Low profile high isolation ultra-wideband (UWB) antennas and arrays are key components in several advanced communications and defense systems. Over the last decade, TCDA has become a widely used array that boasts polarization diversity (both linear and circular), wide scanning volumes, large bandwidths, and inexpensive fabrication. Further, the TCDA is scalable to millimeter wave frequencies and fabricated for operation up to 94GHz using printed circuit technology. Even more importantly, it has been adapted to various aerospace and naval projects due to its wideband yet compact design. The premise of the paper is the challenges associated with extending the TCDA bandwidth beyond 20:1 in a low profile.
