ANALYSIS AND SYNTHESIS OF SUSPENDED AND INVERTED MICROSTRIP LINES.

Closed-form expressions are presented which model the characteristics of suspended and inverted microstrip lines on low dielectric constant substrates (1 less than equivalent to epsilon //r less than equivalent to 3. 8). The equations include the effective dielectric constant and the characteristic impedance. They are accurate to within plus or minus 1%, while the presented synthesis equations are accurate to within plus or minus 2%. The equations are useful for computer aided design of millimeter wave circuits using suspended and inverted microstrip lines.