Design of single thin film resistor network as 20dB attenuator for DC-20GHz application

In this paper a design methodology of a 20dB DC-20GHz attenuator based on single thin film resistor (STFR) on the high-resistivity silicon substrate is presented. The STFR could be equivalent to the π network via the conformal mapping and symmetry. The coplanar waveguide (CPW) is used as signal path for further connection with other devices such as the MEMS switches to make the attenuator reconfigurable. Tantalum nitride is used as the thin film material which could be prepared by a standard integral reactive sputtering process. The simulation results shows the attenuation of STFR attenuator is 20.00±0.03 dB in the DC to 20-GHz range with a return loss better than 27.5 dB.