Multioctave thin planar Traveling-Wave Antennas and Arrays (TWA) with high efficiency

This paper highlights a class of thin planar Traveling-Wave Antennas and Arrays (both abbreviated as TWA) that have high efficiency (without lossy matching) and multioctave bandwidth. The single TWA has unidirectional or omnidirectional pattern; or both pattern types either simultaneously or switching between each other. The thin planar phased-array TWA is still in advanced development, but has shown great promise for multioctave scan-gain bandwidth with high efficiency (without lossy matching). The TWA´s advantages over, and differentiation from, other multioctave planar antennas and phased arrays are also discussed.