In this paper we explore the applicability of the implicit small-gain guara
nteed cost bound for controller synthesis. For flexibility in controller sy
nthesis, we adopt the approach of fixed-structure controller design which a
llows consideration of arbitrary controller structures, including order, in
ternal structure, and decentralization. A numerical example that has been a
ddressed in the literature by means of alternative guaranteed cost bounds i
s presented to demonstrate the fixed-structure/implicit small-gain approach
to robust controller synthesis. (C) 2000 The Franklin Institute. Published
by Elsevier Science Ltd. All rights reserved.