 TITLE:

Nonseparable NthBand Filters as OverlappingSubarray
Tapers
 AUTHORS:
 J. O. Coleman
 ABSTRACT:

In a receive array "overlapped subarrays" refers to an
array output formed as a weighted sum of subarray
outputs themselves formed as identically weighted
combinations of the outputs of overlapping element
subsets. The system array factor becomes a product of
two array factors with different periods, one
associated with each sum, just as the frequency
response of a twostage IFIR filter in a DSP system is
the product of two frequency responses with different
periods. It is well known that an Nthband filter can
be the most efficient choice for an IFIR filter's
first stage, but the corresponding array idea appears
unknown.
Design examples apply modern optimization to
nonseparable tapers, with three of four examples
featuring Nthband subarray tapers. Whether an
Nthband approach is best is not settled here and is
properly context dependent: designs should be carried
out both ways and compared. Further, a very small
subarray taper can easily be Nthband entirely by
accident, so designers should be aware of the
associated arrayfactor features that necessarily
result and cannot be optimized away.
 ERRATA:

In the last line of the Fig. 9 algorithm,
H_{1}^{fixed}(0) should actually be
H_{2}^{fixed}(0).
 ONLINE PDFS:

preprint (1.9 Mbytes)
at IEEE Xplore (2.2 Mbytes)
 STATUS:
 Presentated to the 2011 IEEE
Radar Conference, Kansas City MO, USA,
May 2327, 2011.
 DATE OF ENTRY:

July 2011.