High-accuracy tuning of planar millimeter-wave circuits by laser photochemical etching

A new laser photochemical reaction for etching of molybdenum has been applied to the in situ tuning of coplanar waveguide (CPW) structures used in millimeter wave integrated circuits. Tests on structures operating at 33 GHz have confirmed low insertion losses and demonstrated an improvement in set accuracy by a factor of 10-30 relative to previously developed strip or solder tuners.