Diskwide Spiral Trajectory Impedance Matching Network for Frequency-Diversity Power Transfer

This paper proposes a passive network that exhibits a spiral impedance trajectory as its frequency response. A loose-coupled transmission line generates a pinwheel locus, while another long transmission line makes the locus revolve in multiple turns around the reference impedance origin. This enables the system's output impedance to cover a wide range on the Smith Chart. This scheme is considerably useful in frequency-diversity impedance matching for RF power systems to excite an unknown or time-varying load.