Dispersionless Broadband Impedance Matching with Aperiodically Time-modulated Capacitors

Impedance matching is one of the most important problems in microwave engineering. It allows maximizing the transfer of power from a source to a load. However, the band-width over which a certain amount of power can be transferred is fundamentally limited by the Bode-Fano bound, which applies to any passive, linear, and time-varying matching networks. By revoking the underlying assumption of time invariance, here, we show how a capacitor undergoing a realistic aperiodic time modulation allows going beyond the matching-bandwidth bound. In contrast to previous works, the proposed approach not only allows overcoming the restrictions of the Bode-Fano bound but also preserves the temporal shape of the pulse that needs to be transmitted/radiated (dispersionless). Our findings may open a new avenue in the design of electrically small antennas, resonators, and absorbers with a large operation bandwidth.