Free space material measurements at VHF and UHF bands require antennas that are necessarily large and heavy to accommodate the long wavelengths in these bands. Large antennas make measurements less practical and more expensive. This paper presents a new flat lens antenna technology, which enables significant reductions in size and weight compared to conventional wide bandwidth horn antennas.
These new antennas utilize artificial dielectric loading combined with lossy materials to give directivities similar to much larger and heavier horns. This paper also presents the direct application of these antennas for free space dielectric material characterization. Example measurements of dielectric specimens are shown with a pair of 200 MHz to 4 GHz antennas.
