The conventional MMIC coplanar line covers an impedance range from abo
ut 30-80 Omega. Values outside this range cannot be fabricated reliabl
y or cause excessive losses, For several applications, however, it is
desirable to use high-impedance lines (e.g., for reduced-size couplers
and nonlinear transmission lines). This letter reports results from e
xperiment and electromagnetic simulation for a coplanar waveguide (CPW
) structure with an elevated center conductor realized by an air-bridg
e technique. We achieve wave impedances of about 100 Omega at a lower
attenuation level as conventional 50-Omega CPW's of comparable size.