KAI CHANG, PhD, is the Raytheon E-Systems Endowed Professor in the Department of Electrical Engineering at Texas A&M University where he teaches and performs research in microwave devices, circuits, and antennas. In addition to publishing more than 400 technical papers and twelve books on microwave circuits, components, antennas and subsystems, Dr. Chang is an award-winning author, editor, and Fellow of the IEEE. His awards include a Special Achievement Award from TRW, the Halliburton Research Excellence Award, the Distinguished Teaching Award, and the Distinguished Research Award from Texas A&M. LUNG-HWA HSIEH is a doctoral student at Texas A&M University. He has authored more than fifteen papers on microwave ring circuits. He was previously a senior design engineer at General Instruments involved in RF design.