Numerical studies of the interaction of time-modulated multi-gigabit sequences with metamaterial structures at millimeter-wave frequencies

It is shown with time domain simulations using the finite integration technique (FIT) that a metamaterial that acts as an artificial magnetic conductor (AMC), i.e. a metamaterial which produces an in-phase reflection, exhibits a time delay before its intended response can occur. A millimeter-wave metamaterial AMC is obtained as a generalization of a successfully designed microwave frequency AMC block consisting of an array of capacitively loaded loops (CLLs). It is also shown that while this time delay does distort millimeter-wave frequency signals composed of time-modulated multi-gigabit sequences, it does not have a detrimental impact on the overall system performance when these multi-gigabit/s signals interact with this CLL-based AMC. This time delay behaviour is demonstrated for several different but common communication-based modulation schemes. The presence of peculiar spikes in the output waveforms is tied to the time domain behaviour of the currents on the CLLs in the metamaterial AMC.