| Abstract |
Summary form only given. Phased arrays have seen a phenomenal growth in the last three decades. With the growing need for phased arrays for radar and communication systems (like the DD-X, F-22, JSF and Milstar), phased arrays are on the threshold of even more extensive use around the world. These accomplishments together with future trends will be covered: Passive phased arrays like the PATRIOT, COBRA DANE, AEGIS, ARTHUR, EMPAR, ARABEL, RAFALE RADANT; discrete solid-state active phased arrays like the Swedish Erieye, Israeli Phalcon airborne early-warning system and tactical ballistic missile defense system, PAVE PAWS; integrated-circuit, solid-state MMIC active phased arrays like the L-band cellular-satellite IRIDIUM/spl reg/, Swedish ASEA, Japanese FSX, European COBRA, Dutch APAR, European AMSAR, British MESAR-2 and SAMPSON, and USA F-22, F-18, JSF, THAAD, SPY-3, MEADS systems; The state-of-the-art of active array T/R modules-MMIC and discrete; time-delay steering; narrow-band and octave-bandwidth arrays; single- and multiple-beam array systems; digital beam forming and its advantages (SMART-L, and -S; Discoverer-ll); The development of sophisticated adaptive array algorithms and hardware like: 1) space-time adaptive processing (STAP), 2) sidelobe canceller with 63 degrees of freedom in a compact disc size package now possible, 3) adaptive nulling for jammer and clutter cancellation with massively parallel systolic arrays using the Givens, Gram-Schmidt and householder algorithms, 4) adaptive-adaptive array processing; The rapid advance in A/D converter technology which now makes it possible to do direct A/D sampling at RF frequencies without the need to do down conversion, e.g., sampling at UHF at a 3 GHz rate with an 8 bit A/D at room temperature; The phenomenal advances in signal and data processing speed and memory which will make advanced algorithms feasible - by the year 2015 it will be possible to put 600 GFLOPS on a 14 inch by 12 inch card and 64 Gbits on a chip, by the year 2010 3 TIPS on a TMS320 chip; ultra-low sidelobe antennas; research geared to reducing cost and complexity like through use of: 1) row-column ferroelectric lens antennas; 2) continuous transverse stub (CTS) voltage-variable dielectric (VVD) antennas, 3) 95 GHz reflectarray using two 4 inch MMIC wafers, 4) micro-electro-mechanical semiconductor (MEMS) phase shifters; arrays that electronically scan optical beams; multi-user (radar, communications, ESM, ECM) shared-aperture antennas (AMRFS), wideband-antennas (ASAP: C-band to Ku-band; RECAP); Examples arrays discussed in detail. Covered also will be: (1) Array Fundamentals: Phase and Time- Delay Steering, Grating Lobes, T-space (sine-space), array thinning, blindness phenomenon; (2) array errors: effect on sidelobe level and directivity; (3) system considerations: beam shape and packing losses, sequential detection, array bandwidth and pulse distortion; (4) element types: waveguide, dipole, microstrip, notch; bandwidth, cost, power handling considerations; (5) Array Feeds: Corporate, Butler, Blass, Serial, Lopez; Rotman; (6) Limited-Scanned arrays: fundamental minimum number of elements theorem; realizations of minimum; reflector, lens and corporate array implementations; practical examples; use of spatial filters. |
