Foam Micromachined Aperture-Coupled Antennas for V-Band Low-Cost Applications

In this paper, we present a novel micromachining approach for realizing 60 GHz foam aperture-coupled antennas. The foam is indeed an ideal antenna substrate provided by its electrical properties close to those of the air. At 60 GHz, the optimum foam thickness supporting the printed antenna must be about 400 mum, which is a technological obstacle due to the poor mechanical resistance of the foam. It has been surrounded by this new micromachining method. A single patch and a 2 times 4 antenna array have been realized and measured. They exhibit wideband bandwidth and excellent radiation efficiency. The gains are about 6.7 dBi for the single patch and 13 dBi for the 2 times 4 antenna array. These results demonstrate the great potential of foam substrate for 60 GHz antennas. To the best knowledge of the authors, this work is the first report of a low-cost, high gain and high efficiency 60 GHz foam aperture-coupled antennas.