We present new results on the phi(J) polar decomposition of matrices. We show that every symplectic matrix may be written as a product of symplectic operation matrices. We present a simple form attained under symplectic equivalence, which makes it easy to determine if a matrix does not have a phi(J) polar decomposition. We also determine the rank 4 matrices with phi(J) polar decomposition. (C) 2009 Elsevier Inc. All rights reserved.