Characteristics of valley microstrip lines for use in multilayer MMIC's

A valley microstrip line fabricated by using multilayer monolithic microwave integrated circuit (MMIC) technologies is proposed, and its performance was investigated experimentally. Each transmission line was measured by using on-wafer probers and a HP8510 network analyzer. Four microstrip lines with dielectric overlay, whose polyimide layer thickness/strip conductor widths were 2.5 mu m/5 mu m, 5 mu m/10 mu m, 7.5 mu m/16 mu m, and 10 mu m/22 mu m were measured. Characteristic impedance of each line is 50 Omega . For the valley microstrip line, the polyimide layer thickness underneath varies from 3-10 mu m. With a strip conductor width of 6 mu m, the characteristic impedance is 50 Omega .<>