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.