- TITLE:
-
Optimal array-pattern synthesis for wideband digital transmit arrays
- AUTHORS:
- D. P. Scholnik and J. O. Coleman
- ABSTRACT:
-
Some next-generation RF systems are expected to share
a common transmit aperture among multiple users across
a wide range of frequencies and functions such as
radar and communications. The requisite linear
architectures and digital signal generation will
permit far greater flexibility in the design of array
patterns than traditional time-delay steered wideband
transmit arrays. Merely replicating the traditional
architecture in DSP would generally represent an
inefficient use of computational resources; thus we
propose instead to place an FIR filter per input
signal at each element and to directly optimize the
resulting wideband array pattern. For this
architecture we present a passband-equivalent
transmit-array model and derive expressions for
wideband directivity, efficiency, error sensitivity,
gain, peak and mean-square sidelobes, mainlobe
frequency- response flatness, and polarization. All
can be constrained using second-order cone
programming, a highly-efficient type of convex
optimization. Several examples illustrate the design
tradeoffs, including the need to limit undesirable
superdirective effects in wideband arrays. The system
model and the derivations are general enough to admit
almost any array architecture, including arbitrary
element locations, nonuniform element responses, and
multiple polarizationsn.
- DOWNLOADABLE PDF PREPRINTS:
-
authors' two-column
manuscript, unofficial
but with nicely typeset math (3.1 Mbytes)
IEEE version,
official but
with badly typeset math (9.9
Mbytes)
- STATUS:
- Published in the IEEE Journal on Selected Topics in Signal
Processing, Special Issue on Convex Optimization Methods for
Signal Processing, vol. 1, no. 4, December 2007, pp. 660-677.
- DATE OF ENTRY:
-
September 2007.