Design of Kapton based passive circuits at microwave frequencies

This paper presents a technology based on thin flexible polyimide substrate (Kapton) to develop passive circuits at microwave frequencies. In the first step, we characterize the Kapton polyimide (relative permittivity and loss tangent) by using a ring resonator method. Then a 60 GHz patch antenna is designed, fabricated, and measured to validate our technology. Finally, a design of cross slot dipole antenna with a large bandwidth at 60 GHz is proposed.