Metamaterials have gained much interest in recent years because they offer the potential to provide low cost electronic scanning antennas and to provide target stealth. Target cloaking has been demonstrated at microwave frequencies over a narrow bandwidth using metamaterials. Cloaking has been demonstrated over a 50% bandwidth at L-band using fractal metamaterials.
For Communication Antennas: Using Ku-band antennas which use metamaterial resonators in a very novel way to realize electronic steering potentially at low cost, one company has transmitted to satellites and back while other companies have developed metamaterial arrays for radar. The Army Research Laboratory funded the development of a metamaterial 250 to 505 MHz low profile antenna with a λ/20 thickness for replacement of the very visible tall whip antennas on HMMWVs thus providing greater survivability. Complementing this, a conventional tightly coupled dipole antenna (TCDA) has been developed which provides a 20:1 bandwidth with a λ/40 thickness. The two together could be employed in escort jammer aircraft like the USA Next Generation Jammer on the EA-1G Growler covering the band from VHF to Ku-band. They could serve as conformal or low profile antennas on the aircraft.
Other Applications: Metamaterials have been used in cell phones to provide antennas that are 5X smaller (1/10th λ) having 700 MHz to 2.7 GHz bandwidth. Under Army funding isolation equivalent to 1 m separation has been achieved for antennas with 2.5 cm separation has been achieved allowing simultaneous transmission and reception on a small relay. It has the potential for use in phased array for wide angle impedance matching (WAIM) by placing metamaterial between the radiating elements to reduce mutual coupling. Using metamaterial one can focus 6X beyond diffraction limit at 0.38 μm (Moore’s Law marches on); 40X diffraction limit, λ/80, at 375 MHz demonstrated.