[1] MIT, Res Lab Elect, Cambridge, MA 02139 USA
[2] DEVCOM Army Res Lab, Adelphi, MD 20783 USA
[3] Univ Maryland, Dept Elect & Comp Engn, College Pk, MD 20742 USA
[4] Univ Maryland, Inst Res Elect & Appl Phys, College Pk, MD 20742 USA
[5] Ctr Suisse Elect & Microtech CSEM, CH-2000 Neuchatel, Switzerland
[6] Univ Illinois, Dept Elect & Comp Engn, Chicago, IL 60607 USA
[7] Tulane Univ, New Orleans, LA 70118 USA
[8] Univ Maryland, Lab Phys Sci, College Pk, MD 20740 USA
[9] State Univ New York Polytech Inst, Albany, NY 12203 USA
[10] Raytheon BBN Technol, Cambridge, MA 02138 USA
[11] Tech Univ Denmark, Dept Elect & Photon Engn, DK-2800 Lyngby, Denmark
[12] Air Force Res Lab, Informat Directorate, Rome, NY 13441 USA