Explained in simple physical terms rather than with heavy math. Gives attendees an understanding of where it makes sense to use. Contrary to what is claimed MIMO array radars do not provide 1, 2 or 3 orders of magnitude better resolution and accuracy than conventional array radars; also contrary to claims made MIMO should not provide better minimum detectable velocity for airborne radars. MIMO and JAMMING: MIMO does not provide better barrage-noise-jammer, repeater-jammer or hot-clutter rejection than conventional array radars. 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. Technology and Algorithms: A dual polarized, low profile, (/40), wideband (1:20) antenna can be built using tightly coupled dipole antennas (TCDA); Lincoln Lab increases spurious free dynamic range of receiver plus A/D by 40 dB; MEMS: Has potential to reduce the T/R module count in an array by a factor of 2 to 4; Can provide microwave filters tunable from 8-12 GHz that are 200 MHz wide; LOW COST PRINTED ELECTRONICS: 1.6 GHz printed diodes achieved (goal 2.4 GHz). ELECTRICAL AND OPTICAL SIGNALS ON SAME CHIP: Will allow data transfer at the speed of light; IR transparent in silicon. BIODEGRADABLE ARRAYS OF TRANSISTORS OR LEDS: Imbedded under skin for detecting cancer or low glucose. QUANTUM RADAR: Has potential to defeat stealth targets. NEW POLARIZATIONS: OAMS, (ORBITAL ANGULAR MOMENTUM) unlimited data rate over finite band using new polarizations?? Your Registration Includes: 1 textbook; 15 Reprints; over 800 Vugraphs; trial license of MATLAB and Phased Array System Toolbox from MathWorks with examples demonstrating key array concepts covered in the course.