A broadband quarter-wavelength impedance transformer using vertically installed planar coupler

A broadband quarter-wavelength impedance transformer using a vertically installed planar (VIP) coupler is presented. A wide range of impedance transformation ratios and bandwidths can be achieved using this design. A 50 Ω to 100 Ω impedance transformer covering 0.7 GHz to 2 GHz is designed and implemented using the VIP. The measured results agree well with the simulation results. The design curves generated are useful for the design of this type of impedance transformer.