Future commercial and military systems will require high bandwidth performance from compact antenna systems for communications and sensing applications.  The need to incorporate multiple systems onto small platforms, ranging from handsets to air vehicles, implies that antenna size must be minimised.  This is particularly important at VHF  / UHF frequencies where conventional wideband antennas are physically large. 



Metamaterials and metasurfaces have been shown to be effective technologies for reducing antenna size.  Close coupling exists between the antenna and underlying surface and the assembly must be designed as an integrated structure.  Early metamaterials were characterised by narrow-band phase response which limited their applicability to wideband antenna systems.  However, innovative simulation and fabrication techniques are now being used to realise systems approaching an octave bandwidth.  Techniques include,

• 
  non-uniform metamaterial geometries (matching periodicity to critical regions of the antenna)

• 
  multi-layer ‘stacked’ metamaterials

• 
  inhomogeneous, synthesised material properties.

The IET is supporting a convened session at EucAP 2014 will be an ideal opportunity to compare emerging metamaterial-based antenna technologies with the bandwidth and radiation efficiency requirements anticipated for future systems.  



What are your thoughts on these technologies?