Microcoaxial Interconnects for Signals, Bias, and Supply of MMICs

Microcoaxial cables (MCCs) enable low loss and low inductance interconnects for signals, bias, and supply for MMICs that may be difficult to achieve with existing bond wire. In this work, fabrication and integration strategies of MCCs are presented including RF characterization up to 36.0 GHz. MCCs have been fabricated with total outer diameters between 30.6 mu m to 263 mu m. Targeting 50 Omega, we have fabricated 59 Omega coax with an insertion loss of -0.13 dB/mm at 36 GHz. In addition, low inductance MCCs for bias and supply connections, enabled via thin dielectric coatings, have also been characterized. Measured inductance for a range of wires meant for bias and supply are 27.0 - 41.5 pH/mm. Each cable's bonding inductance has also been extracted with the majority of bond sites having an inductance between 2.0-152 pH.