Effects of DC-Bias Conditions on Low-Loss Thin Film Microstrip Line

This paper presents the microwave characteristics of thin film microstrip line (TFML) under dc-bias conditions. The proposed TFML with 20 μm thick polyimide layer is used as a thin dielectric supporter on low-resistivity silicon (LRS) substrate. Measured frequency-dependent microwave characteristics and equivalent lumped elements are evaluated for the dc-biased TFML over 1-50 GHz. This work presents acceptable attenuation of 0.561, 0.563 and 0.565 dB/mm at 50 GHz with dc-bias conditions, showing that the TFML can be used for high frequency interconnects for any 3D-based microwave devices and monolithic microwave integrated circuits (MMICs).