Resonant-Type Antennas Loaded With CRLH Unit Cell

The concept of loading monopole antennas with composite right/left-handed (CRLH) unit cell is extended to cover other types of resonant antennas, namely loop antennas and printed inverted-F antennas (printed IFAs). By adding one unit cell, these antennas achieve three operating bands while having their sizes unmodified. The new frequencies are lower than the unloaded antenna´s nominal frequency. The printed IFA is fabricated, and measurements are consistent with theoretical predictions.