Spiral type planer antenna for specified low power radio

摘要

The planar antennas for 315MHz and 430MHz-band that have the collinear and spiral structure are proposed and examined. The antenna's gains can be high with the collinear structure. The size of the antennas can be small with the spiral structure. From the results, for 315MHz and 430MHz, the maximum value of the absolute gain were -1.04dBi at 135°, 0.52dBi at 125°, respectively. The antennas are commercialized in January 2014.