For wireless-communications applications like base stations, sectorial radiation patterns are frequently used. Yet such antennas also have proven themselves adept at handling measurement system applications like in a lens-based compact antenna test range (CATR). Some recent work covers the design, fabrication, and measurements of an axisymmetric dielectric lens that features a sectorial radiation pattern at 77 GHz. This antenna was developed by M. Multari, J. Lanteri, J.L. Le Sonn, L. Brochier, C. Pichot, and C. Migliaccio from France's University of Nice-Sophia Antipolis together with J.L. Desvilles from Orange Labs and P. Feil from German's University of Ulm.
For W-band measurements, this lens-based CATR provides an output plane wave that is 25 cm in diameter. Thanks to the symmetry of revolution, the sectorial lens profile can be designed in one dimension using phase-only control. The phase variation is echoed on the lens depth. The researchers fabricated two lenses: one with polyvinyl chloride (PVC) and the other with polyurethane. For the polyurethane lens, which was the preferred choice, less than 0.2 dB ripple was obtained in the central beam. Relatively high secondary lobes did occur at 11 deg., however.
To simulate the stepped lens, France Telecom Orange Labs' SRSRD software was used. The lens was then measured in an anechoic chamber at 77 GHz. Using numerical simulations, comparisons were conducted between the near field of a CATR illuminated by a small horn providing a uniform amplitude taper and the sectorial lens. On-axis oscillations went from 6 to 1 dB with the sectorial lens. See "77 GHz Stepped Lens with Sectorial Radiation Pattern as Primary Feed of a Lens Based CATR," IEEE Transactions On Antennas And Propagation, January 2010, p. 207.
